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| author | Avi Kivity <avi@qumranet.com> | 2007-12-09 17:37:36 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2008-01-30 18:53:20 +0300 |
| commit | 8d87a03aea43535a92efbb180e0ceac94d4bb5db (patch) | |
| tree | 109fc349fbf4010155eab1393fa71c3a7029a110 /drivers/kvm | |
| parent | fe135d2ceb3d7dc08151b3cbad96565d02cc8676 (diff) | |
| download | linux-8d87a03aea43535a92efbb180e0ceac94d4bb5db.tar.xz | |
KVM: MMU: Set nx bit correctly on shadow ptes
While the page table walker correctly generates a guest page fault
if a guest tries to execute a non-executable page, the shadow code does
not mark it non-executable. This means that if a guest accesses an nx
page first with a read access, then subsequent code fetch accesses will
succeed.
Fix by setting the nx bit on shadow ptes.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'drivers/kvm')
| -rw-r--r-- | drivers/kvm/paging_tmpl.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h index 7688cbf413c8..59ba752a6880 100644 --- a/drivers/kvm/paging_tmpl.h +++ b/drivers/kvm/paging_tmpl.h @@ -255,6 +255,8 @@ static void FNAME(set_pte)(struct kvm_vcpu *vcpu, pt_element_t gpte, spte |= gpte & PT64_NX_MASK; if (!dirty) pte_access &= ~ACC_WRITE_MASK; + if (!(pte_access & ACC_EXEC_MASK)) + spte |= PT64_NX_MASK; page = gfn_to_page(vcpu->kvm, gfn); |