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authorAvi Kivity <avi@redhat.com>2010-05-12 11:48:18 +0300
committerAvi Kivity <avi@redhat.com>2010-05-19 11:41:09 +0300
commit3dbe141595faa48a067add3e47bba3205b79d33c (patch)
treea7d37004d0021298ed305810543ae6a3a4ed79e2 /Documentation/kvm
parenta3d204e28579427609c3d15d2310127ebaa47d94 (diff)
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>
Diffstat (limited to 'Documentation/kvm')
-rw-r--r--Documentation/kvm/mmu.txt2
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/kvm/mmu.txt b/Documentation/kvm/mmu.txt
index 0cc28fb84f4..aaed6ab9d7a 100644
--- a/Documentation/kvm/mmu.txt
+++ b/Documentation/kvm/mmu.txt
@@ -163,6 +163,8 @@ Shadow pages contain the following information:
32-bit or 64-bit gptes are in use).
role.cr4_nxe:
Contains the value of efer.nxe for which the page is valid.
+ role.cr0_wp:
+ Contains the value of cr0.wp for which the page is valid.
gfn:
Either the guest page table containing the translations shadowed by this
page, or the base page frame for linear translations. See role.direct.