KVM/x86: Use 32bit xor to clear registers in svm.c
x86_64 zero-extends 32bit xor operation to a full 64bit register.
Also add a comment and remove unnecessary instruction suffix in vmx.c
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 91f4f528..3677609 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -62,7 +62,7 @@
#define __ex(x) __kvm_handle_fault_on_reboot(x)
#define __ex_clear(x, reg) \
- ____kvm_handle_fault_on_reboot(x, "xorl " reg " , " reg)
+ ____kvm_handle_fault_on_reboot(x, "xor " reg ", " reg)
MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");
@@ -11285,6 +11285,10 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
"mov %%r13, %c[r13](%0) \n\t"
"mov %%r14, %c[r14](%0) \n\t"
"mov %%r15, %c[r15](%0) \n\t"
+ /*
+ * Clear host registers marked as clobbered to prevent
+ * speculative use.
+ */
"xor %%r8d, %%r8d \n\t"
"xor %%r9d, %%r9d \n\t"
"xor %%r10d, %%r10d \n\t"