virtio: create admin queues alongside other virtqueues

Admin virtqueue is just another virtqueue nothing that special about it.
The current implementation treats it somehow separate though in terms

virtio: create admin queues alongside other virtqueues

Admin virtqueue is just another virtqueue nothing that special about it.
The current implementation treats it somehow separate though in terms
of creation and deletion. Unify the admin virtqueue creation and
deletion flows to be aligned with the rest of virtqueues, creating
it from vp_find_vqs_*() helpers. Let the admin virtqueue to be deleted
by vp_del_vqs() as the rest.

Call vp_find_one_vq_msix() with slow_path argument being "true" to make
sure that in case of limited interrupt vectors the config vector is used
for admin queue.

Signed-off-by: Jiri Pirko <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio: rename virtio_find_vqs_info() to virtio_find_vqs()

Since the original virtio_find_vqs() is no longer present, rename
virtio_find_vqs_info() back to virtio_find_vqs().

Signed-off-by: Jiri Pi

virtio: rename virtio_find_vqs_info() to virtio_find_vqs()

Since the original virtio_find_vqs() is no longer present, rename
virtio_find_vqs_info() back to virtio_find_vqs().

Signed-off-by: Jiri Pirko <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio: remove unused virtio_find_vqs() and virtio_find_vqs_ctx() helpers

All callers of virtio_find_vqs() and virtio_find_vqs_ctx() were
converted to use virtio_find_vqs_info(). Remove no longer us

virtio: remove unused virtio_find_vqs() and virtio_find_vqs_ctx() helpers

All callers of virtio_find_vqs() and virtio_find_vqs_ctx() were
converted to use virtio_find_vqs_info(). Remove no longer used helpers.

Signed-off-by: Jiri Pirko <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio: rename find_vqs_info() op to find_vqs()

Since the original find_vqs() is no longer present, rename
find_vqs_info() back to find_vqs().

Signed-off-by: Jiri Pirko <[email protected]>
Message-Id

virtio: rename find_vqs_info() op to find_vqs()

Since the original find_vqs() is no longer present, rename
find_vqs_info() back to find_vqs().

Signed-off-by: Jiri Pirko <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio: remove the original find_vqs() op

As it is no longer used, remove it.

Signed-off-by: Jiri Pirko <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Mich

virtio: remove the original find_vqs() op

As it is no longer used, remove it.

Signed-off-by: Jiri Pirko <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio: call virtio_find_vqs_info() from virtio_find_single_vq() directly

Since there are no more implementations of find_vqs() op, call
virtio_find_vqs_info() from virtio_find_single_vq() directly.

virtio: call virtio_find_vqs_info() from virtio_find_single_vq() directly

Since there are no more implementations of find_vqs() op, call
virtio_find_vqs_info() from virtio_find_single_vq() directly.

Signed-off-by: Jiri Pirko <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio: introduce virtio_queue_info struct and find_vqs_info() config op

Introduce a structure virtio_queue_info to carry name, callback and ctx
together. In order to allow config implementations to

virtio: introduce virtio_queue_info struct and find_vqs_info() config op

Introduce a structure virtio_queue_info to carry name, callback and ctx
together. In order to allow config implementations to accept config op
with array of virtio_queue_info structures, introduce a new
find_vqs_info() op. Do the needed conversion in virtio_find_vqs_ctx().
Note that whole virtio_find_vqs_ctx() is going to be eventually removed
at the and of this patchset.

Suggested-by: Xuan Zhuo <[email protected]>
Signed-off-by: Jiri Pirko <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio: make virtio_find_single_vq() call virtio_find_vqs()

In order to prepare for conversion of virtio_find_vqs*() arguments, make
virtio_find_single_vq() to call virtio_find_vqs() instead of
op d

virtio: make virtio_find_single_vq() call virtio_find_vqs()

In order to prepare for conversion of virtio_find_vqs*() arguments, make
virtio_find_single_vq() to call virtio_find_vqs() instead of
op directly.

