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=-8.1 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,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 6D586C433E1 for ; Thu, 21 May 2020 19:06:50 +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 3FA8520872 for ; Thu, 21 May 2020 19:06:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AtmCsKE2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3FA8520872 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:56542 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jbqWn-0004Lh-E6 for qemu-devel@archiver.kernel.org; Thu, 21 May 2020 15:06:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36744) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jbqW5-0003v3-Iy for qemu-devel@nongnu.org; Thu, 21 May 2020 15:06:05 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:42663 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jbqW3-000766-5y for qemu-devel@nongnu.org; Thu, 21 May 2020 15:06:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590087961; 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=J6hD4XRtvPPzO87WAGVfqnPjHpxSsLwhkexPZp+M4BI=; b=AtmCsKE2u/hzSfipI9+Cuxmwr/5FXf7FIVL0hd5hWeKa9D16hwVhcEOygq+wLoJ23HQtMM fmWrM3hhVQkhGnF3Quk6koLl8B4vtR03k+pMblL5nkAVr9qOKvROB1bbjHV5jbwz394srb a/5eo2ndjEYpZnTViihoChvRLTg9MqQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-331-4H7vBDAuO8OyRyhBRmG3OA-1; Thu, 21 May 2020 15:05:57 -0400 X-MC-Unique: 4H7vBDAuO8OyRyhBRmG3OA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E91271005512; Thu, 21 May 2020 19:05:54 +0000 (UTC) Received: from work-vm (ovpn-113-115.ams2.redhat.com [10.36.113.115]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 092C560C05; Thu, 21 May 2020 19:05:43 +0000 (UTC) Date: Thu, 21 May 2020 20:05:41 +0100 From: "Dr. David Alan Gilbert" To: Kirti Wankhede Subject: Re: [PATCH QEMU v23 16/18] vfio: Add ioctl to get dirty pages bitmap during dma unmap. Message-ID: <20200521190541.GN2752@work-vm> References: <1589999088-31477-1-git-send-email-kwankhede@nvidia.com> <1589999088-31477-17-git-send-email-kwankhede@nvidia.com> MIME-Version: 1.0 In-Reply-To: <1589999088-31477-17-git-send-email-kwankhede@nvidia.com> User-Agent: Mutt/1.13.4 (2020-02-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=207.211.31.81; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/21 04:44:45 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] 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, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001, T_HK_NAME_DR=0.01, 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, alex.williamson@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" * Kirti Wankhede (kwankhede@nvidia.com) 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 | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 80 insertions(+), 4 deletions(-) > > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > index 3f7049fbd1b0..2dd9e8b24788 100644 > --- a/hw/vfio/common.c > +++ b/hw/vfio/common.c > @@ -311,11 +311,82 @@ 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) { > + 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; > + } > + } > + } > + 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)); > + if (!unmap) { > + return -ENOMEM; > + } Again that's a fixed size thing so you don't really need to malloc it; g_malloc0 won't return NULL; it'll just assert (which it shouldn't do anyway because those structures are small). Personally I'd just put it on the stack. > + 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_malloc0(bitmap->size); That one should be a g_try_malloc0 and check it's non-null. > + > + 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 : %d", -errno); You're allowed touse %m in hw/vfio for printing the error nicely. > + } > + > + 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 +395,11 @@ 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 +447,7 @@ 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; > } > @@ -519,7 +595,7 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) > iotlb->addr_mask + 1, vaddr, ret); > } > } else { > - 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)", > @@ -822,7 +898,7 @@ 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)", > -- > 2.7.0 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK