Commit Graph

286 Commits

Author SHA1 Message Date
Stefan Hajnoczi
60f782b6b7 aio: remove aio_disable_external() API
All callers now pass is_external=false to aio_set_fd_handler() and
aio_set_event_notifier(). The aio_disable_external() API that
temporarily disables fd handlers that were registered is_external=true
is therefore dead code.

Remove aio_disable_external(), aio_enable_external(), and the
is_external arguments to aio_set_fd_handler() and
aio_set_event_notifier().

The entire test-fdmon-epoll test is removed because its sole purpose was
testing aio_disable_external().

Parts of this patch were generated using the following coccinelle
(https://coccinelle.lip6.fr/) semantic patch:

  @@
  expression ctx, fd, is_external, io_read, io_write, io_poll, io_poll_ready, opaque;
  @@
  - aio_set_fd_handler(ctx, fd, is_external, io_read, io_write, io_poll, io_poll_ready, opaque)
  + aio_set_fd_handler(ctx, fd, io_read, io_write, io_poll, io_poll_ready, opaque)

  @@
  expression ctx, notifier, is_external, io_read, io_poll, io_poll_ready;
  @@
  - aio_set_event_notifier(ctx, notifier, is_external, io_read, io_poll, io_poll_ready)
  + aio_set_event_notifier(ctx, notifier, io_read, io_poll, io_poll_ready)

Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230516190238.8401-21-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-30 17:37:26 +02:00
Stefan Hajnoczi
03d7162a21 virtio: do not set is_external=true on host notifiers
Host notifiers can now use is_external=false since virtio-blk and
virtio-scsi no longer rely on is_external=true for drained sections.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230516190238.8401-20-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-30 17:32:03 +02:00
Stefan Hajnoczi
bd58ab40c3 virtio: make it possible to detach host notifier from any thread
virtio_queue_aio_detach_host_notifier() does two things:
1. It removes the fd handler from the event loop.
2. It processes the virtqueue one last time.

The first step can be peformed by any thread and without taking the
AioContext lock.

The second step may need the AioContext lock (depending on the device
implementation) and runs in the thread where request processing takes
place. virtio-blk and virtio-scsi therefore call
virtio_queue_aio_detach_host_notifier() from a BH that is scheduled in
AioContext.

The next patch will introduce a .drained_begin() function that needs to
call virtio_queue_aio_detach_host_notifier(). .drained_begin() functions
cannot call aio_poll() to wait synchronously for the BH. It is possible
for a .drained_poll() callback to asynchronously wait for the BH, but
that is more complex than necessary here.

Move the virtqueue processing out to the callers of
virtio_queue_aio_detach_host_notifier() so that the function can be
called from any thread. This is in preparation for the next patch.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230516190238.8401-17-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-30 17:32:02 +02:00
Carlos López
f0d634ea19 virtio: refresh vring region cache after updating a virtqueue size
When a virtqueue size is changed by the guest via
virtio_queue_set_num(), its region cache is not automatically updated.
If the size was increased, this could lead to accessing the cache out
of bounds. For example, in vring_get_used_event():

    static inline uint16_t vring_get_used_event(VirtQueue *vq)
    {
        return vring_avail_ring(vq, vq->vring.num);
    }

    static inline uint16_t vring_avail_ring(VirtQueue *vq, int i)
    {
        VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
        hwaddr pa = offsetof(VRingAvail, ring[i]);

        if (!caches) {
            return 0;
        }

        return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
    }

vq->vring.num will be greater than caches->avail.len, which will
trigger a failed assertion down the call path of
virtio_lduw_phys_cached().

Fix this by calling virtio_init_region_cache() after
virtio_queue_set_num() if we are not already calling
virtio_queue_set_rings(). In the legacy path this is already done by
virtio_queue_update_rings().

Signed-off-by: Carlos López <clopez@suse.de>
Message-Id: <20230317002749.27379-1-clopez@suse.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-04-21 03:08:21 -04:00
Carlos López
bbc1c327d7 virtio: fix reachable assertion due to stale value of cached region size
In virtqueue_{split,packed}_get_avail_bytes() descriptors are read
in a loop via MemoryRegionCache regions and calls to
vring_{split,packed}_desc_read() - these take a region cache and the
index of the descriptor to be read.

