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2025-11-08Merge tag 'x86-urgent-2025-11-08' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: - Fix AMD PCI root device caching regression that triggers on certain firmware variants - Fix the zen5_rdseed_microcode[] array to be NULL-terminated - Add more AMD models to microcode signature checking * tag 'x86-urgent-2025-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode/AMD: Add more known models to entry sign checking x86/CPU/AMD: Add missing terminator for zen5_rdseed_microcode x86/amd_node: Fix AMD root device caching
2025-11-05x86: uaccess: don't use runtime-const rewriting in modulesLinus Torvalds2-5/+9
The runtime-const infrastructure was never designed to handle the modular case, because the constant fixup is only done at boot time for core kernel code. But by the time I used it for the x86-64 user space limit handling in commit 86e6b1547b3d ("x86: fix user address masking non-canonical speculation issue"), I had completely repressed that fact. And it all happens to work because the only code that currently actually gets inlined by modules is for the access_ok() limit check, where the default constant value works even when not fixed up. Because at least I had intentionally made it be something that is in the non-canonical address space region. But it's technically very wrong, and it does mean that at least in theory, the use of 'access_ok()' + '__get_user()' can trigger the same speculation issue with non-canonical addresses that the original commit was all about. The pattern is unusual enough that this probably doesn't matter in practice, but very wrong is still very wrong. Also, let's fix it before the nice optimized scoped user accessor helpers that Thomas Gleixner is working on cause this pseudo-constant to then be more widely used. This all came up due to an unrelated discussion with Mateusz Guzik about using the runtime const infrastructure for names_cachep accesses too. There the modular case was much more obviously broken, and Mateusz noted it in his 'v2' of the patch series. That then made me notice how broken 'access_ok()' had been in modules all along. Mea culpa, mea maxima culpa. Fix it by simply not using the runtime-const code in modules, and just using the USER_PTR_MAX variable value instead. This is not performance-critical like the core user accessor functions (get_user() and friends) are. Also make sure this doesn't get forgotten the next time somebody wants to do runtime constant optimizations by having the x86 runtime-const.h header file error out if included by modules. Fixes: 86e6b1547b3d ("x86: fix user address masking non-canonical speculation issue") Acked-by: Borislav Petkov <bp@alien8.de> Acked-by: Sean Christopherson <seanjc@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Triggered-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/all/20251030105242.801528-1-mjguzik@gmail.com/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-11-03x86/amd_node: Fix AMD root device cachingYazen Ghannam1-1/+0
Recent AMD node rework removed the "search and count" method of caching AMD root devices. This depended on the value from a Data Fabric register that was expected to hold the PCI bus of one of the root devices attached to that fabric. However, this expectation is incorrect. The register, when read from PCI config space, returns the bitwise-OR of the buses of all attached root devices. This behavior is benign on AMD reference design boards, since the bus numbers are aligned. This results in a bitwise-OR value matching one of the buses. For example, 0x00 | 0x40 | 0xA0 | 0xE0 = 0xE0. This behavior breaks on boards where the bus numbers are not exactly aligned. For example, 0x00 | 0x07 | 0xE0 | 0x15 = 0x1F. The examples above are for AMD node 0. The first root device on other nodes will not be 0x00. The first root device for other nodes will depend on the total number of root devices, the system topology, and the specific PCI bus number assignment. For example, a system with 2 AMD nodes could have this: Node 0 : 0x00 0x07 0x0e 0x15 Node 1 : 0x1c 0x23 0x2a 0x31 The bus numbering style in the reference boards is not a requirement. The numbering found in other boards is not incorrect. Therefore, the root device caching method needs to be adjusted. Go back to the "search and count" method used before the recent rework. Search for root devices using PCI class code rather than fixed PCI IDs. This keeps the goal of the rework (remove dependency on PCI IDs) while being able to support various board designs. Merge helper functions to reduce code duplication. [ bp: Reflow comment. ] Fixes: 40a5f6ffdfc8 ("x86/amd_nb: Simplify root device search") Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: stable@vger.kernel.org Link: https://patch.msgid.link/all/20251028-fix-amd-root-v2-1-843e38f8be2c@amd.com
2025-10-31x86/mm: Ensure clear_page() variants always have __kcfi_typeid_ symbolsNathan Chancellor1-0/+3
When building with CONFIG_CFI=y and CONFIG_LTO_CLANG_FULL=y, there is a series of errors from the various versions of clear_page() not having __kcfi_typeid_ symbols. $ cat kernel/configs/repro.config CONFIG_CFI=y # CONFIG_LTO_NONE is not set CONFIG_LTO_CLANG_FULL=y $ make -skj"$(nproc)" ARCH=x86_64 LLVM=1 clean defconfig repro.config bzImage ld.lld: error: undefined symbol: __kcfi_typeid_clear_page_rep >>> referenced by ld-temp.o >>> vmlinux.o:(__cfi_clear_page_rep) ld.lld: error: undefined symbol: __kcfi_typeid_clear_page_orig >>> referenced by ld-temp.o >>> vmlinux.o:(__cfi_clear_page_orig) ld.lld: error: undefined symbol: __kcfi_typeid_clear_page_erms >>> referenced by ld-temp.o >>> vmlinux.o:(__cfi_clear_page_erms) With full LTO, it is possible for LLVM to realize that these functions never have their address taken (as they are only used within an alternative, which will make them a direct call) across the whole kernel and either drop or skip generating their kCFI type identification symbols. clear_page_{rep,orig,erms}() are defined in clear_page_64.S with SYM_TYPED_FUNC_START as a result of 2981557cb040 ("x86,kcfi: Fix EXPORT_SYMBOL vs kCFI"), as exported functions are free to be called indirectly thus need kCFI type identifiers. Use KCFI_REFERENCE with these clear_page() functions to force LLVM to see these functions as address-taken and generate then keep the kCFI type identifiers. Fixes: 2981557cb040 ("x86,kcfi: Fix EXPORT_SYMBOL vs kCFI") Closes: https://github.com/ClangBuiltLinux/linux/issues/2128 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Link: https://patch.msgid.link/20251013-x86-fix-clear_page-cfi-full-lto-errors-v1-1-d69534c0be61@kernel.org
2025-10-30x86/cpu: Add/fix core comments for {Panther,Nova} LakeTony Luck1-3/+3
The E-core in Panther Lake is Darkmont, not Crestmont. Nova Lake is built from Coyote Cove (P-core) and Arctic Wolf (E-core). Fixes: 43bb700cff6b ("x86/cpu: Update Intel Family comments") Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://patch.msgid.link/20251028172948.6721-1-tony.luck@intel.com
2025-10-11Merge tag 'x86_core_for_v6.18_rc1' of ↵Linus Torvalds6-127/+72
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more x86 updates from Borislav Petkov: - Remove a bunch of asm implementing condition flags testing in KVM's emulator in favor of int3_emulate_jcc() which is written in C - Replace KVM fastops with C-based stubs which avoids problems with the fastop infra related to latter not adhering to the C ABI due to their special calling convention and, more importantly, bypassing compiler control-flow integrity checking because they're written in asm - Remove wrongly used static branches and other ugliness accumulated over time in hyperv's hypercall implementation with a proper static function call to the correct hypervisor call variant - Add some fixes and modifications to allow running FRED-enabled kernels in KVM even on non-FRED hardware - Add kCFI improvements like validating indirect calls and prepare for enabling kCFI with GCC. Add cmdline params documentation and other code cleanups - Use the single-byte 0xd6 insn as the official #UD single-byte undefined opcode instruction as agreed upon by both x86 vendors - Other smaller cleanups and touchups all over the place * tag 'x86_core_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86,retpoline: Optimize patch_retpoline() x86,ibt: Use UDB instead of 0xEA x86/cfi: Remove __noinitretpoline and __noretpoline x86/cfi: Add "debug" option to "cfi=" bootparam x86/cfi: Standardize on common "CFI:" prefix for CFI reports x86/cfi: Document the "cfi=" bootparam options x86/traps: Clarify KCFI instruction layout compiler_types.h: Move __nocfi out of compiler-specific header objtool: Validate kCFI calls x86/fred: KVM: VMX: Always use FRED for IRQs when CONFIG_X86_FRED=y x86/fred: Play nice with invoking asm_fred_entry_from_kvm() on non-FRED hardware x86/fred: Install system vector handlers even if FRED isn't fully enabled x86/hyperv: Use direct call to hypercall-page x86/hyperv: Clean up hv_do_hypercall() KVM: x86: Remove fastops KVM: x86: Convert em_salc() to C KVM: x86: Introduce EM_ASM_3WCL KVM: x86: Introduce EM_ASM_1SRC2 KVM: x86: Introduce EM_ASM_2CL KVM: x86: Introduce EM_ASM_2W ...
