Commit 3f5d18a9 authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: Return to userspace on emulation failure 



Instead of mindlessly retrying to execute the instruction, report the
failure to userspace.

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 988a2cae

arch/x86/kvm/mmu.c

+3 −2
Original line number Diff line number Diff line
@@ -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();

	}

include/linux/kvm.h

+7 −0
Original line number Diff line number Diff line
@@ -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];

	};