For direct descriptors we use a cache provided by the caller, whose
size matches that of the virtqueue vring. We limit the number of
descriptors we can read by the size of that vring:

    max = vq->vring.num;
    ...
    MemoryRegionCache *desc_cache = &caches->desc;

For indirect descriptors, we initialize a new cache and limit the
number of descriptors by the size of the intermediate descriptor:

    len = address_space_cache_init(&indirect_desc_cache,
                                   vdev->dma_as,
                                   desc.addr, desc.len, false);
    desc_cache = &indirect_desc_cache;
    ...
    max = desc.len / sizeof(VRingDesc);

However, the first initialization of `max` is done outside the loop
where we process guest descriptors, while the second one is done
inside. This means that a sequence of an indirect descriptor followed
by a direct one will leave a stale value in `max`. If the second
descriptor's `next` field is smaller than the stale value, but
greater than the size of the virtqueue ring (and thus the cached
region), a failed assertion will be triggered in
address_space_read_cached() down the call chain.

Fix this by initializing `max` inside the loop in both functions.

Fixes: 9796d0ac8f ("virtio: use address_space_map/unmap to access descriptors")
Signed-off-by: Carlos López <clopez@suse.de>
Message-Id: <20230302100358.3613-1-clopez@suse.de>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-03-07 19:51:07 -05:00
Markus Armbruster
f139b83717 include/hw/virtio: Break inclusion loop
hw/virtio/virtio.h and hw/virtio/vhost.h include each other.  The
former doesn't actually need the latter, so drop that inclusion to
break the loop.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20221222120813.727830-2-armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Edgar E. Iglesias <edgar@zeroasic.com>
2023-01-08 01:54:22 -05:00
Philippe Mathieu-Daudé
9d94c21363 hw/virtio: Extract QMP QOM-specific functions to virtio-qmp.c
virtio.c is big enough, extract more QMP related code to virtio-qmp.c.
To do so, expose qmp_find_virtio_device() and declar virtio_list in
the internal virtio-qmp.h header.

Note we have to leave qmp_x_query_virtio_queue_status() and
qmp_x_query_virtio_queue_element(), because they access VirtQueue
internal fields, and VirtQueue is only declared within virtio.c.

Suggested-by: Jonah Palmer <jonah.palmer@oracle.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221222080005.27616-3-philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-01-08 01:54:22 -05:00
Philippe Mathieu-Daudé
dd92cbb366 hw/virtio: Rename virtio_device_find() -> qmp_find_virtio_device()
To emphasize this function is QMP related, rename it.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221222080005.27616-2-philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-01-08 01:54:22 -05:00
Cindy Lu
7d847d0c9b virtio: add support for configure interrupt
Add the functions to support the configure interrupt in virtio
The function virtio_config_guest_notifier_read will notify the
guest if there is an configure interrupt.
The function virtio_config_set_guest_notifier_fd_handler is
to set the fd hander for the notifier

Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20221222070451.936503-7-lulu@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-01-08 01:54:22 -05:00
Philippe Mathieu-Daudé
28b629ab4a hw/virtio: Extract QMP related code virtio-qmp.c
The monitor decoders are the only functions using the CONFIG_xxx
definitions declared in the target specific CONFIG_DEVICES header.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221213111707.34921-7-philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <a class="moz-txt-link-rfc2396E" href="mailto:philmd@linaro.org">&lt;philmd@linaro.org&gt;</a>
2022-12-21 07:32:24 -05:00
Philippe Mathieu-Daudé
0f4b91f146 hw/virtio: Extract config read/write accessors to virtio-config-io.c
These config helpers use the target-dependent LD/ST API.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221213111707.34921-6-philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-12-21 07:32:24 -05:00
Philippe Mathieu-Daudé
69779192ac hw/virtio: Constify qmp_virtio_feature_map_t[]
These arrays are only accessed read-only, move them to .rodata.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221213111707.34921-5-philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jonah Palmer<jonah.palmer@oracle.com>
Signed-off-by: Philippe Mathieu-Daudé <a class="moz-txt-link-rfc2396E" href="mailto:philmd@linaro.org">&lt;philmd@linaro.org&gt;</a>
2022-12-21 07:32:24 -05:00
Philippe Mathieu-Daudé
f983e598e5 hw/virtio: Guard and restrict scope of qmp_virtio_feature_map_t[]
Commit f3034ad71f ("qmp: decode feature & status bits in
virtio-status") did not guard all qmp_virtio_feature_map_t
arrays with the corresponding #ifdef'ry used in
qmp_decode_features(). Fix that and reduce the arrays scope
by declaring them static.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221213111707.34921-4-philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jonah Palmer<jonah.palmer@oracle.com>
Suggested-by: Richard Henderson <a class="moz-txt-link-rfc2396E" href="mailto:richard.henderson@linaro.org">&lt;richard.henderson@linaro.org&gt;</a>
Signed-off-by: Philippe Mathieu-Daudé <a class="moz-txt-link-rfc2396E" href="mailto:philmd@linaro.org">&lt;philmd@linaro.org&gt;</a>
2022-12-21 07:32:24 -05:00
Philippe Mathieu-Daudé
302f1fe110 hw/virtio: Add missing "hw/core/cpu.h" include
virtio.c uses target_words_bigendian() which is declared in
"hw/core/cpu.h". Add the missing header to avoid when refactoring:

