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| author | Sean Christopherson <seanjc@google.com> | 2025-09-19 15:32:12 -0700 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2025-09-23 09:00:44 -0700 |
| commit | c0a5f298912222f3bb4e8f5dc67c6a1f0e93d83f (patch) | |
| tree | 36ee9e377491684d26f525be6f68e37e047e5ea5 /arch/x86/kvm/x86.c | |
| parent | KVM: x86: Introduce KVM_{G,S}ET_ONE_REG uAPIs support (diff) | |
| download | linux-c0a5f298912222f3bb4e8f5dc67c6a1f0e93d83f.tar.gz linux-c0a5f298912222f3bb4e8f5dc67c6a1f0e93d83f.zip | |
KVM: x86: Report XSS as to-be-saved if there are supported features
Add MSR_IA32_XSS to list of MSRs reported to userspace if supported_xss
is non-zero, i.e. KVM supports at least one XSS based feature.
Before enabling CET virtualization series, guest IA32_MSR_XSS is
guaranteed to be 0, i.e., XSAVES/XRSTORS is executed in non-root mode
with XSS == 0, which equals to the effect of XSAVE/XRSTOR.
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Chao Gao <chao.gao@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>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Chao Gao <chao.gao@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Link: https://lore.kernel.org/r/20250919223258.1604852-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index bc245e0b0443..757878a222a7 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -332,7 +332,7 @@ static const u32 msrs_to_save_base[] = { MSR_IA32_RTIT_ADDR3_A, MSR_IA32_RTIT_ADDR3_B, MSR_IA32_UMWAIT_CONTROL, - MSR_IA32_XFD, MSR_IA32_XFD_ERR, + MSR_IA32_XFD, MSR_IA32_XFD_ERR, MSR_IA32_XSS, }; static const u32 msrs_to_save_pmu[] = { @@ -7503,6 +7503,10 @@ static void kvm_probe_msr_to_save(u32 msr_index) if (!(kvm_get_arch_capabilities() & ARCH_CAP_TSX_CTRL_MSR)) return; break; + case MSR_IA32_XSS: + if (!kvm_caps.supported_xss) + return; + break; default: break; } |