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* virtio: unify virtio_notify_irqfd() and virtio_notify()Stefan Hajnoczi2025-10-051-5/+1
| | | | | | | | | | | | | | | | | | | | | | 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>
* qom: Make InterfaceInfo[] uses constPhilippe Mathieu-Daudé2025-04-251-1/+1
| | | | | | | | | | | Mechanical change using: $ sed -i -E 's/\(InterfaceInfo.?\[/\(const InterfaceInfo\[/g' \ $(git grep -lE '\(InterfaceInfo.?\[\]\)') Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Message-Id: <20250424194905.82506-7-philmd@linaro.org>
* qom: Have class_init() take a const data argumentPhilippe Mathieu-Daudé2025-04-251-2/+2
| | | | | | | | | | Mechanical change using gsed, then style manually adapted to pass checkpatch.pl script. Suggested-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20250424194905.82506-4-philmd@linaro.org>
* virtio-scsi: handle ctrl virtqueue in main loopStefan Hajnoczi2025-03-131-117/+27
| | | | | | | | | | | | | | | | | Previously the ctrl virtqueue was handled in the AioContext where SCSI requests are processed. When IOThread Virtqueue Mapping was added things become more complicated because SCSI requests could run in other AioContexts. Simplify by handling the ctrl virtqueue in the main loop where reset operations can be performed. Note that BHs are still used canceling SCSI requests in their AioContexts but at least the mean loop activity doesn't need BHs anymore. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-ID: <20250311132616.1049687-13-stefanha@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* virtio-scsi: add iothread-vq-mapping parameterStefan Hajnoczi2025-03-131-25/+38
| | | | | | | | | | | | | | | | | | | | | | | | Allow virtio-scsi virtqueues to be assigned to different IOThreads. This makes it possible to take advantage of host multi-queue block layer scalability by assigning virtqueues that have affinity with vCPUs to different IOThreads that have affinity with host CPUs. The same feature was introduced for virtio-blk in the past: https://developers.redhat.com/articles/2024/09/05/scaling-virtio-blk-disk-io-iothread-virtqueue-mapping Here are fio randread 4k iodepth=64 results from a 4 vCPU guest with an Intel P4800X SSD: iothreads IOPS ------------------------------ 1 189576 2 312698 4 346744 Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-ID: <20250311132616.1049687-12-stefanha@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> [kwolf: Updated 051 output, virtio-scsi can now use any iothread] Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* virtio-scsi: perform TMFs in appropriate AioContextsStefan Hajnoczi2025-03-131-64/+206
| | | | | | | | | | | | | | | | | | | | | With IOThread Virtqueue Mapping there will be multiple AioContexts processing SCSI requests. scsi_req_cancel() and other SCSI request operations must be performed from the AioContext where the request is running. Introduce a virtio_scsi_defer_tmf_to_aio_context() function and the necessary VirtIOSCSIReq->remaining refcount infrastructure to move the TMF code into the AioContext where the request is running. For the time being there is still just one AioContext: the main loop or the IOThread. When the iothread-vq-mapping parameter is added in a later patch this will be changed to per-virtqueue AioContexts. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20250311132616.1049687-8-stefanha@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* virtio-scsi: protect events_dropped fieldStefan Hajnoczi2025-03-131-9/+20
| | | | | | | | | | | | | | The block layer can invoke the resize callback from any AioContext that is processing requests. The virtqueue is already protected but the events_dropped field also needs to be protected against races. Cover it using the event virtqueue lock because it is closely associated with accesses to the virtqueue. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20250311132616.1049687-7-stefanha@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* virtio-scsi: introduce event and ctrl virtqueue locksStefan Hajnoczi2025-03-131-38/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | Virtqueues are not thread-safe. Until now this was not a major issue since all virtqueue processing happened in the same thread. The ctrl queue's Task Management Function (TMF) requests sometimes need the main loop, so a BH was used to schedule the virtqueue completion back in the thread that has virtqueue access. When IOThread Virtqueue Mapping is introduced in later commits, event and ctrl virtqueue accesses from other threads will become necessary. Introduce an optional per-virtqueue lock so the event and ctrl virtqueues can be protected in the commits that follow. The addition of the ctrl virtqueue lock makes virtio_scsi_complete_req_from_main_loop() and its BH unnecessary. Instead, take the ctrl virtqueue lock from the main loop thread. The cmd virtqueue does not have a lock because the entirety of SCSI command processing happens in one thread. Only one thread accesses the cmd virtqueue and a lock is unnecessary. