[PATCH 24/58] KVM: VMX: Handle #SS faults from real mode

Avi Kivity
2007-06-17T09:44:05Z

From: Nitin A Kamble <nitin.a.kamble-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

Instructions with address size override prefix opcode 0x67
Cause the #SS fault with 0 error code in VM86 mode. Forward
them to the emulator.

Signed-Off-By: Nitin A Kamble <nitin.a.kamble-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
---
drivers/kvm/vmx.c | 6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index c4c5535..a05bfa0 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1488,7 +1488,11 @@ static int handle_rmode_exception(struct kvm_vcpu *vcpu,
if (!vcpu->rmode.active)
return 0;

- if (vec == GP_VECTOR && err_code == 0)
+ /*
+ * Instruction with address size override prefix opcode 0x67
+ * Cause the #SS fault with 0 error code in VM86 mode.
+ */
+ if (((vec == GP_VECTOR) || (vec == SS_VECTOR)) && err_code == 0)
if (emulate_instruction(vcpu, NULL, 0, 0) == EMULATE_DONE)
return 1;
return 0;