  hw/virtio/virtio.c:2451:9: error: implicit declaration of function 'target_words_bigendian' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
    if (target_words_bigendian()) {
        ^

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221213111707.34921-2-philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-12-21 07:32:24 -05:00
Markus Armbruster
41462e4106 qapi virtio: Elide redundant has_FOO in generated C
The has_FOO for pointer-valued FOO are redundant, except for arrays.
They are also a nuisance to work with.  Recent commit "qapi: Start to
elide redundant has_FOO in generated C" provided the means to elide
them step by step.  This is the step for qapi/virtio.json.

Said commit explains the transformation in more detail.  The invariant
violations mentioned there do not occur here.

Cc: Laurent Vivier <lvivier@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221104160712.3005652-29-armbru@redhat.com>
2022-12-14 20:05:07 +01:00
Michael S. Tsirkin
b7c61789e6 virtio: disable error for out of spec queue-enable
Virtio 1.0 is pretty clear that features have to be
negotiated before enabling VQs. Unfortunately Seabios
ignored this ever since gaining 1.0 support (UEFI is ok).
Comment the error out for now, and add a TODO.

Fixes: 3c37f8b8d1 ("virtio: introduce virtio_queue_enable()")
Cc: "Kangjie Xu" <kangjie.xu@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20221121200339.362452-1-mst@redhat.com>
2022-11-22 05:19:00 -05:00
Kangjie Xu
3c37f8b8d1 virtio: introduce virtio_queue_enable()
Introduce the interface queue_enable() in VirtioDeviceClass and the
fucntion virtio_queue_enable() in virtio, it can be called when
VIRTIO_PCI_COMMON_Q_ENABLE is written and related virtqueue can be
started. It only supports the devices of virtio 1 or later. The
not-supported devices can only start the virtqueue when DRIVER_OK.

Signed-off-by: Kangjie Xu <kangjie.xu@linux.alibaba.com>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20221017092558.111082-4-xuanzhuo@linux.alibaba.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-11-07 13:12:20 -05:00
Xuan Zhuo
b3a8d6f431 virtio: introduce virtio_queue_reset()
Introduce a new interface function virtio_queue_reset() to implement
reset for vq.

Add a new callback to VirtioDeviceClass for queue reset operation for
each child device.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20221017092558.111082-3-xuanzhuo@linux.alibaba.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-11-07 13:12:19 -05:00
Xuan Zhuo
3b43302c71 virtio: introduce __virtio_queue_reset()
Separate the logic of vq reset. This logic will be called directly
later.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20221017092558.111082-2-xuanzhuo@linux.alibaba.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-11-07 13:12:19 -05:00
Laurent Vivier
1ee7bb5bef qmp: add QMP command x-query-virtio-queue-element
This new command shows the information of a VirtQueue element.

[Note: Up until v10 of this patch series, virtio.json had many (15+)
 enums defined (e.g. decoded device features, statuses, etc.). In v10
 most of these enums were removed and replaced with string literals.
 By doing this we get (1) simpler schema, (2) smaller generated code,
 and (3) less maintenance burden for when new things are added (e.g.
 devices, device features, etc.).]

