KVM: SVM: Track dirtiness of PDPTRs even if NPT is disabled

Use the same logic to handle the availability of VCPU_EXREG_PDPTR
as VMX, also removing a branch in svm_vcpu_run().

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20211108124407.12187-4-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 64a10cd..9b63862 100644 (file)
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1598,10 +1598,16 @@ static void svm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
 
 static void svm_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
 {
+       kvm_register_mark_available(vcpu, reg);
+
        switch (reg) {
        case VCPU_EXREG_PDPTR:
-               BUG_ON(!npt_enabled);
-               load_pdptrs(vcpu, vcpu->arch.walk_mmu, kvm_read_cr3(vcpu));
+               /*
+                * When !npt_enabled, mmu->pdptrs[] is already available since
+                * it is always updated per SDM when moving to CRs.
+                */
+               if (npt_enabled)
+                       load_pdptrs(vcpu, vcpu->arch.walk_mmu, kvm_read_cr3(vcpu));
                break;
        default:
                KVM_BUG_ON(1, vcpu->kvm);
@@ -3974,8 +3980,7 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu)
                vcpu->arch.apf.host_apf_flags =
                        kvm_read_and_reset_apf_flags();
 
-       if (npt_enabled)
-               kvm_register_clear_available(vcpu, VCPU_EXREG_PDPTR);
+       kvm_register_clear_available(vcpu, VCPU_EXREG_PDPTR);
 
        /*
         * We need to handle MC intercepts here before the vcpu has a chance to