KVM: MMU: Segregate shadow pages with different cr0.wp
authorAvi Kivity <avi@redhat.com>
Wed, 12 May 2010 08:48:18 +0000 (11:48 +0300)
committerAvi Kivity <avi@redhat.com>
Wed, 19 May 2010 08:41:09 +0000 (11:41 +0300)
commit3dbe141595faa48a067add3e47bba3205b79d33c
treea7d37004d0021298ed305810543ae6a3a4ed79e2
parenta3d204e28579427609c3d15d2310127ebaa47d94
KVM: MMU: Segregate shadow pages with different cr0.wp

When cr0.wp=0, we may shadow a gpte having u/s=1 and r/w=0 with an spte
having u/s=0 and r/w=1.  This allows excessive access if the guest sets
cr0.wp=1 and accesses through this spte.

Fix by making cr0.wp part of the base role; we'll have different sptes for
the two cases and the problem disappears.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Documentation/kvm/mmu.txt
arch/x86/include/asm/kvm_host.h
arch/x86/kvm/mmu.c