Commit Graph

8 Commits

Author SHA1 Message Date
Jason Wang 21bbe18b2d KVM: Fix typos in Documentation/kvm/mmu.txt
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:46:52 +03:00
Avi Kivity 316b95216e KVM: MMU: Document large pages
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:39:23 +03:00
Avi Kivity ec87fe2afc KVM: MMU: Document cr0.wp emulation
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:39:23 +03:00
Lai Jiangshan 2032a93d66 KVM: MMU: Don't allocate gfns page for direct mmu pages
When sp->role.direct is set, sp->gfns does not contain any essential
information, leaf sptes reachable from this sp are for a continuous
guest physical memory range (a linear range).
So sp->gfns[i] (if it was set) equals to sp->gfn + i. (PT_PAGE_TABLE_LEVEL)
Obviously, it is not essential information, we can calculate it when need.

It means we don't need sp->gfns when sp->role.direct=1,
Thus we can save one page usage for every kvm_mmu_page.

Note:
  Access to sp->gfns must be wrapped by kvm_mmu_page_get_gfn()
  or kvm_mmu_page_set_gfn().
  It is only exposed in FNAME(sync_page).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01 10:35:52 +03:00
Gui Jianfeng 6859762e8a KVM: update mmu documetation for role.nxe
There's no member "cr4_nxe" in struct kvm_mmu_page_role, it names "nxe" now.
Update mmu document.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-08-01 10:35:41 +03:00
Avi Kivity 3dbe141595 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>
2010-05-19 11:41:09 +03:00
Avi Kivity c4bd09b289 KVM: Minor MMU documentation edits
Reported by Andrew Jones.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-05-17 12:19:32 +03:00
Avi Kivity 039091875c KVM: Document mmu
Signed-off-by: Avi Kivity <avi@redhat.com>
2010-05-17 12:19:12 +03:00