[PATCH 11/50] KVM: MMU: Ignore reserved bits in cr3 in non-pae mode

From: Avi Kivity
Date: Sun Dec 23 2007 - 09:55:45 EST


From: Ryan Harper <ryanh@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>
---
drivers/kvm/kvm_main.c | 11 ++++-------
1 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index da057cf..b10fd7e 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);
--
1.5.3.7

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