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| author | Boris Ostrovsky <boris.ostrovsky@oracle.com> | 2019-12-05 02:30:51 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-01-30 18:45:55 +0100 |
| commit | 917248144db5d7320655dbb41d3af0b8a0f3d589 (patch) | |
| tree | 4c865f9aeb61137847ce9d283bc33febded17714 /arch/x86 | |
| parent | x86/kvm: Introduce kvm_(un)map_gfn() (diff) | |
| download | linux-917248144db5d7320655dbb41d3af0b8a0f3d589.tar.xz linux-917248144db5d7320655dbb41d3af0b8a0f3d589.zip | |
x86/kvm: Cache gfn to pfn translation
__kvm_map_gfn()'s call to gfn_to_pfn_memslot() is
* relatively expensive
* in certain cases (such as when done from atomic context) cannot be called
Stashing gfn-to-pfn mapping should help with both cases.
This is part of CVE-2019-3016.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 10 |
2 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index b79cd6aa4075..f48a306e1d66 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -689,6 +689,7 @@ struct kvm_vcpu_arch { u64 last_steal; struct gfn_to_hva_cache stime; struct kvm_steal_time steal; + struct gfn_to_pfn_cache cache; } st; u64 tsc_offset; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8c9369151e9f..0795bc876abc 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9088,6 +9088,9 @@ static void fx_init(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu) { void *wbinvd_dirty_mask = vcpu->arch.wbinvd_dirty_mask; + struct gfn_to_pfn_cache *cache = &vcpu->arch.st.cache; + + kvm_release_pfn(cache->pfn, cache->dirty, cache); kvmclock_reset(vcpu); @@ -9761,11 +9764,18 @@ out_free: void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) { + struct kvm_vcpu *vcpu; + int i; + /* * memslots->generation has been incremented. * mmio generation may have reached its maximum value. */ kvm_mmu_invalidate_mmio_sptes(kvm, gen); + + /* Force re-initialization of steal_time cache */ + kvm_for_each_vcpu(i, vcpu, kvm) + kvm_vcpu_kick(vcpu); } int kvm_arch_prepare_memory_region(struct kvm *kvm, |