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>
This commit is contained in:
Avi Kivity
2010-05-12 11:48:18 +03:00
parent a3d204e285
commit 3dbe141595
3 changed files with 5 additions and 1 deletions

View File

@@ -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.