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* virtio: unify virtio_notify_irqfd() and virtio_notify()Stefan Hajnoczi2025-10-051-1/+0
| | | | | | | | | | | | | | | | | | | | | | The difference between these two functions: - virtio_notify() uses the interrupt code path (MSI or classic IRQs) - virtio_notify_irqfd() uses guest notifiers (irqfds) virtio_notify() can only be called with the BQL held because the interrupt code path requires the BQL. Device models use virtio_notify_irqfd() from IOThreads since the BQL is not held. The two functions can be unified by pushing down the if (qemu_in_iothread()) check from virtio-blk and virtio-scsi into core virtio code. This is in preparation for the next commit that will add irqfd support to virtio_notify_config() and where it's unattractive to introduce another irqfd-only API for device model callers. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <20250922220149.498967-3-stefanha@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio: add support for negotiating extended featuresPaolo Abeni2025-10-041-0/+4
| | | | | | | | | | | | | | | | | | | | | | | The virtio specifications allows for a device features space up to 128 bits and more. Soon we are going to use some of the 'extended' bits features for the virtio net driver. Add support to allow extended features negotiation on a per devices basis. Devices willing to negotiated extended features need to implemented a new pair of features getter/setter, the core will conditionally use them instead of the basic one. Note that 'bad_features' don't need to be extended, as they are bound to the 64 bits limit. Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Tested-by: Lei Yang <leiyang@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <9bb29d70adc3f2b8c7756d4e3cd076cffee87826.1758549625.git.pabeni@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio: introduce extended features typePaolo Abeni2025-10-041-3/+4
| | | | | | | | | | | | | | | | | | | | | | 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 (bit 64 and above) for the virtio net driver. Represent the virtio features bitmask with a fixed size array, and introduce a few helpers to help manipulate them. Most drivers will keep using only 64 bits features space: use union to allow them access the lower part of the extended space without any per driver change. Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Tested-by: Lei Yang <leiyang@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <6a9bbb5eb33830f20afbcb7e64d300af4126dd98.1758549625.git.pabeni@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio-net: Add queues for RSS during migrationAkihiko Odaki2025-07-141-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | virtio_net_pre_load_queues() inspects vdev->guest_features to tell if VIRTIO_NET_F_RSS or VIRTIO_NET_F_MQ is enabled to infer the required number of queues. This works for VIRTIO_NET_F_MQ but it doesn't for VIRTIO_NET_F_RSS because only the lowest 32 bits of vdev->guest_features is set at the point and VIRTIO_NET_F_RSS uses bit 60 while VIRTIO_NET_F_MQ uses bit 22. Instead of inferring the required number of queues from vdev->guest_features, use the number loaded from the vm state. This change also has a nice side effect to remove a duplicate peer queue pair change by circumventing virtio_net_set_multiqueue(). Also update the comment in include/hw/virtio/virtio.h to prevent an implementation of pre_load_queues() from refering to any fields being loaded during migration by accident in the future. Fixes: 8c49756825da ("virtio-net: Add only one queue pair when realizing") Tested-by: Lei Yang <leiyang@redhat.com> Cc: qemu-stable@nongnu.org Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
