[PATCH 4/7] KVM: vmx: set rflags.rf during fault injection

[Nadav Amit <namit@cs.technion.ac.il>]

VMX does not automatically set rflags.rf during event injection. This patch
does partial job, setting rflags.rf upon fault injection.  It also marks that
injection of trap/interrupt during rep-string instruction is not properly
emulated. It is unclear how to do it efficiently without decoding the guest
instruction before interrupt injection.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
---
 arch/x86/kvm/vmx.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 0c9569b..8edb785 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2006,6 +2006,7 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
 				bool reinject)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	unsigned long rflags;
 	u32 intr_info = nr | INTR_INFO_VALID_MASK;
 
 	if (!reinject && is_guest_mode(vcpu) &&
@@ -2017,6 +2018,12 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
 		intr_info |= INTR_INFO_DELIVER_CODE_MASK;
 	}
 
+	rflags = vmx_get_rflags(vcpu);
+	if (kvm_exception_type(nr) == EXCPT_FAULT)
+		vmx_set_rflags(vcpu, rflags | X86_EFLAGS_RF);
+
+	/* TODO: Set rflags.rf on trap during rep-string */
+
 	if (vmx->rmode.vm86_active) {
 		int inc_eip = 0;
 		if (kvm_exception_is_soft(nr))
@@ -4631,8 +4638,10 @@ static void vmx_inject_irq(struct kvm_vcpu *vcpu)
 		intr |= INTR_TYPE_SOFT_INTR;
 		vmcs_write32(VM_ENTRY_INSTRUCTION_LEN,
 			     vmx->vcpu.arch.event_exit_inst_len);
-	} else
+	} else {
+		/* TODO: Set rflags.rf during rep-string */
 		intr |= INTR_TYPE_EXT_INTR;
+	}
 	vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, intr);
 }
 
-- 
1.9.1