@@ -385,12 +385,12 @@ static inline bool nested_npt_enabled(struct vcpu_svm *svm)
* if we are emulating VM-Entry into a guest with NPT enabled.
*/
static int nested_svm_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3,
- bool nested_npt)
+ bool nested_npt, bool reload_pdptrs)
{
if (CC(kvm_vcpu_is_illegal_gpa(vcpu, cr3)))
return -EINVAL;
- if (!nested_npt && is_pae_paging(vcpu) &&
+ if (reload_pdptrs && !nested_npt && is_pae_paging(vcpu) &&
(cr3 != kvm_read_cr3(vcpu) || pdptrs_changed(vcpu))) {
if (CC(!load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3)))
return -EINVAL;
@@ -576,7 +576,7 @@ int enter_svm_guest_mode(struct kvm_vcpu *vcpu, u64 vmcb12_gpa,
nested_vmcb02_prepare_save(svm, vmcb12);
ret = nested_svm_load_cr3(&svm->vcpu, vmcb12->save.cr3,
- nested_npt_enabled(svm));
+ nested_npt_enabled(svm), true);
if (ret)
return ret;
@@ -806,7 +806,7 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
nested_svm_uninit_mmu_context(vcpu);
- rc = nested_svm_load_cr3(vcpu, svm->vmcb->save.cr3, false);
+ rc = nested_svm_load_cr3(vcpu, svm->vmcb->save.cr3, false, true);
if (rc)
return 1;
@@ -1291,6 +1291,19 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
!nested_vmcb_valid_sregs(vcpu, save))
goto out_free;
+ /*
+ * While the nested guest CR3 is already checked and set by
+ * KVM_SET_SREGS, it was set when nested state was yet loaded,
+ * thus MMU might not be initialized correctly.
+ * Set it again to fix this.
+ */
+
+ ret = nested_svm_load_cr3(&svm->vcpu, vcpu->arch.cr3,
+ nested_npt_enabled(svm), false);
+ if (WARN_ON_ONCE(ret))
+ goto out_free;
+
+
/*
* All checks done, we can enter guest mode. Userspace provides
* vmcb12.control, which will be combined with L1 and stored into
@@ -1343,9 +1356,14 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu)
if (WARN_ON(!is_guest_mode(vcpu)))
return true;
- if (nested_svm_load_cr3(&svm->vcpu, vcpu->arch.cr3,
- nested_npt_enabled(svm)))
- return false;
+ if (!nested_npt_enabled(svm) && is_pae_paging(vcpu))
+ /*
+ * Reload the guest's PDPTRs since after a migration
+ * the guest CR3 might be restored prior to setting the nested
+ * state which can lead to a load of wrong PDPTRs.
+ */
+ if (CC(!load_pdptrs(vcpu, vcpu->arch.walk_mmu, vcpu->arch.cr3)))
+ return false;
if (!nested_svm_vmrun_msrpm(svm)) {
vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
Document the actual reason why we need to do it on migration and move the call to svm_set_nested_state to be closer to VMX code. To avoid loading the PDPTRs from possibly not up to date memory map, in nested_svm_load_cr3 after the move, move this code to .get_nested_state_pages. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> --- arch/x86/kvm/svm/nested.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-)