path: root/arch/x86/kvm/paging_tmpl.h
diff options
authorXiao Guangrong <xiaoguangrong@cn.fujitsu.com>2010-06-30 16:02:45 +0800
committerAvi Kivity <avi@redhat.com>2010-07-23 09:07:04 +0300
commit6aa0b9dec5d6dde26ea17b0b5be8fccfe19df3c9 (patch)
tree622e57dd0373a86b98f4976096fa6f670540dab6 /arch/x86/kvm/paging_tmpl.h
parentb37fa16e78d6f9790462b3181602a26b5af36260 (diff)
KVM: MMU: fix conflict access permissions in direct sp
In no-direct mapping, we mark sp is 'direct' when we mapping the guest's larger page, but its access is encoded form upper page-struct entire not include the last mapping, it will cause access conflict. For example, have this mapping: [W] / PDE1 -> |---| P[W] | | LPA \ PDE2 -> |---| [R] P have two children, PDE1 and PDE2, both PDE1 and PDE2 mapping the same lage page(LPA). The P's access is WR, PDE1's access is WR, PDE2's access is RO(just consider read-write permissions here) When guest access PDE1, we will create a direct sp for LPA, the sp's access is from P, is W, then we will mark the ptes is W in this sp. Then, guest access PDE2, we will find LPA's shadow page, is the same as PDE's, and mark the ptes is RO. So, if guest access PDE1, the incorrect #PF is occured. Fixed by encode the last mapping access into direct shadow page Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/paging_tmpl.h')
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 89d66ca4d87..2331bdc2b54 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -342,6 +342,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
/* advance table_gfn when emulating 1gb pages with 4k */
if (delta == 0)
table_gfn += PT_INDEX(addr, level);
+ access &= gw->pte_access;
} else {
direct = 0;
table_gfn = gw->table_gfn[level - 2];