[PATCH RFC 4/5] x86: KVM: add xsetbv to the emulator

[Vitaly Kuznetsov <vkuznets@redhat.com>]

To avoid hardcoding xsetbv length to '3' we need to support decoding it in
the emulator.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/include/asm/kvm_emulate.h | 1 +
 arch/x86/kvm/emulate.c             | 9 ++++++++-
 arch/x86/kvm/svm.c                 | 1 +
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index feab24cac610..478f76b0122d 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -429,6 +429,7 @@ enum x86_intercept {
 	x86_intercept_ins,
 	x86_intercept_out,
 	x86_intercept_outs,
+	x86_intercept_xsetbv,
 
 	nr_x86_intercepts
 };
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index d0d5dd44b4f4..ff25d94df684 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -4393,6 +4393,12 @@ static const struct opcode group7_rm1[] = {
 	N, N, N, N, N, N,
 };
 
+static const struct opcode group7_rm2[] = {
+	N,
+	DI(SrcNone | Priv, xsetbv),
+	N, N, N, N, N, N,
+};
+
 static const struct opcode group7_rm3[] = {
 	DIP(SrcNone | Prot | Priv,		vmrun,		check_svme_pa),
 	II(SrcNone  | Prot | EmulateOnUD,	em_hypercall,	vmmcall),
@@ -4482,7 +4488,8 @@ static const struct group_dual group7 = { {
 }, {
 	EXT(0, group7_rm0),
 	EXT(0, group7_rm1),
-	N, EXT(0, group7_rm3),
+	EXT(0, group7_rm2),
+	EXT(0, group7_rm3),
 	II(SrcNone | DstMem | Mov,		em_smsw, smsw), N,
 	II(SrcMem16 | Mov | Priv,		em_lmsw, lmsw),
 	EXT(0, group7_rm7),
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index f980fc43372d..39e61029f401 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6041,6 +6041,7 @@ static const struct __x86_intercept {
 	[x86_intercept_ins]		= POST_EX(SVM_EXIT_IOIO),
 	[x86_intercept_out]		= POST_EX(SVM_EXIT_IOIO),
 	[x86_intercept_outs]		= POST_EX(SVM_EXIT_IOIO),
+	[x86_intercept_xsetbv]		= PRE_EX(SVM_EXIT_XSETBV),
 };
 
 #undef PRE_EX
-- 
2.20.1