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <1660220684-24909-6-git-send-email-jonah.palmer@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-10-09 16:38:45 -04:00
Laurent Vivier
07536ddda7 qmp: add QMP commands for virtio/vhost queue-status
These new commands show the internal status of a VirtIODevice's
VirtQueue and a vhost device's vhost_virtqueue (if active).

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <1660220684-24909-5-git-send-email-jonah.palmer@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-10-09 16:38:45 -04:00
Laurent Vivier
f3034ad71f qmp: decode feature & status bits in virtio-status
Display feature names instead of bitmaps for host, guest, and
backend for VirtIODevices.

Display status names instead of bitmaps for VirtIODevices.

Display feature names instead of bitmaps for backend, protocol,
acked, and features (hdev->features) for vhost devices.

Decode features according to device ID. Decode statuses
according to configuration status bitmap (config_status_map).
Decode vhost user protocol features according to vhost user
protocol bitmap (vhost_user_protocol_map).

Transport features are on the first line. Undecoded bits (if
any) are stored in a separate field.

[Jonah: Several changes made to this patch from prev. version (v14):
 - Moved all device features mappings to hw/virtio/virtio.c
 - Renamed device features mappings (less generic)
 - Generalized @FEATURE_ENTRY macro for all device mappings
 - Virtio device feature map definitions include descriptions of
   feature bits
 - Moved @VHOST_USER_F_PROTOCOL_FEATURES feature bit from transport
   feature map to vhost-user-supported device feature mappings
   (blk, fs, i2c, rng, net, gpu, input, scsi, vsock)
 - New feature bit added for virtio-vsock: @VIRTIO_VSOCK_F_SEQPACKET
 - New feature bit added for virtio-iommu: @VIRTIO_IOMMU_F_BYPASS_CONFIG
 - New feature bit added for virtio-mem: @VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE
 - New virtio transport feature bit added: @VIRTIO_F_IN_ORDER
 - Added device feature map definition for virtio-rng
]

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <1660220684-24909-4-git-send-email-jonah.palmer@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-10-09 16:38:45 -04:00
Laurent Vivier
90c066cd68 qmp: add QMP command x-query-virtio-status
This new command shows the status of a VirtIODevice, including
its corresponding vhost device's status (if active).

Next patch will improve output by decoding feature bits, including
vhost device's feature bits (backend, protocol, acked, and features).
Also will decode status bits of a VirtIODevice.

[Jonah: From patch v12; added a check to @virtio_device_find to ensure
 synchronicity between @virtio_list and the devices in the QOM
 composition tree.]

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <1660220684-24909-3-git-send-email-jonah.palmer@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-10-09 16:38:45 -04:00
Laurent Vivier
a5ebce3857 qmp: add QMP command x-query-virtio
This new command lists all the instances of VirtIODevices with
their canonical QOM path and name.

[Jonah: @virtio_list duplicates information that already exists in
 the QOM composition tree. However, extracting necessary information
 from this tree seems to be a bit convoluted.

 Instead, we still create our own list of realized virtio devices
 but use @qmp_qom_get with the device's canonical QOM path to confirm
 that the device exists and is realized. If the device exists but
 is actually not realized, then we remove it from our list (for
 synchronicity to the QOM composition tree).

 Also, the QMP command @x-query-virtio is redundant as @qom-list
 and @qom-get are sufficient to search '/machine/' for realized
 virtio devices. However, @x-query-virtio is much more convenient
 in listing realized virtio devices.]

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <1660220684-24909-2-git-send-email-jonah.palmer@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-10-09 16:38:45 -04:00
Daniil Tatianin
d74c30c811 virtio: introduce VirtIOConfigSizeParams & virtio_get_config_size
This is the first step towards moving all device config size calculation
logic into the virtio core code. In particular, this adds a struct that
contains all the necessary information for common virtio code to be able
to calculate the final config size for a device. This is expected to be
used with the new virtio_get_config_size helper, which calculates the
final length based on the provided host features.

This builds on top of already existing code like VirtIOFeature and
virtio_feature_get_config_size(), but adds additional fields, as well as
sanity checking so that device-specifc code doesn't have to duplicate it.