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20250311132616.1049687-6-stefanha@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: remove unused BLOCK_OP_TYPE_DATAPLANEStefan Hajnoczi2025-02-061-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | BLOCK_OP_TYPE_DATAPLANE prevents BlockDriverState from being used by virtio-blk/virtio-scsi with IOThread. Commit b112a65c52aa ("block: declare blockjobs and dataplane friends!") eliminated the main reason for this blocker in 2014. Nowadays the block layer supports I/O from multiple AioContexts, so there is even less reason to block IOThread users. Any legitimate reasons related to interference would probably also apply to non-IOThread users. The only remaining users are bdrv_op_unblock(BLOCK_OP_TYPE_DATAPLANE) calls after bdrv_op_block_all(). If we remove BLOCK_OP_TYPE_DATAPLANE their behavior doesn't change. Existing bdrv_op_block_all() callers that don't explicitly unblock BLOCK_OP_TYPE_DATAPLANE seem to do so simply because no one bothered to rather than because it is necessary to keep BLOCK_OP_TYPE_DATAPLANE blocked. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-ID: <20250203182529.269066-1-stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* Merge tag 'exec-20241220' of https://github.com/philmd/qemu into stagingStefan Hajnoczi2024-12-211-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Accel & Exec patch queue - Ignore writes to CNTP_CTL_EL0 on HVF ARM (Alexander) - Add '-d invalid_mem' logging option (Zoltan) - Create QOM containers explicitly (Peter) - Rename sysemu/ -> system/ (Philippe) - Re-orderning of include/exec/ headers (Philippe) Move a lot of declarations from these legacy mixed bag headers: . "exec/cpu-all.h" . "exec/cpu-common.h" . "exec/cpu-defs.h" . "exec/exec-all.h" . "exec/translate-all" to these more specific ones: . "exec/page-protection.h" . "exec/translation-block.h" . "user/cpu_loop.h" . "user/guest-host.h" . "user/page-protection.h" # -----BEGIN PGP SIGNATURE----- # # iQIzBAABCAAdFiEE+qvnXhKRciHc/Wuy4+MsLN6twN4FAmdlnyAACgkQ4+MsLN6t # wN6mBw//QFWi7CrU+bb8KMM53kOU9C507tjn99LLGFb5or73/umDsw6eo/b8DHBt # KIwGLgATel42oojKfNKavtAzLK5rOrywpboPDpa3SNeF1onW+99NGJ52LQUqIX6K # A6bS0fPdGG9ZzEuPpbjDXlp++0yhDcdSgZsS42fEsT7Dyj5gzJYlqpqhiXGqpsn8 # 4Y0UMxSL21K3HEexlzw2hsoOBFA3tUm2ujNDhNkt8QASr85yQVLCypABJnuoe/// # 5Ojl5wTBeDwhANET0rhwHK8eIYaNboiM9fHopJYhvyw1bz6yAu9jQwzF/MrL3s/r # xa4OBHBy5mq2hQV9Shcl3UfCQdk/vDaYaWpgzJGX8stgMGYfnfej1SIl8haJIfcl # VMX8/jEFdYbjhO4AeGRYcBzWjEJymkDJZoiSWp2NuEDi6jqIW+7yW1q0Rnlg9lay # ShAqLK5Pv4zUw3t0Jy3qv9KSW8sbs6PQxtzXjk8p97rTf76BJ2pF8sv1tVzmsidP # 9L92Hv5O34IqzBu2oATOUZYJk89YGmTIUSLkpT7asJZpBLwNM2qLp5jO00WVU0Sd # +kAn324guYPkko/TVnjC/AY7CMu55EOtD9NU35k3mUAnxXT9oDUeL4NlYtfgrJx6 # x1Nzr2FkS68+wlPAFKNSSU5lTjsjNaFM0bIJ4LCNtenJVP+SnRo= # =cjz8 # -----END PGP SIGNATURE----- # gpg: Signature made Fri 20 Dec 2024 11:45:20 EST # gpg: using RSA key FAABE75E12917221DCFD6BB2E3E32C2CDEADC0DE # gpg: Good signature from "Philippe Mathieu-Daudé (F4BUG) <f4bug@amsat.org>" [unknown] # gpg: WARNING: This key is not certified with a trusted signature! # gpg: There is no indication that the signature belongs to the owner. # Primary key fingerprint: FAAB E75E 1291 7221 DCFD 6BB2 E3E3 2C2C DEAD C0DE * tag 'exec-20241220' of https://github.com/philmd/qemu: (59 commits) util/qemu-timer: fix indentation meson: Do not define CONFIG_DEVICES on user emulation system/accel-ops: Remove unnecessary 'exec/cpu-common.h' header system/numa: Remove unnecessary 'exec/cpu-common.h' header hw/xen: Remove unnecessary 'exec/cpu-common.h' header target/mips: Drop left-over comment about Jazz machine target/mips: Remove tswap() calls in semihosting uhi_fstat_cb() target/xtensa: Remove tswap() calls in semihosting simcall() helper accel/tcg: Un-inline translator_is_same_page() accel/tcg: Include missing 'exec/translation-block.h' header accel/tcg: Move tcg_cflags_has/set() to 'exec/translation-block.h' accel/tcg: Restrict curr_cflags() declaration to 'internal-common.h' qemu/coroutine: Include missing 'qemu/atomic.h' header exec/translation-block: Include missing 'qemu/atomic.h' header accel/tcg: Declare cpu_loop_exit_requested() in 'exec/cpu-common.h' exec/cpu-all: Include 'cpu.h' earlier so MMU_USER_IDX is always defined target/sparc: Move sparc_restore_state_to_opc() to cpu.c target/sparc: Uninline cpu_get_tb_cpu_state() target/loongarch: Declare loongarch_cpu_dump_state() locally user: Move various declarations out of 'exec/exec-all.h' ... Conflicts: hw/char/riscv_htif.c hw/intc/riscv_aplic.c target/s390x/cpu.c Apply sysemu header path changes to not in the pull request. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
| * include: Rename sysemu/ -> system/Philippe Mathieu-Daudé2024-12-201-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Headers in include/sysemu/ are not only related to system *emulation*, they are also used by virtualization. Rename as system/ which is clearer. Files renamed manually then mechanical change using sed tool. Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Lei Yang <leiyang@redhat.com> Message-Id: <20241203172445.28576-1-philmd@linaro.org>
* | include/hw/qdev-properties: Remove DEFINE_PROP_END_OF_LISTRichard Henderson2024-12-191-1/+0
