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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5AFDAC433E0 for ; Thu, 25 Jun 2020 15:02:39 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 25F12207D8 for ; Thu, 25 Jun 2020 15:02:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="q7fSDIip" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 25F12207D8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:38308 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1joTOg-0001CH-9q for qemu-devel@archiver.kernel.org; Thu, 25 Jun 2020 11:02:38 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59088) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1joTNj-0000g5-OW for qemu-devel@nongnu.org; Thu, 25 Jun 2020 11:01:39 -0400 Received: from hqnvemgate26.nvidia.com ([216.228.121.65]:4640) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1joTNh-0007rw-85 for qemu-devel@nongnu.org; Thu, 25 Jun 2020 11:01:39 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate26.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 25 Jun 2020 08:01:22 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 25 Jun 2020 08:01:35 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 25 Jun 2020 08:01:35 -0700 Received: from [10.40.100.228] (172.20.13.39) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 25 Jun 2020 15:01:16 +0000 Subject: Re: [PATCH QEMU v25 15/17] vfio: Add ioctl to get dirty pages bitmap during dma unmap. To: Alex Williamson References: <1592684486-18511-1-git-send-email-kwankhede@nvidia.com> <1592684486-18511-16-git-send-email-kwankhede@nvidia.com> <20200624125614.5e742574@x1.home> X-Nvconfidentiality: public From: Kirti Wankhede Message-ID: <8cf7ffdf-8ba4-d42d-cf8d-4af08686841a@nvidia.com> Date: Thu, 25 Jun 2020 20:31:12 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.8.1 MIME-Version: 1.0 In-Reply-To: <20200624125614.5e742574@x1.home> X-Originating-IP: [172.20.13.39] X-ClientProxiedBy: HQMAIL107.nvidia.com (172.20.187.13) To HQMAIL107.nvidia.com (172.20.187.13) Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1593097282; bh=AveRosUOB9EBRLnR+jM6+lA1ALzsFCfCT1Fihe1EQSA=; h=X-PGP-Universal:Subject:To:CC:References:X-Nvconfidentiality:From: Message-ID:Date:User-Agent:MIME-Version:In-Reply-To: X-Originating-IP:X-ClientProxiedBy:Content-Type:Content-Language: Content-Transfer-Encoding; b=q7fSDIip0+CmP0aic2uG+GV6xPjDb7LGoRv9Su7mS+2vx42lDh6rGLxdZ3nmPr2OL m/u7UCR0kK7GSIKoWCpmTcKnUm4N4u4Y4rm9ctFtV9sM/k+zPWVCvbHczEdbHLnVfS dG3a5nrmYXjUoB+Mbojk0Ez+4m+eoTUYmQDKDkV34x3MZQqdbU47jnrf0khDBD6Drv +asEVdWBoys8kBvyeBMUvicx2EFKx3FoHljzsJyRCdcazBMSf/lFsrS0Hr2kkl7q1h E5dRdZNrf+yjakGd4N2InXINbuEfzcYPozKfoyIJsiL4OvMwa4CHhXknnDpgw1Hkqd zzK1Rk4UwMaiQ== Received-SPF: pass client-ip=216.228.121.65; envelope-from=kwankhede@nvidia.com; helo=hqnvemgate26.nvidia.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/25 10:34:30 X-ACL-Warn: Detected OS = Windows 7 or 8 [fuzzy] X-Spam_score_int: -80 X-Spam_score: -8.1 X-Spam_bar: -------- X-Spam_report: (-8.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: cohuck@redhat.com, cjia@nvidia.com, aik@ozlabs.ru, Zhengxiao.zx@Alibaba-inc.com, shuangtai.tst@alibaba-inc.com, qemu-devel@nongnu.org, peterx@redhat.com, eauger@redhat.com, yi.l.liu@intel.com, quintela@redhat.com, ziye.yang@intel.com, armbru@redhat.com, mlevitsk@redhat.com, pasic@linux.ibm.com, felipe@nutanix.com, zhi.a.wang@intel.com, kevin.tian@intel.com, yan.y.zhao@intel.com, dgilbert@redhat.com, changpeng.liu@intel.com, eskultet@redhat.com, Ken.Xue@amd.com, jonathan.davies@nutanix.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 6/25/2020 12:26 AM, Alex Williamson wrote: > On Sun, 21 Jun 2020 01:51:24 +0530 > Kirti Wankhede wrote: > >> With vIOMMU, IO virtual address range can get unmapped while in pre-copy >> phase of migration. In that case, unmap ioctl should return pages pinned >> in that range and QEMU should find its correcponding guest physical >> addresses and report those dirty. >> >> Suggested-by: Alex Williamson >> Signed-off-by: Kirti Wankhede >> Reviewed-by: Neo Jia >> --- >> hw/vfio/common.