[RFC PATCH v3 3/4] x86: Add kvm_inject_realmode_interrupt() wrapper

[Mohammed Gamal <m.gamal005@gmail.com>]

This adds a wrapper function kvm_inject_realmode_interrupt() around the
emulator function emulate_int_real() to allow real mode interrupt injection.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
---
 arch/x86/kvm/x86.c |   21 +++++++++++++++++++++
 arch/x86/kvm/x86.h |    1 +
 2 files changed, 22 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f24e594..59b708c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3958,6 +3958,27 @@ static void init_emulate_ctxt(struct kvm_vcpu *vcpu)
 	memcpy(c->regs, vcpu->arch.regs, sizeof c->regs);
 }
 
+int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq)
+{       
+	struct decode_cache *c = &vcpu->arch.emulate_ctxt.decode;
+	int ret;
+
+	init_emulate_ctxt(vcpu);
+
+	ret = emulate_int_real(&vcpu->arch.emulate_ctxt, &emulate_ops, irq);
+
+	if (ret != X86EMUL_CONTINUE)
+		return EMULATE_FAIL;
+
+	vcpu->arch.emulate_ctxt.eip = c->eip;
+	memcpy(vcpu->arch.regs, c->regs, sizeof c->regs);
+	kvm_rip_write(vcpu, vcpu->arch.emulate_ctxt.eip);
+	kvm_x86_ops->set_rflags(vcpu, vcpu->arch.emulate_ctxt.eflags);
+
+	return EMULATE_DONE;
+}
+EXPORT_SYMBOL_GPL(kvm_inject_realmode_interrupt);
+
 static int handle_emulation_failure(struct kvm_vcpu *vcpu)
 {
 	++vcpu->stat.insn_emulation_fail;
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index b7a4047..8b83da5 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -67,5 +67,6 @@ static inline int is_paging(struct kvm_vcpu *vcpu)
 
 void kvm_before_handle_nmi(struct kvm_vcpu *vcpu);
 void kvm_after_handle_nmi(struct kvm_vcpu *vcpu);
+int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq);
 
 #endif
-- 
1.7.0.4