|/ | | | | | | | | | | | | | Now that all of the Property arrays are counted, we can remove the terminator object from each array. Update the assertions in device_class_set_props to match. With struct Property being 88 bytes, this was a rather large form of terminator. Saves 30k from qemu-system-aarch64. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Lei Yang <leiyang@redhat.com> Link: https://lore.kernel.org/r/20241218134251.4724-21-richard.henderson@linaro.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* hw/scsi: Constify all PropertyRichard Henderson2024-12-151-1/+1
| | | | | Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
* hw/scsi: remove break after g_assert_not_reached()Pierrick Bouvier2024-09-241-1/+0
| | | | | | | | | | | | This patch is part of a series that moves towards a consistent use of g_assert_not_reached() rather than an ad hoc mix of different assertion mechanisms. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> Message-ID: <20240919044641.386068-20-pierrick.bouvier@linaro.org> Signed-off-by: Thomas Huth <thuth@redhat.com>
* virtio-scsi: Attach event vq notifier with no_pollHanna Czenczek2024-02-071-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As of commit 38738f7dbbda90fbc161757b7f4be35b52205552 ("virtio-scsi: don't waste CPU polling the event virtqueue"), we only attach an io_read notifier for the virtio-scsi event virtqueue instead, and no polling notifiers. During operation, the event virtqueue is typically non-empty, but none of the buffers are intended to be used immediately. Instead, they only get used when certain events occur. Therefore, it makes no sense to continuously poll it when non-empty, because it is supposed to be and stay non-empty. We do this by using virtio_queue_aio_attach_host_notifier_no_poll() instead of virtio_queue_aio_attach_host_notifier() for the event virtqueue. Commit 766aa2de0f29b657148e04599320d771c36fd126 ("virtio-scsi: implement BlockDevOps->drained_begin()") however has virtio_scsi_drained_end() use virtio_queue_aio_attach_host_notifier() for all virtqueues, including the event virtqueue. This can lead to it being polled again, undoing the benefit of commit 38738f7dbbda90fbc161757b7f4be35b52205552. Fix it by using virtio_queue_aio_attach_host_notifier_no_poll() for the event virtqueue. Reported-by: Fiona Ebner <f.ebner@proxmox.com> Fixes: 766aa2de0f29b657148e04599320d771c36fd126 ("virtio-scsi: implement BlockDevOps->drained_begin()") Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Tested-by: Fiona Ebner <f.ebner@proxmox.com> Reviewed-by: Fiona Ebner <f.ebner@proxmox.com> Signed-off-by: Hanna Czenczek <hreitz@redhat.com> Message-ID: <20240202153158.788922-2-hreitz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* hw/scsi: Constify VMStateRichard Henderson2023-12-301-1/+1
| | | | | Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20231221031652.119827-52-richard.henderson@linaro.org>
* scsi: remove AioContext lockingStefan Hajnoczi2023-12-211-18/+0
| | | | | | | | | | The AioContext lock no longer has any effect. Remove it. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-ID: <20231205182011.1976568-9-stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* virtio-scsi: replace AioContext lock with tmf_bh_lockStefan Hajnoczi2023-12-211-21/+41
| | | | | | | | | | | | | | | | Protect the Task Management Function BH state with a lock. The TMF BH runs in the main loop thread. An IOThread might process a TMF at the same time as the TMF BH is running. Therefore tmf_bh_list and tmf_bh must be protected by a lock. Run TMF request completion in the IOThread using aio_wait_bh_oneshot(). This avoids more locking to protect the virtqueue and SCSI layer state. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20231205182011.1976568-2-stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* util/defer-call: move defer_call() to util/Stefan Hajnoczi2023-10-311-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The networking subsystem may wish to use defer_call(), so move the code to util/ where it can be reused. As a reminder of what defer_call() does: This API defers a function call within a defer_call_begin()/defer_call_end() section, allowing multiple calls to batch up. This is a performance optimization that is used in the block layer to submit several I/O requests at once instead of individually: defer_call_begin(); <-- start of section ... defer_call(my_func, my_obj); <-- deferred my_func(my_obj) call defer_call(my_func, my_obj); <-- another defer_call(my_func, my_obj); <-- another ... defer_call_end(); <-- end of section, my_func(my_obj) is called once Suggested-by: Ilya Maximets <i.maximets@ovn.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-ID: <20230913200045.1024233-3-stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: rename blk_io_plug_call() API to defer_call()Stefan Hajnoczi2023-10-311-3/+3
| | | | | | | | | | | | | | | | | Prepare to move the blk_io_plug_call() API out of the block layer so that other subsystems call use this deferred call mechanism. Rename it to defer_call() but leave the code in block/plug.c. The next commit will move the code out of the block layer. Suggested-by: Ilya Maximets <i.maximets@ovn.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Paul Durrant <paul@xen.org> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-ID: <20230913200045.1024233-2-stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* hw/scsi/virtio-scsi: Use VIRTIO_SCSI_COMMON() macroPhilippe Mathieu-Daudé2023-10-191-1/+1
