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authorPaolo Bonzini <pbonzini@redhat.com>2025-06-10 20:10:18 -0400
committerPaolo Bonzini <pbonzini@redhat.com>2025-06-12 00:43:39 -0400
commitaa2024c01a9afba6728b362626f868811ca872ee (patch)
treeb6f667cde3395a97721995715e73f8226e873b86
parent179a8427fcbffe36ccfed5e138d7c9b6180caff9 (diff)
KVM: x86/mmu: Embed direct bits into gpa for KVM_PRE_FAULT_MEMORY
Bug[*] reported for TDX case when enabling KVM_PRE_FAULT_MEMORY in QEMU. It turns out that @gpa passed to kvm_mmu_do_page_fault() doesn't have shared bit set when the memory attribute of it is shared, and it leads to wrong root in tdp_mmu_get_root_for_fault(). Fix it by embedding the direct bits in the gpa that is passed to kvm_tdp_map_page(), when the memory of the gpa is not private. [*] https://lore.kernel.org/qemu-devel/4a757796-11c2-47f1-ae0d-335626e818fd@intel.com/ Reported-by: Xiaoyao Li <xiaoyao.li@intel.com> Closes: https://lore.kernel.org/qemu-devel/4a757796-11c2-47f1-ae0d-335626e818fd@intel.com/ Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> Message-ID: <20250611001018.2179964-1-xiaoyao.li@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/mmu/mmu.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index cbc84c6abc2e..a4040578b537 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4896,6 +4896,7 @@ long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu,
{
u64 error_code = PFERR_GUEST_FINAL_MASK;
u8 level = PG_LEVEL_4K;
+ u64 direct_bits;
u64 end;
int r;
@@ -4910,15 +4911,18 @@ long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu,
if (r)
return r;
+ direct_bits = 0;
if (kvm_arch_has_private_mem(vcpu->kvm) &&
kvm_mem_is_private(vcpu->kvm, gpa_to_gfn(range->gpa)))
error_code |= PFERR_PRIVATE_ACCESS;
+ else
+ direct_bits = gfn_to_gpa(kvm_gfn_direct_bits(vcpu->kvm));
/*
* Shadow paging uses GVA for kvm page fault, so restrict to
* two-dimensional paging.
*/
- r = kvm_tdp_map_page(vcpu, range->gpa, error_code, &level);
+ r = kvm_tdp_map_page(vcpu, range->gpa | direct_bits, error_code, &level);
if (r < 0)
return r;