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-rw-r--r--arch/x86/kvm/svm/svm.c39
1 files changed, 38 insertions, 1 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index b6e91de891cb..cf8471890266 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4309,6 +4309,7 @@ static int svm_smi_allowed(struct kvm_vcpu *vcpu, bool for_injection)
static int svm_enter_smm(struct kvm_vcpu *vcpu, char *smstate)
{
struct vcpu_svm *svm = to_svm(vcpu);
+ struct kvm_host_map map_save;
int ret;
if (is_guest_mode(vcpu)) {
@@ -4324,6 +4325,29 @@ static int svm_enter_smm(struct kvm_vcpu *vcpu, char *smstate)
ret = nested_svm_vmexit(svm);
if (ret)
return ret;
+
+ /*
+ * KVM uses VMCB01 to store L1 host state while L2 runs but
+ * VMCB01 is going to be used during SMM and thus the state will
+ * be lost. Temporary save non-VMLOAD/VMSAVE state to the host save
+ * area pointed to by MSR_VM_HSAVE_PA. APM guarantees that the
+ * format of the area is identical to guest save area offsetted
+ * by 0x400 (matches the offset of 'struct vmcb_save_area'
+ * within 'struct vmcb'). Note: HSAVE area may also be used by
+ * L1 hypervisor to save additional host context (e.g. KVM does
+ * that, see svm_prepare_guest_switch()) which must be
+ * preserved.
+ */
+ if (kvm_vcpu_map(vcpu, gpa_to_gfn(svm->nested.hsave_msr),
+ &map_save) == -EINVAL)
+ return 1;
+
+ BUILD_BUG_ON(offsetof(struct vmcb, save) != 0x400);
+
+ svm_copy_vmrun_state(&svm->vmcb01.ptr->save,
+ map_save.hva + 0x400);
+
+ kvm_vcpu_unmap(vcpu, &map_save, true);
}
return 0;
}
@@ -4331,7 +4355,7 @@ static int svm_enter_smm(struct kvm_vcpu *vcpu, char *smstate)
static int svm_leave_smm(struct kvm_vcpu *vcpu, const char *smstate)
{
struct vcpu_svm *svm = to_svm(vcpu);
- struct kvm_host_map map;
+ struct kvm_host_map map, map_save;
int ret = 0;
if (guest_cpuid_has(vcpu, X86_FEATURE_LM)) {
@@ -4355,6 +4379,19 @@ static int svm_leave_smm(struct kvm_vcpu *vcpu, const char *smstate)
ret = enter_svm_guest_mode(vcpu, vmcb12_gpa, map.hva);
kvm_vcpu_unmap(vcpu, &map, true);
+
+ /*
+ * Restore L1 host state from L1 HSAVE area as VMCB01 was
+ * used during SMM (see svm_enter_smm())
+ */
+ if (kvm_vcpu_map(vcpu, gpa_to_gfn(svm->nested.hsave_msr),
+ &map_save) == -EINVAL)
+ return 1;
+
+ svm_copy_vmrun_state(map_save.hva + 0x400,
+ &svm->vmcb01.ptr->save);
+
+ kvm_vcpu_unmap(vcpu, &map_save, true);
}
}