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 873E1C77B7A for ; Fri, 19 May 2023 05:35:06 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pzsl0-0005k3-Su; Fri, 19 May 2023 01:34:26 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pzskx-0005jY-Ow for qemu-devel@nongnu.org; Fri, 19 May 2023 01:34:24 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pzskv-0006sZ-TH for qemu-devel@nongnu.org; Fri, 19 May 2023 01:34:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1684474460; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hyBt3dGF7ywscTlzp6IqhqjH0cOqmeYH/OS6rsKK3KU=; b=IMU5HYw4mnpNgD61jxui4hgu5602sJx/U4gdC1WZJe+uXlvUsbC+cD7yKdfmEJDxAWqJ+I LbwsUXWs5a0N8eqQyoXvhXQiId2T62mrbs9B0AVmbq2f2S1lNIU7FAUuHibi9xU7vzQeIL 87TkPcEDIRy6aNhV4FCiwu0U1q6dxqU= Received: from mail-lf1-f69.google.com (mail-lf1-f69.google.com [209.85.167.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-379-tEGpLuXiOTqXLGxZ1Ge6Sg-1; Fri, 19 May 2023 01:34:18 -0400 X-MC-Unique: tEGpLuXiOTqXLGxZ1Ge6Sg-1 Received: by mail-lf1-f69.google.com with SMTP id 2adb3069b0e04-4f3a9670ae0so680411e87.2 for ; Thu, 18 May 2023 22:34:18 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684474457; x=1687066457; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=hyBt3dGF7ywscTlzp6IqhqjH0cOqmeYH/OS6rsKK3KU=; b=mDwy++eKXctVpb7mdJ5EilG8zgOU9KgbL9vT0hraSW/3i6qut4KONrisWUE10E02A0 abHmNXf3f+IV5JuscaV3XU5IEi8njAKKBhPAvRx5F243cLtWkiywn2BLrSR7AGp2R8r8 aiOMlk7knC/kO24uE8PNOl0fafbpqEPxlkBW9/95Tl1XHCREVGHkEstMe9ek5BrXr/ha E1GHEYImJ866J9ksAzXAOv4B7xR28HRAHGC7EP8vpDdQqWasaxAz03EY6hTJYSYut2LX g/pP3dNwDHfE1kzouneU8l+MlviHP4Z5WyYTlnEUlllzDNwOX8FFhwJClF9PpjoKWxyR pVag== X-Gm-Message-State: AC+VfDwuiyOWS0R0KeGQ3JupfyXSWrLURTmjzzXBr8sCeJ3o08b0SVaT ChxFhvzM/R5uspcgWgXh4IDQ6nlRacIQO/M8Kwyu8vylygEXtsPs6A7Zre/MZ9kw+AXrssgT9Ww 7QBDy4ZwkRlxHD9s= X-Received: by 2002:a19:c202:0:b0:4f3:9001:848c with SMTP id l2-20020a19c202000000b004f39001848cmr400254lfc.33.1684474457064; Thu, 18 May 2023 22:34:17 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ6YJa5m3+xXoUd6LwLV3UCraXx2EdnOWkut4Kt4HSrisrV7qol1KHiRI2b/s0z/+hRZqR5/Cw== X-Received: by 2002:a19:c202:0:b0:4f3:9001:848c with SMTP id l2-20020a19c202000000b004f39001848cmr400242lfc.33.1684474456662; Thu, 18 May 2023 22:34:16 -0700 (PDT) Received: from redhat.com ([2a02:14f:175:3e4d:6703:27b9:6f74:5282]) by smtp.gmail.com with ESMTPSA id b20-20020ac247f4000000b004eaeb0a984csm474515lfp.88.2023.05.18.22.34.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 May 2023 22:34:15 -0700 (PDT) Date: Fri, 19 May 2023 01:34:09 -0400 From: "Michael S. Tsirkin" To: Vladimir Sementsov-Ogievskiy Cc: qemu-devel@nongnu.org, marcel.apfelbaum@gmail.com, philmd@linaro.org, david@redhat.com, peterx@redhat.com, pbonzini@redhat.com, den-plotnikov@yandex-team.ru, lersek@redhat.com, kraxel@redhat.com, dgilbert@redhat.com, quintela@redhat.com, armbru@redhat.com Subject: Re: [PATCH v3 3/3] pci: ROM preallocation for incoming migration Message-ID: <20230519013355-mutt-send-email-mst@kernel.org> References: <20230515125229.44836-1-vsementsov@yandex-team.ru> <20230515125229.44836-4-vsementsov@yandex-team.