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2025-11-27virtio: clean up features qword/dword termsMichael S. Tsirkin
virtio pci uses word to mean "16 bits". mmio uses it to mean "32 bits". To avoid confusion, let's avoid the term in core virtio altogether. Just say U64 to mean "64 bit". Fixes: e7d4c1c5a546 ("virtio: introduce extended features") Cc: Paolo Abeni <pabeni@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-ID: <ad53b7b6be87fc524f45abaeca0bb05fb3633397.1764225384.git.mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-11-27virtio: fix map ops commentMichael S. Tsirkin
@free will free the map handle not sync it. Fix the doc to match. Fixes: bee8c7c24b73 ("virtio: introduce map ops in virtio core") Message-Id: <f6ff1c7aff8401900bf362007d7fb52dfdb6a15b.1763026134.git.mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-11-27virtio: fix virtqueue_set_affinity() docsMichael S. Tsirkin
Rewrite the comment for better grammar and clarity. Fixes: 75a0a52be3c2 ("virtio: introduce an API to set affinity for a virtqueue") Message-Id: <e317e91bd43b070e5eaec0ebbe60c5749d02e2dd.1763026134.git.mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-11-27virtio: standardize Returns documentation styleMichael S. Tsirkin
Remove colons after "Returns" in virtio_map_ops function documentation - both to avoid triggering an htmldoc warning and for consistency with virtio_config_ops. This affects map_page, alloc, need_sync, and max_mapping_size. Fixes: bee8c7c24b73 ("virtio: introduce map ops in virtio core") Message-Id: <c262893fa21f4b1265147ef864574a9bd173348f.1763026134.git.mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-11-27virtio: fix grammar in virtio_map_ops docsMichael S. Tsirkin
Fix grammar issues in the virtio_map_ops docs: - missing article before "transport" - "implements" -> "implement" to match subject Fixes: bee8c7c24b73 ("virtio: introduce map ops in virtio core") Message-Id: <3f7bcae5a984f14b72e67e82572b110acb06fa7e.1763026134.git.mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-11-27virtio: fix grammar in virtio_queue_info docsMichael S. Tsirkin
Fix grammar in the description of @ctx Fixes: c502eb85c34e ("virtio: introduce virtio_queue_info struct and find_vqs_info() config op") Message-Id: <a5cf2b92573200bdb1c1927e559d3930d61a4af2.1763026134.git.mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-11-27virtio: fix whitespace in virtio_config_opsMichael S. Tsirkin
The finalize_features documentation uses a tab between words. Use space instead. Fixes: d16c0cd27331 ("docs: driver-api: virtio: virtio on Linux") Message-Id: <39d7685c82848dc6a876d175e33a1407f6ab3fc1.1763026134.git.mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-11-27virtio: fix typo in virtio_device_ready() commentMichael S. Tsirkin
"coherenct" -> "coherent" Fixes: 8b4ec69d7e09 ("virtio: harden vring IRQ") Message-Id: <db286e9a65449347f6584e68c9960fd5ded2b4b0.1763026134.git.mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-10-01virtio: introduce map ops in virtio coreJason Wang
This patch introduces map operations for virtio device. Virtio used to use DMA API which is not necessarily the case since some devices doesn't do DMA. Instead of using tricks and abusing DMA API, let's simply abstract the current mapping logic into a virtio specific mapping operations. For the device or transport that doesn't do DMA, they can implement their own mapping logic without the need to trick DMA core. In this case the mapping metadata is opaque to the virtio core that will be passed back to the transport or device specific map operations. For other devices, DMA API will still be used, so map token will still be the dma device to minimize the changeset and performance impact. The mapping operations are abstracted as a independent structure instead of reusing virtio_config_ops. This allows the transport can simply reuse the structure for lower layers like vDPA. A set of new mapping helpers were introduced for the device that want to do mapping by themselves. Signed-off-by: Jason Wang <jasowang@redhat.com> Message-Id: <20250821064641.5025-7-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Lei Yang <leiyang@redhat.com> Reviewed-by: Eugenio Pérez <eperezma@redhat.com>
2025-09-21virtio_config: clarify output parametersAlyssa Ross
This was ambiguous enough for a broken patch (206cc44588f7 ("virtio: reject shm region if length is zero")) to make it into the kernel, so make it clearer. Link: https://lore.kernel.org/r/20250816071600-mutt-send-email-mst@kernel.org/ Signed-off-by: Alyssa Ross <hi@alyssa.is> Message-Id: <20250829150944.233505-1-hi@alyssa.is> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-08-26Revert "virtio: reject shm region if length is zero"Igor Torrente
