KVM: x86 emulator: fix writes to registers with modrm encodings

A register destination encoded with a mod=3 encoding left dst.ptr NULL.
Normally we don't trap writes to registers, but in the case of smsw, we do.

Fix by pointing dst.ptr at the destination register.

Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/asm-x86/kvm_x86_emulate.h b/include/asm-x86/kvm_x86_emulate.h
index d6337f941c9..b877bbd2d3a 100644
--- a/include/asm-x86/kvm_x86_emulate.h
+++ b/include/asm-x86/kvm_x86_emulate.h
@@ -135,6 +135,7 @@ struct decode_cache {
         u8 modrm_rm;
         u8 use_modrm_ea;
         unsigned long modrm_ea;
+        void *modrm_ptr;
         unsigned long modrm_val;
         struct fetch_cache fetch;
 };