diff options
author | Marcelo Tosatti <mtosatti@redhat.com> | 2008-04-04 14:56:44 -0300 |
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committer | Avi Kivity <avi@qumranet.com> | 2008-04-27 12:00:58 +0300 |
commit | bed1d1dfc4a458d82bcd258082638cbba860190d (patch) | |
tree | 344f9cbf54082161e54ba77164f55aec695b9403 /arch/s390/kvm/kvm-s390.c | |
parent | fcd6dbac9267c1c06a205ad8bb4bd027c0ace7f7 (diff) |
KVM: MMU: prepopulate guest pages after write-protecting
Zdenek reported a bug where a looping "dmsetup status" eventually hangs
on SMP guests.
The problem is that kvm_mmu_get_page() prepopulates the shadow MMU
before write protecting the guest page tables. By doing so, it leaves a
window open where the guest can mark a pte as present while the host has
shadow cached such pte as "notrap". Accesses to such address will fault
in the guest without the host having a chance to fix the situation.
Fix by moving the write protection before the pte prefetch.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch/s390/kvm/kvm-s390.c')
0 files changed, 0 insertions, 0 deletions