Updating the event index has a memory barrier and causes more work
on the other side to actually signal the event. It is unnecessary
if a new buffer has already appeared on the ring, so poll once before
doing the update.
The effect of this on the 0.9 ring implementation is pretty much
invisible, but on the new-style ring it provides a consistent 3%
performance improvement.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Provide new primitives used_empty/avail_empty and
build poll_avail/poll_used on top of it.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
By using -flto and -fwhole-program, all functions from the ring implementation
can be treated as static and possibly inlined. Force this to happen through
the GCC flatten attribute.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Recent changes to ptr_ring broke the ringtest
which lacks a likely() stub. Fix it up.
Fixes: 982fb490c2
("ptr_ring: support zero length ring")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Sometimes, we need support resizing multiple queues at once. This is
because it was not easy to recover to recover from a partial failure
of multiple queues resizing.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Several cases of overlapping changes, except the packet scheduler
conflicts which deal with the addition of the free list parameter
to qdisc_enqueue().
Signed-off-by: David S. Miller <davem@davemloft.net>
/dev/cpu is only available on x86 with certain modules (e.g. msr) enabled.
Using lscpu to get processors count is more portable.
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Having typical usage example in the README file is more convinient than in
the git history...
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
virtio_ring currently sends the device (usually a hypervisor)
physical addresses of its I/O buffers. This is okay when DMA
addresses and physical addresses are the same thing, but this isn't
always the case. For example, this never works on Xen guests, and
it is likely to fail if a physical "virtio" device ever ends up
behind an IOMMU or swiotlb.
The immediate use case for me is to enable virtio on Xen guests.
For that to work, we need vring to support DMA address translation
as well as a corresponding change to virtio_pci or to another
driver.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This adds micro-benchmarks useful for tuning virtio ring layouts.
Three layouts are currently implemented:
- virtio 0.9 compatible one
- an experimental extension bypassing the ring index, polling ring
itself instead
- an experimental extension bypassing avail and used ring completely
Typical use:
sh run-on-all.sh perf stat -r 10 --log-fd 1 -- ./ring
It doesn't depend on the kernel directly, but it's handy
to have as much virtio stuff as possible in one tree.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
commit cf561f0d2e ("virtio: introduce
virtio_is_little_endian() helper") changed byteswap logic to
skip feature bit checks for LE platforms, but didn't
update tools/virtio, so vring_bench started failing.
Update the copy under tools/virtio/ (TODO: find a way to avoid this code
duplication).
Cc: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Change u32 to u64, and use BIT_ULL and 1ULL everywhere.
Note: transports are unchanged, and only set low 32 bit.
This guarantees that no transport sets e.g. VERSION_1
by mistake without proper support.
Based on patch by Rusty.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
It seemed like a good idea to use bitmap for features
in struct virtio_device, but it's actually a pain,
and seems to become even more painful when we get more
than 32 feature bits. Just change it to a u32 for now.
Based on patch by Rusty.
Suggested-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Combine all definitions into a common tools/include/linux/types.h and
kill the wild growth elsewhere. Move DECLARE_BITMAP to its proper
bitmap.h header.
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Link: http://lkml.kernel.org/n/tip-azczs7qcv6h9xek9od10hiv2@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
So tools/ has been growing three, at a different stage of their
development export.h headers and so we should unite into one. Add
tools/include/ to the include path of virtio and liblockdep to pick the
shared header now.