* vhost-user: return failure if backend crash when live migrationHaoqian He2025-05-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Live migration should be terminated if the vhost-user backend crashes before the migration completes. Specifically, since the vhost device will be stopped when VM is stopped before the end of the live migration, in current implementation if the backend crashes, vhost-user device set_status() won't return failure, live migration won't perceive the disconnection between QEMU and the backend. When the VM is migrated to the destination, the inflight IO will be resubmitted, and if the IO was completed out of order before, it will cause IO error. To fix this issue: 1. Add the return value to set_status() for VirtioDeviceClass. a. For the vhost-user device, return failure when the backend crashes. b. For other virtio devices, always return 0. 2. Return failure if vhost_dev_stop() failed for vhost-user device. If QEMU loses connection with the vhost-user backend, virtio set_status() can return failure to the upper layer, migration_completion() can handle the error, terminate the live migration, and restore the VM, so that inflight IO can be completed normally. Signed-off-by: Haoqian He <haoqian.he@smartx.com> Message-Id: <20250416024729.3289157-4-haoqian.he@smartx.com> Tested-by: Lei Yang <leiyang@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* include/system: Move exec/memory.h to system/memory.hRichard Henderson2025-04-231-1/+1
| | | | | | | | | | | | Convert the existing includes with sed -i ,exec/memory.h,system/memory.h,g Move the include within cpu-all.h into a !CONFIG_USER_ONLY block. Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
* virtio-net: Add queues before loading themAkihiko Odaki2024-11-261-0/+2
| | | | | | | | | | | | | Call virtio_net_set_multiqueue() to add queues before loading their states. Otherwise the loaded queues will not have handlers and elements in them will not be processed. Cc: qemu-stable@nongnu.org Fixes: 8c49756825da ("virtio-net: Add only one queue pair when realizing") Reported-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
* virtio: Allow .get_vhost() without vhost_startedHanna Czenczek2024-09-101-0/+1
| | | | | | | | | | | | | | | | | | | Historically, .get_vhost() was probably only called when vdev->vhost_started is true. However, we now decidedly want to call it also when vhost_started is false, specifically so we can issue a reset to the vhost back-end while device operation is stopped. Some .get_vhost() implementations dereference some pointers (or return offsets from them) that are probably guaranteed to be non-NULL when vhost_started is true, but not necessarily otherwise. This patch makes all such implementations check all such pointers, returning NULL if any is NULL. Signed-off-by: Hanna Czenczek <hreitz@redhat.com> Message-Id: <20240723163941.48775-2-hreitz@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
* virtio-net: Fix network stall at the host side waiting for kickthomas2024-08-021-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch 06b12970174 ("virtio-net: fix network stall under load") added double-check to test whether the available buffer size can satisfy the request or not, in case the guest has added some buffers to the avail ring simultaneously after the first check. It will be lucky if the available buffer size becomes okay after the double-check, then the host can send the packet to the guest. If the buffer size still can't satisfy the request, even if the guest has added some buffers, viritio-net would stall at the host side forever. The patch enables notification and checks whether the guest has added some buffers since last check of available buffers when the available buffers are insufficient. If no buffer is added, return false, else recheck the available buffers in the loop. If the available buffers are sufficient, disable notification and return true. Changes: 1. Change the return type of virtqueue_get_avail_bytes() from void to int, it returns an opaque that represents the shadow_avail_idx of the virtqueue on success, else -1 on error. 2. Add a new API: virtio_queue_enable_notification_and_check(), it takes an opaque as input arg which is returned from virtqueue_get_avail_bytes(). It enables notification firstly, then checks whether the guest has added some buffers since last check of available buffers or not by virtio_queue_poll(), return ture if yes. The patch also reverts patch "06b12970174". The case below can reproduce the stall. Guest 0 +--------+ | iperf | ---------------> | server | Host | +--------+ +--------+ | ... | iperf |---- | client |---- Guest n +--------+ | +--------+ | | iperf | ---------------> | server | +--------+ Boot many guests from qemu with virtio network: qemu ... -netdev tap,id=net_x \ -device virtio-net-pci-non-transitional,\ iommu_platform=on,mac=xx:xx:xx:xx:xx:xx,netdev=net_x Each guest acts as iperf