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 7635a38fe84d03d206576c5932f40974b84437da..d9680b3c40ef30845db636489f7d23539a7a89ec 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -484,7 +484,7 @@ EXPORT_SYMBOL_GPL(kvm_set_cr0);
 
 void kvm_lmsw(struct kvm_vcpu *vcpu, unsigned long msw)
 {
-       kvm_set_cr0(vcpu, kvm_read_cr0_bits(vcpu, ~0x0ful) | (msw & 0x0f));
+       kvm_set_cr0(vcpu, kvm_read_cr0_bits(vcpu, ~0x0eul) | (msw & 0x0f));
 }
 EXPORT_SYMBOL_GPL(kvm_lmsw);