kernel/linux.git/drivers/vhost/vhost.c, branch v3.4.98

vhost: zerocopy: poll vq in zerocopy callback

2013-09-14T13:02:10+00:00

commit c70aa540c7a9f67add11ad3161096fb95233aa2e upstream. We add used and signal guest in worker thread but did not poll the virtqueue during the zero copy callback. This may lead the missing of adding and signalling during zerocopy. Solve this by polling the virtqueue and let it wakeup the worker during callback. Signed-off-by: Jason Wang Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman

vhost: fix length for cross region descriptor

2013-03-03T22:06:43+00:00

commit bd97120fc3d1a11f3124c7c9ba1d91f51829eb85 upstream. If a single descriptor crosses a region, the second chunk length should be decremented by size translated so far, instead it includes the full descriptor length. Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

skbuff: struct ubuf_info callback type safety

2012-04-13T17:09:19+00:00

The skb struct ubuf_info callback gets passed struct ubuf_info itself, not the arg value as the field name and the function signature seem to imply. Rename the arg field to ctx to match usage, add documentation and change the callback argument type to make usage clear and to have compiler check correctness. Signed-off-by: Michael S. Tsirkin Signed-off-by: David S. Miller

Merge branch 'vhost-net' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2012-03-23T18:46:48+00:00

vhost: remove the second argument of k[un]map_atomic()

2012-03-20T13:48:21+00:00

Signed-off-by: Cong Wang

vhost: fix release path lockdep checks

2012-02-28T07:13:22+00:00

We shouldn't hold any locks on release path. Pass a flag to vhost_dev_cleanup to use the lockdep info correctly. Signed-off-by: Michael S. Tsirkin Tested-by: Sasha Levin

vhost: don't forget to schedule()

2012-02-28T07:13:19+00:00

This is a tiny, but important, patch to vhost. Vhost's worker thread only called schedule() when it had no work to do, and it wanted to go to sleep. But if there's always work to do, e.g., the guest is running a network-intensive program like netperf with small message sizes, schedule() was *never* called. This had several negative implications (on non-preemptive kernels): 1. Passing time was not properly accounted to the "vhost" process (ps and top would wrongly show it using zero CPU time). 2. Sometimes error messages about RCU timeouts would be printed, if the core running the vhost thread didn't schedule() for a very long time. 3. Worst of all, a vhost thread would "hog" the core. If several vhost threads need to share the same core, typically one would get most of the CPU time (and its associated guest most of the performance), while the others hardly get any work done. The trivial solution is to add if (need_resched()) schedule(); After doing every piece of work. This will not do the heavy schedule() all the time, just when the timer interrupt decided a reschedule is warranted (so need_resched returns true). Thanks to Abel Gordon for this patch. Signed-off-by: Nadav Har'El Signed-off-by: Michael S. Tsirkin

vhost: optimize interrupt enable/disable

2011-07-19T14:17:28+00:00

As we now only update used ring after enabling the backend, we can write flags with __put_user: as that's done on data path, it matters. Signed-off-by: Michael S. Tsirkin

vhost: fix zcopy reference counting

2011-07-19T10:28:34+00:00

Fix get/put refcount imbalance with zero copy, which caused qemu to hang forever on guest driver unload. Signed-off-by: Michael S. Tsirkin

vhost: set log when updating used flags or avail event

2011-07-19T10:28:34+00:00

We need to log writes when updating used flags and avail event fields. Otherwise the guest may see a stale value after migration and miss notifying the host. Signed-off-by: Jason Wang Signed-off-by: Michael S. Tsirkin