The commit 206cc44588f7 ("virtio: reject shm region if length is zero") breaks the Virtio-gpu `host_visible` feature. As you can see in the snippet below, host_visible_region is zero because of the `kzalloc`. It's using the `vm_get_shm_region` (drivers/virtio/virtio_mmio.c:536) to read the `addr` and `len` from qemu/crosvm. ``` drivers/gpu/drm/virtio/virtgpu_kms.c 132 vgdev = drmm_kzalloc(dev, sizeof(struct virtio_gpu_device), GFP_KERNEL); [...] 177 if (virtio_get_shm_region(vgdev->vdev, &vgdev->host_visible_region, 178 VIRTIO_GPU_SHM_ID_HOST_VISIBLE)) { ``` Now it always fails. To fix, revert the offending commit. Fixes: 206cc44588f7 ("virtio: reject shm region if length is zero") Signed-off-by: Igor Torrente <igor.torrente@collabora.com> Message-Id: <20250807124145.81816-1-igor.torrente@collabora.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2025-07-08virtio: introduce extended featuresPaolo Abeni
The virtio specifications allows for up to 128 bits for the device features. Soon we are going to use some of the 'extended' bits features (above 64) for the virtio_net driver. Introduce extended features as a fixed size array of u64. To minimize the diffstat allows legacy driver to access the low 64 bits via a transparent union. Introduce an extended get_extended_features configuration callback that devices supporting the extended features range must implement in place of the traditional one. Note that legacy and transport features don't need any change, as they are always in the low 64 bit range. Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-05-28virtio: reject shm region if length is zeroSami Uddin
Prevent usage of shared memory regions where the length is zero, as such configurations are not valid and may lead to unexpected behavior. Signed-off-by: Sami Uddin <sami.md.ko@gmail.com> Message-Id: <20250511222153.2332-1-sami.md.ko@gmail.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-07-17virtio: create admin queues alongside other virtqueuesJiri Pirko
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 <jiri@nvidia.com> Message-Id: <20240716113552.80599-10-jiri@resnulli.us> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-07-17virtio: rename virtio_find_vqs_info() to virtio_find_vqs()Jiri Pirko
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 <jiri@nvidia.com> Message-Id: <20240708074814.1739223-20-jiri@resnulli.us> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-07-17virtio: remove unused virtio_find_vqs() and virtio_find_vqs_ctx() helpersJiri Pirko
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 <jiri@nvidia.com> Message-Id: <20240708074814.1739223-19-jiri@resnulli.us> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-07-17virtio: rename find_vqs_info() op to find_vqs()Jiri Pirko
Since the original find_vqs() is no longer present, rename find_vqs_info() back to find_vqs(). Signed-off-by: Jiri Pirko <jiri@nvidia.com> Message-Id: <20240708074814.1739223-10-jiri@resnulli.us> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-07-17virtio: remove the original find_vqs() opJiri Pirko
As it is no longer used, remove it. Signed-off-by: Jiri Pirko <jiri@nvidia.com> Message-Id: <20240708074814.1739223-9-jiri@resnulli.us> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-07-17virtio: call virtio_find_vqs_info() from virtio_find_single_vq() directlyJiri Pirko
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 <jiri@nvidia.com> Message-Id: <20240708074814.1739223-8-jiri@resnulli.us> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-07-17virtio: introduce virtio_queue_info struct and find_vqs_info() config opJiri Pirko
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 <xuanzhuo@linux.alibaba.com> Signed-off-by: Jiri Pirko <jiri@nvidia.com> Message-Id: <20240708074814.1739223-5-jiri@resnulli.us> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-07-17virtio: make virtio_find_single_vq() call virtio_find_vqs()Jiri Pirko
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 <jiri@nvidia.com> Message-Id: <20240708074814.1739223-4-jiri@resnulli.us> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-07-17virtio: make virtio_find_vqs() call virtio_find_vqs_ctx()Jiri Pirko
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 <jiri@nvidia.com> Message-Id: <20240708074814.1739223-3-jiri@resnulli.us> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2023-12-19virtio-pci: Introduce admin virtqueueFeng Liu
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 <feliu@nvidia.com> Reviewed-by: Parav Pandit <parav@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Link: https://lore.kernel.org/r/20231219093247.170936-3-yishaih@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-02-15docs: driver-api: virtio: virtio on LinuxRicardo Cañuelo
