From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6B777C433F5 for ; Thu, 6 Oct 2022 18:07:54 +0000 (UTC) Received: from localhost ([::1]:33936 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ogVHl-0002YP-AV for qemu-devel@archiver.kernel.org; Thu, 06 Oct 2022 14:07:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45162) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ogUjg-0002hc-H0 for qemu-devel@nongnu.org; Thu, 06 Oct 2022 13:32:42 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:27480) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ogUjb-0001nP-Up for qemu-devel@nongnu.org; Thu, 06 Oct 2022 13:32:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1665077554; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=iEXNRgx/RDn5nxZajmoACrbSX4OGt/JNnoDexXqCBkw=; b=cFiaZxKj5ReUlxh5T3FuSWq4dS0h1xmT9e2YUOwtXkB1MCpKWs1vBMcT6gCHlLaDnMn9UK 86gKDAbj0d/8qz7+peA0tmtaIkpSSgYaPfCQ0zVFATNrirqFqHr3ENyHK338fSMg8PvzPE pDQgxsWeInFsNgj0bsDvqhwKIQlSXdE= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-57-SqaY2pR7OmKNSSWlBW-QAg-1; Thu, 06 Oct 2022 13:32:31 -0400 X-MC-Unique: SqaY2pR7OmKNSSWlBW-QAg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 32AB08027FE; Thu, 6 Oct 2022 17:32:30 +0000 (UTC) Received: from localhost (unknown [10.39.193.119]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6CFC82024CBB; Thu, 6 Oct 2022 17:32:28 +0000 (UTC) Date: Thu, 6 Oct 2022 13:32:26 -0400 From: Stefan Hajnoczi To: Stefano Garzarella Cc: qemu-devel@nongnu.org, Yanan Wang , Kevin Wolf , Markus Armbruster , John Snow , "Denis V. Lunev" , Xie Changlong , Eric Blake , integration@gluster.org, David Hildenbrand , Wen Congyang , Laurent Vivier , "Richard W.M. Jones" , afaria@redhat.com, Fam Zheng , Thomas Huth , Hanna Reitz , Eduardo Habkost , Peter Xu , Raphael Norwitz , Marcel Apfelbaum , Vladimir Sementsov-Ogievskiy , Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= , Jeff Cody , qemu-block@nongnu.org, Paolo Bonzini , Richard Henderson , "Michael S. Tsirkin" Subject: Re: [PATCH v5 00/12] blkio: add libblkio BlockDriver Message-ID: References: <20220927193431.22302-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="7KrLp3hww3Zx0w3B" Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --7KrLp3hww3Zx0w3B Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Oct 06, 2022 at 02:18:35PM +0200, Stefano Garzarella wrote: > Hi Stefan, > I tested this series with the vDPA block simulator in Linux v6.0. > It worked well, but I had a segfault when blkio_map_mem_region() fails. >=20 > In my case, it failed because I forgot to increase the `memlock` limit=20 > with `ulimit -l unlimited` since the simulator still requires locking=20 > all the VM memory. >=20 > QEMU failed with this messages: > $ qemu-system-x86_64 ... \ > -blockdev node-name=3Ddrive_src1,driver=3Dvirtio-blk-vhost-vdpa,path=3D= /dev/vhost-vdpa-0,cache.direct=3Don > qemu-system-x86_64: -device virtio-blk-pci,id=3Dsrc1,bootindex=3D2,drive= =3Ddrive_src1,iothread=3Diothread0: Failed to add blkio mem region 0x7f60bf= e00000 with size 536870912: Bad address (os error 14) > qemu-system-x86_64: -device virtio-blk-pci,id=3Dsrc1,bootindex=3D2,drive= =3Ddrive_src1,iothread=3Diothread0: Failed to add blkio mem region 0x7f60be= 400000 with size 16777216: Bad address (os error 14) > [1] 20803 segmentation fault >=20 > IIUC this could be related to a double call