[PATCH v2 12/18] KVM: x86/mmu: clear MMIO cache when unloading the MMU

Paolo Bonzini
2022-02-17T21:04:21Z

For cleanliness, do not leave a stale GVA in the cache after all the roots are
cleared. In practice, kvm_mmu_load will go through kvm_mmu_sync_roots if
paging is on, and will not use vcpu_match_mmio_gva at all if paging is off.
However, leaving data in the cache might cause bugs in the future.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/mmu/mmu.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index b01160716c6a..4e8e3e9530ca 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5111,6 +5111,7 @@ void kvm_mmu_unload(struct kvm_vcpu *vcpu)
{
__kvm_mmu_unload(vcpu->kvm, &vcpu->arch.root_mmu);
__kvm_mmu_unload(vcpu->kvm, &vcpu->arch.guest_mmu);
+ vcpu_clear_mmio_info(vcpu, MMIO_GVA_ANY);
}

static bool need_remote_flush(u64 old, u64 new)
--
2.31.1