| | | | | | | | | | Access QOM parent with the proper QOM VIRTIO_SCSI_COMMON() macro. Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org> Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Message-Id: <20231017140150.44995-5-philmd@linaro.org>
* virtio-scsi: avoid dangling host notifier in ->ioeventfd_stop()Stefan Hajnoczi2023-06-261-2/+18
| | | | | | | | | | | | | | | | | | | | virtio_scsi_dataplane_stop() calls blk_drain_all(), which invokes ->drained_begin()/->drained_end() after we've already detached the host notifier. virtio_scsi_drained_end() currently attaches the host notifier again and leaves it dangling after dataplane has stopped. This results in the following assertion failure because virtio_scsi_defer_to_dataplane() is called from the IOThread instead of the main loop thread: qemu-system-x86_64: ../softmmu/memory.c:1111: memory_region_transaction_commit: Assertion `qemu_mutex_iothread_locked()' failed. Buglink: https://gitlab.com/qemu-project/qemu/-/issues/1680 Reported-by: Jean-Louis Dupond <jean-louis@dupond.be> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20230611193924.2444914-1-stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* block: add blk_io_plug_call() APIStefan Hajnoczi2023-06-011-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a new API for thread-local blk_io_plug() that does not traverse the block graph. The goal is to make blk_io_plug() multi-queue friendly. Instead of having block drivers track whether or not we're in a plugged section, provide an API that allows them to defer a function call until we're unplugged: blk_io_plug_call(fn, opaque). If blk_io_plug_call() is called multiple times with the same fn/opaque pair, then fn() is only called once at the end of the function - resulting in batching. This patch introduces the API and changes blk_io_plug()/blk_io_unplug(). blk_io_plug()/blk_io_unplug() no longer require a BlockBackend argument because the plug state is now thread-local. Later patches convert block drivers to blk_io_plug_call() and then we can finally remove .bdrv_co_io_plug() once all block drivers have been converted. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Acked-by: Kevin Wolf <kwolf@redhat.com> Message-id: 20230530180959.1108766-2-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* virtio-scsi: implement BlockDevOps->drained_begin()Stefan Hajnoczi2023-05-301-0/+38
| | | | | | | | | | | | | | | | | | | | | | | | The virtio-scsi Host Bus Adapter provides access to devices on a SCSI bus. Those SCSI devices typically have a BlockBackend. When the BlockBackend enters a drained section, the SCSI device must temporarily stop submitting new I/O requests. Implement this behavior by temporarily stopping virtio-scsi virtqueue processing when one of the SCSI devices enters a drained section. The new scsi_device_drained_begin() API allows scsi-disk to message the virtio-scsi HBA. scsi_device_drained_begin() uses a drain counter so that multiple SCSI devices can have overlapping drained sections. The HBA only sees one pair of .drained_begin/end() calls. After this commit, virtio-scsi no longer depends on hw/virtio's ioeventfd aio_set_event_notifier(is_external=true). This commit is a step towards removing the aio_disable_external() API. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20230516190238.8401-19-stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* virtio-scsi: stop using aio_disable_external() during unplugStefan Hajnoczi2023-05-301-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is part of an effort to remove the aio_disable_external() API because it does not fit in a multi-queue block layer world where many AioContexts may be submitting requests to the same disk. The SCSI emulation code is already in good shape to stop using aio_disable_external(). It was only used by commit 9c5aad84da1c ("virtio-scsi: fixed virtio_scsi_ctx_check failed when detaching scsi disk") to ensure that virtio_scsi_hotunplug() works while the guest driver is submitting I/O. Ensure virtio_scsi_hotunplug() is safe as follows: 1. qdev_simple_device_unplug_cb() -> qdev_unrealize() -> device_set_realized() calls qatomic_set(&dev->realized, false) so that future scsi_device_get() calls return NULL because they exclude SCSIDevices with realized=false. That means virtio-scsi will reject new I/O requests to this SCSIDevice with VIRTIO_SCSI_S_BAD_TARGET even while virtio_scsi_hotunplug() is still executing. We are protected against new requests! 2. scsi_qdev_unrealize() already contains a call to scsi_device_purge_requests() so that in-flight requests are cancelled synchronously. This ensures that no in-flight requests remain once qdev_simple_device_unplug_cb() returns. Thanks to these two conditions we don't need aio_disable_external() anymore. Cc: Zhengui Li <lizhengui@huawei.