2025-10-11Merge tag 'x86_cleanups_for_v6.18_rc1' of ↵Linus Torvalds14-109/+32
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Borislav Petkov: - Simplify inline asm flag output operands now that the minimum compiler version supports the =@ccCOND syntax - Remove a bunch of AS_* Kconfig symbols which detect assembler support for various instruction mnemonics now that the minimum assembler version supports them all - The usual cleanups all over the place * tag 'x86_cleanups_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm: Remove code depending on __GCC_ASM_FLAG_OUTPUTS__ x86/sgx: Use ENCLS mnemonic in <kernel/cpu/sgx/encls.h> x86/mtrr: Remove license boilerplate text with bad FSF address x86/asm: Use RDPKRU and WRPKRU mnemonics in <asm/special_insns.h> x86/idle: Use MONITORX and MWAITX mnemonics in <asm/mwait.h> x86/entry/fred: Push __KERNEL_CS directly x86/kconfig: Remove CONFIG_AS_AVX512 crypto: x86 - Remove CONFIG_AS_VPCLMULQDQ crypto: X86 - Remove CONFIG_AS_VAES crypto: x86 - Remove CONFIG_AS_GFNI x86/kconfig: Drop unused and needless config X86_64_SMP
2025-10-06Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds9-31/+118
Pull x86 kvm updates from Paolo Bonzini: "Generic: - Rework almost all of KVM's exports to expose symbols only to KVM's x86 vendor modules (kvm-{amd,intel}.ko and PPC's kvm-{pr,hv}.ko x86: - Rework almost all of KVM x86's exports to expose symbols only to KVM's vendor modules, i.e. to kvm-{amd,intel}.ko - Add support for virtualizing Control-flow Enforcement Technology (CET) on Intel (Shadow Stacks and Indirect Branch Tracking) and AMD (Shadow Stacks). It is worth noting that while SHSTK and IBT can be enabled separately in CPUID, it is not really possible to virtualize them separately. Therefore, Intel processors will really allow both SHSTK and IBT under the hood if either is made visible in the guest's CPUID. The alternative would be to intercept XSAVES/XRSTORS, which is not feasible for performance reasons - Fix a variety of fuzzing WARNs all caused by checking L1 intercepts when completing userspace I/O. KVM has already committed to allowing L2 to to perform I/O at that point - Emulate PERF_CNTR_GLOBAL_STATUS_SET for PerfMonV2 guests, as the MSR is supposed to exist for v2 PMUs - Allow Centaur CPU leaves (base 0xC000_0000) for Zhaoxin CPUs - Add support for the immediate forms of RDMSR and WRMSRNS, sans full emulator support (KVM should never need to emulate the MSRs outside of forced emulation and other contrived testing scenarios) - Clean up the MSR APIs in preparation for CET and FRED virtualization, as well as mediated vPMU support - Clean up a pile of PMU code in anticipation of adding support for mediated vPMUs - Reject in-kernel IOAPIC/PIT for TDX VMs, as KVM can't obtain EOI vmexits needed to faithfully emulate an I/O APIC for such guests - Many cleanups and minor fixes - Recover possible NX huge pages within the TDP MMU under read lock to reduce guest jitter when restoring NX huge pages - Return -EAGAIN during prefault if userspace concurrently deletes/moves the relevant memslot, to fix an issue where prefaulting could deadlock with the memslot update x86 (AMD): - Enable AVIC by default for Zen4+ if x2AVIC (and other prereqs) is supported - Require a minimum GHCB version of 2 when starting SEV-SNP guests via KVM_SEV_INIT2 so that invalid GHCB versions result in immediate errors instead of latent guest failures - Add support for SEV-SNP's CipherText Hiding, an opt-in feature that prevents unauthorized CPU accesses from reading the ciphertext of SNP guest private memory, e.g. to attempt an offline attack. This feature splits the shared SEV-ES/SEV-SNP ASID space into separate ranges for SEV-ES and SEV-SNP guests, therefore a new module parameter is needed to control the number of ASIDs that can be used for VMs with CipherText Hiding vs. how many can be used to run SEV-ES guests - Add support for Secure TSC for SEV-SNP guests, which prevents the untrusted host from tampering with the guest's TSC frequency, while still allowing the the VMM to configure the guest's TSC frequency prior to launch - Validate the XCR0 provided by the guest (via the GHCB) to avoid bugs resulting from bogus XCR0 values - Save an SEV guest's policy if and only if LAUNCH_START fully succeeds to avoid leaving behind stale state (thankfully not consumed in KVM) - Explicitly reject non-positive effective lengths during SNP's LAUNCH_UPDATE instead of subtly relying on guest_memfd to deal with them - Reload the pre-VMRUN TSC_AUX on #VMEXIT for SEV-ES guests, not the host's desired TSC_AUX, to fix a bug where KVM was keeping a different vCPU's TSC_AUX in the host MSR until return to userspace KVM (Intel): - Preparation for FRED support - Don't retry in TDX's anti-zero-step mitigation if the target memslot is invalid, i.e. is being deleted or moved, to fix a deadlock scenario similar to the aforementioned prefaulting case - Misc bugfixes and minor cleanups" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (142 commits) KVM: x86: Export KVM-internal symbols for sub-modules only KVM: x86: Drop pointless exports of kvm_arch_xxx() hooks KVM: x86: Move kvm_intr_is_single_vcpu() to lapic.c KVM: Export KVM-internal symbols for sub-modules only KVM: s390/vfio-ap: Use kvm_is_gpa_in_memslot() instead of open coded equivalent KVM: VMX: Make CR4.CET a guest owned bit KVM: selftests: Verify MSRs are (not) in save/restore list when (un)supported KVM: selftests: Add coverage for KVM-defined registers in MSRs test KVM: selftests: Add KVM_{G,S}ET_ONE_REG coverage to MSRs test KVM: selftests: Extend MSRs test to validate vCPUs without supported features KVM: selftests: Add support for MSR_IA32_{S,U}_CET to MSRs test KVM: selftests: Add an MSR test to exercise guest/host and read/write KVM: x86: Define AMD's #HV, #VC, and #SX exception vectors KVM: x86: Define Control Protection Exception (#CP) vector KVM: x86: Add human friendly formatting for #XM, and #VE KVM: SVM: Enable shadow stack virtualization for SVM KVM: SEV: Synchronize MSR_IA32_XSS from the GHCB when it's valid KVM: SVM: Pass through shadow stack MSRs as appropriate KVM: SVM: Update dump_vmcb with shadow stack save area additions KVM: nSVM: Save/load CET Shadow Stack state to/from vmcb12/vmcb02 ...
2025-10-04Merge tag 'x86_tdx_for_6.18-rc1' of ↵Linus Torvalds3-3/+46
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 TDX updates from Dave Hansen: "The biggest change here is making TDX and kexec play nicely together. Before this, the memory encryption hardware (which doesn't respect cache coherency) could write back old cachelines on top of data in the new kernel, so kexec and TDX were made mutually exclusive. This removes the limitation. There is also some work to tighten up a hardware bug workaround and some MAINTAINERS updates. - Make TDX and kexec work together - Skip TDX bug workaround when the bug is not present - Update maintainers entries" * tag 'x86_tdx_for_6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/virt/tdx: Use precalculated TDVPR page physical address KVM/TDX: Explicitly do WBINVD when no more TDX SEAMCALLs x86/virt/tdx: Update the kexec section in the TDX documentation x86/virt/tdx: Remove the !KEXEC_CORE dependency x86/kexec: Disable kexec/kdump on platforms with TDX partial write erratum x86/virt/tdx: Mark memory cache state incoherent when making SEAMCALL x86/sme: Use percpu boolean to control WBINVD during kexec x86/kexec: Consolidate relocate_kernel() function parameters x86/tdx: Skip clearing reclaimed pages unless X86_BUG_TDX_PW_MCE is present x86/tdx: Tidy reset_pamt functions x86/tdx: Eliminate duplicate code in tdx_clear_page() MAINTAINERS: Add KVM mail list to the TDX entry MAINTAINERS: Add Rick Edgecombe as a TDX reviewer MAINTAINERS: Update the file list in the TDX entry.
2025-10-04Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds3-7/+3
Pull kvm updates from Paolo Bonzini: "This excludes the bulk of the x86 changes, which I will send separately. They have two not complex but relatively unusual conflicts so I will wait for other dust to settle. guest_memfd: - Add support for host userspace mapping of guest_memfd-backed memory for VM types that do NOT use support KVM_MEMORY_ATTRIBUTE_PRIVATE (which isn't precisely the same thing as CoCo VMs, since x86's SEV-MEM and SEV-ES have no way to detect private vs. shared). This lays the groundwork for removal of guest memory from the kernel direct map, as well as for limited mmap() for guest_memfd-backed memory. For more information see: - commit a6ad54137af9 ("Merge branch 'guest-memfd-mmap' into HEAD") - guest_memfd in Firecracker: https://github.com/firecracker-microvm/firecracker/tree/feature/secret-hiding - direct map removal: https://lore.kernel.org/all/20250221160728.1584559-1-roypat@amazon.co.uk/ - mmap support: https://lore.kernel.org/all/20250328153133.3504118-1-tabba@google.com/ ARM: - Add support for FF-A 1.2 as the secure memory conduit for pKVM, allowing more registers to be used as part of the message payload. - Change the way pKVM allocates its VM handles, making sure that the privileged hypervisor is never tricked into using uninitialised data. - Speed up MMIO range registration by avoiding unnecessary RCU synchronisation, which results in VMs starting much quicker. - Add the dump of the instruction stream when panic-ing in the EL2 payload, just like the rest of the kernel has always done. This will hopefully help debugging non-VHE setups. - Add 52bit PA support to the stage-1 page-table walker, and make use of it to populate the fault level reported to the guest on failing to translate a stage-1 walk. - Add NV support to the GICv3-on-GICv5 emulation code, ensuring feature parity for guests, irrespective of the host platform. - Fix some really ugly architecture problems when dealing with debug in a nested VM. This has some bad performance impacts, but is at least correct. - Add enough infrastructure to be able to disable EL2 features and give effective values to the EL2 control registers. This then allows a bunch of features to be turned off, which helps cross-host migration. - Large rework of the selftest infrastructure to allow most tests to transparently run at EL2. This is the first step towards enabling NV testing. - Various fixes and improvements all over the map, including one BE fix, just in time for the removal of the feature. LoongArch: - Detect page table walk feature on new hardware - Add sign extension with kernel MMIO/IOCSR emulation - Improve in-kernel IPI emulation - Improve in-kernel PCH-PIC emulation - Move kvm_iocsr tracepoint out of generic code RISC-V: - Added SBI FWFT extension for Guest/VM with misaligned delegation and pointer masking PMLEN features - Added ONE_REG interface for SBI FWFT extension - Added Zicbop and bfloat16 extensions for Guest/VM - Enabled more common KVM selftests for RISC-V - Added SBI v3.0 PMU enhancements in KVM and perf driver s390: - Improve interrupt cpu for wakeup, in particular the heuristic to decide which vCPU to deliver a floating interrupt to. - Clear the PTE when discarding a swapped page because of CMMA; this bug was introduced in 6.16 when refactoring gmap code. x86 selftests: - Add #DE coverage in the fastops test (the only exception that's guest- triggerable in fastop-emulated instructions). - Fix PMU selftests errors encountered on Granite Rapids (GNR), Sierra Forest (SRF) and Clearwater Forest (CWF). - Minor cleanups and improvements x86 (guest side): - For the legacy PCI hole (memory between TOLUD and 4GiB) to UC when overriding guest MTRR for TDX/SNP to fix an issue where ACPI auto-mapping could map devices as WB and prevent the device drivers from mapping their devices with UC/UC-. - Make kvm_async_pf_task_wake() a local static helper and remove its export. - Use native qspinlocks when running in a VM with dedicated vCPU=>pCPU bindings even when PV_UNHALT is unsupported. Generic: - Remove a redundant __GFP_NOWARN from kvm_setup_async_pf() as __GFP_NOWARN is now included in GFP_NOWAIT. * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (178 commits) KVM: s390: Fix to clear PTE when discarding a swapped page KVM: arm64: selftests: Cover ID_AA64ISAR3_EL1 in set_id_regs KVM: arm64: selftests: Remove a duplicate register listing in set_id_regs KVM: arm64: selftests: Cope with arch silliness in EL2 selftest KVM: arm64: selftests: Add basic test for running in VHE EL2 KVM: arm64: selftests: Enable EL2 by default KVM: arm64: selftests: Initialize HCR_EL2 KVM: arm64: selftests: Use the vCPU attr for setting nr of PMU counters KVM: arm64: selftests: Use hyp timer IRQs when test runs at EL2 KVM: arm64: selftests: Select SMCCC conduit based on current EL KVM: arm64: selftests: Provide helper for getting default vCPU target KVM: arm64: selftests: Alias EL1 registers to EL2 counterparts KVM: arm64: selftests: Create a VGICv3 for 'default' VMs KVM: arm64: selftests: Add unsanitised helpers for VGICv3 creation KVM: arm64: selftests: Add helper to check for VGICv3 support KVM: arm64: selftests: Initialize VGICv3 only once KVM: arm64: selftests: Provide kvm_arch_vm_post_create() in library code KVM: selftests: Add ex_str() to print human friendly name of exception vectors selftests/kvm: remove stale TODO in xapic_state_test KVM: selftests: Handle Intel Atom errata that leads to PMU event overcount ...
