[RFC][PATCH] ignore set_cr3 GP fault in non-pae mode

[Ryan Harper <ryanh-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>]

[-- Attachment #1: Type: text/plain, Size: 599 bytes --]

Playing around with running VMware-server within a KVM guest and noticed
that whenever we launch a VM within the guest, KVM reports a GP fault in
set_cr3.  Removing the fault injection (raised for attempting to set
reserved bits) for the non-pae case allows memtest to boot and run 
within VMWare Server, running in a KVM Linux guest.

This same test (Linux, VMware-server, booting/running memtest iso) works
fine on bare-metal.  Thoughts?

-- 
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
(512) 838-9253   T/L: 678-9253
ryanh-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org

[-- Attachment #2: ignore_gp_fault_in_nonpae_paging.patch --]
[-- Type: text/plain, Size: 789 bytes --]


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-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 353e585..386f9c1 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -573,13 +573,6 @@ 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;
-			}
 		}
 	}
 

[-- Attachment #3: Type: text/plain, Size: 228 bytes --]

-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2005.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/

[-- Attachment #4: Type: text/plain, Size: 186 bytes --]

_______________________________________________
kvm-devel mailing list
kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
https://lists.sourceforge.net/lists/listinfo/kvm-devel