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20230515125229.44836-4-vsementsov@yandex-team.ru> Received-SPF: pass client-ip=170.10.129.124; envelope-from=mst@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, T_SCC_BODY_TEXT_LINE=-0.01 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-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mon, May 15, 2023 at 03:52:29PM +0300, Vladimir Sementsov-Ogievskiy wrote: > On incoming migration we have the following sequence to load option > ROM: > > 1. On device realize we do normal load ROM from the file > > 2. Than, on incoming migration we rewrite ROM from the incoming RAM > block. If sizes mismatch we fail, like this: > > Size mismatch: 0000:00:03.0/virtio-net-pci.rom: 0x40000 != 0x80000: Invalid argument > > This is not ideal when we migrate to updated distribution: we have to > keep old ROM files in new distribution and be careful around romfile > property to load correct ROM file. Which is loaded actually just to > allocate the ROM with correct length. > > Note, that romsize property doesn't really help: if we try to specify > it when default romfile is larger, it fails with something like: > > romfile "efi-virtio.rom" (160768 bytes) is too large for ROM size 65536 > > Let's just ignore ROM file when romsize is specified and we are in > incoming migration state. In other words, we need only to preallocate > ROM of specified size, local ROM file is unrelated. > > This way: > > If romsize was specified on source, we just use same commandline as on > source, and migration will work independently of local ROM files on > target. > > If romsize was not specified on source (and we have mismatching local > ROM file on target host), we have to specify romsize on target to match > source romsize. romfile parameter may be kept same as on source or may > be dropped, the file is not loaded anyway. > > As a bonus we avoid extra reading from ROM file on target. > > Note: when we don't have romsize parameter on source command line and > need it for target, it may be calculated as aligned up to power of two > size of ROM file on source (if we know, which file is it) or, > alternatively it may be retrieved from source QEMU by QMP qom-get > command, like > > { "execute": "qom-get", > "arguments": { > "path": "/machine/peripheral/CARD_ID/virtio-net-pci.rom[0]", > "property": "size" } } > > Suggested-by: Michael S. Tsirkin > Signed-off-by: Vladimir Sementsov-Ogievskiy > Reviewed-by: David Hildenbrand > Reviewed-by: Juan Quintela Breaks build here: In function ‘pci_add_option_rom’, inlined from ‘pci_qdev_realize’ at ../hw/pci/pci.c:2155:5: ../hw/pci/pci.c:2395:13: error: ‘size’ may be used uninitialized [-Werror=maybe-uninitialized] 2395 | if (load_image_size(path, ptr, size) < 0) { | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../hw/pci/pci.c: In function ‘pci_qdev_realize’: ../hw/pci/pci.c:2312:13: note: ‘size’ was declared here 2312 | int64_t size; | ^~~~ > --- > hw/pci/pci.c | 77 ++++++++++++++++++++++++++++++---------------------- > 1 file changed, 45 insertions(+), 32 deletions(-) > > diff --git a/hw/pci/pci.c b/hw/pci/pci.c > index 3a0107758c..0f0c83c02f 100644 > --- a/hw/pci/pci.c > +++ b/hw/pci/pci.c > @@ -36,6 +36,7 @@ > #include "migration/vmstate.h" > #include "net/net.h" > #include "sysemu/numa.h" > +#include "sysemu/runstate.h" > #include "sysemu/sysemu.h" > #include "hw/loader.h" > #include "qemu/error-report.h" > @@ -2308,10 +2309,16 @@ static void pci_add_option_rom(PCIDevice *pdev, bool is_default_rom, > { > int64_t size; > g_autofree char *path = NULL; > - void *ptr; > char name[32]; > const VMStateDescription *vmsd; > > + /* > + * In case of incoming migration ROM will come with migration stream, no > + * reason to load the file. Neither we want to fail if local ROM file > + * mismatches with specified romsize. > + */ > + bool load_file = !runstate_check(RUN_STATE_INMIGRATE); > + > if (!pdev->romfile || !strlen(pdev->romfile)) { > return; > } > @@ -2341,32 +2348,35 @@ static void pci_add_option_rom(PCIDevice *pdev, bool is_default_rom, > return; > } > > - path = qemu_find_file(QEMU_FILE_TYPE_BIOS, pdev->romfile); > - if (path == NULL) { > - path = g_strdup(pdev->romfile); > - } > + if (load_file || pdev->romsize == -1) { > + path = qemu_find_file(QEMU_FILE_TYPE_BIOS, pdev->romfile); > + if (path == NULL) { > + path = g_strdup(pdev->romfile); > + } > > - size = get_image_size(path); > - if (size < 0) { > - error_setg(errp, "failed to find romfile \"%s\"", pdev->romfile); > - return; > - } else if (size == 0) { > - error_setg(errp, "romfile \"%s\" is empty", pdev->romfile); > - return; > - } else if (size > 2 * GiB) { > - error_setg(errp, "romfile \"%s\" too large (size cannot exceed 2 GiB)", > - pdev->romfile); > - return; > - } > - if (pdev->romsize != -1) { > - if (size > pdev->romsize) { > - error_setg(errp, "romfile \"%s\" (%u bytes) " > - "is too large for ROM size %u", > - pdev->romfile, (uint32_t)size, pdev->romsize); > + size = get_image_size(path); > + if (size < 0) { > + error_setg(errp, "failed to find romfile \"%s\"", pdev->romfile); > + return; > + } else if (size == 0) { > + error_setg(errp, "romfile \"%s\" is empty", pdev->romfile); > + return; > + } else if (size > 2 * GiB) { > + error_setg(errp, > + "romfile \"%s\" too large (size cannot exceed 2 GiB)", > + pdev->romfile); > return; > } > - } else { > - pdev->romsize = pow2ceil(size); > + if (pdev->romsize != -1) { > + if (size > pdev->romsize) { > + error_setg(errp, "romfile \"%s\" (%u bytes) " > + "is too large for ROM size %u", > + pdev->romfile, (uint32_t)size, pdev->romsize); > + return; > + } > + } else { > + pdev->romsize = pow2ceil(size); > + } > } > > vmsd = qdev_get_vmsd(DEVICE(pdev)); > @@ -2377,15 +2387,18 @@ static void pci_add_option_rom(PCIDevice *pdev, bool is_default_rom, > memory_region_init_rom(&pdev->rom, OBJECT(pdev), name, pdev->romsize, > &error_fatal); > > - ptr = memory_region_get_ram_ptr(&pdev->rom); > - if (load_image_size(path, ptr, size) < 0) { > - error_setg(errp, "failed to load romfile \"%s\"", pdev->romfile); > - return; > - } > + if (load_file) { > + void *ptr = memory_region_get_ram_ptr(&pdev->rom); > > - if (is_default_rom) { > - /* Only the default rom images will be patched (if needed). */ > - pci_patch_ids(pdev, ptr, size); > + if (load_image_size(path, ptr, size) < 0) { > + error_setg(errp, "failed to load romfile \"%s\"", pdev->romfile); > + return; > + } > + > + if (is_default_rom) { > + /* Only the default rom images will be patched (if needed). */ > + pci_patch_ids(pdev, ptr, size); > + } > } > > pci_register_bar(pdev, PCI_ROM_SLOT, 0, &pdev->rom); > -- > 2.34.1