[PATCH v2 1/4] KVM: x86: Fixup "Get active PCID only when writing a CR3 value"

From: Sean Christopherson
Date: Tue Mar 09 2021 - 17:43:01 EST


From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>

Fix a merge conflict gone bad.

Fixes: a16241ae56fa ("KVM: x86: Get active PCID only when writing a CR3 value")
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/svm/svm.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 7876ddf896b8..58f4dc0e7864 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3907,7 +3907,7 @@ static void svm_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa,
struct vcpu_svm *svm = to_svm(vcpu);
unsigned long cr3;

- cr3 = __sme_set(root_hpa);
+ root_hpa = __sme_set(root_hpa);
if (npt_enabled) {
svm->vmcb->control.nested_cr3 = root_hpa;
vmcb_mark_dirty(svm->vmcb, VMCB_NPT);
@@ -3916,6 +3916,12 @@ static void svm_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa,
if (!test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail))
return;
cr3 = vcpu->arch.cr3;
+ } else if (vcpu->arch.mmu->shadow_root_level >= PT64_ROOT_4LEVEL) {
+ cr3 = root_hpa | kvm_get_active_pcid(vcpu);
+ } else {
+ /* PCID in the guest should be impossible with a 32-bit MMU. */
+ WARN_ON_ONCE(kvm_get_active_pcid(vcpu));
+ cr3 = root_hpa;
}

svm->vmcb->save.cr3 = cr3;
--
2.30.1.766.gb4fecdf3b7-goog