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: virtio-dev@lists.oasis-open.org
Cc: virtualization@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/1397493185-19521-2-git-send-email-bp@alien8.de
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Fixes the following build failure:
cc -g -O2 -Wall -I. -I ../../usr/include/ -Wno-pointer-sign
-fno-strict-overflow -fno-strict-aliasing -fno-common -MMD
-U_FORTIFY_SOURCE -c -o virtio_test.o virtio_test.c
virtio_test.c: In function ‘run_test’:
virtio_test.c:176:7: error: expected ‘)’ before ‘r’
r = -1;
^
Fixes: 53c18c9906 (virtio_test: verify if virtqueue_kick() succeeded)
Cc: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
In commit bb478d8b16 virtio_ring: plug kmemleak false positive,
kmemleak_ignore was introduced. This broke compilation of virtio_test:
cc -g -O2 -Wall -I. -I ../../usr/include/ -Wno-pointer-sign
-fno-strict-overflow -fno-strict-aliasing -fno-common -MMD
-U_FORTIFY_SOURCE -c -o virtio_ring.o ../../drivers/virtio/virtio_ring.c
../../drivers/virtio/virtio_ring.c: In function ‘vring_add_indirect’:
../../drivers/virtio/virtio_ring.c:177:2: warning: implicit declaration
of function ‘kmemleak_ignore’ [-Wimplicit-function-declaration]
kmemleak_ignore(desc);
^
cc virtio_test.o virtio_ring.o -o virtio_test
virtio_ring.o: In function `vring_add_indirect':
tools/virtio/../../drivers/virtio/virtio_ring.c:177:
undefined reference to `kmemleak_ignore'
Add a dummy header for tools/virtio, and add #incldue <linux/kmemleak.h>
to drivers/virtio/virtio_ring.c so it is picked up by the userspace
tools.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The virtio headers have changed recently:
5b1bf7cb67 virtio_ring: let virtqueue_{kick()/notify()} return a bool
46f9c2b925 virtio_ring: change host notification API
Update the internal copies to fix the build of virtio_test:
cc -g -O2 -Wall -I. -I ../../usr/include/ -Wno-pointer-sign
-fno-strict-overflow -fno-strict-aliasing -fno-common -MMD -U_FORTIFY_SOURCE
-c -o virtio_test.o virtio_test.c
In file included from virtio_test.c:15:0:
./linux/virtio.h:76:19: error: conflicting types for ‘vring_new_virtqueue’
struct virtqueue *vring_new_virtqueue(unsigned int index,
^
In file included from ./linux/virtio_ring.h:1:0,
from ../../usr/include/linux/vhost.h:17,
from virtio_test.c:14:
./linux/../../../include/linux/virtio_ring.h:68:19: note: previous
declaration of ‘vring_new_virtqueue’ was here
struct virtqueue *vring_new_virtqueue(unsigned int index,
virtio_test.c: In function ‘vq_info_add’:
virtio_test.c:103:12: warning: passing argument 7 of ‘vring_new_virtqueue’
from incompatible pointer type [enabled by default]
vq_notify, vq_callback, "test");
^
In file included from virtio_test.c:15:0:
./linux/virtio.h:76:19: note: expected ‘void (*)(struct virtqueue *)’ but
argument is of type ‘_Bool (*)(struct virtqueue *)’
struct virtqueue *vring_new_virtqueue(unsigned int index,
^
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Verify if a host kick succeeded by checking return value of virtqueue_kick().
Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Currently a host kick error is silently ignored and not reflected in
the virtqueue of a particular virtio device.
Changing the notify API for guest->host notification seems to be one
prerequisite in order to be able to handle such errors in the context
where the kick is triggered.
This patch changes the notify API. The notify function must return a
bool return value. It returns false if the host notification failed.
Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
virtio_scsi can really use this, to avoid the current hack of copying
the whole sg array. Some other things get slightly neater, too.
This causes a slowdown in virtqueue_add_buf(), which is implemented as
a wrapper. This is addressed in the next patches.
for i in `seq 50`; do /usr/bin/time -f 'Wall time:%e' ./vringh_test --indirect --eventidx --parallel --fast-vringh; done 2>&1 | stats --trim-outliers:
Before:
Using CPUS 0 and 3
Guest: notified 0, pinged 39009-39063(39062)
Host: notified 39009-39063(39062), pinged 0
Wall time:1.700000-1.950000(1.723542)
After:
Using CPUS 0 and 3
Guest: notified 0, pinged 39062-39063(39063)
Host: notified 39062-39063(39063), pinged 0
Wall time:1.760000-2.220000(1.789167)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Reviewed-by: Asias He <asias@redhat.com>
This is mainly to test the drivers/vhost/vringh.c code, but it also
uses the drivers/virtio/virtio_ring.c code for the guest side.
