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| author | Peter Feiner <pfeiner@google.com> | 2017-06-30 17:26:30 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-07-03 10:43:31 +0200 |
| commit | dcdca5fed5f6ef2521f927ba3b5cd6b328054be1 (patch) | |
| tree | 3b75f3d0972d24d532ac11c5f1c73b686649f48c /arch/x86/kvm/mmu.c | |
| parent | ce00053b1cfca312c22e2a6465451f1862561eab (diff) | |
| download | lwn-dcdca5fed5f6ef2521f927ba3b5cd6b328054be1.tar.gz lwn-dcdca5fed5f6ef2521f927ba3b5cd6b328054be1.zip | |
x86: kvm: mmu: make spte mmio mask more explicit
Specify both a mask (i.e., bits to consider) and a value (i.e.,
pattern of bits that indicates a special PTE) for mmio SPTEs. On
Intel, this lets us pack even more information into the
(SPTE_SPECIAL_MASK | EPT_VMX_RWX_MASK) mask we use for access
tracking liberating all (SPTE_SPECIAL_MASK | (non-misconfigured-RWX))
values.
Signed-off-by: Peter Feiner <pfeiner@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index dfd4cd67e5a6..10b3cfc7b411 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -183,6 +183,7 @@ static u64 __read_mostly shadow_user_mask; static u64 __read_mostly shadow_accessed_mask; static u64 __read_mostly shadow_dirty_mask; static u64 __read_mostly shadow_mmio_mask; +static u64 __read_mostly shadow_mmio_value; static u64 __read_mostly shadow_present_mask; /* @@ -207,8 +208,10 @@ static const u64 shadow_acc_track_saved_bits_shift = PT64_SECOND_AVAIL_BITS_SHIF static void mmu_spte_set(u64 *sptep, u64 spte); static void mmu_free_roots(struct kvm_vcpu *vcpu); -void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask) +void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask, u64 mmio_value) { + BUG_ON((mmio_mask & mmio_value) != mmio_value); + shadow_mmio_value = mmio_value | SPTE_SPECIAL_MASK; shadow_mmio_mask = mmio_mask | SPTE_SPECIAL_MASK; } EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask); @@ -270,7 +273,7 @@ static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, u64 mask = generation_mmio_spte_mask(gen); access &= ACC_WRITE_MASK | ACC_USER_MASK; - mask |= shadow_mmio_mask | access | gfn << PAGE_SHIFT; + mask |= shadow_mmio_value | access | gfn << PAGE_SHIFT; trace_mark_mmio_spte(sptep, gfn, access, gen); mmu_spte_set(sptep, mask); @@ -278,7 +281,7 @@ static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn, static bool is_mmio_spte(u64 spte) { - return (spte & shadow_mmio_mask) == shadow_mmio_mask; + return (spte & shadow_mmio_mask) == shadow_mmio_value; } static gfn_t get_mmio_spte_gfn(u64 spte) |