KVM: SVM: Fix schedule-while-atomic on nested exception handling

Move the actual vmexit routine out of code that runs with
irqs and preemption disabled.

Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 19 insertions, 4 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index f9da35b06ec7..c27da0ad040c 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -129,6 +129,7 @@ static void svm_flush_tlb(struct kvm_vcpu *vcpu);
 static void svm_complete_interrupts(struct vcpu_svm *svm);
 
 static int nested_svm_exit_handled(struct vcpu_svm *svm);
+static int nested_svm_intercept(struct vcpu_svm *svm);
 static int nested_svm_vmexit(struct vcpu_svm *svm);
 static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
                                       bool has_error_code, u32 error_code);
@@ -1384,6 +1385,8 @@ static int nested_svm_check_permissions(struct vcpu_svm *svm)
 static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
                                       bool has_error_code, u32 error_code)
 {
+        int vmexit;
+
         if (!is_nested(svm))
                 return 0;
 
@@ -1392,7 +1395,11 @@ static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
         svm->vmcb->control.exit_info_1 = error_code;
         svm->vmcb->control.exit_info_2 = svm->vcpu.arch.cr2;
 
-        return nested_svm_exit_handled(svm);
+        vmexit = nested_svm_intercept(svm);
+        if (vmexit == NESTED_EXIT_DONE)
+                svm->nested.exit_required = true;
+
+        return vmexit;
 }
 
 static inline int nested_svm_intr(struct vcpu_svm *svm)
@@ -1521,7 +1528,7 @@ static int nested_svm_exit_special(struct vcpu_svm *svm)
 /*
  * If this function returns true, this #vmexit was already handled
  */
-static int nested_svm_exit_handled(struct vcpu_svm *svm)
+static int nested_svm_intercept(struct vcpu_svm *svm)
 {
         u32 exit_code = svm->vmcb->control.exit_code;
         int vmexit = NESTED_EXIT_HOST;
@@ -1567,9 +1574,17 @@ static int nested_svm_exit_handled(struct vcpu_svm *svm)
         }
         }
 
-        if (vmexit == NESTED_EXIT_DONE) {
+        return vmexit;
+}
+
+static int nested_svm_exit_handled(struct vcpu_svm *svm)
+{
+        int vmexit;
+
+        vmexit = nested_svm_intercept(svm);
+
+        if (vmexit == NESTED_EXIT_DONE)
                 nested_svm_vmexit(svm);
-        }
 
         return vmexit;
 }