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: 53c18c99 (virtio_test: verify if virtqueue_kick() succeeded)
Cc: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

In commit bb478d8b 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: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

The virtio headers have changed recently:

 5b1bf7cb virtio_ring: let virtqueue_{kick()/notify()} return a bool
 46f9c2b9 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: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Verify if a host kick succeeded by checking return value of virtqueue_kick().
Signed-off-by: NHeinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: NRusty 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: NHeinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Signed-off-by: NRamkumar Ramachandra <artagnon@gmail.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This fixes build for the vringh test:
[linux]$ make -C tools/virtio/
make: Entering directory `/home/mst/scm/linux/tools/virtio'
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 vringh.o ../../drivers/vhost/vringh.c
../../drivers/vhost/vringh.c:1010:16: error: expected declaration
specifiers or ‘...’ before string constant
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Make the rest of the paths use virtqueue_add_sgs or add_outbuf.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

As expected, the simplified accessors are faster.

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 39062-39063(39063)
	Host: notified 39062-39063(39063), pinged 0
	Wall time:1.760000-2.220000(1.789167)

After:
	Using CPUS 0 and 3
	Guest: notified 0, pinged 39037-39063(39062)
	Host: notified 39037-39063(39062), pinged 0
	Wall time:1.640000-1.810000(1.676875)
Signed-off-by: NRusty 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: NRusty Russell <rusty@rustcorp.com.au>
Reviewed-by: NWanlong Gao <gaowanlong@cn.fujitsu.com>
Reviewed-by: NAsias 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: NRusty 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: NRusty Russell <rusty@rustcorp.com.au>

Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

We simplified virtqueue_add_buf(), make it clear in the callers.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

We do not allow old-style function definition.  Always spell foo(void) if
a function does not take any parameters.
Signed-off-by: NCong Ding <dinggnu@gmail.com>
Signed-off-by: NMichael 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: NYoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Signed-off-by: NRusty 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: NYoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Acked-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

The tool should never use them, abort if it does.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

Make tool build after virtio changes broke it.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

Make the tool build again after virtio changes broke it.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

Remove wrapper functions. This makes the allocation type explicit in
all callers; I used GPF_KERNEL where it seemed obvious, left it at
GFP_ATOMIC otherwise.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

We were cheating with our barriers; using the smp ones rather than the
real device ones.  That was fine, until rpmsg came along, which is
used to talk to a real device (a non-SMP CPU).

Unfortunately, just putting back the real barriers (reverting
d57ed95d) causes a performance regression on virtio-pci.  In
particular, Amos reports netbench's TCP_RR over virtio_net CPU
utilization increased up to 35% while throughput went down by up to
14%.

By comparison, this branch is in the noise.

Reference: https://lkml.org/lkml/2011/12/11/22Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Add ability to test the new event idx feature,
enable by default.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This is the userspace part of the tool: it includes a bunch of stubs for
linux APIs, somewhat simular to linuxsched. This makes it possible to
recompile the ring code in userspace.

A small test example is implemented combining this with vhost_test
module.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

This adds a test module for vhost infrastructure.
Intentionally not tied to kbuild to prevent people
from installing and loading it accidentally.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>