server with commands below: iperf3 -s -D -i 10 -p 8001 iperf3 -s -D -i 10 -p 8002 The host as iperf client: iperf3 -c guest_IP -p 8001 -i 30 -w 256k -P 20 -t 40000 iperf3 -c guest_IP -p 8002 -i 30 -w 256k -P 20 -t 40000 After some time, the host loses connection to the guest, the guest can send packet to the host, but can't receive packet from the host. It's more likely to happen if SWIOTLB is enabled in the guest, allocating and freeing bounce buffer takes some CPU ticks, copying from/to bounce buffer takes more CPU ticks, compared with that there is no bounce buffer in the guest. Once the rate of producing packets from the host approximates the rate of receiveing packets in the guest, the guest would loop in NAPI. receive packets --- | | v | free buf virtnet_poll | | v | add buf to avail ring --- | | need kick the host? | NAPI continues v receive packets --- | | v | free buf virtnet_poll | | v | add buf to avail ring --- | v ... ... On the other hand, the host fetches free buf from avail ring, if the buf in the avail ring is not enough, the host notifies the guest the event by writing the avail idx read from avail ring to the event idx of used ring, then the host goes to sleep, waiting for the kick signal from the guest. Once the guest finds the host is waiting for kick singal (in virtqueue_kick_prepare_split()), it kicks the host. The host may stall forever at the sequences below: Host Guest ------------ ----------- fetch buf, send packet receive packet --- ... ... | fetch buf, send packet add buf | ... add buf virtnet_poll buf not enough avail idx-> add buf | read avail idx add buf | add buf --- receive packet --- write event idx ... | wait for kick add buf virtnet_poll ... | --- no more packet, exit NAPI In the first loop of NAPI above, indicated in the range of virtnet_poll above, the host is sending packets while the guest is receiving packets and adding buffers. step 1: The buf is not enough, for example, a big packet needs 5 buf, but the available buf count is 3. The host read current avail idx. step 2: The guest adds some buf, then checks whether the host is waiting for kick signal, not at this time. The used ring is not empty, the guest continues the second loop of NAPI. step 3: The host writes the avail idx read from avail ring to used ring as event idx via virtio_queue_set_notification(q->rx_vq, 1). step 4: At the end of the second loop of NAPI, recheck whether kick is needed, as the event idx in the used ring written by the host is beyound the range of kick condition, the guest will not send kick signal to the host. Fixes: 06b12970174 ("virtio-net: fix network stall under load") Cc: qemu-stable@nongnu.org Signed-off-by: Wencheng Yang <east.moutain.yang@gmail.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
* virtio: Add VIRTIO_F_IN_ORDER property definitionJonah Palmer2024-07-211-1/+3
| | | | | | | | | | | | | | Extend the virtio device property definitions to include the VIRTIO_F_IN_ORDER feature. The default state of this feature is disabled, allowing it to be explicitly enabled where it's supported. Acked-by: Eugenio Pérez <eperezma@redhat.com> Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com> Message-Id: <20240710125522.4168043-7-jonah.palmer@oracle.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio: Add bool to VirtQueueElementJonah Palmer2024-07-211-0/+2
| | | | | | | | | | | | | Add the boolean 'in_order_filled' member to the VirtQueueElement structure. The use of this boolean will signify whether the element has been processed and is ready to be flushed (so long as the element is in-order). This boolean is used to support the VIRTIO_F_IN_ORDER feature. Reviewed-by: Eugenio Pérez <eperezma@redhat.com> Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com> Message-Id: <20240710125522.4168043-2-jonah.palmer@oracle.