diff options
| author | Sean Christopherson <seanjc@google.com> | 2024-05-17 17:04:25 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2024-05-23 12:27:26 -0400 |
| commit | 837d557aba6b816985141ddbeb7649444ed26d3b (patch) | |
| tree | fbae9dffb641230fb789cb25335acd07af307220 /arch/x86/kvm/mmu/spte.h | |
| parent | 9031b42139b9d45ef806c9a7fee166c1b6443c3c (diff) | |
KVM: x86/mmu: Add sanity checks that KVM doesn't create EPT #VE SPTEs
Assert that KVM doesn't set a SPTE to a value that could trigger an EPT
Violation #VE on a non-MMIO SPTE, e.g. to help detect bugs even without
KVM_INTEL_PROVE_VE enabled, and to help debug actual #VE failures.
Note, this will run afoul of TDX support, which needs to reflect emulated
MMIO accesses into the guest as #VEs (which was the whole point of adding
EPT Violation #VE support in KVM). The obvious fix for that is to exempt
MMIO SPTEs, but that's annoyingly difficult now that is_mmio_spte() relies
on a per-VM value. However, resolving that conundrum is a future problem,
whereas getting KVM_INTEL_PROVE_VE healthy is a current problem.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20240518000430.1118488-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu/spte.h')
| -rw-r--r-- | arch/x86/kvm/mmu/spte.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h index 5dd5405fa07a..52fa004a1fbc 100644 --- a/arch/x86/kvm/mmu/spte.h +++ b/arch/x86/kvm/mmu/spte.h @@ -3,6 +3,8 @@ #ifndef KVM_X86_MMU_SPTE_H #define KVM_X86_MMU_SPTE_H +#include <asm/vmx.h> + #include "mmu.h" #include "mmu_internal.h" @@ -276,6 +278,13 @@ static inline bool is_shadow_present_pte(u64 pte) return !!(pte & SPTE_MMU_PRESENT_MASK); } +static inline bool is_ept_ve_possible(u64 spte) +{ + return (shadow_present_mask & VMX_EPT_SUPPRESS_VE_BIT) && + !(spte & VMX_EPT_SUPPRESS_VE_BIT) && + (spte & VMX_EPT_RWX_MASK) != VMX_EPT_MISCONFIG_WX_VALUE; +} + /* * Returns true if A/D bits are supported in hardware and are enabled by KVM. * When enabled, KVM uses A/D bits for all non-nested MMUs. Because L1 can |