An example usage would be:

    static const VirtIOFeature dev_features[] = {
        {.flags = 1ULL << FEATURE_1_BIT,
         .end = endof(struct virtio_dev_config, feature_1)},
        {.flags = 1ULL << FEATURE_2_BIT,
         .end = endof(struct virtio_dev_config, feature_2)},
        {}
    };

    static const VirtIOConfigSizeParams dev_cfg_size_params = {
        .min_size = DEV_BASE_CONFIG_SIZE,
        .max_size = sizeof(struct virtio_dev_config),
        .feature_sizes = dev_features
    };

    // code inside my_dev_device_realize()
    size_t config_size = virtio_get_config_size(&dev_cfg_size_params,
                                                host_features);
    virtio_init(vdev, VIRTIO_ID_MYDEV, config_size);

Currently every device is expected to write its own boilerplate from the
example above in device_realize(), however, the next step of this
transition is moving VirtIOConfigSizeParams into VirtioDeviceClass,
so that it can be done automatically by the virtio initialization code.

All of the users of virtio_feature_get_config_size have been converted
to use virtio_get_config_size so it's no longer needed and is removed
with this commit.

Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Message-Id: <20220906073111.353245-2-d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-10-07 09:41:51 -04:00
Alex Bennée
8d11c10d06 hw/virtio: log potentially buggy guest drivers
If the guest driver attempts to use the UNUSED(30) bit it is
potentially buggy as 6.3 Legacy Interface: Reserved Feature Bits
states it "SHOULD NOT be negotiated". For now just log this guest
error.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220802095010.3330793-9-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-10-07 09:41:51 -04:00
Jonah Palmer
c255488d67 virtio: add vhost support for virtio devices
This patch adds a get_vhost() callback function for VirtIODevices that
returns the device's corresponding vhost_dev structure, if the vhost
device is running. This patch also adds a vhost_started flag for
VirtIODevices.

Previously, a VirtIODevice wouldn't be able to tell if its corresponding
vhost device was active or not.

Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <1648819405-25696-3-git-send-email-jonah.palmer@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-05-16 04:38:40 -04:00
Jonah Palmer
3857cd5c7f virtio: drop name parameter for virtio_init()
This patch drops the name parameter for the virtio_init function.

The pair between the numeric device ID and the string device ID
(name) of a virtio device already exists, but not in a way that
lets us map between them.

This patch lets us do this and removes the need for the name
parameter in the virtio_init function.

Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <1648819405-25696-2-git-send-email-jonah.palmer@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-05-16 04:38:40 -04:00
Stefan Hajnoczi
38738f7dbb virtio-scsi: don't waste CPU polling the event virtqueue
The virtio-scsi event virtqueue is not emptied by its handler function.
This is typical for rx virtqueues where the device uses buffers when
some event occurs (e.g. a packet is received, an error condition
happens, etc).

Polling non-empty virtqueues wastes CPU cycles. We are not waiting for
new buffers to become available, we are waiting for an event to occur,
so it's a misuse of CPU resources to poll for buffers.

Introduce the new virtio_queue_aio_attach_host_notifier_no_poll() API,
which is identical to virtio_queue_aio_attach_host_notifier() except
that it does not poll the virtqueue.

Before this patch the following command-line consumed 100% CPU in the
IOThread polling and calling virtio_scsi_handle_event():

  $ qemu-system-x86_64 -M accel=kvm -m 1G -cpu host \
      --object iothread,id=iothread0 \
      --device virtio-scsi-pci,iothread=iothread0 \
      --blockdev file,filename=test.img,aio=native,cache.direct=on,node-name=drive0 \
      --device scsi-hd,drive=drive0

After this patch CPU is no longer wasted.

Reported-by: Nir Soffer <nsoffer@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Nir Soffer <nsoffer@redhat.com>
Message-id: 20220427143541.119567-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-05-09 10:45:04 +01:00
Marc-André Lureau
9edc6313da Replace GCC_FMT_ATTR with G_GNUC_PRINTF
One less qemu-specific macro. It also helps to make some headers/units
only depend on glib, and thus moved in standalone projects eventually.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
2022-03-22 14:40:51 +04:00
Markus Armbruster
b21e238037 Use g_new() & friends where that makes obvious sense
g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
for two reasons.  One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.

This commit only touches allocations with size arguments of the form
sizeof(T).

