KVM: Don't allow lmsw to clear cr0.pe

The current lmsw implementation allows the guest to clear cr0.pe, contrary
to the manual, which breaks EMM386.EXE.

Fix by ORing the old cr0.pe with lmsw's operand.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
(cherry picked from commit f78e917688edbf1f14c318d2e50dc8e7dad20445)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2782509a061673321bfdd5176700032d1fbfdfc4..fa536e8db69ef6238e0dba4b4ea68deec69aa893 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -345,7 +345,7 @@ EXPORT_SYMBOL_GPL(kvm_set_cr0);
 
 void kvm_lmsw(struct kvm_vcpu *vcpu, unsigned long msw)
 {
-       kvm_set_cr0(vcpu, (vcpu->arch.cr0 & ~0x0ful) | (msw & 0x0f));
+       kvm_set_cr0(vcpu, (vcpu->arch.cr0 & ~0x0eul) | (msw & 0x0f));
 }
 EXPORT_SYMBOL_GPL(kvm_lmsw);