2025-10-02Merge tag 'drm-next-2025-10-01' of https://gitlab.freedesktop.org/drm/kernelLinus Torvalds1-0/+2
Pull drm updates from Dave Airlie: "cross-subsystem: - i2c-hid: Make elan touch controllers power on after panel is enabled - dt bindings for STM32MP25 SoC - pci vgaarb: use screen_info helpers - rust pin-init updates - add MEI driver for late binding firmware update/load uapi: - add ioctl for reassigning GEM handles - provide boot_display attribute on boot-up devices core: - document DRM_MODE_PAGE_FLIP_EVENT - add vendor specific recovery method to drm device wedged uevent gem: - Simplify gpuvm locking ttm: - add interface to populate buffers sched: - Fix race condition in trace code atomic: - Reallow no-op async page flips display: - dp: Fix command length video: - Improve pixel-format handling for struct screen_info rust: - drop Opaque<> from ioctl args - Alloc: - BorrowedPage type and AsPageIter traits - Implement Vmalloc::to_page() and VmallocPageIter - DMA/Scatterlist: - Add dma::DataDirection and type alias for dma_addr_t - Abstraction for struct scatterlist and sg_table - DRM: - simplify use of generics - add DriverFile type alias - drop Object::SIZE - Rust: - pin-init tree merge - Various methods for AsBytes and FromBytes traits gpuvm: - Support madvice in Xe driver gpusvm: - fix hmm_pfn_to_map_order usage in gpusvm bridge: - Improve and fix ref counting on bridge management - cdns-dsi: Various improvements to mode setting - Support Solomon SSD2825 plus DT bindings - Support Waveshare DSI2DPI plus DT bindings - Support Content Protection property - display-connector: Improve DP display detection - Add support for Radxa Ra620 plus DT bindings - adv7511: Provide SPD and HDMI infoframes - it6505: Replace crypto_shash with sha() - synopsys: Add support for DW DPTX Controller plus DT bindings - adv7511: Write full Audio infoframe - ite6263: Support vendor-specific infoframes - simple: Add support for Realtek RTD2171 DP-to-HDMI plus DT bindings panel: - panel-edp: Support mt8189 Chromebooks; Support BOE NV140WUM-N64; Support SHP LQ134Z1; Fixes - panel-simple: Support Olimex LCD-OLinuXino-5CTS plus DT bindings - Support Samsung AMS561RA01 - Support Hydis HV101HD1 plus DT bindings - ilitek-ili9881c: Refactor mode setting; Add support for Bestar BSD1218-A101KL68 LCD plus DT bindings - lvds: Add support for Ampire AMP19201200B5TZQW-T03 to DT bindings - edp: Add support for additonal mt8189 Chromebook panels - lvds: Add DT bindings for EDT ETML0700Z8DHA amdgpu: - add CRIU support for gem objects - RAS updates - VCN SRAM load fixes - EDID read fixes - eDP ALPM support - Documentation updates - Rework PTE flag generation - DCE6 fixes - VCN devcoredump cleanup - MMHUB client id fixes - VCN 5.0.1 RAS support - SMU 13.0.x updates - Expanded PCIe DPC support - Expanded VCN reset support - VPE per queue reset support - give kernel jobs unique id for tracing - pre-populate exported buffers - cyan skillfish updates - make vbios build number available in sysfs - userq updates - HDCP updates - support MMIO remap page as ttm pool - JPEG parser updates - DCE6 DC updates - use devm for i2c buses - GPUVM locking updates - Drop non-DC DCE11 code - improve fallback handling for pixel encoding amdkfd: - SVM/page migration fixes - debugfs fixes - add CRIO support for gem objects - SVM updates radeon: - use dev_warn_once in CS parsers xe: - add madvise interface - add DRM_IOCTL_XE_VM_QUERY_MEMORY_RANGE_ATTRS to query VMA count and memory attributes - drop L# bank mask reporting from media GT3 on Xe3+. - add SLPC power_profile sysfs interface - add configs attribs to add post/mid context-switch commands - handle firmware reported hardware errors notifying userspace with device wedged uevent - use same dir structure across sysfs/debugfs - cleanup and future proof vram region init - add G-states and PCI link states to debugfs - Add SRIOV support for CCS surfaces on Xe2+ - Enable SRIOV PF mode by default on supported platforms - move flush to common code - extended core workarounds for Xe2/3 - use DRM scheduler for delayed GT TLB invalidations - configs improvements and allow VF device enablement - prep work to expose mmio regions to userspace - VF migration support added - prepare GPU SVM for THP migration - start fixing XE_PAGE_SIZE vs PAGE_SIZE - add PSMI support for hw validation - resize VF bars to max possible size according to number of VFs - Ensure GT is in C0 during resume - pre-populate exported buffers - replace xe_hmm with gpusvm - add more SVM GT stats to debugfs - improve fake pci and WA kunnit handle for new platform testing - Test GuC to GuC comms to add debugging - use attribute groups to simplify sysfs registration - add Late Binding firmware code to interact with MEI i915: - apply multiple JSL/EHL/Gen7/Gen6 workarounds properly - protect against overflow in active_engine() - Use try_cmpxchg64() in __active_lookup() - include GuC registers in error state - get rid of dev->struct_mutex - iopoll: generalize read_poll_timout - lots more display refactoring - Reject HBR3 in any eDP Panel - Prune modes for YUV420 - Display Wa fix, additions, and updates - DP: Fix 2.7 Gbps link training on g4x - DP: Adjust the idle pattern handling - DP: Shuffle the link training code a bit - Don't set/read the DSI C clock divider on GLK - Enable_psr kernel parameter changes - Type-C enabled/disconnected dp-alt sink - Wildcat Lake enabling - DP HDR updates - DRAM detection - wait PSR idle on dsb commit - Remove FBC modulo 4 restriction for ADL-P+ - panic: refactor framebuffer allocation habanalabs: - debug/visibility improvements - vmalloc-backed coherent mmap support - HLDIO infrastructure nova-core: - various register!() macro improvements - minor vbios/firmware fixes/refactoring - advance firmware boot stages; process Booter and patch signatures - process GSP and GSP bootloader - Add r570.144 firmware bindings and update to it - Move GSP boot code to own module - Use new pin-init features to store driver's private data in a single allocation - Update ARef import from sync::aref nova-drm: - Update ARef import from sync::aref tyr: - initial driver skeleton for a rust driver for ARM Mali GPUs - capable of powering up, query metadata and provide it to userspace. msm: - GPU and Core: - in DT bindings describe clocks per GPU type - GMU bandwidth voting for x1-85 - a623/a663 speedbins - cleanup some remaining no-iommu leftovers after VM_BIND conversion - fix GEM obj 32b size truncation - add missing VM_BIND param validation - IFPC for x1-85 and a750 - register xml and gen_header.py sync from mesa - Display: - add missing bindings for display on SC8180X - added DisplayPort MST bindings - conversion from round_rate() to determine_rate() amdxdna: - add IOCTL_AMDXDNA_GET_ARRAY - support user space allocated buffers - streamline PM interfaces - Refactoring wrt. hardware contexts - improve error reporting nouveau: - use GSP firmware by default - improve error reporting - Pre-populate exported buffers ast: - Clean up detection of DRAM config exynos: - add DSIM bridge driver support for Exynos7870 - Document Exynos7870 DSIM compatible in dt-binding panthor: - Print task/pid on errors - Add support for Mali G710, G510, G310, Gx15, Gx20, Gx25 - Improve cache flushing - Fail VM bind if BO has offset renesas: - convert to RUNTIME_PM_OPS rcar-du: - Make number of lanes configurable - Use RUNTIME_PM_OPS - Add support for DSI commands rocket: - Add driver for Rockchip NPU plus DT bindings - Use kfree() and sizeof() correctly - Test DMA status rockchip: - dsi2: Add support for RK3576 plus DT bindings - Add support for RK3588 DPTX output tidss: - Use crtc_ fields for programming display mode - Remove other drivers from aperture pixpaper: - Add support for Mayqueen Pixpaper plus DT bindings v3d: - Support querying nubmer of GPU resets for KHR_robustness stm: - Clean up logging - ltdc: Add support support for STM32MP257F-EV1 plus DT bindings sitronix: - st7571-i2c: Add support for inverted displays and 2-bit grayscale tidss: - Convert to kernel's FIELD_ macros vesadrm: - Support 8-bit palette mode imagination: - Improve power management - Add support for TH1520 GPU - Support Risc-V architectures v3d: - Improve job management and locking vkms: - Support variants of ARGB8888, ARGB16161616, RGB565, RGB888 and P01x - Spport YUV with 16-bit components" * tag 'drm-next-2025-10-01' of https://gitlab.freedesktop.org/drm/kernel: (1455 commits) drm/amd: Add name to modes from amdgpu_connector_add_common_modes() drm/amd: Drop some common modes from amdgpu_connector_add_common_modes() drm/amdgpu: update MODULE_PARM_DESC for freesync_video drm/amd: Use dynamic array size declaration for amdgpu_connector_add_common_modes() drm/amd/display: Share dce100_validate_global with DCE6-8 drm/amd/display: Share dce100_validate_bandwidth with DCE6-8 drm/amdgpu: Fix fence signaling race condition in userqueue amd/amdkfd: enhance kfd process check in switch partition amd/amdkfd: resolve a race in amdgpu_amdkfd_device_fini_sw drm/amd/display: Reject modes with too high pixel clock on DCE6-10 drm/amd: Drop unnecessary check in amdgpu_connector_add_common_modes() drm/amd/display: Only enable common modes for eDP and LVDS drm/amdgpu: remove the redeclaration of variable i drm/amdgpu/userq: assign an error code for invalid userq va drm/amdgpu: revert "rework reserved VMID handling" v2 drm/amdgpu: remove leftover from enforcing isolation by VMID drm/amdgpu: Add fallback to pipe reset if KCQ ring reset fails accel/habanalabs: add Infineon version check accel/habanalabs/gaudi2: read preboot status after recovering from dirty state accel/habanalabs: add HL_GET_P_STATE passthrough type ...