Patch created mechanically with:

    $ spatch --in-place --sp-file scripts/coccinelle/use-g_new-etc.cocci \
	     --macro-file scripts/cocci-macro-file.h FILES...

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20220315144156.1595462-4-armbru@redhat.com>
Reviewed-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
2022-03-21 15:44:44 +01:00
Peter Maydell
17e3134061 Remove unnecessary minimum_version_id_old fields
The migration code will not look at a VMStateDescription's
minimum_version_id_old field unless that VMSD has set the
load_state_old field to something non-NULL.  (The purpose of
minimum_version_id_old is to specify what migration version is needed
for the code in the function pointed to by load_state_old to be able
to handle it on incoming migration.)

We have exactly one VMSD which still has a load_state_old,
in the PPC CPU; every other VMSD which sets minimum_version_id_old
is doing so unnecessarily. Delete all the unnecessary ones.

Commit created with:
  sed -i '/\.minimum_version_id_old/d' $(git grep -l '\.minimum_version_id_old')
with the one legitimate use then hand-edited back in.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>

Signed-off-by: Juan Quintela <quintela@redhat.com>

---

It missed vmstate_ppc_cpu.
2022-01-28 15:38:23 +01:00
Stefan Hajnoczi
db608fb784 virtio: unify dataplane and non-dataplane ->handle_output()
Now that virtio-blk and virtio-scsi are ready, get rid of
the handle_aio_output() callback. It's no longer needed.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20211207132336.36627-7-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-01-12 17:09:39 +00:00
Stefan Hajnoczi
d6fbfe2b83 virtio: use ->handle_output() instead of ->handle_aio_output()
The difference between ->handle_output() and ->handle_aio_output() was
that ->handle_aio_output() returned a bool return value indicating
progress. This was needed by the old polling API but now that the bool
return value is gone, the two functions can be unified.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20211207132336.36627-6-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-01-12 17:09:39 +00:00
Stefan Hajnoczi
d93d16c045 virtio: get rid of VirtIOHandleAIOOutput
The virtqueue host notifier API
virtio_queue_aio_set_host_notifier_handler() polls the virtqueue for new
buffers. AioContext previously required a bool progress return value
indicating whether an event was handled or not. This is no longer
necessary because the AioContext polling API has been split into a poll
check function and an event handler function. The event handler is only
run when we know there is work to do, so it doesn't return bool.

The VirtIOHandleAIOOutput function signature is now the same as
VirtIOHandleOutput. Get rid of the bool return value.

Further simplifications will be made for virtio-blk and virtio-scsi in
the next patch.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20211207132336.36627-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-01-12 17:09:39 +00:00
Stefan Hajnoczi
826cc32423 aio-posix: split poll check from ready handler
Adaptive polling measures the execution time of the polling check plus
handlers called when a polled event becomes ready. Handlers can take a
significant amount of time, making it look like polling was running for
a long time when in fact the event handler was running for a long time.

For example, on Linux the io_submit(2) syscall invoked when a virtio-blk
device's virtqueue becomes ready can take 10s of microseconds. This
can exceed the default polling interval (32 microseconds) and cause
adaptive polling to stop polling.

By excluding the handler's execution time from the polling check we make
the adaptive polling calculation more accurate. As a result, the event
loop now stays in polling mode where previously it would have fallen
back to file descriptor monitoring.

The following data was collected with virtio-blk num-queues=2
event_idx=off using an IOThread. Before:

168k IOPS, IOThread syscalls:

  9837.115 ( 0.020 ms): IO iothread1/620155 io_submit(ctx_id: 140512552468480, nr: 16, iocbpp: 0x7fcb9f937db0)    = 16
  9837.158 ( 0.002 ms): IO iothread1/620155 write(fd: 103, buf: 0x556a2ef71b88, count: 8)                         = 8
  9837.161 ( 0.001 ms): IO iothread1/620155 write(fd: 104, buf: 0x556a2ef71b88, count: 8)                         = 8
  9837.163 ( 0.001 ms): IO iothread1/620155 ppoll(ufds: 0x7fcb90002800, nfds: 4, tsp: 0x7fcb9f1342d0, sigsetsize: 8) = 3
  9837.164 ( 0.001 ms): IO iothread1/620155 read(fd: 107, buf: 0x7fcb9f939cc0, count: 512)                        = 8
  9837.174 ( 0.001 ms): IO iothread1/620155 read(fd: 105, buf: 0x7fcb9f939cc0, count: 512)                        = 8
  9837.176 ( 0.001 ms): IO iothread1/620155 read(fd: 106, buf: 0x7fcb9f939cc0, count: 512)                        = 8
  9837.209 ( 0.035 ms): IO iothread1/620155 io_submit(ctx_id: 140512552468480, nr: 32, iocbpp: 0x7fca7d0cebe0)    = 32

