KVM: x86: hardware task switching support

This emulates the x86 hardware task switch mechanism in software, as it is
unsupported by either vmx or svm.  It allows operating systems which use it,
like freedos, to run as kvm guests.

Signed-off-by: Izik Eidus <izike@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/x86/kvm/svm.h b/arch/x86/kvm/svm.h
index 5fd50491b555..1b8afa78e869 100644
--- a/arch/x86/kvm/svm.h
+++ b/arch/x86/kvm/svm.h
@@ -238,6 +238,9 @@ struct __attribute__ ((__packed__)) vmcb {
 #define SVM_EXITINTINFO_VALID SVM_EVTINJ_VALID
 #define SVM_EXITINTINFO_VALID_ERR SVM_EVTINJ_VALID_ERR
 
+#define SVM_EXITINFOSHIFT_TS_REASON_IRET 36
+#define SVM_EXITINFOSHIFT_TS_REASON_JMP 38
+
 #define SVM_EXIT_READ_CR0       0x000
 #define SVM_EXIT_READ_CR3       0x003
 #define SVM_EXIT_READ_CR4       0x004