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* hw/virtio: Fix the de-initialization of vhost-user devicesThomas Huth2024-07-031-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The unrealize functions of the various vhost-user devices are calling the corresponding vhost_*_set_status() functions with a status of 0 to shut down the device correctly. Now these vhost_*_set_status() functions all follow this scheme: bool should_start = virtio_device_should_start(vdev, status); if (vhost_dev_is_started(&vvc->vhost_dev) == should_start) { return; } if (should_start) { /* ... do the initialization stuff ... */ } else { /* ... do the cleanup stuff ... */ } The problem here is virtio_device_should_start(vdev, 0) currently always returns "true" since it internally only looks at vdev->started instead of looking at the "status" parameter. Thus once the device got started once, virtio_device_should_start() always returns true and thus the vhost_*_set_status() functions return early, without ever doing any clean-up when being called with status == 0. This causes e.g. problems when trying to hot-plug and hot-unplug a vhost user devices multiple times since the de-initialization step is completely skipped during the unplug operation. This bug has been introduced in commit 9f6bcfd99f ("hw/virtio: move vm_running check to virtio_device_started") which replaced should_start = status & VIRTIO_CONFIG_S_DRIVER_OK; with should_start = virtio_device_started(vdev, status); which later got replaced by virtio_device_should_start(). This blocked the possibility to set should_start to false in case the status flag VIRTIO_CONFIG_S_DRIVER_OK was not set. Fix it by adjusting the virtio_device_should_start() function to only consider the status flag instead of vdev->started. Since this function is only used in the various vhost_*_set_status() functions for exactly the same purpose, it should be fine to fix it in this central place there without any risk to change the behavior of other code. Fixes: 9f6bcfd99f ("hw/virtio: move vm_running check to virtio_device_started") Buglink: https://issues.redhat.com/browse/RHEL-40708 Signed-off-by: Thomas Huth <thuth@redhat.com> Message-Id: <20240618121958.88673-1-thuth@redhat.com> Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio/virtio-pci: Handle extra notification dataJonah Palmer2024-07-011-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | Add support to virtio-pci devices for handling the extra data sent from the driver to the device when the VIRTIO_F_NOTIFICATION_DATA transport feature has been negotiated. The extra data that's passed to the virtio-pci device when this feature is enabled varies depending on the device's virtqueue layout. In a split virtqueue layout, this data includes: - upper 16 bits: shadow_avail_idx - lower 16 bits: virtqueue index In a packed virtqueue layout, this data includes: - upper 16 bits: 1-bit wrap counter & 15-bit shadow_avail_idx - lower 16 bits: virtqueue index Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com> Message-Id: <20240315165557.26942-2-jonah.palmer@oracle.com> Reviewed-by: Eugenio Pérez <eperezma@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* hw/virtio: Introduce virtio_bh_new_guarded() helperPhilippe Mathieu-Daudé2024-04-101-0/+7
| | | | | | | | | | | | | Introduce virtio_bh_new_guarded(), similar to qemu_bh_new_guarded() but using the transport memory guard, instead of the device one (there can only be one virtio device per virtio bus). Inspired-by: Gerd Hoffmann <kraxel@redhat.com> Reviewed-by: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Message-Id: <20240409105537.18308-2-philmd@linaro.org>
* Revert "hw/virtio: Add support for VDPA network simulation devices"Michael S. Tsirkin2024-04-091-19/+0
| | | | | | | | | | | | | | | This reverts commit cd341fd1ffded978b2aa0b5309b00be7c42e347c. The patch adds non-upstream code in include/standard-headers/linux/virtio_pci.h which would make maintainance harder. Revert for now. Suggested-by: Jason Wang <jasowang@redhat.com> Message-Id: <df6b6b465753e754a19459e8cd61416548f89a42.1712569644.git.mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* hw/virtio: Add support for VDPA network simulation devicesHao Chen2024-03-121-0/+19
| | | | | | | | | | | | | This patch adds support for VDPA network simulation devices. The device is developed based on virtio-net and tap backend, and supports hardware live migration function. For more details, please refer to "docs/system/devices/vdpa-net.rst" Signed-off-by: Hao Chen <chenh@yusur.tech> Message-Id: <20240221073802.2888022-1-chenh@yusur.tech> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* include/hw/virtio: document some more usage of notifiersAlex Bennée2023-07-101-0/+8
