From 3f5d18a96577fd78277e08c467041573b9a65eaf Mon Sep 17 00:00:00 2001
From: Avi Kivity <avi@redhat.com>
Date: Thu, 11 Jun 2009 15:43:28 +0300
Subject: [PATCH] KVM: Return to userspace on emulation failure
Instead of mindlessly retrying to execute the instruction, report the
failure to userspace.
Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/mmu.c | 5 +++--
include/linux/kvm.h | 7 +++++++
2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 5f97dbd242916..b6e4cda770478 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2673,8 +2673,9 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
++vcpu->stat.mmio_exits;
return 0;
case EMULATE_FAIL:
- kvm_report_emulation_failure(vcpu, "pagetable");
- return 1;
+ vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
+ return 0;
default:
BUG();
}
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 5037e170a70d2..671051829da61 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -95,6 +95,10 @@ struct kvm_pit_config {
#define KVM_EXIT_S390_RESET 14
#define KVM_EXIT_DCR 15
#define KVM_EXIT_NMI 16
+#define KVM_EXIT_INTERNAL_ERROR 17
+
+/* For KVM_EXIT_INTERNAL_ERROR */
+#define KVM_INTERNAL_ERROR_EMULATION 1
/* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */
struct kvm_run {
@@ -181,6 +185,9 @@ struct kvm_run {
__u32 data;
__u8 is_write;
} dcr;
+ struct {
+ __u32 suberror;
+ } internal;
/* Fix the size of the union. */
char padding[256];
};
--
2.39.5