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230516190238.8401-5-stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* virtio-scsi: avoid race between unplug and transport eventStefan Hajnoczi2023-05-301-25/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Only report a transport reset event to the guest after the SCSIDevice has been unrealized by qdev_simple_device_unplug_cb(). qdev_simple_device_unplug_cb() sets the SCSIDevice's qdev.realized field to false so that scsi_device_find/get() no longer see it. scsi_target_emulate_report_luns() also needs to be updated to filter out SCSIDevices that are unrealized. Change virtio_scsi_push_event() to take event information as an argument instead of the SCSIDevice. This allows virtio_scsi_hotunplug() to emit a VIRTIO_SCSI_T_TRANSPORT_RESET event after the SCSIDevice has already been unrealized. These changes ensure that the guest driver does not see the SCSIDevice that's being unplugged if it responds very quickly to the transport reset event. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Daniil Tatianin <d-tatianin@yandex-team.ru> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230516190238.8401-4-stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* virtio-scsi: reset SCSI devices from main loop threadStefan Hajnoczi2023-02-231-36/+133
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When an IOThread is configured, the ctrl virtqueue is processed in the IOThread. TMFs that reset SCSI devices are currently called directly from the IOThread and trigger an assertion failure in blk_drain() from the following call stack: virtio_scsi_handle_ctrl_req -> virtio_scsi_do_tmf -> device_code_reset -> scsi_disk_reset -> scsi_device_purge_requests -> blk_drain ../block/block-backend.c:1780: void blk_drain(BlockBackend *): Assertion `qemu_in_main_thread()' failed. The blk_drain() function is not designed to be called from an IOThread because it needs the Big QEMU Lock (BQL). This patch defers TMFs that reset SCSI devices to a Bottom Half (BH) that runs in the main loop thread under the BQL. This way it's safe to call blk_drain() and the assertion failure is avoided. Introduce s->tmf_bh_list for tracking TMF requests that have been deferred to the BH. When the BH runs it will grab the entire list and process all requests. Care must be taken to clear the list when the virtio-scsi device is reset or unrealized. Otherwise deferred TMF requests could execute later and lead to use-after-free or other undefined behavior. The s->resetting counter that's used by TMFs that reset SCSI devices is accessed from multiple threads. This patch makes that explicit by using atomic accessor functions. With this patch applied the counter is only modified by the main loop thread under the BQL but can be read by any thread. Reported-by: Qing Wang <qinwang@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20230221212218.1378734-4-stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* include/hw/pci: Break inclusion loop pci_bridge.h and cxl.hMarkus Armbruster2023-01-081-0/+1
| | | | | | | | | | | | | hw/pci/pci_bridge.h and hw/cxl/cxl.h include each other. Fortunately, breaking the loop is merely a matter of deleting unnecessary includes from headers, and adding them back in places where they are now missing. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20221222100330.380143-2-armbru@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* scsi: Use device_cold_reset() and bus_cold_reset()Peter Maydell2022-10-181-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | In the SCSI subsystem we currently use the legacy functions qdev_reset_all() and qbus_reset_all(). These perform a recursive reset, starting from either a qbus or a qdev. However they do not permit any of the devices in the tree to use three-phase reset, because device reset goes through the device_legacy_reset() function that only calls the single DeviceClass::reset method. Switch to using the device_cold_reset() and bus_cold_reset() functions. These also perform a recursive reset, where first the children are reset and then finally the parent, but they use the new (...in 2020...) Resettable mechanism, which supports both the old style single-reset method and also the new 3-phase reset handling. Since no devices attached to SCSI buses currently try to use 3-phase reset, this should be a no-behaviour-change commit which just reduces the use of a deprecated API. Commit created with: sed -i -e 's/qdev_reset_all/device_cold_reset/g;s/qbus_reset_all/bus_cold_reset/g' hw/scsi/*.c Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20221013160623.1296109-2-peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* virtio-scsi: Send "REPORTED LUNS CHANGED" sense data upon disk hotplug eventsVenu Busireddy2022-10-131-0/+2
| | | | | | | | | | | | | | | | | | | Section 5.6.6.3 of VirtIO specification states, "Events will also be reported via sense codes..." However, no sense data is sent when VIRTIO_SCSI_EVT_RESET_RESCAN or VIRTIO_SCSI_EVT_RESET_REMOVED events are reported (when disk hotplug/hotunplug events occur). SCSI layer on Solaris depends on this sense data, and hence does not handle disk hotplug/hotunplug events. When the disk inventory changes, use the bus unit attention mechanism to return a CHECK_CONDITION status with sense data of 0x06/0x3F/0x0E (sense code REPORTED_LUNS_CHANGED). The first device on the bus to execute a command successfully will report and consume the unit attention status. Signed-off-by: Venu Busireddy <venu.busireddy@oracle.com> Message-Id: <20221006194946.24134-1-venu.busireddy@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* scsi: Add buf_len parameter to scsi_req_new()John Millikin2022-09-011-2/+3