Signed-off-by: Jiri Pirko <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio: make virtio_find_vqs() call virtio_find_vqs_ctx()

In order to prepare for conversion of virtio_find_vqs*() arguments, make
virtio_find_vqs() to call virtio_find_vqs_ctx() instead of op direc

virtio: make virtio_find_vqs() call virtio_find_vqs_ctx()

In order to prepare for conversion of virtio_find_vqs*() arguments, make
virtio_find_vqs() to call virtio_find_vqs_ctx() instead of op directly.

Signed-off-by: Jiri Pirko <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio-pci: Introduce admin virtqueue

Introduce support for the admin virtqueue. By negotiating
VIRTIO_F_ADMIN_VQ feature, driver detects capability and creates one
administration virtqueue. Adminis

virtio-pci: Introduce admin virtqueue

Introduce support for the admin virtqueue. By negotiating
VIRTIO_F_ADMIN_VQ feature, driver detects capability and creates one
administration virtqueue. Administration virtqueue implementation in
virtio pci generic layer, enables multiple types of upper layer
drivers such as vfio, net, blk to utilize it.

Signed-off-by: Feng Liu <[email protected]>
Reviewed-by: Parav Pandit <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Yishai Hadas <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alex Williamson <[email protected]>

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docs: driver-api: virtio: virtio on Linux

Basic doc about Virtio on Linux and a short tutorial on Virtio drivers.

includes the following fixup:

virtio: fix virtio_config_ops kerneldocs

Fixes two

docs: driver-api: virtio: virtio on Linux

Basic doc about Virtio on Linux and a short tutorial on Virtio drivers.

includes the following fixup:

virtio: fix virtio_config_ops kerneldocs

Fixes two warning messages when building htmldocs:

warning: duplicate section name 'Note'
warning: expecting prototype for virtio_config_ops().
Prototype was for vq_callback_t() instead

Message-Id: <[email protected]>
Signed-off-by: Ricardo Cañuelo <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
Message-Id: <[email protected]>
Reported-by: Stephen Rothwell <[email protected]>
Reviewed-by: Bagas Sanjaya <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio: kerneldocs fixes and enhancements

Fix variable names in some kerneldocs, naming in others.
Add kerneldocs for struct vring_desc and vring_interrupt.

Signed-off-by: Ricardo Cañuelo <ricardo.

virtio: kerneldocs fixes and enhancements

Fix variable names in some kerneldocs, naming in others.
Add kerneldocs for struct vring_desc and vring_interrupt.

Signed-off-by: Ricardo Cañuelo <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>

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virtio: Revert "virtio: find_vqs() add arg sizes"

This reverts commit a10fba0377145fccefea4dc4dd5915b7ed87e546: the
proposed API isn't supported on all transports but no
effort was made to address t

virtio: Revert "virtio: find_vqs() add arg sizes"

This reverts commit a10fba0377145fccefea4dc4dd5915b7ed87e546: the
proposed API isn't supported on all transports but no
effort was made to address this.

It might not be hard to fix if we want to: maybe just
rename size to size_hint and make sure legacy
transports ignore the hint.

But it's not sure what the benefit is in any case, so
let's drop it.

Fixes: a10fba037714 ("virtio: find_vqs() add arg sizes")
Signed-off-by: Michael S. Tsirkin <[email protected]>
Message-Id: <[email protected]>

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virtio: Revert "virtio: add helper virtio_find_vqs_ctx_size()"

This reverts commit fe3dc04e31aa51f91dc7f741a5f76cc4817eb5b4: the
API is now unused and in fact can't be implemented on top of a legacy

virtio: Revert "virtio: add helper virtio_find_vqs_ctx_size()"

This reverts commit fe3dc04e31aa51f91dc7f741a5f76cc4817eb5b4: the
API is now unused and in fact can't be implemented on top of a legacy
device.

Fixes: fe3dc04e31aa ("virtio: add helper virtio_find_vqs_ctx_size()")
Cc: "Xuan Zhuo" <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Message-Id: <[email protected]>

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virtio: add helper virtio_find_vqs_ctx_size()

Introduce helper virtio_find_vqs_ctx_size() to call find_vqs and specify
the maximum size of each vq ring.

