From 6819af7597d87d40769b47bb377472877a6b56c0 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 3 Mar 2022 20:20:17 -0800 Subject: KVM: x86: Clean up and document nested #PF workaround Replace the per-vendor hack-a-fix for KVM's #PF => #PF => #DF workaround with an explicit, common workaround in kvm_inject_emulated_page_fault(). Aside from being a hack, the current approach is brittle and incomplete, e.g. nSVM's KVM_SET_NESTED_STATE fails to set ->inject_page_fault(), and nVMX fails to apply the workaround when VMX is intercepting #PF due to allow_smaller_maxphyaddr=1. Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/nested.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'arch/x86/kvm/svm/nested.c') diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index caa691229b71..bed5e1692cef 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -55,24 +55,26 @@ static void nested_svm_inject_npf_exit(struct kvm_vcpu *vcpu, nested_svm_vmexit(svm); } -static void svm_inject_page_fault_nested(struct kvm_vcpu *vcpu, struct x86_exception *fault) +static bool nested_svm_handle_page_fault_workaround(struct kvm_vcpu *vcpu, + struct x86_exception *fault) { struct vcpu_svm *svm = to_svm(vcpu); struct vmcb *vmcb = svm->vmcb; - WARN_ON(!is_guest_mode(vcpu)); + WARN_ON(!is_guest_mode(vcpu)); if (vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_EXCEPTION_OFFSET + PF_VECTOR) && - !svm->nested.nested_run_pending) { - vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + PF_VECTOR; + !WARN_ON_ONCE(svm->nested.nested_run_pending)) { + vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + PF_VECTOR; vmcb->control.exit_code_hi = 0; vmcb->control.exit_info_1 = fault->error_code; vmcb->control.exit_info_2 = fault->address; nested_svm_vmexit(svm); - } else { - kvm_inject_page_fault(vcpu, fault); + return true; } + + return false; } static u64 nested_svm_get_tdp_pdptr(struct kvm_vcpu *vcpu, int index) @@ -751,9 +753,6 @@ int enter_svm_guest_mode(struct kvm_vcpu *vcpu, u64 vmcb12_gpa, if (ret) return ret; - if (!npt_enabled) - vcpu->arch.mmu->inject_page_fault = svm_inject_page_fault_nested; - if (!from_vmrun) kvm_make_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu); @@ -1659,6 +1658,7 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu) struct kvm_x86_nested_ops svm_nested_ops = { .leave_nested = svm_leave_nested, .check_events = svm_check_nested_events, + .handle_page_fault_workaround = nested_svm_handle_page_fault_workaround, .triple_fault = nested_svm_triple_fault, .get_nested_state_pages = svm_get_nested_state_pages, .get_state = svm_get_nested_state, -- cgit v1.2.3