| | | | | | | | | Lets document some more of the core VirtIODevice structure. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230710153522.3469097-7-alex.bennee@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* include/hw/virtio: add kerneldoc for virtio_initAlex Bennée2023-07-101-0/+6
| | | | | | | Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230710153522.3469097-6-alex.bennee@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* include/hw/virtio: document virtio_notify_configAlex Bennée2023-07-101-0/+7
| | | | | | | Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20230710153522.3469097-5-alex.bennee@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* include/hw/virtio: make some VirtIODevice constHawkins Jiawei2023-06-261-1/+1
| | | | | | | | | | | | | | | The VirtIODevice structure is not modified in virtio_vdev_has_feature(). Therefore, make it const to allow this function to accept const variables. Signed-off-by: Hawkins Jiawei <yin31149@gmail.com> Reviewed-by: Eugenio Pérez Martin <eperezma@redhat.com> Message-Id: <16c0561b921310a32c240a4fb6e8cee3ffee16fe.1685704856.git.yin31149@gmail.com> Tested-by: Lei Yang <leiyang@redhat.com> Reviewed-by: Eugenio Pérez <eperezma@redhat.com> Tested-by: Eugenio Pérez <eperezma@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio-pci: add handling of PCI ATS and Device-TLB enable/disableViktor Prutyanov2023-05-191-0/+2
| | | | | | | | | | | | | According to PCIe Address Translation Services specification 5.1.3., ATS Control Register has Enable bit to enable/disable ATS. Guest may enable/disable PCI ATS and, accordingly, Device-TLB for the VirtIO PCI device. So, raise/lower a flag and call a trigger function to pass this event to a device implementation. Signed-off-by: Viktor Prutyanov <viktor@daynix.com> Message-Id: <20230512135122.70403-2-viktor@daynix.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio: refresh vring region cache after updating a virtqueue sizeCarlos López2023-04-211-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* replace TABs with spacesYeqi Fu2023-03-201-1/+1
| | | | | | | | | | | Bring the files in line with the QEMU coding style, with spaces for indentation. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/378 Signed-off-by: Yeqi Fu <fufuyqqqqqq@gmail.com> Message-Id: <20230315032649.57568-1-fufuyqqqqqq@gmail.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
* include/hw/virtio: Break inclusion loopMarkus Armbruster2023-01-081-1/+0
| | | | | | | | | | | | | | | | 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>
* virtio: add support for configure interruptCindy Lu2023-01-081-0/+4
| | | | | | | | | | | | | | 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>
* virtio: introduce macro VIRTIO_CONFIG_IRQ_IDXCindy Lu2023-01-081-0/+3
| | | | | | | | | | | | | | To support configure interrupt for vhost-vdpa Introduce VIRTIO_CONFIG_IRQ_IDX -1 as configure interrupt's queue index, Then we can reuse the functions guest_notifier_mask and guest_notifier_pending. Add the check of queue index in these drivers, if the driver does not support configure interrupt, the function will just return Signed-off-by: Cindy Lu <lulu@redhat.com> Message-Id: <20221222070451.936503-2-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>
* include/hw: attempt to document VirtIO feature variablesAlex Bennée2022-12-211-1/+18
| | | | | | | | | | | | | | | | We have a bunch of variables associated with the device and the vhost backend which are used inconsistently throughout the code base. Lets start trying to bring some order by agreeing what each variable is for. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Cc: Stefano Garzarella <sgarzare@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Stefan Hajnoczi <stefanha@gmail.com> Message-Id: <20221123152134.179929-2-alex.bennee@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* include/hw: VM state takes precedence in virtio_device_should_startAlex Bennée2022-12-011-5/+18
