From: Kirti Wankhede <kwankhede@nvidia.com>
To: Yan Zhao <yan.y.zhao@intel.com>
Cc: "Zhengxiao.zx@Alibaba-inc.com" <Zhengxiao.zx@Alibaba-inc.com>,
"Tian, Kevin" <kevin.tian@intel.com>,
"Liu, Yi L" <yi.l.liu@intel.com>,
"cjia@nvidia.com" <cjia@nvidia.com>,
"eskultet@redhat.com" <eskultet@redhat.com>,
"Yang, Ziye" <ziye.yang@intel.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
"cohuck@redhat.com" <cohuck@redhat.com>,
"shuangtai.tst@alibaba-inc.com" <shuangtai.tst@alibaba-inc.com>,
"dgilbert@redhat.com" <dgilbert@redhat.com>,
"Wang, Zhi A" <zhi.a.wang@intel.com>,
"mlevitsk@redhat.com" <mlevitsk@redhat.com>,
"pasic@linux.ibm.com" <pasic@linux.ibm.com>,
"aik@ozlabs.ru" <aik@ozlabs.ru>,
"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
"eauger@redhat.com" <eauger@redhat.com>,
"felipe@nutanix.com" <felipe@nutanix.com>,
"jonathan.davies@nutanix.com" <jonathan.davies@nutanix.com>,
"Liu, Changpeng" <changpeng.liu@intel.com>,
"Ken.Xue@amd.com" <Ken.Xue@amd.com>
Subject: Re: [PATCH v16 QEMU 14/16] vfio: Add vfio_listener_log_sync to mark dirty pages
Date: Sat, 4 Apr 2020 01:41:45 +0530 [thread overview]
Message-ID: <d431bdfb-f0ca-b8be-4e70-4b376a0e1f0b@nvidia.com> (raw)
In-Reply-To: <20200401055004.GE6631@joy-OptiPlex-7040>
On 4/1/2020 11:20 AM, Yan Zhao wrote:
> On Wed, Mar 25, 2020 at 05:09:12AM +0800, 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 <kwankhede@nvidia.com>
>> Reviewed-by: Neo Jia <cjia@nvidia.com>
>> ---
>> 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();
>> +
>
> the requirement of iova < address_limit is not right. reason as blow:
> when vIOMMU is NOT on,
> iova is section->offset_within_address_space,
> address_limit is section->size,
> but iova has not reason to be less than address_limit.
>
> for example, when vm memory size is large than 3G (e.g.4G)
> for memory region section of range (0x100000000-0x13fffffff),
> its iova is 0x100000000, address_limit is 0x40000000,
> then as iova is not less than address_limit, dirty pages query for memory
> 3G-4G will be skipped.
> Therefore dirty pages in 3G-4G will be lost.
>
>
Right, thanks. Fixing it. address_limit should be iova + size - 1
I did basic API testing with 2G memory. I'll make sure to test with more
than 4G to catch such bugs.
Thanks,
Kirti
>> + 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) {
>> + 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.