| | | | | | | | | | | | | | | | When a SCSI command is received from the guest, the CDB length implied by the first byte might exceed the number of bytes the guest sent. In this case scsi_req_new() will read uninitialized data, causing unpredictable behavior. Adds the buf_len parameter to scsi_req_new() and plumbs it through the call stack. Signed-off-by: John Millikin <john@john-millikin.com> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1127 Message-Id: <20220817053458.698416-1-john@john-millikin.com> [Fill in correct length for adapters other than ESP. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* virtio: drop name parameter for virtio_init()Jonah Palmer2022-05-161-2/+1
| | | | | | | | | | | | | | | | 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: move request-related items from .h to .cStefan Hajnoczi2022-05-091-4/+41
| | | | | | | | | | | | | There is no longer a need to expose the request and related APIs in virtio-scsi.h since there are no callers outside virtio-scsi.c. Note the block comment in VirtIOSCSIReq has been adjusted to meet the coding style. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20220427143541.119567-7-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* virtio-scsi: clean up virtio_scsi_handle_cmd_vq()Stefan Hajnoczi2022-05-091-4/+1
| | | | | | | | | | | virtio_scsi_handle_cmd_vq() is only called from hw/scsi/virtio-scsi.c now and its return value is no longer used. Remove the function prototype from virtio-scsi.h and drop the return value. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20220427143541.119567-6-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* virtio-scsi: clean up virtio_scsi_handle_ctrl_vq()Stefan Hajnoczi2022-05-091-4/+1
| | | | | | | | | | | virtio_scsi_handle_ctrl_vq() is only called from hw/scsi/virtio-scsi.c now and its return value is no longer used. Remove the function prototype from virtio-scsi.h and drop the return value. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20220427143541.119567-5-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* virtio-scsi: clean up virtio_scsi_handle_event_vq()Stefan Hajnoczi2022-05-091-3/+1
| | | | | | | | | | | virtio_scsi_handle_event_vq() is only called from hw/scsi/virtio-scsi.c now and its return value is no longer used. Remove the function prototype from virtio-scsi.h and drop the return value. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20220427143541.119567-4-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* virtio-scsi: fix ctrl and event handler functions in dataplane modeStefan Hajnoczi2022-05-091-15/+27
| | | | | | | | | | | | | | | | | | | | | | | | | Commit f34e8d8b8d48d73f36a67b6d5e492ef9784b5012 ("virtio-scsi: prepare virtio_scsi_handle_cmd for dataplane") prepared the virtio-scsi cmd virtqueue handler function to be used in both the dataplane and non-datpalane code paths. It failed to convert the ctrl and event virtqueue handler functions, which are not designed to be called from the dataplane code path but will be since the ioeventfd is set up for those virtqueues when dataplane starts. Convert the ctrl and event virtqueue handler functions now so they operate correctly when called from the dataplane code path. Avoid code duplication by extracting this code into a helper function. Fixes: f34e8d8b8d48d73f36a67b6d5e492ef9784b5012 ("virtio-scsi: prepare virtio_scsi_handle_cmd for dataplane") Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20220427143541.119567-2-stefanha@redhat.com [Fixed s/by used/be used/ typo pointed out by Michael Tokarev <mjt@tls.msk.ru>. --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* virtio-scsi: prepare virtio_scsi_handle_cmd for dataplaneStefan Hajnoczi2022-01-121-1/+1
| | | | | | | | | | | | Prepare virtio_scsi_handle_cmd() to be used by both dataplane and non-dataplane by making the condition for starting ioeventfd more specific. This way it won't trigger when dataplane has already been started. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Message-id: 20211207132336.36627-5-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* scsi: Replace scsi_bus_new() with scsi_bus_init(), scsi_bus_init_named()Peter Maydell2021-09-301-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function scsi_bus_new() creates a new SCSI bus; callers can either pass in a name argument to specify the name of the new bus, or they can pass in NULL to allow the bus to be given an automatically generated unique name. Almost all callers want to use the autogenerated name; the only exception is the virtio-scsi device. Taking a name argument that should almost always be NULL is an easy-to-misuse API design -- it encourages callers to think perhaps they should pass in some standard name like "scsi" or "scsi-bus". We don't do this anywhere for SCSI, but we do (incorrectly) do it for other bus types such as i2c. The function name also implies that it will return a newly allocated object, when it in fact does in-place allocation. We more commonly name such functions foo_init(), with foo_new() being the allocate-and-return variant. Replace all the scsi_bus_new() callsites with either: * scsi_bus_init() for the usual case where the caller wants an autogenerated bus name * scsi_bus_init_named() for the rare case where the caller needs to specify the bus name and document that for the _named() version it's then the caller's responsibility to think about uniqueness of bus names. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20210923121153.23754-2-peter.maydell@linaro.org