| | | | | | | | | | | | | | | | | | The VM status should always preempt the device status for these checks. This ensures the device is in the correct state when we suspend the VM prior to migrations. This restores the checks to the order they where in before the refactoring moved things around. While we are at it lets improve our documentation of the various fields involved and document the two functions. Fixes: 9f6bcfd99f (hw/virtio: move vm_running check to virtio_device_started) Fixes: 259d69c00b (hw/virtio: introduce virtio_device_should_start) Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Message-Id: <20221130112439.2527228-6-alex.bennee@linaro.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio-net: fix for heap-buffer-overflowXuan Zhuo2022-11-101-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Run shell script: cat << EOF | valgrind qemu-system-i386 -display none -machine accel=qtest, -m \ 512M -M q35 -nodefaults -device virtio-net,netdev=net0 -netdev \ user,id=net0 -qtest stdio outl 0xcf8 0x80000810 outl 0xcfc 0xc000 outl 0xcf8 0x80000804 outl 0xcfc 0x01 outl 0xc00d 0x0200 outl 0xcf8 0x80000890 outb 0xcfc 0x4 outl 0xcf8 0x80000889 outl 0xcfc 0x1c000000 outl 0xcf8 0x80000893 outw 0xcfc 0x100 EOF Got: ==68666== Invalid read of size 8 ==68666== at 0x688536: virtio_net_queue_enable (virtio-net.c:575) ==68666== by 0x6E31AE: memory_region_write_accessor (memory.c:492) ==68666== by 0x6E098D: access_with_adjusted_size (memory.c:554) ==68666== by 0x6E4DB3: memory_region_dispatch_write (memory.c:1521) ==68666== by 0x6E31AE: memory_region_write_accessor (memory.c:492) ==68666== by 0x6E098D: access_with_adjusted_size (memory.c:554) ==68666== by 0x6E4DB3: memory_region_dispatch_write (memory.c:1521) ==68666== by 0x6EBCD3: flatview_write_continue (physmem.c:2820) ==68666== by 0x6EBFBF: flatview_write (physmem.c:2862) ==68666== by 0x6EF5E7: address_space_write (physmem.c:2958) ==68666== by 0x6DFDEC: cpu_outw (ioport.c:70) ==68666== by 0x6F6DF0: qtest_process_command (qtest.c:480) ==68666== Address 0x29087fe8 is 24 bytes after a block of size 416 in arena "client" That is reported by Alexander Bulekov. https://gitlab.com/qemu-project/qemu/-/issues/1309 Here, the queue_index is the index of the cvq, but in some cases cvq does not have the corresponding NetClientState, so overflow appears. I add a check here, ignore illegal queue_index and cvq queue_index. Note the queue_index is below the VIRTIO_QUEUE_MAX but greater or equal than cvq index could hit this. Other devices are similar. Fixes: 7f863302 ("virtio-net: support queue_enable") Fixes: https://gitlab.com/qemu-project/qemu/-/issues/1309 Reported-by: Alexander Bulekov <alxndr@bu.edu> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Message-Id: <20221110095739.130393-1-xuanzhuo@linux.alibaba.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* hw/virtio: introduce virtio_device_should_startAlex Bennée2022-11-071-0/+18
| | | | | | | | | | | | | | | | | The previous fix to virtio_device_started revealed a problem in its use by both the core and the device code. The core code should be able to handle the device "starting" while the VM isn't running to handle the restoration of migration state. To solve this duel use introduce a new helper for use by the vhost-user backends who all use it to feed a should_start variable. We can also pick up a change vhost_user_blk_set_status while we are at it which follows the same pattern. Fixes: 9f6bcfd99f (hw/virtio: move vm_running check to virtio_device_started) Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Message-Id: <20221107121407.1010913-1-alex.bennee@linaro.org>
* virtio: core: vq reset feature negotation supportKangjie Xu2022-11-071-1/+3
| | | | | | | | | | | | | A a new command line parameter "queue_reset" is added. Meanwhile, the vq reset feature is disabled for pre-7.2 machines. 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: <20221017092558.111082-5-xuanzhuo@linux.alibaba.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio: introduce virtio_queue_enable()Kangjie Xu2022-11-071-0/+2
| | | | | | | | | | | | | | | 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>
* virtio: introduce virtio_queue_reset()Xuan Zhuo2022-11-071-0/+2
| | | | | | | | | | | | | | 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>
* qmp: decode feature & status bits in virtio-statusLaurent Vivier2022-10-091-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* qmp: add QMP command x-query-virtioLaurent Vivier2022-10-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* virtio: introduce VirtIOConfigSizeParams & virtio_get_config_sizeDaniil Tatianin2022-10-071-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* hw/virtio: move vm_running check to virtio_device_startedAlex Bennée2022-10-071-0/+5