2025-10-02Merge tag 'for-6.18/block-20250929' of ↵Linus Torvalds1-5/+3
git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux Pull block updates from Jens Axboe: - NVMe pull request via Keith: - FC target fixes (Daniel) - Authentication fixes and updates (Martin, Chris) - Admin controller handling (Kamaljit) - Target lockdep assertions (Max) - Keep-alive updates for discovery (Alastair) - Suspend quirk (Georg) - MD pull request via Yu: - Add support for a lockless bitmap. A key feature for the new bitmap are that the IO fastpath is lockless. If a user issues lots of write IO to the same bitmap bit in a short time, only the first write has additional overhead to update bitmap bit, no additional overhead for the following writes. By supporting only resync or recover written data, means in the case creating new array or replacing with a new disk, there is no need to do a full disk resync/recovery. - Switch ->getgeo() and ->bios_param() to using struct gendisk rather than struct block_device. - Rust block changes via Andreas. This series adds configuration via configfs and remote completion to the rnull driver. The series also includes a set of changes to the rust block device driver API: a few cleanup patches, and a few features supporting the rnull changes. The series removes the raw buffer formatting logic from `kernel::block` and improves the logic available in `kernel::string` to support the same use as the removed logic. - floppy arch cleanups - Reduce the number of dereferencing needed for ublk commands - Restrict supported sockets for nbd. Mostly done to eliminate a class of issues perpetually reported by syzbot, by using nonsensical socket setups. - A few s390 dasd block fixes - Fix a few issues around atomic writes - Improve DMA interation for integrity requests - Improve how iovecs are treated with regards to O_DIRECT aligment constraints. We used to require each segment to adhere to the constraints, now only the request as a whole needs to. - Clean up and improve p2p support, enabling use of p2p for metadata payloads - Improve locking of request lookup, using SRCU where appropriate - Use page references properly for brd, avoiding very long RCU sections - Fix ordering of recursively submitted IOs - Clean up and improve updating nr_requests for a live device - Various fixes and cleanups * tag 'for-6.18/block-20250929' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (164 commits) s390/dasd: enforce dma_alignment to ensure proper buffer validation s390/dasd: Return BLK_STS_INVAL for EINVAL from do_dasd_request ublk: remove redundant zone op check in ublk_setup_iod() nvme: Use non zero KATO for persistent discovery connections nvmet: add safety check for subsys lock nvme-core: use nvme_is_io_ctrl() for I/O controller check nvme-core: do ioccsz/iorcsz validation only for I/O controllers nvme-core: add method to check for an I/O controller blk-cgroup: fix possible deadlock while configuring policy blk-mq: fix null-ptr-deref in blk_mq_free_tags() from error path blk-mq: Fix more tag iteration function documentation selftests: ublk: fix behavior when fio is not installed ublk: don't access ublk_queue in ublk_unmap_io() ublk: pass ublk_io to __ublk_complete_rq() ublk: don't access ublk_queue in ublk_need_complete_req() ublk: don't access ublk_queue in ublk_check_commit_and_fetch() ublk: don't pass ublk_queue to ublk_fetch() ublk: don't access ublk_queue in ublk_config_io_buf() ublk: don't access ublk_queue in ublk_check_fetch_buf() ublk: pass q_id and tag to __ublk_check_and_get_req() ...
2025-09-30Merge tag 'core-core-2025-09-29' of ↵Linus Torvalds1-45/+31
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull TIF bit unification updates from Thomas Gleixner: "A set of changes to consolidate the generic TIF (thread info flag) bits accross architectures. All architectures define the same set of generic TIF bits. This makes it pointlessly hard to add a new generic TIF bit or to change an existing one. Provide a generic variant and convert the architectures which utilize the generic entry code over to use it. The TIF space is divided into 16 generic bits and 16 architecture specific bits, which turned out to provide enough space on both sides" * tag 'core-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: LoongArch: Fix bitflag conflict for TIF_FIXADE riscv: Use generic TIF bits loongarch: Use generic TIF bits s390/entry: Remove unused TIF flags s390: Use generic TIF bits x86: Use generic TIF bits asm-generic: Provide generic TIF infrastructure
2025-09-30Merge tag 'x86_apic_for_v6.18_rc1' of ↵Linus Torvalds10-38/+67
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 SEV and apic updates from Borislav Petkov: - Add functionality to provide runtime firmware updates for the non-x86 parts of an AMD platform like the security processor (ASP) firmware, modules etc, for example. The intent being that these updates are interim, live fixups before a proper BIOS update can be attempted - Add guest support for AMD's Secure AVIC feature which gives encrypted guests the needed protection against a malicious hypervisor generating unexpected interrupts and injecting them into such guest, thus interfering with its operation in an unexpected and negative manner. The advantage of this scheme is that the guest determines which interrupts and when to accept them vs leaving that to the benevolence (or not) of the hypervisor - Strictly separate the startup code from the rest of the kernel where former is executed from the initial 1:1 mapping of memory. The problem was that the toolchain-generated version of the code was being executed from a different mapping of memory than what was "assumed" during code generation, needing an ever-growing pile of fixups for absolute memory references which are invalid in the early, 1:1 memory mapping during boot. The major advantage of this is that there's no need to check the 1:1 mapping portion of the code for absolute relocations anymore and get rid of the RIP_REL_REF() macro sprinkling all over the place. For more info, see Ard's very detailed writeup on this [1] - The usual cleanups and fixes Link: https://lore.kernel.org/r/CAMj1kXEzKEuePEiHB%2BHxvfQbFz0sTiHdn4B%2B%2BzVBJ2mhkPkQ4Q@mail.gmail.com [1] * tag 'x86_apic_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (49 commits) x86/boot: Drop erroneous __init annotation from early_set_pages_state() crypto: ccp - Add AMD Seamless Firmware Servicing (SFS) driver crypto: ccp - Add new HV-Fixed page allocation/free API x86/sev: Add new dump_rmp parameter to snp_leak_pages() API x86/startup/sev: Document the CPUID flow in the boot #VC handler objtool: Ignore __pi___cfi_ prefixed symbols x86/sev: Zap snp_abort() x86/apic/savic: Do not use snp_abort() x86/boot: Get rid of the .head.text section x86/boot: Move startup code out of __head section efistub/x86: Remap inittext read-execute when needed x86/boot: Create a confined code area for startup code x86/kbuild: Incorporate boot/startup/ via Kbuild makefile x86/boot: Revert "Reject absolute references in .head.text" x86/boot: Check startup code for absence of absolute relocations objtool: Add action to check for absence of absolute relocations x86/sev: Export startup routines for later use x86/sev: Move __sev_[get|put]_ghcb() into separate noinstr object x86/sev: Provide PIC aliases for SEV related data objects x86/boot: Provide PIC aliases for 5-level paging related constants ...
