Hi all: The code used to busy poll for cvq command which turns out to have several side effects:
1) infinite poll for buggy devices 2) bad interaction with scheduler So this series tries to use cond_resched() in the waiting loop. Before doing this we need first make sure the cvq command is not executed in atomic environment, so we need first convert rx mode handling to a workqueue. Note that, this doesn't try to solve the case that a malicous device may block networking stack (RTNL) or break freezer which requries more thought to gracefully exit and resend the commands. Please review. Changes since V3: - Tweak the comments - Tweak the changelog to explain the rx mode lost after resuming. - No functional changes Changes since V2: - Don't use interrupt but cond_resched() Changes since V1: - use RTNL to synchronize rx mode worker - use completion for simplicity - don't try to harden CVQ command Changes since RFC: - switch to use BAD_RING in virtio_break_device() - check virtqueue_is_broken() after being woken up - use more_used() instead of virtqueue_get_buf() to allow caller to get buffers afterwards - break the virtio-net device when timeout - get buffer manually since the virtio core check more_used() instead Jason Wang (2): virtio-net: convert rx mode setting to use workqueue virtio-net: add cond_resched() to the command waiting loop drivers/net/virtio_net.c | 59 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 55 insertions(+), 4 deletions(-) -- 2.39.3 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
