On Thu, Jul 11, 2024 at 06:44:23PM +0530, Prasad Pandit wrote: > From: Prasad Pandit <p...@fedoraproject.org> > > QEMU threads use vhost_user_write/read calls to send > and receive messages from a vhost-user device. When multiple > threads communicate with the same vhost-user device, they can > receive each other's messages, resulting in an erroneous state. > > vhost_user_read_header: > 700871,700871: Failed to read msg header. Flags 0x0 instead of 0x5. > vhost_device_iotlb_miss: > 700871,700871: Fail to update device iotlb > vhost_user_postcopy_end: > 700871,700900: Failed to receive reply to postcopy_end > vhost_user_read_header: > 700871,700871: Failed to read msg header. Flags 0x0 instead of 0x5. > > Here fault thread seems to end the postcopy migration while > another thread is starting the vhost-user device. > > Add a rw lock to hold for one vhost_user_write/read cycle > and avoid such race conditions. > > Suggested-by: Peter Xu <pet...@redhat.com> > Signed-off-by: Prasad Pandit <p...@fedoraproject.org> > --- > hw/virtio/vhost-user.c | 423 +++++++++++++++++++-------------- > include/hw/virtio/vhost-user.h | 3 +
I apologize if I suggested WITH_QEMU_LOCK_GUARD when we talked.. I don't remember which one I suggested, but in this case IIUC it'll be much easier to review if you use the other sister function QEMU_LOCK_GUARD() instead.. That should make the diff much, much less. -- Peter Xu