Usage for testing the basic implementation:
./vringh_test
# Test with indirect descriptors
./vringh_test --indirect
# Test with indirect descriptors and event indexex
./vringh_test --indirect --eventidx
You can run a parallel stress test by adding --parallel to any of the
above options.
eg ./vringh_test --parallel:
Using CPUS 0 and 3
Guest: notified 10107974, pinged 107970
Host: notified 108158, pinged 3172148
./vringh_test --indirect --eventidx --parallel:
Using CPUS 0 and 3
Guest: notified 156357, pinged 156251
Host: notified 156251, pinged 78179
Average of 50 times doing ./vringh_test --indirect --eventidx --parallel:
2.840000-3.040000(2.927292)user
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This makes them a bit more like the kernel headers, so we can include more
real kernel headers in our tests.
In addition this means that we don't break tools/virtio with the next
patch.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Latinoware 2012.
There's a slightly non-trivial merge in virtio-net, as we cleaned up the
virtio add_buf interface while DaveM accepted the mq virtio-net patches.
You can see my solution in my pending-rebases branch, if that helps, but I
know you love merging:
https://git.kernel.org/?p=linux/kernel/git/rusty/linux.git;a=commit;h=12e4e64fa66a4c812e4855de32abdb4d819526fe
Cheers,
Rusty.
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Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull virtio update from Rusty Russell:
"Some nice cleanups, and even a patch my wife did as a "live" demo for
Latinoware 2012.
There's a slightly non-trivial merge in virtio-net, as we cleaned up
the virtio add_buf interface while DaveM accepted the mq virtio-net
patches."
* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (27 commits)
virtio_console: Add support for remoteproc serial
virtio_console: Merge struct buffer_token into struct port_buffer
virtio: add drv_to_virtio to make code clearly
virtio: use dev_to_virtio wrapper in virtio
virtio-mmio: Fix irq parsing in command line parameter
virtio_console: Free buffers from out-queue upon close
virtio: Convert dev_printk(KERN_<LEVEL> to dev_<level>(
virtio_console: Use kmalloc instead of kzalloc
virtio_console: Free buffer if splice fails
virtio: tools: make it clear that virtqueue_add_buf() no longer returns > 0
virtio: scsi: make it clear that virtqueue_add_buf() no longer returns > 0
virtio: rpmsg: make it clear that virtqueue_add_buf() no longer returns > 0
virtio: net: make it clear that virtqueue_add_buf() no longer returns > 0
virtio: console: make it clear that virtqueue_add_buf() no longer returns > 0
virtio: make virtqueue_add_buf() returning 0 on success, not capacity.
virtio: console: don't rely on virtqueue_add_buf() returning capacity.
virtio_net: don't rely on virtqueue_add_buf() returning capacity.
virtio-net: remove unused skb_vnet_hdr->num_sg field
virtio-net: correct capacity math on ring full
virtio: move queue_index and num_free fields into core struct virtqueue.
...
We do not allow old-style function definition. Always spell foo(void) if
a function does not take any parameters.
Signed-off-by: Cong Ding <dinggnu@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
pthread flag should not be -lpthread but -pthread using gcc. The -lpthread
links the external multithread library. On the other hand, the -pthread manages
both the gcc's preprocessor and linker to be able to compile with pthread.
Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This patch adds a user tool, "trace agent" for sending trace data of a guest to
a Host in low overhead. This agent has the following functions:
- splice a page of ring-buffer to read_pipe without memory copying
- splice the page from write_pipe to virtio-console without memory copying
- write trace data to stdout by using -o option
- controlled by start/stop orders from a Host
Changes in v2:
- Cleanup (change fprintf() to pr_err() and an include guard)
Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Acked-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Paolo Bonzini