KVM: MMU: Ignore reserved bits in cr3 in non-pae mode

This patch removes the fault injected when the guest attempts to set reserved
bits in cr3.  X86 hardware doesn't generate a fault when setting reserved bits.
The result of this patch is that vmware-server, running within a kvm guest,
boots and runs memtest from an iso.

Signed-off-by: Ryan Harper <ryanh@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 4 insertions, 7 deletions

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 82cc7ae0fc83..2d55bab41634 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -554,14 +554,11 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
                                 inject_gp(vcpu);
                                 return;
                         }
-                } else {
-                        if (cr3 & CR3_NONPAE_RESERVED_BITS) {
-                                printk(KERN_DEBUG
-                                       "set_cr3: #GP, reserved bits\n");
-                                inject_gp(vcpu);
-                                return;
-                        }
                 }
+                /*
+                 * We don't check reserved bits in nonpae mode, because
+                 * this isn't enforced, and VMware depends on this.
+                 */
         }
 
         mutex_lock(&vcpu->kvm->lock);