174k IOPS (+3.6%), IOThread syscalls:

  9809.566 ( 0.036 ms): IO iothread1/623061 io_submit(ctx_id: 140539805028352, nr: 32, iocbpp: 0x7fd0cdd62be0)    = 32
  9809.625 ( 0.001 ms): IO iothread1/623061 write(fd: 103, buf: 0x5647cfba5f58, count: 8)                         = 8
  9809.627 ( 0.002 ms): IO iothread1/623061 write(fd: 104, buf: 0x5647cfba5f58, count: 8)                         = 8
  9809.663 ( 0.036 ms): IO iothread1/623061 io_submit(ctx_id: 140539805028352, nr: 32, iocbpp: 0x7fd0d0388b50)    = 32

Notice that ppoll(2) and eventfd read(2) syscalls are eliminated because
the IOThread stays in polling mode instead of falling back to file
descriptor monitoring.

As usual, polling is not implemented on Windows so this patch ignores
the new io_poll_read() callback in aio-win32.c.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20211207132336.36627-2-stefanha@redhat.com

[Fixed up aio_set_event_notifier() calls in
tests/unit/test-fdmon-epoll.c added after this series was queued.
--Stefan]

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-01-12 17:09:39 +00:00
Michael S. Tsirkin
81c3ebc32f Revert "virtio: add support for configure interrupt"
This reverts commit 081f864f56.

Fixes: 081f864f56 ("virtio: add support for configure interrupt")
Cc: "Cindy Lu" <lulu@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-01-10 16:01:28 -05:00
Stefan Hajnoczi
750539c4c4 virtio: signal after wrapping packed used_idx
Packed Virtqueues wrap used_idx instead of letting it run freely like
Split Virtqueues do. If the used ring wraps more than once there is no
way to compare vq->signalled_used and vq->used_idx in
virtio_packed_should_notify() since they are modulo vq->vring.num.

This causes the device to stop sending used buffer notifications when
when virtio_packed_should_notify() is called less than once each time
around the used ring.

It is possible to trigger this with virtio-blk's dataplane
notify_guest_bh() irq coalescing optimization. The call to
virtio_notify_irqfd() (and virtio_packed_should_notify()) is deferred to
a BH. If the guest driver is polling it can complete and submit more
requests before the BH executes, causing the used ring to wrap more than
once. The result is that the virtio-blk device ceases to raise
interrupts and I/O hangs.

Cc: Tiwei Bie <tiwei.bie@intel.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20211130134510.267382-1-stefanha@redhat.com>
Fixes: 86044b24e8 ("virtio: basic packed virtqueue support")
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-01-07 19:30:13 -05:00
Cindy Lu
081f864f56 virtio: add support for configure interrupt
Add the functions to support the configure interrupt in virtio
The function virtio_config_guest_notifier_read will notify the
guest if there is an configure interrupt.
The function virtio_config_set_guest_notifier_fd_handler is
to set the fd hander for the notifier

Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20211104164827.21911-7-lulu@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-01-06 06:11:39 -05:00
Philippe Mathieu-Daudé
a1d4b0a305 dma: Let dma_memory_map() take MemTxAttrs argument
Let devices specify transaction attributes when calling
dma_memory_map().

Patch created mechanically using spatch with this script:

  @@
  expression E1, E2, E3, E4;
  @@
  - dma_memory_map(E1, E2, E3, E4)
  + dma_memory_map(E1, E2, E3, E4, MEMTXATTRS_UNSPECIFIED)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20211223115554.3155328-7-philmd@redhat.com>
2021-12-30 17:16:32 +01:00
Jason Wang
d152cdd6f6 virtio: use virtio accessor to access packed event
We used to access packed descriptor event and off_wrap via
address_space_{write|read}_cached(). When we hit the cache, memcpy()
is used which is not atomic which may lead a wrong value to be read or
wrote.

