diff options
| author | Avi Kivity <avi@qumranet.com> | 2007-10-11 15:12:24 +0200 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2008-01-30 17:52:52 +0200 |
| commit | cc70e7374df1e3a56d718e8ca330619f316511a6 (patch) | |
| tree | 6746e9724eb51486104800be264e6baa64c8fefd | |
| parent | c22e3514fceb2f514093ce1d19a2f660ac7347ae (diff) | |
KVM: MMU: Disable write access on clean large pages
By forcing clean huge pages to be read-only, we have separate roles
for the shadow of a clean large page and the shadow of a dirty large
page. This is necessary because different ptes will be instantiated
for the two cases, even for read faults.
Signed-off-by: Avi Kivity <avi@qumranet.com>
| -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 e07cb2e006c..4538b1533d5 100644 --- a/drivers/kvm/paging_tmpl.h +++ b/drivers/kvm/paging_tmpl.h @@ -382,6 +382,8 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, metaphysical = 1; hugepage_access = walker->pte; hugepage_access &= PT_USER_MASK | PT_WRITABLE_MASK; + if (!is_dirty_pte(walker->pte)) + hugepage_access &= ~PT_WRITABLE_MASK; hugepage_access >>= PT_WRITABLE_SHIFT; if (walker->pte & PT64_NX_MASK) hugepage_access |= (1 << 2); |