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: <20221010064359.1324353-2-ricardo.canuelo@collabora.com> Signed-off-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Message-Id: <20221220100035.2712449-1-ricardo.canuelo@collabora.com> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-16virtio: kerneldocs fixes and enhancementsRicardo Cañuelo
Fix variable names in some kerneldocs, naming in others. Add kerneldocs for struct vring_desc and vring_interrupt. Signed-off-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com> Message-Id: <20220810094004.1250-2-ricardo.canuelo@collabora.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
2022-08-16virtio: Revert "virtio: find_vqs() add arg sizes"Michael S. Tsirkin
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 <mst@redhat.com> Message-Id: <20220816053602.173815-8-mst@redhat.com>
2022-08-16virtio: Revert "virtio: add helper virtio_find_vqs_ctx_size()"Michael S. Tsirkin
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" <xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-Id: <20220816053602.173815-3-mst@redhat.com>
2022-08-11virtio: add helper virtio_find_vqs_ctx_size()Xuan Zhuo
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 <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220801063902.129329-37-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11virtio: find_vqs() add arg sizesXuan Zhuo
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 <xuanzhuo@linux.alibaba.com> Acked-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220801063902.129329-34-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-08-11virtio: struct virtio_config_ops add callbacks for queue_resetXuan Zhuo
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 <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220801063902.129329-3-xuanzhuo@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-06-24virtio: disable notification hardening by defaultJason Wang
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 <jasowang@redhat.com> Message-Id: <20220622012940.21441-1-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
2022-06-06virtio: replace arch_has_restricted_virtio_memory_access()Juergen Gross
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 <jgross@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 only Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Borislav Petkov <bp@suse.de>
2022-05-31virtio: use WARN_ON() to warning illegal status valueJason Wang
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 <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Halil Pasic <pasic@linux.ibm.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: Vineeth Vijayan <vneethv@linux.ibm.com> Cc: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: linux-s390@vger.kernel.org Signed-off-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220527060120.20964-10-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
2022-05-31virtio: harden vring IRQJason Wang
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 <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Halil Pasic <pasic@linux.ibm.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: Vineeth Vijayan <vneethv@linux.ibm.com> Cc: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: linux-s390@vger.kernel.org Signed-off-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220527060120.20964-9-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
2022-05-31virtio: introduce config op to synchronize vring callbacksJason Wang
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 <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Halil Pasic <pasic@linux.ibm.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: Vineeth Vijayan <vneethv@linux.ibm.com> Cc: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: linux-s390@vger.kernel.org Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Message-Id: <20220527060120.20964-4-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2022-03-30Revert "virtio_config: introduce a new .enable_cbs method"Michael S. Tsirkin
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 <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2022-03-04virtio: acknowledge all features before accessMichael S. Tsirkin
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 <jasowang@redhat.com> 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" <pasic@linux.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-11-01virtio_config: introduce a new .enable_cbs methodJason Wang