| | | | | | | | | | | | All the boilerplate virtio code does the same thing (or should at least) of checking to see if the VM is running before attempting to start VirtIO. Push the logic up to the common function to avoid getting a copy and paste wrong. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20220802095010.3330793-11-alex.bennee@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* include/hw/virtio: more comment for VIRTIO_F_BAD_FEATUREAlex Bennée2022-10-071-1/+6
| | | | | | | | | | | | | | When debugging a new vhost user you may be surprised to see VHOST_USER_F_PROTOCOL getting squashed in the maze of backend_features, acked_features and guest_features. Expand the description here to help the next poor soul trying to work through this. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Message-Id: <20220802095010.3330793-6-alex.bennee@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio: add vhost support for virtio devicesJonah Palmer2022-05-161-0/+3
| | | | | | | | | | | | | | | 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>
* virtio: drop name parameter for virtio_init()Jonah Palmer2022-05-161-2/+2
| | | | | | | | | | | | | | | | 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>
* virtio-scsi: don't waste CPU polling the event virtqueueStefan Hajnoczi2022-05-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Replace GCC_FMT_ATTR with G_GNUC_PRINTFMarc-André Lureau2022-03-221-1/+1
| | | | | | | | 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>
* virtio: unify dataplane and non-dataplane ->handle_output()Stefan Hajnoczi2022-01-121-2/+2
| | | | | | | | | | 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>
* virtio: get rid of VirtIOHandleAIOOutputStefan Hajnoczi2022-01-121-2/+1
| | | | | | | | | | | | | | | | | | | | | 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>
* Revert "virtio: introduce macro IRTIO_CONFIG_IRQ_IDX"Michael S. Tsirkin2022-01-101-3/+0
| | | | | | | | This reverts commit bf1d85c166c19af95dbd27b1faba1d2909732323. Fixes: bf1d85c166 ("virtio: introduce macro IRTIO_CONFIG_IRQ_IDX") Cc: "Cindy Lu" <lulu@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* Revert "virtio: add support for configure interrupt"Michael S. Tsirkin2022-01-101-4/+0
| | | | | | | | This reverts commit 081f864f56307551f59c5e934e3f30a7290d0faa. Fixes: 081f864f56 ("virtio: add support for configure interrupt") Cc: "Cindy Lu" <lulu@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio: add support for configure interruptCindy Lu2022-01-061-0/+4
| | | | | | | | | | | | | 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>
* virtio: introduce macro IRTIO_CONFIG_IRQ_IDXCindy Lu2022-01-061-0/+3
| | | | | | | | | | | | | To support configure interrupt for vhost-vdpa Introduce VIRTIO_CONFIG_IRQ_IDX -1 as configure interrupt's queue index, Then we can reuse the functions guest_notifier_mask and guest_notifier_pending. Add the check of queue index in these drivers, if the driver does not support configure interrupt, the function will just return Signed-off-by: Cindy Lu <lulu@redhat.com> Message-Id: <20211104164827.21911-2-lulu@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* hw/virtio: Pass virtio_feature_get_config_size() a const argumentPhilippe Mathieu-Daudé2021-05-141-1/+1
| | | | | | | The VirtIOFeature structure isn't modified, mark it const. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20210511104157.2880306-2-philmd@redhat.com>
* virtio: skip legacy support check on machine types less than 5.1Stefano Garzarella2020-09-291-0/+2
| | | | | | | | | | | | | | | | | | | | | | | Commit 9b3a35ec82 ("virtio: verify that legacy support is not accidentally on") added a check that returns an error if legacy support is on, but the device does not support legacy. Unfortunately some devices were wrongly declared legacy capable even if they were not (e.g vhost-vsock). To avoid migration issues, we add a virtio-device property (x-disable-legacy-check) to skip the legacy error, printing a warning instead, for machine types < 5.1. Cc: qemu-stable@nongnu.org Fixes: 9b3a35ec82 ("virtio: verify that legacy support is not accidentally on") Suggested-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Suggested-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Message-Id: <20200921122506.82515-2-sgarzare@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>