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Thu, 26 Mar 2020 19:46:53 +0000 (UTC) Received: from x1.home (ovpn-112-162.phx2.redhat.com [10.3.112.162]) by smtp.corp.redhat.com (Postfix) with ESMTP id 369D690538; Thu, 26 Mar 2020 19:46:51 +0000 (UTC) Date: Thu, 26 Mar 2020 13:46:50 -0600 From: Alex Williamson To: Kirti Wankhede Subject: Re: [PATCH v16 QEMU 14/16] vfio: Add vfio_listener_log_sync to mark dirty pages Message-ID: <20200326134650.0c7245e9@x1.home> In-Reply-To: <1585084154-29461-15-git-send-email-kwankhede@nvidia.com> References: <1585084154-29461-1-git-send-email-kwankhede@nvidia.com> <1585084154-29461-15-git-send-email-kwankhede@nvidia.com> Organization: Red Hat MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 63.128.21.74 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: Zhengxiao.zx@Alibaba-inc.com, kevin.tian@intel.com, yi.l.liu@intel.com, cjia@nvidia.com, eskultet@redhat.com, ziye.yang@intel.com, qemu-devel@nongnu.org, cohuck@redhat.com, shuangtai.tst@alibaba-inc.com, dgilbert@redhat.com, zhi.a.wang@intel.com, mlevitsk@redhat.com, pasic@linux.ibm.com, aik@ozlabs.ru, eauger@redhat.com, felipe@nutanix.com, jonathan.davies@nutanix.com, yan.y.zhao@intel.com, changpeng.liu@intel.com, Ken.Xue@amd.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 25 Mar 2020 02:39:12 +0530 Kirti Wankhede wrote: > vfio_listener_log_sync gets list of dirty pages from container using > VFIO_IOMMU_GET_DIRTY_BITMAP ioctl and mark those pages dirty when all > devices are stopped and saving state. > Return early for the RAM block section of mapped MMIO region. > > Signed-off-by: Kirti Wankhede > Reviewed-by: Neo Jia > --- > hw/vfio/common.c | 200 +++++++++++++++++++++++++++++++++++++++++++++++++-- > hw/vfio/trace-events | 1 + > 2 files changed, 196 insertions(+), 5 deletions(-) > > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > index 4a2f0d6a2233..6d41e1ac5c2f 100644 > --- a/hw/vfio/common.c > +++ b/hw/vfio/common.c > @@ -29,6 +29,7 @@ > #include "hw/vfio/vfio.h" > #include "exec/address-spaces.h" > #include "exec/memory.h" > +#include "exec/ram_addr.h" > #include "hw/hw.h" > #include "qemu/error-report.h" > #include "qemu/main-loop.h" > @@ -38,6 +39,7 @@ > #include "sysemu/reset.h" > #include "trace.h" > #include "qapi/error.h" > +#include "migration/migration.h" > > VFIOGroupList vfio_group_list = > QLIST_HEAD_INITIALIZER(vfio_group_list); > @@ -288,6 +290,28 @@ const MemoryRegionOps vfio_region_ops = { > }; > > /* > + * Device state interfaces > + */ > + > +static bool vfio_devices_are_stopped_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; > +} > + > +/* > * DMA - Mapping and unmapping for the "type1" IOMMU interface used on x86 > */ > static int vfio_dma_unmap(VFIOContainer *container, > @@ -408,8 +432,8 @@ static bool vfio_listener_skipped_section(MemoryRegionSection *section) > } > > /* Called with rcu_read_lock held. */ > -static bool vfio_get_vaddr(IOMMUTLBEntry *iotlb, void **vaddr, > - bool *read_only) > +static bool vfio_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr, > + ram_addr_t *ram_addr, bool *read_only) > { > MemoryRegion *mr; > hwaddr xlat; > @@ -440,9 +464,17 @@ static bool vfio_get_vaddr(IOMMUTLBEntry *iotlb, void **vaddr, > return false; > } > > - *vaddr = memory_region_get_ram_ptr(mr) + xlat; > - *read_only = !writable || mr->readonly; > + if (vaddr) { > + *vaddr = memory_region_get_ram_ptr(mr) + xlat; > + } > > + if (ram_addr) { > + *ram_addr = memory_region_get_ram_addr(mr) + xlat; > + } > + > + if (read_only) { > + *read_only = !writable || mr->readonly; > + } > return true; > } > > @@ -467,7 +499,7 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb) > rcu_read_lock(); > > if ((iotlb->perm & IOMMU_RW) != IOMMU_NONE) { > - if (!vfio_get_vaddr(iotlb, &vaddr, &read_only)) { > + if (!vfio_get_xlat_addr(iotlb, &vaddr, NULL, &read_only)) { > goto out; > } > /* > @@ -813,9 +845,167 @@ static void vfio_listener_region_del(MemoryListener *listener, > } > } > > +static int vfio_get_dirty_bitmap(MemoryListener *listener, > + MemoryRegionSection *section) > +{ > + VFIOContainer *container = container_of(listener, VFIOContainer, listener); > + VFIOGuestIOMMU *giommu; > + IOMMUTLBEntry iotlb; > + hwaddr granularity, address_limit, iova; > + int ret; > + > + if (memory_region_is_iommu(section->mr)) { > + QLIST_FOREACH(giommu, &container->giommu_list, giommu_next) { > + if (MEMORY_REGION(giommu->iommu) == section->mr && > + giommu->n.start == section->offset_within_region) { > + break; > + } > + } > + > + if (!giommu) { > + return -EINVAL; > + } > + } > + > + if (memory_region_is_iommu(section->mr)) { > + granularity = memory_region_iommu_get_min_page_size(giommu->iommu); > + > + address_limit = MIN(int128_get64(section->size), > + memory_region_iommu_get_address_limit(giommu->iommu, > + int128_get64(section->size))); > + } else { > + granularity = memory_region_size(section->mr); > + address_limit = int128_get64(section->size); > + } > + > + iova = TARGET_PAGE_ALIGN(section->offset_within_address_space); > + > + RCU_READ_LOCK_GUARD(); > + > + while (iova < address_limit) { > + struct vfio_iommu_type1_dirty_bitmap *dbitmap; > + struct vfio_iommu_type1_dirty_bitmap_get *range; > + ram_addr_t start, pages; > + uint64_t iova_xlat, size; > + > + if (memory_region_is_iommu(section->mr)) { > + iotlb = address_space_get_iotlb_entry(container->space->as, iova, > + true, MEMTXATTRS_UNSPECIFIED); > + if ((iotlb.target_as == NULL) || (iotlb.addr_mask == 0)) { > + if ((iova + granularity) < iova) { > + break; > + } > + iova += granularity; > + continue; > + } > + iova_xlat = iotlb.iova + giommu->iommu_offset; > + size = iotlb.addr_mask + 1; > + } else { > + iova_xlat = iova; > + size = address_limit; > + } > + > + dbitmap = g_malloc0(sizeof(*dbitmap) + sizeof(*range)); > + if (!dbitmap) { AIUI, QEMU aborts if this fails, so no need to check. Because reasons. > + return -ENOMEM; > + } > + > + dbitmap->argsz = sizeof(*dbitmap) + sizeof(*range); > + dbitmap->flags = VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP; > + range = (struct vfio_iommu_type1_dirty_bitmap_get *)&dbitmap->data; > + range->iova = iova_xlat; > + range->size = size; > + > + /* > + * cpu_physical_memory_set_dirty_lebitmap() expects pages in bitmap of > + * TARGET_PAGE_SIZE to mark those dirty. Hence set bitmap's pgsize to > + * TARGET_PAGE_SIZE. > + */ > + range->bitmap.pgsize = TARGET_PAGE_SIZE; > + > + /* > + * Comment from kvm_physical_sync_dirty_bitmap() since same applies here > + * XXX bad kernel interface alert > + * For dirty bitmap, kernel allocates array of size aligned to > + * bits-per-long. But for case when the kernel is 64bits