[PATCH 7/9] KVM: x86: When judging setting CR3 valid or not, consider LAM bits

Robert Hoo
2022-10-17T07:05:49Z

Before apply to kvm_vcpu_is_illegal_gpa(), clear LAM bits if it's valid.

Signed-off-by: Robert Hoo <robert.hu@linux.intel.com>
Reviewed-by: Jingqi Liu <jingqi.liu@intel.com>
---
arch/x86/kvm/x86.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3fa532cd1911..e9b465bff8d3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1217,6 +1217,14 @@ static void kvm_invalidate_pcid(struct kvm_vcpu *vcpu, unsigned long pcid)
kvm_mmu_free_roots(vcpu->kvm, mmu, roots_to_free);
}

+static bool kvm_is_valid_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
+{
+ if (guest_cpuid_has(vcpu, X86_FEATURE_LAM))
+ cr3 &= ~(X86_CR3_LAM_U48 | X86_CR3_LAM_U57);
+
+ return kvm_vcpu_is_legal_gpa(vcpu, cr3);
+}
+
int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
{
bool skip_tlb_flush = false;
@@ -1240,7 +1248,7 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
* stuff CR3, e.g. for RSM emulation, and there is no guarantee that
* the current vCPU mode is accurate.
*/
- if (kvm_vcpu_is_illegal_gpa(vcpu, cr3))
+ if (!kvm_is_valid_cr3(vcpu, cr3))
return 1;

if (is_pae_paging(vcpu) && !load_pdptrs(vcpu, cr3))
--
2.31.1