* scsi: move host_status handling into SCSI driversHannes Reinecke2021-03-061-0/+46
| | | | | | | | | | | Some SCSI drivers like virtio have an internal mapping for the host_status. This patch moves the host_status translation into the SCSI drivers to allow those drivers to set up the correct values. Signed-off-by: Hannes Reinecke <hare@suse.de>. [Added default handling to avoid touching all drivers. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* scsi: drop 'result' argument from command_complete callbackHannes Reinecke2021-02-251-3/+2
| | | | | | | | | | The command complete callback has a SCSIRequest as the first argument, and the status field of that structure is identical to the 'status' argument. So drop the argument from the callback. Signed-off-by: Hannes Reinecke <hare@suse.de> Message-Id: <20201116184041.60465-3-hare@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* block: Honor blk_set_aio_context() context requirementsSergio Lopez2021-01-201-2/+4
| | | | | | | | | | | | | | | | | | | The documentation for bdrv_set_aio_context_ignore() states this: * The caller must own the AioContext lock for the old AioContext of bs, but it * must not own the AioContext lock for new_context (unless new_context is the * same as the current context of bs). As blk_set_aio_context() makes use of this function, this rule also applies to it. Fix all occurrences where this rule wasn't honored. Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Sergio Lopez <slp@redhat.com> Message-Id: <20201214170519.223781-2-slp@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
* virtio-scsi: trace eventsHannes Reinecke2021-01-121-1/+29
| | | | | | | | Add trace events for virtio command and response tracing. Signed-off-by: Hannes Reinecke <hare@suse.de> Message-Id: <20201116183114.55703-2-hare@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* virtio-scsi: use scsi_device_getMaxim Levitsky2020-10-121-8/+13
| | | | | | | | | | | | | | | | This will help us to avoid the scsi device disappearing after we took a reference to it. It doesn't by itself forbid case when we try to access an unrealized device Suggested-by: Stefan Hajnoczi <stefanha@gmail.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200913160259.32145-9-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20201006123904.610658-13-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* device-core: use RCU for list of children of a busMaxim Levitsky2020-10-121-1/+5
| | | | | | | | | | | | | | | | | | | | | This fixes the race between device emulation code that tries to find a child device to dispatch the request to (e.g a scsi disk), and hotplug of a new device to that bus. Note that this doesn't convert all the readers of the list but only these that might go over that list without BQL held. This is a very small first step to make this code thread safe. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200913160259.32145-5-mlevitsk@redhat.com> [Use RCU_READ_LOCK_GUARD in more places, adjust testcase now that the delay in DEVICE_DELETED due to RCU is more consistent. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20201006123904.610658-9-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* virtio-scsi-pci: default num_queues to -smp NStefan Hajnoczi2020-08-271-1/+5
| | | | | | | | | | | | | | | | | | Automatically size the number of virtio-scsi-pci, vhost-scsi-pci, and vhost-user-scsi-pci request virtqueues to match the number of vCPUs. Other transports continue to default to 1 request virtqueue. A 1:1 virtqueue:vCPU mapping ensures that completion interrupts are handled on the same vCPU that submitted the request. No IPI is necessary to complete an I/O request and performance is improved. The maximum number of MSI-X vectors and virtqueues limit are respected. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20200818143348.310613-6-stefanha@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> 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>
* virtio-scsi: introduce a constant for fixed virtqueuesStefan Hajnoczi2020-08-271-3/+4