to=20 > ram_block_notifier_remove() in the error path of ram_block_added()=20 > (block/block-ram-registrar.c) callback. >=20 > Maybe we should call blk_register_buf() only if r->ok is true. Thanks for pointing this out! The notifiers don't use QLIST_FOREACH_SAFE() so calling ram_block_notifier_remove() from within .ram_block_added() is incorrect. Stefan >=20 > The stack trace is the following: > #0 0x00005641a8b097dd in ram_block_notifier_remove (n=3Dn@entry=3D0x5641= ab8354d8) at ../hw/core/numa.c:850 > #1 0x00005641a89c4701 in ram_block_added > (n=3D0x5641ab8354d8, host=3D, size=3D,= max_size=3D) > at ../block/block-ram-registrar.c:20 > #2 0x00005641a8b083af in ram_block_notify_add_single (rb=3D0x5641ab3d281= 0, opaque=3D0x5641ab8354d8) > at ../hw/core/numa.c:820 > #3 0x00005641a8b92d8d in qemu_ram_foreach_block > (func=3Dfunc@entry=3D0x5641a8b08370 , op= aque=3Dopaque@entry=3D0x5641ab8354d8) > at ../softmmu/physmem.c:3571 > #4 0x00005641a8b097af in ram_block_notifier_add (n=3Dn@entry=3D0x5641ab8= 354d8) at ../hw/core/numa.c:844 > #5 0x00005641a89c474f in blk_ram_registrar_init (r=3Dr@entry=3D0x5641ab8= 354d0, blk=3D) > at ../block/block-ram-registrar.c:46 > #6 0x00005641a8affe88 in virtio_blk_device_realize (dev=3D0x5641ab835230= , errp=3D0x7ffc72657190) > at ../hw/block/virtio-blk.c:1239 > #7 0x00005641a8b4b716 in virtio_device_realize (dev=3D0x5641ab835230, er= rp=3D0x7ffc726571f0) > at ../hw/virtio/virtio.c:3684 > #8 0x00005641a8c2049b in device_set_realized (obj=3D, val= ue=3D, errp=3D0x7ffc72657380) > at ../hw/core/qdev.c:553 > #9 0x00005641a8c24738 in property_set_bool > (obj=3D0x5641ab835230, v=3D, name=3D, o= paque=3D0x5641aa518820, errp=3D0x7ffc72657380) > at ../qom/object.c:2273 > #10 0x00005641a8c27683 in object_property_set > =20 > (obj=3Dobj@entry=3D0x5641ab835230, name=3Dname@entry=3D0x5641a8e9719= a "realized", v=3Dv@entry=3D0x5641ab83f5b0, errp=3Derrp@entry=3D0x7ffc72657= 380) at ../qom/object.c:1408 > #11 0x00005641a8c2a97f in object_property_set_qobject > (obj=3Dobj@entry=3D0x5641ab835230, name=3Dname@entry=3D0x5641a8e9719a= "realized", value=3Dvalue@entry=3D0x5641ab83f4f0, errp=3Derrp@entry=3D0x7f= fc72657380) at ../qom/qom-qobject.c:28 > #12 0x00005641a8c27c84 in object_property_set_bool > (obj=3D0x5641ab835230, name=3D0x5641a8e9719a "realized", value=3D, errp=3D0x7ffc72657380) > at ../qom/object.c:1477 > #13 0x00005641a8929b74 in pci_qdev_realize (qdev=3D, errp= =3D) at ../hw/pci/pci.c:2218 > #14 0x00005641a8c2049b in device_set_realized (obj=3D, val= ue=3D, errp=3D0x7ffc726575b0) > at ../hw/core/qdev.c:553 > #15 0x00005641a8c24738 in property_set_bool > (obj=3D0x5641ab82ce70, v=3D, name=3D, o= paque=3D0x5641aa518820, errp=3D0x7ffc726575b0) > at ../qom/object.c:2273 > #16 0x00005641a8c27683 in object_property_set >=20 > Thanks, > Stefano >=20 > On Tue, Sep 27, 2022 at 9:34 PM Stefan Hajnoczi wro= te: > > > > v5: > > - Drop "RFC" since libblkio 1.0 has been released and the library API i= s stable > > - Disable BDRV_REQ_REGISTERED_BUF if we run out of blkio_mem_regions. T= he > > bounce buffer slow path is taken when there are not enough blkio_mem_= regions > > to cover guest RAM. [Hanna & David Hildenbrand] > > - Call ram_block_discard_disable() when mem-region-pinned property is t= rue or > > absent [David Hildenbrand] > > - Use a bounce buffer pool instead of allocating/freeing a