2025-09-30Merge tag 'x86_cache_for_v6.18_rc1' of ↵Linus Torvalds3-16/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 resource control updates from Borislav Petkov: "Add support on AMD for assigning QoS bandwidth counters to resources (RMIDs) with the ability for those resources to be tracked by the counters as long as they're assigned to them. Previously, due to hw limitations, bandwidth counts from untracked resources would get lost when those resources are not tracked. Refactor the code and user interfaces to be able to also support other, similar features on ARM, for example" * tag 'x86_cache_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits) fs/resctrl: Fix counter auto-assignment on mkdir with mbm_event enabled MAINTAINERS: resctrl: Add myself as reviewer x86/resctrl: Configure mbm_event mode if supported fs/resctrl: Introduce the interface to switch between monitor modes fs/resctrl: Disable BMEC event configuration when mbm_event mode is enabled fs/resctrl: Introduce the interface to modify assignments in a group fs/resctrl: Introduce mbm_L3_assignments to list assignments in a group fs/resctrl: Auto assign counters on mkdir and clean up on group removal fs/resctrl: Introduce mbm_assign_on_mkdir to enable assignments on mkdir fs/resctrl: Provide interface to update the event configurations fs/resctrl: Add event configuration directory under info/L3_MON/ fs/resctrl: Support counter read/reset with mbm_event assignment mode x86/resctrl: Implement resctrl_arch_reset_cntr() and resctrl_arch_cntr_read() x86/resctrl: Refactor resctrl_arch_rmid_read() fs/resctrl: Introduce counter ID read, reset calls in mbm_event mode fs/resctrl: Pass struct rdtgroup instead of individual members fs/resctrl: Add the functionality to unassign MBM events fs/resctrl: Add the functionality to assign MBM events x86,fs/resctrl: Implement resctrl_arch_config_cntr() to assign a counter with ABMC fs/resctrl: Introduce event configuration field in struct mon_evt ...
2025-09-30Merge tag 'x86_cpu_for_v6.18_rc1' of ↵Linus Torvalds3-4/+10
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cpuid updates from Borislav Petkov: - Make UMIP instruction detection more robust - Correct and cleanup AMD CPU topology detection; document the relevant CPUID leaves topology parsing precedence on AMD - Add support for running the kernel as guest on FreeBSD's Bhyve hypervisor - Cleanups and improvements * tag 'x86_cpu_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/umip: Fix decoding of register forms of 0F 01 (SGDT and SIDT aliases) x86/umip: Check that the instruction opcode is at least two bytes Documentation/x86/topology: Detail CPUID leaves used for topology enumeration x86/cpu/topology: Define AMD64_CPUID_EXT_FEAT MSR x86/cpu/topology: Check for X86_FEATURE_XTOPOLOGY instead of passing has_xtopology x86/cpu/cacheinfo: Simplify cacheinfo_amd_init_llc_id() using _cpuid4_info x86/cpu: Rename and move CPU model entry for Diamond Rapids x86/cpu: Detect FreeBSD Bhyve hypervisor
2025-09-30Merge tag 'x86_bugs_for_v6.18_rc1' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mitigation updates from Borislav Petkov: - Add VMSCAPE to the attack vector controls infrastructure - A bunch of the usual cleanups and fixlets, some of them resulting from fuzzing the different mitigation options * tag 'x86_bugs_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/bugs: Report correct retbleed mitigation status x86/bugs: Fix reporting of LFENCE retpoline x86/bugs: Fix spectre_v2 forcing x86/bugs: Remove uses of cpu_mitigations_off() x86/bugs: Simplify SSB cmdline parsing x86/bugs: Use early_param() for spectre_v2 x86/bugs: Use early_param() for spectre_v2_user x86/bugs: Add attack vector controls for VMSCAPE x86/its: Move ITS indirect branch thunks to .text..__x86.indirect_thunk
2025-09-30Merge tag 'ras_core_for_v6.18_rc1' of ↵Linus Torvalds1-8/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 RAS updates from Borislav Petkov: - Unify and refactor the MCA arch side and better separate code - Cleanup and simplify the AMD RAS side, unify code, drop unused stuff * tag 'ras_core_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce: Add a clear_bank() helper x86/mce: Move machine_check_poll() status checks to helper functions x86/mce: Separate global and per-CPU quirks x86/mce: Do 'UNKNOWN' vendor check early x86/mce: Define BSP-only SMCA init x86/mce: Define BSP-only init x86/mce: Set CR4.MCE last during init x86/mce: Remove __mcheck_cpu_init_early() x86/mce: Cleanup bank processing on init x86/mce/amd: Put list_head in threshold_bank x86/mce/amd: Remove smca_banks_map x86/mce/amd: Remove return value for mce_threshold_{create,remove}_device() x86/mce/amd: Rename threshold restart function
2025-09-30Merge tag 'x86_asm_for_v6.18_rc1' of ↵Linus Torvalds1-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm update from Borislav Petkov: - Fix RDPID's output operand size in inline asm and use the insn mnemonic because the minimum binutils version supports it * tag 'x86_asm_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso: Fix output operand size of RDPID
2025-09-30Merge tag 'x86_misc_for_v6.18_rc1' of ↵Linus Torvalds2-3/+63
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 instruction decoder update from Borislav Petkov: - Add instruction decoding support for the XOP-prefixed instruction set present on the AMD Bulldozer uarch [ These instructions don't normally happen, but a X86_NATIVE_CPU build on a bulldozer host can make the compiler then use these unusual instruction encodings ] * tag 'x86_misc_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/insn: Add XOP prefix instructions decoder support
2025-09-30Merge tag 'perf-core-2025-09-26' of ↵Linus Torvalds4-8/+25
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull performance events updates from Ingo Molnar: "Core perf code updates: - Convert mmap() related reference counts to refcount_t. This is in reaction to the recently fixed refcount bugs, which could have been detected earlier and could have mitigated the bug somewhat (Thomas Gleixner, Peter Zijlstra) - Clean up and simplify the callchain code, in preparation for sframes (Steven Rostedt, Josh Poimboeuf) Uprobes updates: - Add support to optimize usdt probes on x86-64, which gives a substantial speedup (Jiri Olsa) - Cleanups and fixes on x86 (Peter Zijlstra) PMU driver updates: - Various optimizations and fixes to the Intel PMU driver (Dapeng Mi) Misc cleanups and fixes: - Remove redundant __GFP_NOWARN (Qianfeng Rong)" * tag 'perf-core-2025-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits) selftests/bpf: Fix uprobe_sigill test for uprobe syscall error value uprobes/x86: Return error from uprobe syscall when not called from trampoline perf: Skip user unwind if the task is a kernel thread perf: Simplify get_perf_callchain() user logic perf: Use current->flags & PF_KTHREAD|PF_USER_WORKER instead of current->mm == NULL perf: Have get_perf_callchain() return NULL if crosstask and user are set perf: Remove get_perf_callchain() init_nr argument perf/x86: Print PMU counters bitmap in x86_pmu_show_pmu_cap() perf/x86/intel: Add ICL_FIXED_0_ADAPTIVE bit into INTEL_FIXED_BITS_MASK perf/x86/intel: Change macro GLOBAL_CTRL_EN_PERF_METRICS to BIT_ULL(48) perf/x86: Add PERF_CAP_PEBS_TIMING_INFO flag perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error perf/x86/intel: Use early_initcall() to hook bts_init() uprobes: Remove redundant __GFP_NOWARN selftests/seccomp: validate uprobe syscall passes through seccomp seccomp: passthrough uprobe systemcall without filtering selftests/bpf: Fix uprobe syscall shadow stack test selftests/bpf: Change test_uretprobe_regs_change for uprobe and uretprobe selftests/bpf: Add uprobe_regs_equal test selftests/bpf: Add optimized usdt variant for basic usdt test ...