| | | | | | | | | | | | | | | The event and control virtqueues are always present, regardless of the multi-queue configuration. Define a constant so that virtqueue number calculations are easier to read. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com> Message-Id: <20200818143348.310613-5-stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* qdev: Drop qbus_set_hotplug_handler() parameter @errpMarkus Armbruster2020-07-021-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | qbus_set_hotplug_handler() is a simple wrapper around object_property_set_link(). object_property_set_link() fails when the property doesn't exist, is not settable, or its .check() method fails. These are all programming errors here, so passing &error_abort to qbus_set_hotplug_handler() is appropriate. Most of its callers do. Exceptions: * pcie_cap_slot_init(), shpc_init(), spapr_phb_realize() pass NULL, i.e. they ignore errors. * spapr_machine_init() passes &error_fatal. * s390_pcihost_realize(), virtio_serial_device_realize(), s390_pcihost_plug() pass the error to their callers. The latter two keep going after the error, which looks wrong. Drop the @errp parameter, and instead pass &error_abort to object_property_set_link(). Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Daniel P. Berrangé" <berrange@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20200630090351.1247703-15-armbru@redhat.com>
* qdev: Unrealize must not failMarkus Armbruster2020-05-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Devices may have component devices and buses. Device realization may fail. Realization is recursive: a device's realize() method realizes its components, and device_set_realized() realizes its buses (which should in turn realize the devices on that bus, except bus_set_realized() doesn't implement that, yet). When realization of a component or bus fails, we need to roll back: unrealize everything we realized so far. If any of these unrealizes failed, the device would be left in an inconsistent state. Must not happen. device_set_realized() lets it happen: it ignores errors in the roll back code starting at label child_realize_fail. Since realization is recursive, unrealization must be recursive, too. But how could a partly failed unrealize be rolled back? We'd have to re-realize, which can fail. This design is fundamentally broken. device_set_realized() does not roll back at all. Instead, it keeps unrealizing, ignoring further errors. It can screw up even for a device with no buses: if the lone dc->unrealize() fails, it still unregisters vmstate, and calls listeners' unrealize() callback. bus_set_realized() does not roll back either. Instead, it stops unrealizing. Fortunately, no unrealize method can fail, as we'll see below. To fix the design error, drop parameter @errp from all the unrealize methods. Any unrealize method that uses @errp now needs an update. This leads us to unrealize() methods that can fail. Merely passing it to another unrealize method cannot cause failure, though. Here are the ones that do other things with @errp: * virtio_serial_device_unrealize() Fails when qbus_set_hotplug_handler() fails, but still does all the other work. On failure, the device would stay realized with its resources completely gone. Oops. Can't happen, because qbus_set_hotplug_handler() can't actually fail here. Pass &error_abort to qbus_set_hotplug_handler() instead. * hw/ppc/spapr_drc.c's unrealize() Fails when object_property_del() fails, but all the other work is already done. On failure, the device would stay realized with its vmstate registration gone. Oops. Can't happen, because object_property_del() can't actually fail here. Pass &error_abort to object_property_del() instead. * spapr_phb_unrealize() Fails and bails out when remove_drcs() fails, but other work is already done. On failure, the device would stay realized with some of its resources gone. Oops. remove_drcs() fails only when chassis_from_bus()'s object_property_get_uint() fails, and it can't here. Pass &error_abort to remove_drcs() instead. Therefore, no unrealize method can fail before this patch. device_set_realized()'s recursive unrealization via bus uses object_property_set_bool(). Can't drop @errp there, so pass &error_abort. We similarly unrealize with object_property_set_bool() elsewhere, always ignoring errors. Pass &error_abort instead. Several unrealize methods no longer handle errors from other unrealize methods: virtio_9p_device_unrealize(), virtio_input_device_unrealize(), scsi_qdev_unrealize(), ... Much of the deleted error handling looks wrong anyway. One unrealize methods no longer ignore such errors: usb_ehci_pci_exit(). Several realize methods no longer ignore errors when rolling back: v9fs_device_realize_common(), pci_qdev_unrealize(), spapr_phb_realize(), usb_qdev_realize(), vfio_ccw_realize(), virtio_device_realize(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200505152926.18877-17-armbru@redhat.com>
* virtio: increase virtqueue size for virtio-scsi and virtio-blkDenis Plotnikov2020-02-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | The goal is to reduce the amount of requests issued by a guest on 1M reads/writes. This rises the performance up to 4% on that kind of disk access pattern. The maximum chunk size to be used for the guest disk accessing is limited with seg_max parameter, which represents the max amount of pices in the scatter-geather list in one guest disk request. Since seg_max is virqueue_size dependent, increasing the virtqueue size increases seg_max, which, in turn, increases the maximum size of data to be read/write from a guest disk. More details in the original problem statment: https://lists.gnu.org/archive/html/qemu-devel/2017-12/msg03721.html Suggested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com> Message-id: 20200214074648.958-1-dplotnikov@virtuozzo.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>