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author | Paolo Bonzini <pbonzini@redhat.com> | 2017-06-06 12:57:05 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-10-05 09:44:02 +0200 |
commit | ff5eb8f28ff260873909fbd259cf892594621fc4 (patch) | |
tree | d66a58effd8f3c6f767cbe2fcd8ebc5b9110b894 /lib/locking-selftest-rsem.h | |
parent | 01c58b0edeb1d7cab6976462aef585e928924ab9 (diff) |
KVM: VMX: avoid double list add with VT-d posted interrupts
commit 8b306e2f3c41939ea528e6174c88cfbfff893ce1 upstream.
In some cases, for example involving hot-unplug of assigned
devices, pi_post_block can forget to remove the vCPU from the
blocked_vcpu_list. When this happens, the next call to
pi_pre_block corrupts the list.
Fix this in two ways. First, check vcpu->pre_pcpu in pi_pre_block
and WARN instead of adding the element twice in the list. Second,
always do the list removal in pi_post_block if vcpu->pre_pcpu is
set (not -1).
The new code keeps interrupts disabled for the whole duration of
pi_pre_block/pi_post_block. This is not strictly necessary, but
easier to follow. For the same reason, PI.ON is checked only
after the cmpxchg, and to handle it we just call the post-block
code. This removes duplication of the list removal code.
Cc: Huangweidong <weidong.huang@huawei.com>
Cc: Gonglei <arei.gonglei@huawei.com>
Cc: wangxin <wangxinxin.wang@huawei.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Tested-by: Longpeng (Mike) <longpeng2@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib/locking-selftest-rsem.h')
0 files changed, 0 insertions, 0 deletions