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 <jasowang@redhat.com> Link: https://lore.kernel.org/r/20211019070152.8236-4-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-10-23Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds
Pull virtio updates from Michael Tsirkin: "vhost, vdpa, and virtio cleanups and fixes A very quiet cycle, no new features" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: MAINTAINERS: add URL for virtio-mem vhost_vdpa: remove unnecessary spin_lock in vhost_vring_call vringh: fix __vringh_iov() when riov and wiov are different vdpa/mlx5: Setup driver only if VIRTIO_CONFIG_S_DRIVER_OK s390: virtio: PV needs VIRTIO I/O device protection virtio: let arch advertise guest's memory access restrictions vhost_vdpa: Fix duplicate included kernel.h vhost: reduce stack usage in log_used virtio-mem: Constify mem_id_table virtio_input: Constify id_table virtio-balloon: Constify id_table vdpa/mlx5: Fix failure to bring link up vdpa/mlx5: Make use of a specific 16 bit endianness API
2020-10-21virtio: let arch advertise guest's memory access restrictionsPierre Morel
An architecture may restrict host access to guest memory, e.g. IBM s390 Secure Execution or AMD SEV. Provide a new Kconfig entry the architecture can select, CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, when it provides the arch_has_restricted_virtio_memory_access callback to advertise to VIRTIO common code when the architecture restricts memory access from the host. The common code can then fail the probe for any device where VIRTIO_F_ACCESS_PLATFORM is required, but not set. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> Link: https://lore.kernel.org/r/1599728030-17085-2-git-send-email-pmorel@linux.ibm.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-09-10virtio: Add get_shm_region methodSebastien Boeuf
Virtio defines 'shared memory regions' that provide a continuously shared region between the host and guest. Provide a method to find a particular region on a device. Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: kvm@vger.kernel.org Cc: virtualization@lists.linux-foundation.org Cc: "Michael S. Tsirkin" <mst@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-08-05virtio_config: fix up warnings on pariscMichael S. Tsirkin
Apparently, on parisc le16_to_cpu returns an int. virtio_cread_le is very strict about type sizes so it causes a warning. Fix it up by casting to the correct type. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Link: https://lore.kernel.org/r/20200805235550.1451637-1-mst@redhat.com
2020-08-05virtio_config: drop LE option from config spaceMichael S. Tsirkin
All drivers now use virtio_cread/write_le for LE config space fields. Drop LE option from virtio_cread/write, only leaving the option to access transitional fields. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05virtio_config: add virtio_cread_le_featureMichael S. Tsirkin
Mirrors virtio_cread_feature but for LE fields. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05virtio_config: LE config space accessorsMichael S. Tsirkin
To be used by modern code, as well as to handle LE only fields such as balloon. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05virtio_config: disallow native type fields (again)Michael S. Tsirkin
_Generic version allowed __uXX types but that is no longer necessary: Transitional devices should all use __virtioXX types (and __leXX for fields not present in the legacy devices). Modern ones should use __leXX. _uXX type would be a bug. Let's prevent that. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05virtio_config: rewrite using _GenericMichael S. Tsirkin
Min compiler version has been raised, so that's ok now. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05virtio_config: cread/write cleanupMichael S. Tsirkin
Use vars of the correct type instead of casting. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05virtio_config: disallow native type fieldsMichael S. Tsirkin
Transitional devices should all use __virtioXX types (and __leXX for fields not present in legacy devices). Modern ones should use __leXX. _uXX type would be a bug. Let's prevent that. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05virtio: allow __virtioXX, __leXX in config spaceMichael S. Tsirkin
Currently all config space fields are of the type __uXX. This confuses people and some drivers (notably vdpa) access them using CPU endian-ness - which only works well for legacy or LE platforms. Update virtio_cread/virtio_cwrite macros to allow __virtioXX and __leXX field types. Follow-up patches will convert config space to use these types. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Cornelia Huck <cohuck@redhat.com>
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