Signed-off-by: Xuan Zhuo <[email protected]

virtio: add helper virtio_find_vqs_ctx_size()

Introduce helper virtio_find_vqs_ctx_size() to call find_vqs and specify
the maximum size of each vq ring.

Signed-off-by: Xuan Zhuo <[email protected]>
Acked-by: Jason Wang <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio: find_vqs() add arg sizes

find_vqs() adds a new parameter sizes to specify the size of each vq
vring.

NULL as sizes means that all queues in find_vqs() use the maximum size.
A value in the a

virtio: find_vqs() add arg sizes

find_vqs() adds a new parameter sizes to specify the size of each vq
vring.

NULL as sizes means that all queues in find_vqs() use the maximum size.
A value in the array is 0, which means that the corresponding queue uses
the maximum size.

In the split scenario, the meaning of size is the largest size, because
it may be limited by memory, the virtio core will try a smaller size.
And the size is power of 2.

Signed-off-by: Xuan Zhuo <[email protected]>
Acked-by: Hans de Goede <[email protected]>
Reviewed-by: Mathieu Poirier <[email protected]>
Acked-by: Jason Wang <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio: struct virtio_config_ops add callbacks for queue_reset

reset can be divided into the following four steps (example):
1. transport: notify the device to reset the queue
2. vring: recycl

virtio: struct virtio_config_ops add callbacks for queue_reset

reset can be divided into the following four steps (example):
1. transport: notify the device to reset the queue
2. vring: recycle the buffer submitted
3. vring: reset/resize the vring (may re-alloc)
4. transport: mmap vring to device, and enable the queue

In order to support queue reset, add two callbacks in struct
virtio_config_ops to implement steps 1 and 4.

Signed-off-by: Xuan Zhuo <[email protected]>
Acked-by: Jason Wang <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio: disable notification hardening by default

We try to harden virtio device notifications in 8b4ec69d7e09 ("virtio:
harden vring IRQ"). It works with the assumption that the driver or
core can

virtio: disable notification hardening by default

We try to harden virtio device notifications in 8b4ec69d7e09 ("virtio:
harden vring IRQ"). It works with the assumption that the driver or
core can properly call virtio_device_ready() at the right
place. Unfortunately, this seems to be not true and uncover various
bugs of the existing drivers, mainly the issue of using
virtio_device_ready() incorrectly.

So let's add a Kconfig option and disable it by default. It gives
us time to fix the drivers and then we can consider re-enabling it.

Signed-off-by: Jason Wang <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>

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virtio: replace arch_has_restricted_virtio_memory_access()

Instead of using arch_has_restricted_virtio_memory_access() together
with CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, replace those
wi

virtio: replace arch_has_restricted_virtio_memory_access()

Instead of using arch_has_restricted_virtio_memory_access() together
with CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, replace those
with platform_has() and a new platform feature
PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS.

Signed-off-by: Juergen Gross <[email protected]>
Reviewed-by: Oleksandr Tyshchenko <[email protected]>
Tested-by: Oleksandr Tyshchenko <[email protected]> # Arm64 only
Reviewed-by: Christoph Hellwig <[email protected]>
Acked-by: Borislav Petkov <[email protected]>

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virtio: use WARN_ON() to warning illegal status value

We used to use BUG_ON() in virtio_device_ready() to detect illegal
status value, this seems sub-optimal since the value is under the
control of

virtio: use WARN_ON() to warning illegal status value

We used to use BUG_ON() in virtio_device_ready() to detect illegal
status value, this seems sub-optimal since the value is under the
control of the device. Switch to use WARN_ON() instead.

