From 8c985b2d8e682edac84bde63cef660cc574f795e Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 22 Jun 2021 10:57:14 -0700 Subject: [PATCH] KVM: x86/mmu: Don't grab CR4.PSE for calculating shadow reserved bits Unconditionally pass pse=false when calculating reserved bits for shadow PTEs. CR4.PSE is only relevant for 32-bit non-PAE paging, which KVM does not use for shadow paging (including nested NPT). Signed-off-by: Sean Christopherson Message-Id: <20210622175739.3610207-30-seanjc@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/mmu.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index f5a55c9..d017352 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4281,19 +4281,22 @@ static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, * MMU contexts. Note, KVM forces EFER.NX=1 when TDP is disabled. */ bool uses_nx = context->nx || !tdp_enabled; + + /* @amd adds a check on bit of SPTEs, which KVM shouldn't use anyways. */ + bool is_amd = true; + /* KVM doesn't use 2-level page tables for the shadow MMU. */ + bool is_pse = false; struct rsvd_bits_validate *shadow_zero_check; int i; - /* - * Passing "true" to the last argument is okay; it adds a check - * on bit 8 of the SPTEs which KVM doesn't use anyway. - */ + WARN_ON_ONCE(context->shadow_root_level < PT32E_ROOT_LEVEL); + shadow_zero_check = &context->shadow_zero_check; __reset_rsvds_bits_mask(vcpu, shadow_zero_check, reserved_hpa_bits(), context->shadow_root_level, uses_nx, guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES), - is_pse(vcpu), true); + is_pse, is_amd); if (!shadow_me_mask) return; @@ -4329,7 +4332,7 @@ reset_tdp_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, reserved_hpa_bits(), context->shadow_root_level, false, boot_cpu_has(X86_FEATURE_GBPAGES), - true, true); + false, true); else __reset_rsvds_bits_mask_ept(shadow_zero_check, reserved_hpa_bits(), false); -- 2.7.4