When "halt" is emulated, skip_emulated_instruction() is called and
interruptibility state is cleared.
But when halt is emulated in real mode, skip_emulated_instruction() is not
called and the interruptiblity state is not cleared.
The following code, from gPXE, never exits from loop because interrupts are not
delivered to increase %fs:(0x6c):
movl %fs:(0x6c), %eax
1: pushf
sti
hlt
popf
cmpl %fs:(0x6c), %eax
je 1b
This patch clears the interruptibility state when halt is emulated in real mode.
Signed-off-by: Laurent Vivier <[EMAIL PROTECTED]>
---
arch/x86/kvm/vmx.c | 10 ++++++++++
1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c4510fe..82c4324 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2329,7 +2329,17 @@ static int handle_exception(struct kvm_vcpu *vcpu,
struct kvm_run *kvm_run)
handle_rmode_exception(vcpu, intr_info & INTR_INFO_VECTOR_MASK,
error_code)) {
if (vcpu->arch.halt_request) {
+ u32 interruptibility;
vcpu->arch.halt_request = 0;
+ /*
+ * We emulated an instruction, so temporary interrupt
blocking
+ * should be removed, if set.
+ */
+ interruptibility =
vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);
+ if (interruptibility & 3)
+ vmcs_write32(GUEST_INTERRUPTIBILITY_INFO,
+ interruptibility & ~3);
+ vcpu->arch.interrupt_window_open = 1;
return kvm_emulate_halt(vcpu);
}
return 1;
--
1.5.2.4
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