2025-09-30KVM: x86: Move kvm_intr_is_single_vcpu() to lapic.cSean Christopherson1-3/+0
Move kvm_intr_is_single_vcpu() to lapic.c, drop its export, and make its "fast" helper local to lapic.c. kvm_intr_is_single_vcpu() is only usable if the local APIC is in-kernel, i.e. it most definitely belongs in the local APIC code. No functional change intended. Fixes: cf04ec393ed0 ("KVM: x86: Dedup AVIC vs. PI code for identifying target vCPU") Link: https://lore.kernel.org/r/20250919003303.1355064-4-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-09-30KVM: Export KVM-internal symbols for sub-modules onlySean Christopherson1-0/+10
Rework the vast majority of KVM's exports to expose symbols only to KVM submodules, i.e. to x86's kvm-{amd,intel}.ko and PPC's kvm-{pr,hv}.ko. With few exceptions, KVM's exported APIs are intended (and safe) for KVM- internal usage only. Keep kvm_get_kvm(), kvm_get_kvm_safe(), and kvm_put_kvm() as normal exports, as they are needed by VFIO, and are generally safe for external usage (though ideally even the get/put APIs would be KVM-internal, and VFIO would pin a VM by grabbing a reference to its associated file). Implement a framework in kvm_types.h in anticipation of providing a macro to restrict KVM-specific kernel exports, i.e. to provide symbol exports for KVM if and only if KVM is built as one or more modules. Link: https://lore.kernel.org/r/20250919003303.1355064-3-seanjc@google.com Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-09-30Merge tag 'kvm-x86-cet-6.18' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini3-2/+47
KVM x86 CET virtualization support for 6.18 Add support for virtualizing Control-flow Enforcement Technology (CET) on Intel (Shadow Stacks and Indirect Branch Tracking) and AMD (Shadow Stacks). CET is comprised of two distinct features, Shadow Stacks (SHSTK) and Indirect Branch Tracking (IBT), that can be utilized by software to help provide Control-flow integrity (CFI). SHSTK defends against backward-edge attacks (a.k.a. Return-oriented programming (ROP)), while IBT defends against forward-edge attacks (a.k.a. similarly CALL/JMP-oriented programming (COP/JOP)). Attackers commonly use ROP and COP/JOP methodologies to redirect the control- flow to unauthorized targets in order to execute small snippets of code, a.k.a. gadgets, of the attackers choice. By chaining together several gadgets, an attacker can perform arbitrary operations and circumvent the system's defenses. SHSTK defends against backward-edge attacks, which execute gadgets by modifying the stack to branch to the attacker's target via RET, by providing a second stack that is used exclusively to track control transfer operations. The shadow stack is separate from the data/normal stack, and can be enabled independently in user and kernel mode. When SHSTK is is enabled, CALL instructions push the return address on both the data and shadow stack. RET then pops the return address from both stacks and compares the addresses. If the return addresses from the two stacks do not match, the CPU generates a Control Protection (#CP) exception. IBT defends against backward-edge attacks, which branch to gadgets by executing indirect CALL and JMP instructions with attacker controlled register or memory state, by requiring the target of indirect branches to start with a special marker instruction, ENDBRANCH. If an indirect branch is executed and the next instruction is not an ENDBRANCH, the CPU generates a #CP. Note, ENDBRANCH behaves as a NOP if IBT is disabled or unsupported. From a virtualization perspective, CET presents several problems. While SHSTK and IBT have two layers of enabling, a global control in the form of a CR4 bit, and a per-feature control in user and kernel (supervisor) MSRs (U_CET and S_CET respectively), the {S,U}_CET MSRs can be context switched via XSAVES/XRSTORS. Practically speaking, intercepting and emulating XSAVES/XRSTORS is not a viable option due to complexity, and outright disallowing use of XSTATE to context switch SHSTK/IBT state would render the features unusable to most guests. To limit the overall complexity without sacrificing performance or usability, simply ignore the potential virtualization hole, but ensure that all paths in KVM treat SHSTK/IBT as usable by the guest if the feature is supported in hardware, and the guest has access to at least one of SHSTK or IBT. I.e. allow userspace to advertise one of SHSTK or IBT if both are supported in hardware, even though doing so would allow a misbehaving guest to use the unadvertised feature. Fully emulating SHSTK and IBT would also require significant complexity, e.g. to track and update branch state for IBT, and shadow stack state for SHSTK. Given that emulating large swaths of the guest code stream isn't necessary on modern CPUs, punt on emulating instructions that meaningful impact or consume SHSTK or IBT. However, instead of doing nothing, explicitly reject emulation of such instructions so that KVM's emulator can't be abused to circumvent CET. Disable support for SHSTK and IBT if KVM is configured such that emulation of arbitrary guest instructions may be required, specifically if Unrestricted Guest (Intel only) is disabled, or if KVM will emulate a guest.MAXPHYADDR that is smaller than host.MAXPHYADDR. Lastly disable SHSTK support if shadow paging is enabled, as the protections for the shadow stack are novel (shadow stacks require Writable=0,Dirty=1, so that they can't be directly modified by software), i.e. would require non-trivial support in the Shadow MMU. Note, AMD CPUs currently only support SHSTK. Explicitly disable IBT support so that KVM doesn't over-advertise if AMD CPUs add IBT, and virtualizing IBT in SVM requires KVM modifications.
2025-09-30Merge tag 'kvm-x86-misc-6.18' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini5-19/+37
KVM x86 changes for 6.18 - Don't (re)check L1 intercepts when completing userspace I/O to fix a flaw where a misbehaving usersepace (a.k.a. syzkaller) could swizzle L1's intercepts and trigger a variety of WARNs in KVM. - Emulate PERF_CNTR_GLOBAL_STATUS_SET for PerfMonV2 guests, as the MSR is supposed to exist for v2 PMUs. - Allow Centaur CPU leaves (base 0xC000_0000) for Zhaoxin CPUs. - Clean up KVM's vector hashing code for delivering lowest priority IRQs. - Clean up the fastpath handler code to only handle IPIs and WRMSRs that are actually "fast", as opposed to handling those that KVM _hopes_ are fast, and in the process of doing so add fastpath support for TSC_DEADLINE writes on AMD CPUs. - Clean up a pile of PMU code in anticipation of adding support for mediated vPMUs. - Add support for the immediate forms of RDMSR and WRMSRNS, sans full emulator support (KVM should never need to emulate the MSRs outside of forced emulation and other contrived testing scenarios). - Clean up the MSR APIs in preparation for CET and FRED virtualization, as well as mediated vPMU support. - Rejecting a fully in-kernel IRQCHIP if EOIs are protected, i.e. for TDX VMs, as KVM can't faithfully emulate an I/O APIC for such guests. - KVM_REQ_MSR_FILTER_CHANGED into a generic RECALC_INTERCEPTS in preparation for mediated vPMU support, as KVM will need to recalculate MSR intercepts in response to PMU refreshes for guests with mediated vPMUs. - Misc cleanups and minor fixes.
2025-09-30Merge tag 'kvm-x86-svm-6.18' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini3-0/+4
KVM SVM changes for 6.18 - Require a minimum GHCB version of 2 when starting SEV-SNP guests via KVM_SEV_INIT2 so that invalid GHCB versions result in immediate errors instead of latent guest failures. - Add support for Secure TSC for SEV-SNP guests, which prevents the untrusted host from tampering with the guest's TSC frequency, while still allowing the the VMM to configure the guest's TSC frequency prior to launch. - Mitigate the potential for TOCTOU bugs when accessing GHCB fields by wrapping all accesses via READ_ONCE(). - Validate the XCR0 provided by the guest (via the GHCB) to avoid tracking a bogous XCR0 value in KVM's software model. - Save an SEV guest's policy if and only if LAUNCH_START fully succeeds to avoid leaving behind stale state (thankfully not consumed in KVM). - Explicitly reject non-positive effective lengths during SNP's LAUNCH_UPDATE instead of subtly relying on guest_memfd to do the "heavy" lifting. - Reload the pre-VMRUN TSC_AUX on #VMEXIT for SEV-ES guests, not the host's desired TSC_AUX, to fix a bug where KVM could clobber a different vCPU's TSC_AUX due to hardware not matching the value cached in the user-return MSR infrastructure. - Enable AVIC by default for Zen4+ if x2AVIC (and other prereqs) is supported, and clean up the AVIC initialization code along the way.
2025-09-30Merge tag 'kvm-x86-mmu-6.18' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini1-13/+26
KVM x86 MMU changes for 6.18 - Recover possible NX huge pages within the TDP MMU under read lock to reduce guest jitter when restoring NX huge pages. - Return -EAGAIN during prefault if userspace concurrently deletes/moves the relevant memslot to fix an issue where prefaulting could deadlock with the memslot update. - Don't retry in TDX's anti-zero-step mitigation if the target memslot is invalid, i.e. is being deleted or moved, to fix a deadlock scenario similar to the aforementioned prefaulting case.
2025-09-30Merge tag 'kvm-x86-guest-6.18' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini1-2/+0
x86/kvm guest side changes for 6.18 - For the legacy PCI hole (memory between TOLUD and 4GiB) to UC when overriding guest MTRR for TDX/SNP to fix an issue where ACPI auto-mapping could map devices as WB and prevent the device drivers from mapping their devices with UC/UC-. - Make kvm_async_pf_task_wake() a local static helper and remove its export. - Use native qspinlocks when running in a VM with dedicated vCPU=>pCPU bindings even when PV_UNHALT is unsupported.
2025-09-30Merge tag 'loongarch-kvm-6.18' of ↵Paolo Bonzini4-19/+30
git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD LoongArch KVM changes for v6.18 1. Add PTW feature detection on new hardware. 2. Add sign extension with kernel MMIO/IOCSR emulation. 3. Improve in-kernel IPI emulation. 4. Improve in-kernel PCH-PIC emulation. 5. Move kvm_iocsr tracepoint out of generic code.
