linux.git/drivers/virtio, branch v5.15.114

virtio_ring: don't update event idx on get_buf

2023-05-11T14:00:34+00:00

[ Upstream commit 6c0b057cec5eade4c3afec3908821176931a9997 ]

In virtio_net, if we disable napi_tx, when we trigger a tx interrupt,
the vq->event_triggered will be set to true. It is then never reset
until we explicitly call virtqueue_enable_cb_delayed or
virtqueue_enable_cb_prepare.

If we disable the napi_tx, virtqueue_enable_cb* will only be called when
the tx ring is getting relatively empty.

Since event_triggered is true, VRING_AVAIL_F_NO_INTERRUPT or
VRING_PACKED_EVENT_FLAG_DISABLE will not be set. As a result we update
vring_used_event(&vq->split.vring) or vq->packed.vring.driver->off_wrap
every time we call virtqueue_get_buf_ctx. This causes more interrupts.

To summarize:
1) event_triggered was set to true in vring_interrupt()
2) after this nothing will happen in virtqueue_disable_cb() so
   VRING_AVAIL_F_NO_INTERRUPT is not set in avail_flags_shadow
3) virtqueue_get_buf_ctx_split() will still think the cb is enabled
   and then it will publish a new event index

To fix:
update VRING_AVAIL_F_NO_INTERRUPT or VRING_PACKED_EVENT_FLAG_DISABLE in
the vq when we call virtqueue_disable_cb even when event_triggered is
true.

Tested with iperf:
iperf3 tcp stream:
vm1 -----------------> vm2
vm2 just receives tcp data stream from vm1, and sends acks to vm1,
there are many tx interrupts in vm2.
with the patch applied there are just a few tx interrupts.

v2->v3:
-update the interrupt disable flag even with the event_triggered is set,
-instead of checking whether event_triggered is set in
-virtqueue_get_buf_ctx_{packed/split}, will cause the drivers  which have
-not called virtqueue_{enable/disable}_cb to miss notifications.

v3->v4:
-remove change for
-"if (vq->packed.event_flags_shadow != VRING_PACKED_EVENT_FLAG_DISABLE)"
-in virtqueue_disable_cb_packed

Fixes: 8d622d21d248 ("virtio: fix up virtio_disable_cb")
Signed-off-by: Albert Huang 
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Jason Wang 
Message-Id: <20230329102300.61000-1-huangjie.albert@bytedance.com>
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Sasha Levin

virtio_pci: modify ENOENT to EINVAL

2023-01-24T06:22:41+00:00

[ Upstream commit b66ead2d0ecac00c3a06a6218af5411cb5fcb5d5 ]

Virtio_crypto use max_data_queues+1 to setup vqs,
we use vp_modern_get_num_queues to protect the vq range in setup_vq.
We could enter index >= vp_modern_get_num_queues(mdev) in setup_vq
if common->num_queues is not set well,and it return -ENOENT.
It is better to use -EINVAL instead.

Signed-off-by: Angus Chen 
Message-Id: <20221101111655.1947-1-angus.chen@jaguarmicro.com>
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Sasha Levin

virtio_mmio: Restore guest page size on resume

2022-07-21T19:24:33+00:00

[ Upstream commit e0c2ce8217955537dd5434baeba061f209797119 ]

Virtio devices might lose their state when the VMM is restarted
after a suspend to disk (hibernation) cycle. This means that the
guest page size register must be restored for the virtio_mmio legacy
interface, since otherwise the virtio queues are not functional.

This is particularly problematic for QEMU that currently still defaults
to using the legacy interface for virtio_mmio. Write the guest page
size register again in virtio_mmio_restore() to make legacy virtio_mmio
devices work correctly after hibernation.

Signed-off-by: Stephan Gerhold 
Message-Id: <20220621110621.3638025-3-stephan.gerhold@kernkonzept.com>
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Sasha Levin

virtio_mmio: Add missing PM calls to freeze/restore

2022-07-21T19:24:33+00:00

[ Upstream commit ed7ac37fde33ccd84e4bd2b9363c191f925364c7 ]

Most virtio drivers provide freeze/restore callbacks to finish up
device usage before suspend and to reinitialize the virtio device after
resume. However, these callbacks are currently only called when using
virtio_pci. virtio_mmio does not have any PM ops defined.

This causes problems for example after suspend to disk (hibernation),
since the virtio devices might lose their state after the VMM is
restarted. Calling virtio_device_freeze()/restore() ensures that
the virtio devices are re-initialized correctly.

Fix this by implementing the dev_pm_ops for virtio_mmio,
similar to virtio_pci_common.

Signed-off-by: Stephan Gerhold 
Message-Id: <20220621110621.3638025-2-stephan.gerhold@kernkonzept.com>
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Sasha Levin

virtio-pci: Remove wrong address verification in vp_del_vqs()

2022-06-22T12:22:05+00:00

commit 7e415282b41bf0d15c6e0fe268f822d9b083f2f7 upstream.