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++++--- >> 1 file changed, 81 insertions(+), 4 deletions(-) >> >> diff --git a/hw/vfio/common.c b/hw/vfio/common.c >> index 0518cf228ed5..a06b8f2f66e2 100644 >> --- a/hw/vfio/common.c >> +++ b/hw/vfio/common.c >> @@ -311,11 +311,83 @@ static bool vfio_devices_are_stopped_and_saving(void) >> return true; >> } >> >> +static bool vfio_devices_are_running_and_saving(void) >> +{ >> + VFIOGroup *group; >> + VFIODevice *vbasedev; >> + >> + QLIST_FOREACH(group, &vfio_group_list, next) { > > Same as previous, I'm curious if we should instead be looking at > container granularity. It especially seems to make sense here where > we're unmapping from a container, so iterating every device in every > group seems excessive. > changing it with container argument. >> + QLIST_FOREACH(vbasedev, &group->device_list, next) { >> + if ((vbasedev->device_state & VFIO_DEVICE_STATE_SAVING) && >> + (vbasedev->device_state & VFIO_DEVICE_STATE_RUNNING)) { >> + continue; >> + } else { >> + return false; >> + } > > I'm also not sure about the polarity of this function, should it be if > any device is _SAVING we should report the dirty bitmap? For example, > what if we have a set of paried failover NICs where we intend to unplug > one just prior to stopping the devices, aren't we going to lose dirtied > pages with this logic that they all must be running and saving? Thanks, > If migration is initiated, is device unplug allowed? Ideally it shouldn't. If it is, then how QEMU handles data stream of device which doesn't exist at destination? _SAVING flag is set during pre-copy and stop-and-copy phase. Here we only want to track pages which are unmapped during pre-copy phase, i.e. when vCPU are running. In case of VM suspend /saveVM, there is no pre-copy phase, but ideally we shouldn't see unmaps when vCPUs are stopped, right? But still for safer side, since we know exact phase, I would prefer to check for _SAVING and _RUNNING flags. Thanks, Kirti > Alex > >> + } >> + } >> + return true; >> +} >> + >> +static int vfio_dma_unmap_bitmap(VFIOContainer *container, >> + hwaddr iova, ram_addr_t size, >> + IOMMUTLBEntry *iotlb) >> +{ >> + struct vfio_iommu_type1_dma_unmap *unmap; >> + struct vfio_bitmap *bitmap; >> + uint64_t pages = TARGET_PAGE_ALIGN(size) >> TARGET_PAGE_BITS; >> + int ret; >> + >> + unmap = g_malloc0(sizeof(*unmap) + sizeof(*bitmap)); >> + >> + unmap->argsz = sizeof(*unmap) + sizeof(*bitmap); >> + unmap->iova = iova; >> + unmap->size = size; >> + unmap->flags |= VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP; >> + bitmap = (struct vfio_bitmap *)&unmap->data; >> + >> + /* >> + * cpu_physical_memory_set_dirty_lebitmap() expects pages in bitmap of >> + * TARGET_PAGE_SIZE to mark those dirty. Hence set bitmap_pgsize to >> + * TARGET_PAGE_SIZE. >> + */ >> + >> + bitmap->pgsize = TARGET_PAGE_SIZE; >> + bitmap->size = ROUND_UP(pages, sizeof(__u64) * BITS_PER_BYTE) / >> + BITS_PER_BYTE; >> + >> + if (bitmap->size > container->max_dirty_bitmap_size) { >> + error_report("UNMAP: Size of bitmap too big 0x%llx", bitmap->size); >> + ret = -E2BIG; >> + goto unmap_exit; >> + } >> + >> + bitmap->data = g_try_malloc0(bitmap->size); >> + if (!bitmap->data) { >> + ret = -ENOMEM; >> + goto unmap_exit; >> + } >> + >> + ret = ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, unmap); >> + if (!ret) { >> + cpu_physical_memory_set_dirty_lebitmap((uint64_t *)bitmap->data, >> + iotlb->translated_addr, pages); >> + } else { >> + error_report("VFIO_UNMAP_DMA with DIRTY_BITMAP : %m"); >> + } >> + >> + g_free(bitmap->data); >> +unmap_exit: >> + g_free(unmap); >> + return ret; >> +} >> + >> /* >> * DMA - Mapping and unmapping for the "type1" IOMMU interface used on x86 >> */ >> static int vfio_dma_unmap(VFIOContainer *container, >> - hwaddr iova, ram_addr_t size) >> + hwaddr iova, ram_addr_t size, >> + IOMMUTLBEntry *iotlb) >> { >> struct vfio_iommu_type1_dma_unmap unmap = { >> .argsz = sizeof(unmap), >> @@ -324,6 +396,11 @@ static int vfio_dma_unmap(VFIOContainer *container, >> .size = size, >> }; >> >> + if (iotlb && container->dirty_pages_supported && >> + vfio_devices_are_running_and_saving()) { >> + return vfio_dma_unmap_bitmap(container, iova, size, iotlb); >> + } >> + >> while (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, &unmap)) { >> /* >> * The type1 backend has an off-by-one bug in the kernel (71a7d3d78e3c >> @@ -371,7 +448,7 @@ static int vfio_dma_map(VFIOContainer *container, hwaddr iova, >> * the VGA ROM space. >> */ >> if (ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map) == 0 || >> - (errno == EBUSY && vfio_dma_unmap(container, iova, size) == 0 && >> + (errno == EBUSY && vfio_dma_unmap(container, iova, size, NULL) == 0 && >> ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map) == 0)) { >> return 0; >> } >> @@ -542,7 +619,7 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) >> } >> } >> >> - ret = vfio_dma_unmap(container, iova, iotlb->addr_mask + 1); >> + ret = vfio_dma_unmap(container, iova, iotlb->addr_mask + 1, iotlb); >> if (ret) { >> error_report("vfio_dma_unmap(%p, 0x%"HWADDR_PRIx", " >> "0x%"HWADDR_PRIx") = %d (%m)", >> @@ -853,7 +930,7 @@ static void vfio_listener_region_del(MemoryListener *listener, >> } >> >> if (try_unmap) { >> - ret = vfio_dma_unmap(container, iova, int128_get64(llsize)); >> + ret = vfio_dma_unmap(container, iova, int128_get64(llsize), NULL); >> if (ret) { >> error_report("vfio_dma_unmap(%p, 0x%"HWADDR_PRIx", " >> "0x%"HWADDR_PRIx") = %d (%m)", >