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 c3d8c0c21e7a449b696390e7efb6af6f4cb7ff00..9950b87edb0dcf1de42e9234f752a017d0a87c67 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -432,7 +432,7 @@ 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);