On 5/7/2024 11:58 PM, Paolo Bonzini wrote:
From: Sean Christopherson <seanjc@xxxxxxxxxx>
Explicitly detect and disallow private accesses to emulated MMIO in
kvm_handle_noslot_fault() instead of relying on kvm_faultin_pfn_private()
to perform the check. This will allow the page fault path to go straight
to kvm_handle_noslot_fault() without bouncing through __kvm_faultin_pfn().
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Message-ID: <20240228024147.41573-12-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Reviewed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
arch/x86/kvm/mmu/mmu.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index a8e14c2b68a7..fdae6d19e72b 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3262,6 +3262,11 @@ static int kvm_handle_noslot_fault(struct kvm_vcpu *vcpu,
{
gva_t gva = fault->is_tdp ? 0 : fault->addr;
+ if (fault->is_private) {
+ kvm_mmu_prepare_memory_fault_exit(vcpu, fault);
+ return -EFAULT;
+ }
+
vcpu_cache_mmio_info(vcpu, gva, fault->gfn,
access & shadow_mmio_access_mask);