buffer for e= ach > > request. This reduces the number of blkio_mem_regions required for bo= unce > > buffers to 1 and avoids frequent blkio_mem_region_map/unmap() calls. > > - Switch to .bdrv_co_*() instead of .bdrv_aio_*(). Needed for the bounc= e buffer > > pool's CoQueue. > > v4: > > - Patch 1: > > - Add virtio-blk-vhost-user driver [Kevin] > > - Drop .bdrv_parse_filename() and .bdrv_needs_filename for virtio-blk= -vhost-vdpa [Stefano] > > - Add copyright and license header [Hanna] > > - Drop .bdrv_parse_filename() in favor of --blockdev or json: [Hanna] > > - Clarify that "filename" is always non-NULL for io_uring [Hanna] > > - Check that virtio-blk-vhost-vdpa "path" option is non-NULL [Hanna] > > - Fix virtio-blk-vhost-vdpa cache.direct=3Doff logic [Hanna] > > - Use macros for driver names [Hanna] > > - Assert that the driver name is valid [Hanna] > > - Update "readonly" property name to "read-only" [Hanna] > > - Call blkio_detach_aio_context() in blkio_close() [Hanna] > > - Avoid uint32_t * to int * casts in blkio_refresh_limits() [Hanna] > > - Remove write zeroes and discard from the todo list [Hanna] > > - Use PRIu32 instead of %d for uint32_t [Hanna] > > - Fix error messages with buf-alignment instead of optimal-io-size [H= anna] > > - Call map/unmap APIs since libblkio alloc/free APIs no longer do that > > - Update QAPI schema QEMU version to 7.2 > > - Patch 5: > > - Expand the BDRV_REQ_REGISTERED_BUF flag passthrough and drop assert= (!flags) > > in drivers [Hanna] > > - Patch 7: > > - Fix BLK->BDRV typo [Hanna] > > - Make BlockRAMRegistrar handle failure [Hanna] > > - Patch 8: > > - Replace memory_region_get_fd() approach with qemu_ram_get_fd() > > - Patch 10: > > - Use (void)ret; to discard unused return value [Hanna] > > - libblkio's blkio_unmap_mem_region() API no longer has a return value > > - Check for registered bufs that cross RAMBlocks [Hanna] > > - Patch 11: > > - Handle bdrv_register_buf() errors [Hanna] > > v3: > > - Add virtio-blk-vhost-vdpa for vdpa-blk devices including VDUSE > > - Add discard and write zeroes support > > - Rebase and adopt latest libblkio APIs > > v2: > > - Add BDRV_REQ_REGISTERED_BUF to bs.supported_write_flags [Stefano] > > - Use new blkioq_get_num_completions() API > > - Implement .bdrv_refresh_limits() > > > > This patch series adds a QEMU BlockDriver for libblkio > > (https://gitlab.com/libblkio/libblkio/), a library for high-performance= block > > device I/O. This work was presented at KVM Forum 2022 and slides are av= ailable > > here: > > https://static.sched.com/hosted_files/kvmforum2022/8c/libblkio-kvm-foru= m-2022.pdf > > > > The second patch adds the core BlockDriver and most of the libblkio API= usage. > > Three libblkio drivers are included: > > - io_uring > > - virtio-blk-vhost-user > > - virtio-blk-vhost-vdpa > > > > The remainder of the patch series reworks the existing QEMU bdrv_regist= er_buf() > > API so virtio-blk emulation efficiently map guest RAM for libblkio - so= me > > libblkio drivers require that I/O buffer memory is pre-registered (thin= k VFIO, > > vhost, etc). > > > > Vladimir requested performance results that show the effect of the > > BDRV_REQ_REGISTERED_BUF flag. I ran the patches against qemu-storage-da= emon's > > vhost-user-blk export with iodepth=3D1 bs=3D512 to see the per-request = overhead due > > to bounce buffer allocation/mapping: > > > > Name IOPS Error > > bounce-buf 4373.81 =B1 0.01% > > registered-buf 13062.80 =B1 0.67% > > > > The BDRV_REQ_REGISTERED_BUF optimization version is about 3x faster. > > > > See the BlockDriver struct in block/blkio.c for a list of APIs that sti= ll need > > to be implemented. The core functionality is covered. > > > > Regarding the design: each libblkio driver is a separately named BlockD= river. > > That means there is an "io_uring" BlockDriver and not a generic "libblk= io" > > BlockDriver. This way QAPI and open parameters are type-safe and mandat= ory > > parameters can be checked by QEMU. > > > > Stefan Hajnoczi (12): > > coroutine: add flag to re-queue at front of CoQueue > > blkio: add libblkio block driver > > numa: call ->ram_block_removed() in ram_block_notifer_remove() > > block: pass size to bdrv_unregister_buf() > > block: use BdrvRequestFlags type for supported flag fields > > block: add BDRV_REQ_REGISTERED_BUF request flag > > block: return errors from bdrv_register_buf() > > block: add BlockRAMRegistrar > > exec/cpu-common: add qemu_ram_get_fd() > > stubs: add qemu_ram_block_from_host() and qemu_ram_get_fd() > > blkio: implement BDRV_REQ_REGISTERED_BUF optimization > > virtio-blk: use BDRV_REQ_REGISTERED_BUF optimization hint > > > > MAINTAINERS | 7 + > > meson_options.txt | 2 + > > qapi/block-core.json | 53 +- > > meson.build | 9 + > > include/block/block-common.h | 9 + > > include/block/block-global-state.h | 10 +- > > include/block/block_int-common.h | 15 +- > > include/exec/cpu-common.h | 1 + > > include/hw/virtio/virtio-blk.h | 2 + > > include/qemu/coroutine.h | 15 +- > > include/sysemu/block-backend-global-state.h | 4 +- > > include/sysemu/block-ram-registrar.h | 37 + > > block.c | 14 + > > block/blkio.c | 1017 +++++++++++++++++++ > > block/blkverify.c | 4 +- > > block/block-backend.c | 8 +- > > block/block-ram-registrar.c | 54 + > > block/crypto.c | 4 +- > > block/file-posix.c | 1 - > > block/gluster.c | 1 - > > block/io.c | 101 +- > > block/mirror.c | 2 + > > block/nbd.c | 1 - > > block/nvme.c | 20 +- > > block/parallels.c | 1 - > > block/qcow.c | 2 - > > block/qed.c | 1 - > > block/raw-format.c | 2 + > > block/replication.c | 1 - > > block/ssh.c | 1 - > > block/vhdx.c | 1 - > > hw/block/virtio-blk.c | 39 +- > > hw/core/numa.c | 17 + > > qemu-img.c | 6 +- > > softmmu/physmem.c | 5 + > > stubs/physmem.c | 13 + > > tests/qtest/modules-test.c | 3 + > > util/qemu-coroutine-lock.c | 9 +- > > util/vfio-helpers.c | 5 +- > > block/meson.build | 2 + > > scripts/meson-buildoptions.sh | 3 + > > stubs/meson.build | 1 + > > 42 files changed, 1412 insertions(+), 91 deletions(-) > > create mode 100644 include/sysemu/block-ram-registrar.h > > create mode 100644 block/blkio.c > > create mode 100644 block/block-ram-registrar.c > > create mode 100644 stubs/physmem.c > > > > -- > > 2.37.3 > > >=20 --7KrLp3hww3Zx0w3B Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmM/ESoACgkQnKSrs4Gr c8jEbQgAtVcPRYumevBA7TZjJ3SsDcRg9QCaXgBxfIoYAjM3X5eEeJcWVkj7mxj5 Ae421mghRJU/T1KRbhUZBLADuyY5hT+iv0YAXN1HF8T1Kn51UZFcwgGmUX5SWwhp i7507ixp6rea8QKfaRi5r7QZaKQ21iCuPdWvUPYZJYs1bj4MjZloxDEegy80Sk0W B5C6QsZ/Mtzv6wRrQvDAe42NsfhX9mT1H4NkMEQQbCaXbyQpA+n9e8C9t1BhnVpZ 0l+fvFoV4KEulKM0zgEqUzIIZaN5HgAdl/RLzhhanjxRRZ/TT4XF449FUcmqe/gJ 4MrkW8/Ip0OjBQlsoLdD1kjCPTTKZQ== =fm8s -----END PGP SIGNATURE----- --7KrLp3hww3Zx0w3B--