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| author | Marcelo Tosatti <mtosatti@redhat.com> | 2010-12-22 09:01:57 -0200 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-01-12 11:31:13 +0200 |
| commit | e49146dce8c3dc6f4485c1904b6587855f393e71 (patch) | |
| tree | 1a7db0516cee7ff2810445e16d21dadd960237af /arch/x86/kvm/mmu.c | |
| parent | 16d8f72f70a85ce333788204a69318827130ca75 (diff) | |
| download | lwn-e49146dce8c3dc6f4485c1904b6587855f393e71.tar.gz lwn-e49146dce8c3dc6f4485c1904b6587855f393e71.zip | |
KVM: MMU: only write protect mappings at pagetable level
If a pagetable contains a writeable large spte, all of its sptes will be
write protected, including non-leaf ones, leading to endless pagefaults.
Do not write protect pages above PT_PAGE_TABLE_LEVEL, as the spte fault
paths assume non-leaf sptes are writable.
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index b77a5ba398be..a2127f82e786 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3445,6 +3445,9 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot) if (!test_bit(slot, sp->slot_bitmap)) continue; + if (sp->role.level != PT_PAGE_TABLE_LEVEL) + continue; + pt = sp->spt; for (i = 0; i < PT64_ENT_PER_PAGE; ++i) /* avoid RMW */ |