This patch fixes this by switching to use
virito_{stw|lduw}_phys_cached() to make sure the access is atomic.

Fixes: 683f766567 ("virtio: event suppression support for packed ring")
Cc: qemu-stable@nongnu.org
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20211111063854.29060-2-jasowang@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-11-15 09:44:46 -05:00
Jason Wang
f463e761a4 virtio: use virtio accessor to access packed descriptor flags
We used to access packed descriptor flags via
address_space_{write|read}_cached(). When we hit the cache, memcpy()
is used which is not an atomic operation which may lead a wrong value
is read or wrote.

So this patch switches to use virito_{stw|lduw}_phys_cached() to make
sure the aceess is atomic.

Fixes: 86044b24e8 ("virtio: basic packed virtqueue support")
Cc: qemu-stable@nongnu.org
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20211111063854.29060-1-jasowang@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-11-15 09:44:46 -05:00
Philippe Mathieu-Daudé
d6ed27bae7 hw/virtio: Have virtqueue_get_avail_bytes() pass caches arg to callees
Both virtqueue_packed_get_avail_bytes() and
virtqueue_split_get_avail_bytes() access the region cache, but
their caller also does. Simplify by having virtqueue_get_avail_bytes
calling both with RCU lock held, and passing the caches as argument.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210906104318.1569967-4-philmd@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2021-10-05 11:19:40 -04:00
Philippe Mathieu-Daudé
ab4dd2746c hw/virtio: Acquire RCU read lock in virtqueue_packed_drop_all()
vring_get_region_caches() must be called with the RCU read lock
acquired. virtqueue_packed_drop_all() does not, and uses the
'caches' pointer. Fix that by using the RCU_READ_LOCK_GUARD()
macro.

Reported-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210906104318.1569967-3-philmd@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2021-10-05 11:19:40 -04:00
Peter Xu
142518bda5 memory: Name all the memory listeners
Provide a name field for all the memory listeners.  It can be used to identify
which memory listener is which.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210817013553.30584-2-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30 15:30:24 +02:00
Philippe Mathieu-Daudé
b116d6c319 hw/virtio: Remove NULL check in virtio_free_region_cache()
virtio_free_region_cache() is called within call_rcu(),
always with a non-NULL argument. Ensure new code keep it
that way by replacing the NULL check by an assertion.
Add a comment this function is called within call_rcu().

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210826172658.2116840-3-philmd@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-09-04 17:34:05 -04:00
Philippe Mathieu-Daudé
7f51beddad hw/virtio: Document virtio_queue_packed_empty_rcu is called within RCU
While virtio_queue_packed_empty_rcu() uses the '_rcu' suffix,
it is not obvious it is called within rcu_read_lock(). All other
functions from this file called with the RCU locked have a comment
describing it. Document this one similarly for consistency.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210826172658.2116840-2-philmd@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2021-09-04 17:34:05 -04:00
Philippe Mathieu-Daudé
4c6dd9a026 hw/virtio: Document *_should_notify() are called within rcu_read_lock()
Such comments make reviewing this file somehow easier.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210523094040.3516968-1-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-07-09 18:42:46 +02:00
Greg Kurz
9cf4fd872d virtio: Clarify MR transaction optimization
The device model batching its ioeventfds in a single MR transaction is
an optimization. Clarify this in virtio-scsi, virtio-blk and generic
virtio code. Also clarify that the transaction must commit before
closing ioeventfds so that no one is tempted to merge the loops
in the start functions error path and in the stop functions.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <162125799728.1394228.339855768563326832.stgit@bahia.lan>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-07-02 11:13:39 -04:00
Philippe Mathieu-Daudé
cdba7e2f49 cpu: Introduce cpu_virtio_is_big_endian()
Introduce the cpu_virtio_is_big_endian() generic helper to avoid
calling CPUClass internal virtio_is_big_endian() one.

Similarly to commit bf7663c4bd ("cpu: introduce
CPUClass::virtio_is_big_endian()"), we keep 'virtio' in the method
name to hint this handler shouldn't be called anywhere but from the
virtio code.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-8-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-05-26 15:33:59 -07:00