>> + */
>> +
>> + pages = TARGET_PAGE_ALIGN(range->size) >> TARGET_PAGE_BITS;
>> + range->bitmap.size = ROUND_UP(pages, 64) / 8;
>> + range->bitmap.data = g_malloc0(range->bitmap.size);
>> + if (range->bitmap.data == NULL) {
>> + 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
>> --
>> 2.7.0
>>
next prev parent reply other threads:[~2020-04-03 20:13 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-24 21:08 [PATCH v16 QEMU 00/16] Add migration support for VFIO devices Kirti Wankhede
2020-03-24 21:08 ` [PATCH v16 QEMU 01/16] vfio: KABI for migration interface - Kernel header placeholder Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 02/16] vfio: Add function to unmap VFIO region Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 03/16] vfio: Add vfio_get_object callback to VFIODeviceOps Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 04/16] vfio: Add save and load functions for VFIO PCI devices Kirti Wankhede
2020-03-25 19:56 ` Alex Williamson
2020-03-26 17:29 ` Dr. David Alan Gilbert
2020-03-26 17:38 ` Alex Williamson
2020-05-04 23:18 ` Kirti Wankhede
2020-05-05 4:37 ` Alex Williamson
2020-05-06 6:11 ` Yan Zhao
2020-05-06 19:48 ` Kirti Wankhede
2020-05-06 20:03 ` Alex Williamson
2020-05-07 5:40 ` Kirti Wankhede
2020-05-07 18:14 ` Alex Williamson
2020-03-26 17:46 ` Dr. David Alan Gilbert
2020-05-04 23:19 ` Kirti Wankhede
2020-04-07 4:10 ` Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
2020-05-04 23:21 ` Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 05/16] vfio: Add migration region initialization and finalize function Kirti Wankhede
2020-03-26 17:52 ` Dr. David Alan Gilbert
2020-05-04 23:19 ` Kirti Wankhede
2020-05-19 19:32 ` Dr. David Alan Gilbert
2020-03-24 21:09 ` [PATCH v16 QEMU 06/16] vfio: Add VM state change handler to know state of VM Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 07/16] vfio: Add migration state change notifier Kirti Wankhede
2020-04-01 11:27 ` Dr. David Alan Gilbert
2020-05-04 23:20 ` Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 08/16] vfio: Register SaveVMHandlers for VFIO device Kirti Wankhede
2020-03-25 21:02 ` Alex Williamson
2020-05-04 23:19 ` Kirti Wankhede
2020-05-05 4:37 ` Alex Williamson
2020-05-06 6:38 ` Yan Zhao
2020-05-06 9:58 ` Cornelia Huck
2020-05-06 16:53 ` Dr. David Alan Gilbert
2020-05-06 19:30 ` Kirti Wankhede
2020-05-07 6:37 ` Cornelia Huck
2020-05-07 20:29 ` Alex Williamson
2020-04-01 17:36 ` Dr. David Alan Gilbert
2020-05-04 23:20 ` Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 09/16] vfio: Add save state functions to SaveVMHandlers Kirti Wankhede
2020-03-25 22:03 ` Alex Williamson
2020-05-04 23:18 ` Kirti Wankhede
2020-05-05 4:37 ` Alex Williamson
2020-05-11 9:53 ` Kirti Wankhede
2020-05-11 15:59 ` Alex Williamson
2020-05-12 2:06 ` Yan Zhao
2020-05-09 5:31 ` Yan Zhao
2020-05-11 10:22 ` Kirti Wankhede
2020-05-12 0:50 ` Yan Zhao
2020-03-24 21:09 ` [PATCH v16 QEMU 10/16] vfio: Add load " Kirti Wankhede
2020-03-25 22:36 ` Alex Williamson
2020-04-01 18:58 ` Dr. David Alan Gilbert
2020-05-04 23:20 ` Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 11/16] iommu: add callback to get address limit IOMMU supports Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 12/16] memory: Set DIRTY_MEMORY_MIGRATION when IOMMU is enabled Kirti Wankhede
2020-04-01 19:00 ` Dr. David Alan Gilbert
2020-04-01 19:42 ` Alex Williamson
2020-03-24 21:09 ` [PATCH v16 QEMU 13/16] vfio: Add function to start and stop dirty pages tracking Kirti Wankhede
2020-03-26 19:10 ` Alex Williamson
2020-05-04 23:20 ` Kirti Wankhede
2020-04-01 19:03 ` Dr. David Alan Gilbert
2020-05-04 23:21 ` Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 14/16] vfio: Add vfio_listener_log_sync to mark dirty pages Kirti Wankhede
2020-03-25 2:19 ` Yan Zhao
2020-03-26 19:46 ` Alex Williamson
2020-04-01 19:08 ` Dr. David Alan Gilbert
2020-04-01 5:50 ` Yan Zhao
2020-04-03 20:11 ` Kirti Wankhede [this message]
2020-03-24 21:09 ` [PATCH v16 QEMU 15/16] vfio: Add ioctl to get dirty pages bitmap during dma unmap Kirti Wankhede
2020-03-24 21:09 ` [PATCH v16 QEMU 16/16] vfio: Make vfio-pci device migration capable Kirti Wankhede
2020-03-24 23:36 ` [PATCH v16 QEMU 00/16] Add migration support for VFIO devices no-reply
2020-03-31 18:34 ` Alex Williamson
2020-04-01 6:41 ` Yan Zhao
2020-04-01 18:34 ` Alex Williamson
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