2025-09-30Merge tag 'kvm-riscv-6.18-1' of https://github.com/kvm-riscv/linux into HEADPaolo Bonzini1-0/+3
KVM/riscv changes for 6.18 - Added SBI FWFT extension for Guest/VM with misaligned delegation and pointer masking PMLEN features - Added ONE_REG interface for SBI FWFT extension - Added Zicbop and bfloat16 extensions for Guest/VM - Enabled more common KVM selftests for RISC-V such as access_tracking_perf_test, dirty_log_perf_test, memslot_modification_stress_test, memslot_perf_test, mmu_stress_test, and rseq_test - Added SBI v3.0 PMU enhancements in KVM and perf driver
2025-09-29Merge tag 'for-linus-6.18-rc1-tag' of ↵Linus Torvalds1-7/+7
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from Juergen Gross: - fix the migration of a Xen virq to another cpu plus some related cleanup work - clean up Xen-PV mode specific code, resulting in removing some of that code in the resulting binary in case CONFIG_XEN_PV is not set - fixes and cleanup for suspend handling under Xen * tag 'for-linus-6.18-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: take system_transition_mutex on suspend xen/manage: Fix suspend error path xen/events: Update virq_to_irq on migration xen/events: Return -EEXIST for bound VIRQs xen/events: Cleanup find_virq() return codes x86/xen: select HIBERNATE_CALLBACKS more directly drivers/xen/gntdev: use xen_pv_domain() instead of cached value xen: replace XENFEAT_auto_translated_physmap with xen_pv_domain() xen: rework xen_pv_domain()
2025-09-29Merge tag 'hardening-v6.18-rc1' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening updates from Kees Cook: "One notable addition is the creation of the 'transitional' keyword for kconfig so CONFIG renaming can go more smoothly. This has been a long-standing deficiency, and with the renaming of CONFIG_CFI_CLANG to CONFIG_CFI (since GCC will soon have KCFI support), this came up again. The breadth of the diffstat is mainly this renaming. - Clean up usage of TRAILING_OVERLAP() (Gustavo A. R. Silva) - lkdtm: fortify: Fix potential NULL dereference on kmalloc failure (Junjie Cao) - Add str_assert_deassert() helper (Lad Prabhakar) - gcc-plugins: Remove TODO_verify_il for GCC >= 16 - kconfig: Fix BrokenPipeError warnings in selftests - kconfig: Add transitional symbol attribute for migration support - kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI" * tag 'hardening-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: lib/string_choices: Add str_assert_deassert() helper kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFI kconfig: Add transitional symbol attribute for migration support kconfig: Fix BrokenPipeError warnings in selftests gcc-plugins: Remove TODO_verify_il for GCC >= 16 stddef: Introduce __TRAILING_OVERLAP() stddef: Remove token-pasting in TRAILING_OVERLAP() lkdtm: fortify: Fix potential NULL dereference on kmalloc failure
2025-09-29Merge tag 'ffs-const-v6.18-rc1' of ↵Linus Torvalds1-6/+6
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull ffs const-attribute cleanups from Kees Cook: "While working on various hardening refactoring a while back we encountered inconsistencies in the application of __attribute_const__ on the ffs() family of functions. This series fixes this across all archs and adds KUnit tests. Notably, this found a theoretical underflow in PCI (also fixed here) and uncovered an inefficiency in ARC (fixed in the ARC arch PR). I kept the series separate from the general hardening PR since it is a stand-alone "topic". - PCI: Fix theoretical underflow in use of ffs(). - Universally apply __attribute_const__ to all architecture's ffs()-family of functions. - Add KUnit tests for ffs() behavior and const-ness" * tag 'ffs-const-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: KUnit: ffs: Validate all the __attribute_const__ annotations sparc: Add __attribute_const__ to ffs()-family implementations xtensa: Add __attribute_const__ to ffs()-family implementations s390: Add __attribute_const__ to ffs()-family implementations parisc: Add __attribute_const__ to ffs()-family implementations mips: Add __attribute_const__ to ffs()-family implementations m68k: Add __attribute_const__ to ffs()-family implementations openrisc: Add __attribute_const__ to ffs()-family implementations riscv: Add __attribute_const__ to ffs()-family implementations hexagon: Add __attribute_const__ to ffs()-family implementations alpha: Add __attribute_const__ to ffs()-family implementations sh: Add __attribute_const__ to ffs()-family implementations powerpc: Add __attribute_const__ to ffs()-family implementations x86: Add __attribute_const__ to ffs()-family implementations csky: Add __attribute_const__ to ffs()-family implementations bitops: Add __attribute_const__ to generic ffs()-family implementations KUnit: Introduce ffs()-family tests PCI: Test for bit underflow in pcie_set_readrq()
2025-09-29Merge tag 'kernel-6.18-rc1.clone3' of ↵Linus Torvalds2-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull copy_process updates from Christian Brauner: "This contains the changes to enable support for clone3() on nios2 which apparently is still a thing. The more exciting part of this is that it cleans up the inconsistency in how the 64-bit flag argument is passed from copy_process() into the various other copy_*() helpers" [ Fixed up rv ltl_monitor 32-bit support as per Sasha Levin in the merge ] * tag 'kernel-6.18-rc1.clone3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: nios2: implement architecture-specific portion of sys_clone3 arch: copy_thread: pass clone_flags as u64 copy_process: pass clone_flags as u64 across calltree copy_sighand: Handle architectures where sizeof(unsigned long) < sizeof(u64)
2025-09-24kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFIKees Cook1-2/+2
The kernel's CFI implementation uses the KCFI ABI specifically, and is not strictly tied to a particular compiler. In preparation for GCC supporting KCFI, rename CONFIG_CFI_CLANG to CONFIG_CFI (along with associated options). Use new "transitional" Kconfig option for old CONFIG_CFI_CLANG that will enable CONFIG_CFI during olddefconfig. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20250923213422.1105654-3-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-09-23KVM: x86: Define AMD's #HV, #VC, and #SX exception vectorsSean Christopherson1-0/+4
Add {HV,CP,SX}_VECTOR definitions for AMD's Hypervisor Injection Exception, VMM Communication Exception, and SVM Security Exception vectors, along with human friendly formatting for trace_kvm_inj_exception(). Note, KVM is all but guaranteed to never observe or inject #SX, and #HV is also unlikely to go unused. Add the architectural collateral mostly for completeness, and on the off chance that hardware goes off the rails. Link: https://lore.kernel.org/r/20250919223258.1604852-44-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-09-23KVM: x86: Define Control Protection Exception (#CP) vectorSean Christopherson1-0/+1
Add a CP_VECTOR definition for CET's Control Protection Exception (#CP), along with human friendly formatting for trace_kvm_inj_exception(). Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Link: https://lore.kernel.org/r/20250919223258.1604852-43-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-09-23KVM: x86: Enable CET virtualization for VMX and advertise to userspaceYang Weijiang1-0/+1
Add support for the LOAD_CET_STATE VM-Enter and VM-Exit controls, the CET XFEATURE bits in XSS, and advertise support for IBT and SHSTK to userspace. Explicitly clear IBT and SHSTK onn SVM, as additional work is needed to enable CET on SVM, e.g. to context switch S_CET and other state. Disable KVM CET feature if unrestricted_guest is unsupported/disabled as KVM does not support emulating CET, as running without Unrestricted Guest can result in KVM emulating large swaths of guest code. While it's highly unlikely any guest will trigger emulation while also utilizing IBT or SHSTK, there's zero reason to allow CET without Unrestricted Guest as that combination should only be possible when explicitly disabling unrestricted_guest for testing purposes. Disable CET if VMX_BASIC[bit56] == 0, i.e. if hardware strictly enforces the presence of an Error Code based on exception vector, as attempting to inject a #CP with an Error Code (#CP architecturally has an Error Code) will fail due to the #CP vector historically not having an Error Code. Clear S_CET and SSP-related VMCS on "reset" to emulate the architectural of CET MSRs and SSP being reset to 0 after RESET, power-up and INIT. Note, KVM already clears guest CET state that is managed via XSTATE in kvm_xstate_reset(). Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> Signed-off-by: Mathias Krause <minipli@grsecurity.net> Tested-by: Mathias Krause <minipli@grsecurity.net> Tested-by: John Allen <john.allen@amd.com> Tested-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Chao Gao <chao.gao@intel.com> [sean: move some bits to separate patches, massage changelog] Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Link: https://lore.kernel.org/r/20250919223258.1604852-29-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-09-23KVM: x86: Allow setting CR4.CET if IBT or SHSTK is supportedYang Weijiang1-1/+1
Drop X86_CR4_CET from CR4_RESERVED_BITS and instead mark CET as reserved if and only if IBT *and* SHSTK are unsupported, i.e. allow CR4.CET to be set if IBT or SHSTK is supported. This creates a virtualization hole if the CPU supports both IBT and SHSTK, but the kernel or vCPU model only supports one of the features. However, it's entirely legal for a CPU to have only one of IBT or SHSTK, i.e. the hole is a flaw in the architecture, not in KVM. More importantly, so long as KVM is careful to initialize and context switch both IBT and SHSTK state (when supported in hardware) if either feature is exposed to the guest, a misbehaving guest can only harm itself. E.g. VMX initializes host CET VMCS fields based solely on hardware capabilities. Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> Signed-off-by: Mathias Krause <minipli@grsecurity.net> Tested-by: Mathias Krause <minipli@grsecurity.net> Tested-by: John Allen <john.allen@amd.com> Tested-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Chao Gao <chao.gao@intel.com> [sean: split to separate patch, write changelog] Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Link: https://lore.kernel.org/r/20250919223258.1604852-24-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-09-23KVM: x86/mmu: WARN on attempt to check permissions for Shadow Stack #PFSean Christopherson1-0/+1
Add PFERR_SS_MASK, a.k.a. Shadow Stack access, and WARN if KVM attempts to check permissions for a Shadow Stack access as KVM hasn't been taught to understand the magic Writable=0,Dirty=1 combination that is required for Shadow Stack accesses, and likely will never learn. There are no plans to support Shadow Stacks with the Shadow MMU, and the emulator rejects all instructions that affect Shadow Stacks, i.e. it should be impossible for KVM to observe a #PF due to a shadow stack access. Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Link: https://lore.kernel.org/r/20250919223258.1604852-22-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-09-23KVM: x86: Enable guest SSP read/write interface with new uAPIsYang Weijiang1-0/+3