Cc: Thomas Gleixner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Halil Pasic <[email protected]>
Cc: Cornelia Huck <[email protected]>
Cc: Vineeth Vijayan <[email protected]>
Cc: Peter Oberparleiter <[email protected]>
Cc: [email protected]
Signed-off-by: Jason Wang <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Xuan Zhuo <[email protected]>

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virtio: harden vring IRQ

This is a rework on the previous IRQ hardening that is done for
virtio-pci where several drawbacks were found and were reverted:

1) try to use IRQF_NO_AUTOEN which is not f

virtio: harden vring IRQ

This is a rework on the previous IRQ hardening that is done for
virtio-pci where several drawbacks were found and were reverted:

1) try to use IRQF_NO_AUTOEN which is not friendly to affinity managed IRQ
that is used by some device such as virtio-blk
2) done only for PCI transport

The vq->broken is re-used in this patch for implementing the IRQ
hardening. The vq->broken is set to true during both initialization
and reset. And the vq->broken is set to false in
virtio_device_ready(). Then vring_interrupt() can check and return
when vq->broken is true. And in this case, switch to return IRQ_NONE
to let the interrupt core aware of such invalid interrupt to prevent
IRQ storm.

The reason of using a per queue variable instead of a per device one
is that we may need it for per queue reset hardening in the future.

Note that the hardening is only done for vring interrupt since the
config interrupt hardening is already done in commit 22b7050a024d7
("virtio: defer config changed notifications"). But the method that is
used by config interrupt can't be reused by the vring interrupt
handler because it uses spinlock to do the synchronization which is
expensive.

Cc: Thomas Gleixner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Halil Pasic <[email protected]>
Cc: Cornelia Huck <[email protected]>
Cc: Vineeth Vijayan <[email protected]>
Cc: Peter Oberparleiter <[email protected]>
Cc: [email protected]
Signed-off-by: Jason Wang <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Xuan Zhuo <[email protected]>

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virtio: introduce config op to synchronize vring callbacks

This patch introduces new virtio config op to vring
callbacks. Transport specific method is required to make sure the
write before this fun

virtio: introduce config op to synchronize vring callbacks

This patch introduces new virtio config op to vring
callbacks. Transport specific method is required to make sure the
write before this function is visible to the vring_interrupt() that is
called after the return of this function. For the transport that
doesn't provide synchronize_vqs(), use synchornize_rcu() which
synchronize with IRQ implicitly as a fallback.

Cc: Thomas Gleixner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Marc Zyngier <[email protected]>
Cc: Halil Pasic <[email protected]>
Cc: Cornelia Huck <[email protected]>
Cc: Vineeth Vijayan <[email protected]>
Cc: Peter Oberparleiter <[email protected]>
Cc: [email protected]
Reviewed-by: Cornelia Huck <[email protected]>
Signed-off-by: Jason Wang <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Xuan Zhuo <[email protected]>
Reviewed-by: Stefano Garzarella <[email protected]>

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Revert "virtio_config: introduce a new .enable_cbs method"

This reverts commit d50497eb4e554e1f0351e1836ee7241c059592e6.

The new callback ended up not being used, and it's asymmetrical:
just enable

Revert "virtio_config: introduce a new .enable_cbs method"

This reverts commit d50497eb4e554e1f0351e1836ee7241c059592e6.

The new callback ended up not being used, and it's asymmetrical:
just enable, no disable.

Signed-off-by: Michael S. Tsirkin <[email protected]>
Acked-by: Jason Wang <[email protected]>

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virtio: acknowledge all features before access

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 brok

virtio: acknowledge all features before access

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 <[email protected]>
Cc: [email protected]
Fixes: 404123c2db79 ("virtio: allow drivers to validate features")
Fixes: 2f9a174f918e ("virtio: write back F_VERSION_1 before validate")
Cc: "Halil Pasic" <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>

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virtio_config: introduce a new .enable_cbs method

This patch introduces a new method to enable the callbacks for config
and virtqueues. This will be used for making sure the virtqueue
callbacks are

virtio_config: introduce a new .enable_cbs method

This patch introduces a new method to enable the callbacks for config
and virtqueues. This will be used for making sure the virtqueue
callbacks are only enabled after virtio_device_ready() if transport
implements this method.

Signed-off-by: Jason Wang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michael S. Tsirkin <[email protected]>

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