and > + * the userspace is 32bits, userspace can't align to the same > + * bits-per-long, since sizeof(long) is different between kernel > + * and user space. This way, userspace will provide buffer which > + * may be 4 bytes less than the kernel will use, resulting in > + * userspace memory corruption (which is not detectable by valgrind > + * too, in most cases). > + * So for now, let's align to 64 instead of HOST_LONG_BITS here, in > + * a hope that sizeof(long) won't become >8 any time soon. > + */ This seems like the problem we've avoided by defining our bitmap as an array of u64s rather than an array of longs. Does this comment really still apply? > + > + pages = TARGET_PAGE_ALIGN(range->size) >> TARGET_PAGE_BITS; > + range->bitmap.size = ROUND_UP(pages, 64) / 8; ROUND_UP(npages/8, sizeof(u64))? > + range->bitmap.data = g_malloc0(range->bitmap.size); We don't require this to be pre-zero'd currently. > + if (range->bitmap.data == NULL) { Same as above. Seems strange to me too. > + error_report("Error allocating bitmap of size 0x%llx", > + range->bitmap.size); > + ret = -ENOMEM; > + goto err_out; > + } > + > + ret = ioctl(container->fd, VFIO_IOMMU_DIRTY_PAGES, dbitmap); > + if (ret) { > + error_report("Failed to get dirty bitmap for iova: 0x%llx " > + "size: 0x%llx err: %d", > + range->iova, range->size, errno); > + goto err_out; > + } > + > + if (memory_region_is_iommu(section->mr)) { > + if (!vfio_get_xlat_addr(&iotlb, NULL, &start, NULL)) { > + ret = -EINVAL; > + goto err_out; > + } > + } else { > + start = memory_region_get_ram_addr(section->mr) + > + section->offset_within_region + iova - > + TARGET_PAGE_ALIGN(section->offset_within_address_space); > + } > + > + cpu_physical_memory_set_dirty_lebitmap((uint64_t *)range->bitmap.data, > + start, pages); > + > + trace_vfio_get_dirty_bitmap(container->fd, range->iova, range->size, > + range->bitmap.size, start); > +err_out: > + g_free(range->bitmap.data); > + g_free(dbitmap); > + > + if (ret) { > + return ret; > + } > + > + if ((iova + size) < iova) { > + break; > + } > + > + iova += size; > + } > + > + return 0; > +} > + > +static void vfio_listerner_log_sync(MemoryListener *listener, > + MemoryRegionSection *section) > +{ > + if (vfio_listener_skipped_section(section)) { > + return; > + } > + > + if (vfio_devices_are_stopped_and_saving()) { > + vfio_get_dirty_bitmap(listener, section); > + } > +} > + > static const MemoryListener vfio_memory_listener = { > .region_add = vfio_listener_region_add, > .region_del = vfio_listener_region_del, > + .log_sync = vfio_listerner_log_sync, > }; > > static void vfio_listener_release(VFIOContainer *container) > diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events > index ac065b559f4e..bc8f35ee9356 100644 > --- a/hw/vfio/trace-events > +++ b/hw/vfio/trace-events > @@ -160,3 +160,4 @@ vfio_save_complete_precopy(char *name) " (%s)" > vfio_load_device_config_state(char *name) " (%s)" > vfio_load_state(char *name, uint64_t data) " (%s) data 0x%"PRIx64 > vfio_load_state_device_data(char *name, uint64_t data_offset, uint64_t data_size) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64 > +vfio_get_dirty_bitmap(int fd, uint64_t iova, uint64_t size, uint64_t bitmap_size, uint64_t start) "container fd=%d, iova=0x%"PRIx64" size= 0x%"PRIx64" bitmap_size=0x%"PRIx64" start=0x%"PRIx64