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| author |   Sean Christopherson <seanjc@google.com> | 2022-07-15 23:00:15 +0000 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2022-07-28 13:22:21 -0400 |
| commit | 38bf9d7bf277bb40c4dceedd2b5eb87d02c36d5b (patch) | |
| tree | dd4b07988900c60d8455c5c777c1e6e9124c182a /arch/x86/kvm | |
| parent | KVM: x86: Drop unnecessary goto+label in kvm_arch_init() (diff) | |
| download | linux-dev-38bf9d7bf277bb40c4dceedd2b5eb87d02c36d5b.tar.xz linux-dev-38bf9d7bf277bb40c4dceedd2b5eb87d02c36d5b.zip | |
KVM: x86/mmu: Add shadow mask for effective host MTRR memtype
Add shadow_memtype_mask to capture that EPT needs a non-zero memtype mask
instead of relying on TDP being enabled, as NPT doesn't need a non-zero
mask. This is a glorified nop as kvm_x86_ops.get_mt_mask() returns zero
for NPT anyways.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20220715230016.3762909-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/mmu/spte.c | 21 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/spte.h | 1 |
2 files changed, 19 insertions, 3 deletions
diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index fb1f17504138..7314d27d57a4 100644 --- a/arch/x86/kvm/mmu/spte.c +++ b/arch/x86/kvm/mmu/spte.c @@ -33,6 +33,7 @@ u64 __read_mostly shadow_mmio_value; u64 __read_mostly shadow_mmio_mask; u64 __read_mostly shadow_mmio_access_mask; u64 __read_mostly shadow_present_mask; +u64 __read_mostly shadow_memtype_mask; u64 __read_mostly shadow_me_value; u64 __read_mostly shadow_me_mask; u64 __read_mostly shadow_acc_track_mask; @@ -161,10 +162,10 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, if (level > PG_LEVEL_4K) spte |= PT_PAGE_SIZE_MASK; - if (tdp_enabled) - spte |= static_call(kvm_x86_get_mt_mask)(vcpu, gfn, - kvm_is_mmio_pfn(pfn)); + if (shadow_memtype_mask) + spte |= static_call(kvm_x86_get_mt_mask)(vcpu, gfn, + kvm_is_mmio_pfn(pfn)); if (host_writable) spte |= shadow_host_writable_mask; else @@ -391,6 +392,13 @@ void kvm_mmu_set_ept_masks(bool has_ad_bits, bool has_exec_only) shadow_nx_mask = 0ull; shadow_x_mask = VMX_EPT_EXECUTABLE_MASK; shadow_present_mask = has_exec_only ? 0ull : VMX_EPT_READABLE_MASK; + /* + * EPT overrides the host MTRRs, and so KVM must program the desired + * memtype directly into the SPTEs. Note, this mask is just the mask + * of all bits that factor into the memtype, the actual memtype must be + * dynamically calculated, e.g. to ensure host MMIO is mapped UC. + */ + shadow_memtype_mask = VMX_EPT_MT_MASK | VMX_EPT_IPAT_BIT; shadow_acc_track_mask = VMX_EPT_RWX_MASK; shadow_host_writable_mask = EPT_SPTE_HOST_WRITABLE; shadow_mmu_writable_mask = EPT_SPTE_MMU_WRITABLE; @@ -441,6 +449,13 @@ void kvm_mmu_reset_all_pte_masks(void) shadow_nx_mask = PT64_NX_MASK; shadow_x_mask = 0; shadow_present_mask = PT_PRESENT_MASK; + + /* + * For shadow paging and NPT, KVM uses PAT entry '0' to encode WB + * memtype in the SPTEs, i.e. relies on host MTRRs to provide the + * correct memtype (WB is the "weakest" memtype). + */ + shadow_memtype_mask = 0; shadow_acc_track_mask = 0; shadow_me_mask = 0; shadow_me_value = 0; diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h index ba3dccb202bc..cabe3fbb4f39 100644 --- a/arch/x86/kvm/mmu/spte.h +++ b/arch/x86/kvm/mmu/spte.h @@ -147,6 +147,7 @@ extern u64 __read_mostly shadow_mmio_value; extern u64 __read_mostly shadow_mmio_mask; extern u64 __read_mostly shadow_mmio_access_mask; extern u64 __read_mostly shadow_present_mask; +extern u64 __read_mostly shadow_memtype_mask; extern u64 __read_mostly shadow_me_value; extern u64 __read_mostly shadow_me_mask; |