Add a KVM-defined ONE_REG register, KVM_REG_GUEST_SSP, to let userspace save and restore the guest's Shadow Stack Pointer (SSP). On both Intel and AMD, SSP is a hardware register that can only be accessed by software via dedicated ISA (e.g. RDSSP) or via VMCS/VMCB fields (used by hardware to context switch SSP at entry/exit). As a result, SSP doesn't fit in any of KVM's existing interfaces for saving/restoring state. Internally, treat SSP as a fake/synthetic MSR, as the semantics of writes to SSP follow that of several other Shadow Stack MSRs, e.g. the PLx_SSP MSRs. Use a translation layer to hide the KVM-internal MSR index so that the arbitrary index doesn't become ABI, e.g. so that KVM can rework its implementation as needed, so long as the ONE_REG ABI is maintained. Explicitly reject accesses to SSP if the vCPU doesn't have Shadow Stack support to avoid running afoul of ignore_msrs, which unfortunately applies to host-initiated accesses (which is a discussion for another day). I.e. ensure consistent behavior for KVM-defined registers irrespective of ignore_msrs. Link: https://lore.kernel.org/all/aca9d389-f11e-4811-90cf-d98e345a5cc2@intel.com Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> Tested-by: Mathias Krause <minipli@grsecurity.net> Tested-by: John Allen <john.allen@amd.com> Tested-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Chao Gao <chao.gao@intel.com> Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Link: https://lore.kernel.org/r/20250919223258.1604852-14-seanjc@google.com Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-09-23KVM: VMX: Introduce CET VMCS fields and control bitsYang Weijiang1-0/+8
Control-flow Enforcement Technology (CET) is a kind of CPU feature used to prevent Return/CALL/Jump-Oriented Programming (ROP/COP/JOP) attacks. It provides two sub-features(SHSTK,IBT) to defend against ROP/COP/JOP style control-flow subversion attacks. Shadow Stack (SHSTK): A shadow stack is a second stack used exclusively for control transfer operations. The shadow stack is separate from the data/normal stack and can be enabled individually in user and kernel mode. When shadow stack is enabled, CALL pushes the return address on both the data and shadow stack. RET pops the return address from both stacks and compares them. If the return addresses from the two stacks do not match, the processor generates a #CP. Indirect Branch Tracking (IBT): IBT introduces instruction(ENDBRANCH)to mark valid target addresses of indirect branches (CALL, JMP etc...). If an indirect branch is executed and the next instruction is _not_ an ENDBRANCH, the processor generates a #CP. These instruction behaves as a NOP on platforms that have no CET. Several new CET MSRs are defined to support CET: MSR_IA32_{U,S}_CET: CET settings for {user,supervisor} CET respectively. MSR_IA32_PL{0,1,2,3}_SSP: SHSTK pointer linear address for CPL{0,1,2,3}. MSR_IA32_INT_SSP_TAB: Linear address of SHSTK pointer table, whose entry is indexed by IST of interrupt gate desc. Two XSAVES state bits are introduced for CET: IA32_XSS:[bit 11]: Control saving/restoring user mode CET states IA32_XSS:[bit 12]: Control saving/restoring supervisor mode CET states. Six VMCS fields are introduced for CET: {HOST,GUEST}_S_CET: Stores CET settings for kernel mode. {HOST,GUEST}_SSP: Stores current active SSP. {HOST,GUEST}_INTR_SSP_TABLE: Stores current active MSR_IA32_INT_SSP_TAB. On Intel platforms, two additional bits are defined in VM_EXIT and VM_ENTRY control fields: If VM_EXIT_LOAD_CET_STATE = 1, host CET states are loaded from following VMCS fields at VM-Exit: HOST_S_CET HOST_SSP HOST_INTR_SSP_TABLE If VM_ENTRY_LOAD_CET_STATE = 1, guest CET states are loaded from following VMCS fields at VM-Entry: GUEST_S_CET GUEST_SSP GUEST_INTR_SSP_TABLE Co-developed-by: Zhang Yi Z <yi.z.zhang@linux.intel.com> Signed-off-by: Zhang Yi Z <yi.z.zhang@linux.intel.com> Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> Reviewed-by: Chao Gao <chao.gao@intel.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Tested-by: Mathias Krause <minipli@grsecurity.net> Tested-by: John Allen <john.allen@amd.com> Tested-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Chao Gao <chao.gao@intel.com> Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Link: https://lore.kernel.org/r/20250919223258.1604852-13-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-09-23KVM: x86: Check XSS validity against guest CPUIDsChao Gao1-1/+2
Maintain per-guest valid XSS bits and check XSS validity against them rather than against KVM capabilities. This is to prevent bits that are supported by KVM but not supported for a guest from being set. Opportunistically return KVM_MSR_RET_UNSUPPORTED on IA32_XSS MSR accesses if guest CPUID doesn't enumerate X86_FEATURE_XSAVES. Since KVM_MSR_RET_UNSUPPORTED takes care of host_initiated cases, drop the host_initiated check. Signed-off-by: Chao Gao <chao.gao@intel.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Link: https://lore.kernel.org/r/20250919223258.1604852-7-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-09-23KVM: x86: Introduce KVM_{G,S}ET_ONE_REG uAPIs supportYang Weijiang1-0/+26
Enable KVM_{G,S}ET_ONE_REG uAPIs so that userspace can access MSRs and other non-MSR registers through them, along with support for KVM_GET_REG_LIST to enumerate support for KVM-defined registers. This is in preparation for allowing userspace to read/write the guest SSP register, which is needed for the upcoming CET virtualization support. Currently, two types of registers are supported: KVM_X86_REG_TYPE_MSR and KVM_X86_REG_TYPE_KVM. All MSRs are in the former type; the latter type is added for registers that lack existing KVM uAPIs to access them. The "KVM" in the name is intended to be vague to give KVM flexibility to include other potential registers. More precise names like "SYNTHETIC" and "SYNTHETIC_MSR" were considered, but were deemed too confusing (e.g. can be conflated with synthetic guest-visible MSRs) and may put KVM into a corner (e.g. if KVM wants to change how a KVM-defined register is modeled internally). Enumerate only KVM-defined registers in KVM_GET_REG_LIST to avoid duplicating KVM_GET_MSR_INDEX_LIST, and so that KVM can return _only_ registers that are fully supported (KVM_GET_REG_LIST is vCPU-scoped, i.e. can be precise, whereas KVM_GET_MSR_INDEX_LIST is system-scoped). Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> Link: https://lore.kernel.org/all/20240219074733.122080-18-weijiang.yang@intel.com [1] Tested-by: Mathias Krause <minipli@grsecurity.net> Tested-by: John Allen <john.allen@amd.com> Tested-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Chao Gao <chao.gao@intel.com> Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20250919223258.1604852-5-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-09-23KVM: x86: Merge 'svm' into 'cet' to pick up GHCB dependenciesSean Christopherson3-0/+3
Merge the queue of SVM changes for 6.18 to pick up the KVM-defined GHCB helpers so that kvm_ghcb_get_xss() can be used to virtualize CET for SEV-ES+ guests.
2025-09-23KVM: x86: Add helper to retrieve current value of user return MSRHou Wenlong1-0/+1
In the user return MSR support, the cached value is always the hardware value of the specific MSR. Therefore, add a helper to retrieve the cached value, which can replace the need for RDMSR, for example, to allow SEV-ES guests to restore the correct host hardware value without using RDMSR. Cc: stable@vger.kernel.org Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com> [sean: drop "cache" from the name, make it a one-liner, tag for stable] Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Link: https://lore.kernel.org/r/20250923153738.1875174-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-09-23KVM: SEV: Validate XCR0 provided by guest in GHCBSean Christopherson1-0/+1
Use __kvm_set_xcr() to propagate XCR0 changes from the GHCB to KVM's software model in order to validate the new XCR0 against KVM's view of the supported XCR0. Allowing garbage is thankfully mostly benign, as kvm_load_{guest,host}_xsave_state() bail early for vCPUs with protected state, xstate_required_size() will simply provide garbage back to the guest, and attempting to save/restore the bad value via KVM_{G,S}ET_XCRS will only harm the guest (setting XCR0 will fail). However, allowing the guest to put junk into a field that KVM assumes is valid is a CVE waiting to happen. And as a bonus, using the proper API eliminates the ugly open coding of setting arch.cpuid_dynamic_bits_dirty. Simply ignore bad values, as either the guest managed to get an unsupported value into hardware, or the guest is misbehaving and providing pure garbage. In either case, KVM can't fix the broken guest. Note, using __kvm_set_xcr() also avoids recomputing dynamic CPUID bits if XCR0 isn't actually changing (relatively to KVM's previous snapshot). Cc: Tom Lendacky <thomas.lendacky@amd.com> Fixes: 291bd20d5d88 ("KVM: SVM: Add initial support for a VMGEXIT VMEXIT") Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20250919223258.1604852-4-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-09-22x86/topology: Implement topology_is_core_online() to address SMT regressionThomas Gleixner1-0/+10
Christian reported that commit a430c11f4015 ("intel_idle: Rescan "dead" SMT siblings during initialization") broke the use case in which both 'nosmt' and 'maxcpus' are on the kernel command line because it onlines primary threads, which were offline due to the maxcpus limit. The initially proposed fix to skip primary threads in the loop is inconsistent. While it prevents the primary thread to be onlined, it then onlines the corresponding hyperthread(s), which does not really make sense. The CPU iterator in cpuhp_smt_enable() contains a check which excludes all threads of a core, when the primary thread is offline. The default implementation is a NOOP and therefore not effective on x86. Implement topology_is_core_online() on x86 to address this issue. This makes the behaviour consistent between x86 and PowerPC. Fixes: a430c11f4015 ("intel_idle: Rescan "dead" SMT siblings during initialization") Fixes: f694481b1d31 ("ACPI: processor: Rescan "dead" SMT siblings during initialization") Closes: https://lore.kernel.org/linux-pm/724616a2-6374-4ba3-8ce3-ea9c45e2ae3b@arm.com/ Reported-by: Christian Loehle <christian.loehle@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org> Tested-by: Christian Loehle <christian.loehle@arm.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/12740505.O9o76ZdvQC@rafael.j.wysocki
2025-09-18KVM: x86: Rework KVM_REQ_MSR_FILTER_CHANGED into a generic RECALC_INTERCEPTSSean Christopherson2-3/+3
Rework the MSR_FILTER_CHANGED request into a more generic RECALC_INTERCEPTS request, and expand the responsibilities of vendor code to recalculate all intercepts that vary based on userspace input, e.g. instruction intercepts that are tied to guest CPUID. Providing a generic recalc request will allow the upcoming mediated PMU support to trigger a recalc when PMU features, e.g. PERF_CAPABILITIES, are set by userspace, without having to make multiple calls to/from PMU code. As a bonus, using a request will effectively coalesce recalcs, e.g. will reduce the number of recalcs for normal usage from 3+ to 1 (vCPU create, set CPUID, set PERF_CAPABILITIES (Intel only), set filter). The downside is that MSR filter changes that are done in isolation will do a small amount of unnecessary work, but that's already a relatively slow path, and the cost of recalculating instruction intercepts is negligible. Tested-by: Xudong Hao <xudong.hao@intel.com> Link: https://lore.kernel.org/r/20250806195706.1650976-25-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-09-18KVM: x86/pmu: Move PMU_CAP_{FW_WRITES,LBR_FMT} into msr-index.h headerDapeng Mi1-6/+9
Move PMU_CAP_{FW_WRITES,LBR_FMT} into msr-index.h and rename them with PERF_CAP prefix to keep consistent with other perf capabilities macros. No functional change intended. Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Mingwei Zhang <mizhang@google.com> Tested-by: Xudong Hao <xudong.hao@intel.com> Link: https://lore.kernel.org/r/20250806195706.1650976-24-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>