GCC 12 enhanced -Waddress when comparing array address to null [0],
which warns:

    drivers/virtio/virtio_pci_common.c: In function ‘vp_del_vqs’:
    drivers/virtio/virtio_pci_common.c:257:29: warning: the comparison will always evaluate as ‘true’ for the pointer operand in ‘vp_dev->msix_affinity_masks + (sizetype)((long unsigned int)i * 256)’ must not be NULL [-Waddress]
      257 |                         if (vp_dev->msix_affinity_masks[i])
          |                             ^~~~~~

In fact, the verification is comparing the result of a pointer
arithmetic, the address "msix_affinity_masks + i", which will always
evaluate to true.

Under the hood, free_cpumask_var() calls kfree(), which is safe to pass
NULL, not requiring non-null verification.  So remove the verification
to make compiler happy (happy compiler, happy life).

[0] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102103

Signed-off-by: Murilo Opsfelder Araujo 
Message-Id: <20220415023002.49805-1-muriloo@linux.ibm.com>
Signed-off-by: Michael S. Tsirkin 
Acked-by: Christophe de Dinechin 
Cc: Sudip Mukherjee 
Signed-off-by: Greg Kroah-Hartman

virtio-mmio: fix missing put_device() when vm_cmdline_parent registration failed

2022-06-22T12:21:58+00:00

[ Upstream commit a58a7f97ba11391d2d0d408e0b24f38d86ae748e ]

The reference must be released when device_register(&vm_cmdline_parent)
failed. Add the corresponding 'put_device()' in the error handling path.

Signed-off-by: chengkaitao 
Message-Id: <20220602005542.16489-1-chengkaitao@didiglobal.com>
Signed-off-by: Michael S. Tsirkin 
Acked-by: Jason Wang 
Signed-off-by: Sasha Levin

virtio: pci: Fix an error handling path in vp_modern_probe()

2022-06-14T16:36:12+00:00

[ Upstream commit 7a836a2aba09479c8e71fa43249eecc4af945f61 ]

If an error occurs after a successful pci_request_selected_regions() call,
it should be undone by a corresponding pci_release_selected_regions() call,
as already done in vp_modern_remove().

Fixes: fd502729fbbf ("virtio-pci: introduce modern device module")
Signed-off-by: Christophe JAILLET 
Message-Id: <237109725aad2c3c03d14549f777b1927c84b045.1648977064.git.christophe.jaillet@wanadoo.fr>
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Sasha Levin

virtio: acknowledge all features before access

2022-03-16T13:23:43+00:00

commit 4fa59ede95195f267101a1b8916992cf3f245cdb upstream.

The feature negotiation was designed in a way that
makes it possible for devices to know which config
fields will be accessed by drivers.

This is broken since commit 404123c2db79 ("virtio: allow drivers to
validate features") with fallout in at least block and net.  We have a
partial work-around in commit 2f9a174f918e ("virtio: write back
F_VERSION_1 before validate") which at least lets devices find out which
format should config space have, but this is a partial fix: guests
should not access config space without acknowledging features since
otherwise we'll never be able to change the config space format.

To fix, split finalize_features from virtio_finalize_features and
call finalize_features with all feature bits before validation,
and then - if validation changed any bits - once again after.

Since virtio_finalize_features no longer writes out features
rename it to virtio_features_ok - since that is what it does:
checks that features are ok with the device.

As a side effect, this also reduces the amount of hypervisor accesses -
we now only acknowledge features once unless we are clearing any
features when validating (which is uncommon).

IRC I think that this was more or less always the intent in the spec but
unfortunately the way the spec is worded does not say this explicitly, I
plan to address this at the spec level, too.

Acked-by: Jason Wang 
Cc: stable@vger.kernel.org
Fixes: 404123c2db79 ("virtio: allow drivers to validate features")
Fixes: 2f9a174f918e ("virtio: write back F_VERSION_1 before validate")
Cc: "Halil Pasic" 
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Greg Kroah-Hartman

virtio: unexport virtio_finalize_features

2022-03-16T13:23:43+00:00

commit 838d6d3461db0fdbf33fc5f8a69c27b50b4a46da upstream.

virtio_finalize_features is only used internally within virtio.
No reason to export it.

Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Cornelia Huck 
Acked-by: Jason Wang 
Signed-off-by: Greg Kroah-Hartman

virtio_ring: mark ring unused on error

2022-01-27T10:05:35+00:00

commit 1861ba626ae9b98136f3e504208cdef6b29cd3ec upstream.

A recently added error path does not mark ring unused when exiting on
OOM, which will lead to BUG on the next entry in debug builds.

TODO: refactor code so we have START_USE and END_USE in the same function.

Fixes: fc6d70f40b3d ("virtio_ring: check desc == NULL when using indirect with packed")
Cc: "Xuan Zhuo" 
Cc: Jiasheng Jiang 
Reviewed-by: Xuan Zhuo 
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Greg Kroah-Hartman