[PATCH 33/50] KVM: MMU: Disable write access on clean large pages

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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 <[email protected]>
---
 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 e07cb2e..4538b15 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);
-- 
1.5.3.7

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux