[PATCHv2] KVM: handle exit due to INVD in VMX

[Gleb Natapov <gleb@redhat.com>]

Currently the exit is unhandled, so guest halts with error if it tries
to execute INVD instruction. Call into emulator when INVD instruction
is executed by a guest instead. This instruction is not needed by ordinary
guests, but firmware (like OpenBIOS) use it and fail.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
---
 ChangeLog:
 v1->v2
  - New and improved patch description

diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 9f0cbd9..42d9590 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -239,6 +239,7 @@ enum vmcs_field {
 #define EXIT_REASON_TASK_SWITCH         9
 #define EXIT_REASON_CPUID               10
 #define EXIT_REASON_HLT                 12
+#define EXIT_REASON_INVD                13
 #define EXIT_REASON_INVLPG              14
 #define EXIT_REASON_RDPMC               15
 #define EXIT_REASON_RDTSC               16
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 993e332..200533e 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3350,6 +3350,11 @@ static int handle_vmx_insn(struct kvm_vcpu *vcpu)
 	return 1;
 }
 
+static int handle_invd(struct kvm_vcpu *vcpu)
+{
+	return emulate_instruction(vcpu, 0, 0, 0) == EMULATE_DONE;
+}
+
 static int handle_invlpg(struct kvm_vcpu *vcpu)
 {
 	unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
@@ -3650,6 +3655,7 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
 	[EXIT_REASON_MSR_WRITE]               = handle_wrmsr,
 	[EXIT_REASON_PENDING_INTERRUPT]       = handle_interrupt_window,
 	[EXIT_REASON_HLT]                     = handle_halt,
+	[EXIT_REASON_INVD]		      = handle_invd,
 	[EXIT_REASON_INVLPG]		      = handle_invlpg,
 	[EXIT_REASON_VMCALL]                  = handle_vmcall,
 	[EXIT_REASON_VMCLEAR]	              = handle_vmx_insn,
--
			Gleb.