KVM: x86: Push potential exception error code on task switches

When a fault triggers a task switch, the error code, if existent, has to
be pushed on the new task's stack. Implement the missing bits.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 87b36fbbfec8..78af52222fd2 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2222,6 +2222,8 @@ static int task_switch_interception(struct vcpu_svm *svm)
                 svm->vmcb->control.exit_int_info & SVM_EXITINTINFO_TYPE_MASK;
         uint32_t idt_v =
                 svm->vmcb->control.exit_int_info & SVM_EXITINTINFO_VALID;
+        bool has_error_code = false;
+        u32 error_code = 0;
 
         tss_selector = (u16)svm->vmcb->control.exit_info_1;
 
@@ -2242,6 +2244,12 @@ static int task_switch_interception(struct vcpu_svm *svm)
                         svm->vcpu.arch.nmi_injected = false;
                         break;
                 case SVM_EXITINTINFO_TYPE_EXEPT:
+                        if (svm->vmcb->control.exit_info_2 &
+                            (1ULL << SVM_EXITINFOSHIFT_TS_HAS_ERROR_CODE)) {
+                                has_error_code = true;
+                                error_code =
+                                        (u32)svm->vmcb->control.exit_info_2;
+                        }
                         kvm_clear_exception_queue(&svm->vcpu);
                         break;
                 case SVM_EXITINTINFO_TYPE_INTR:
@@ -2258,7 +2266,8 @@ static int task_switch_interception(struct vcpu_svm *svm)
              (int_vec == OF_VECTOR || int_vec == BP_VECTOR)))
                 skip_emulated_instruction(&svm->vcpu);
 
-        return kvm_task_switch(&svm->vcpu, tss_selector, reason);
+        return kvm_task_switch(&svm->vcpu, tss_selector, reason,
+                               has_error_code, error_code);
 }
 
 static int cpuid_interception(struct vcpu_svm *svm)