| Message ID | 1589998088-3250-1-git-send-email-kwankhede@nvidia.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Add UAPIs to support migration for VFIO devices | expand |
The whole series works for us in general: Reviewed-by: Yan Zhao <yan.y.zhao@intel.com> On Wed, May 20, 2020 at 11:38:00PM +0530, Kirti Wankhede wrote: > Hi, > > This patch set adds: > * IOCTL VFIO_IOMMU_DIRTY_PAGES to get dirty pages bitmap with > respect to IOMMU container rather than per device. All pages pinned by > vendor driver through vfio_pin_pages external API has to be marked as > dirty during migration. When IOMMU capable device is present in the > container and all pages are pinned and mapped, then all pages are marked > dirty. > When there are CPU writes, CPU dirty page tracking can identify dirtied > pages, but any page pinned by vendor driver can also be written by > device. As of now there is no device which has hardware support for > dirty page tracking. So all pages which are pinned should be considered > as dirty. > This ioctl is also used to start/stop dirty pages tracking for pinned and > unpinned pages while migration is active. > > * Updated IOCTL VFIO_IOMMU_UNMAP_DMA to get dirty pages bitmap before > unmapping IO virtual address range. > With vIOMMU, during pre-copy phase of migration, while CPUs are still > running, IO virtual address unmap can happen while device still keeping > reference of guest pfns. Those pages should be reported as dirty before > unmap, so that VFIO user space application can copy content of those > pages from source to destination. > > * Patch 8 detect if IOMMU capable device driver is smart to report pages > to be marked dirty by pinning pages using vfio_pin_pages() API. > > > Yet TODO: > Since there is no device which has hardware support for system memmory > dirty bitmap tracking, right now there is no other API from vendor driver > to VFIO IOMMU module to report dirty pages. In future, when such hardware > support will be implemented, an API will be required such that vendor > driver could report dirty pages to VFIO module during migration phases. > > v22 -> v23 > - Fixed issue reported by Yan > https://lore.kernel.org/kvm/97977ede-3c5b-c5a5-7858-7eecd7dd531c@nvidia.com/ > - Fixed nit picks suggested by Cornelia > > v21 -> v22 > - Fixed issue raised by Alex : > https://lore.kernel.org/kvm/20200515163307.72951dd2@w520.home/ > > v20 -> v21 > - Added checkin for GET_BITMAP ioctl for vfio_dma boundaries. > - Updated unmap ioctl function - as suggested by Alex. > - Updated comments in DIRTY_TRACKING ioctl definition - as suggested by > Cornelia. > > v19 -> v20 > - Fixed ioctl to get dirty bitmap to get bitmap of multiple vfio_dmas > - Fixed unmap ioctl to get dirty bitmap of multiple vfio_dmas. > - Removed flag definition from migration capability. > > v18 -> v19 > - Updated migration capability with supported page sizes bitmap for dirty > page tracking and maximum bitmap size supported by kernel module. > - Added patch to calculate and cache pgsize_bitmap when iommu->domain_list > is updated. > - Removed extra buffers added in previous version for bitmap manipulation > and optimised the code. > > v17 -> v18 > - Add migration capability to the capability chain for VFIO_IOMMU_GET_INFO > ioctl > - Updated UMAP_DMA ioctl to return bitmap of multiple vfio_dma > > v16 -> v17 > - Fixed errors reported by kbuild test robot <lkp@intel.com> on i386 > > v15 -> v16 > - Minor edits and nit picks (Auger Eric) > - On copying bitmap to user, re-populated bitmap only for pinned pages, > excluding unmapped pages and CPU dirtied pages. > - Patches are on tag: next-20200318 and 1-3 patches from Yan's series > https://lkml.org/lkml/2020/3/12/1255 > > v14 -> v15 > - Minor edits and nit picks. > - In the verification of user allocated bitmap memory, added check of > maximum size. > - Patches are on tag: next-20200318 and 1-3 patches from Yan's series > https://lkml.org/lkml/2020/3/12/1255 > > v13 -> v14 > - Added struct vfio_bitmap to kabi. updated structure > vfio_iommu_type1_dirty_bitmap_get and vfio_iommu_type1_dma_unmap. > - All small changes suggested by Alex. > - Patches are on tag: next-20200318 and 1-3 patches from Yan's series > https://lkml.org/lkml/2020/3/12/1255 > > v12 -> v13 > - Changed bitmap allocation in vfio_iommu_type1 to per vfio_dma > - Changed VFIO_IOMMU_DIRTY_PAGES ioctl behaviour to be per vfio_dma range. > - Changed vfio_iommu_type1_dirty_bitmap structure to have separate data > field. > > v11 -> v12 > - Changed bitmap allocation in vfio_iommu_type1. > - Remove atomicity of ref_count. > - Updated comments for migration device state structure about error > reporting. > - Nit picks from v11 reviews > > v10 -> v11 > - Fix pin pages API to free vpfn if it is marked as unpinned tracking page. > - Added proposal to detect if IOMMU capable device calls external pin pages > API to mark pages dirty. > - Nit picks from v10 reviews > > v9 -> v10: > - Updated existing VFIO_IOMMU_UNMAP_DMA ioctl to get dirty pages bitmap > during unmap while migration is active > - Added flag in VFIO_IOMMU_GET_INFO to indicate driver support dirty page > tracking. > - If iommu_mapped, mark all pages dirty. > - Added unpinned pages tracking while migration is active. > - Updated comments for migration device state structure with bit > combination table and state transition details. > > v8 -> v9: > - Split patch set in 2 sets, Kernel and QEMU. > - Dirty pages bitmap is queried from IOMMU container rather than from > vendor driver for per device. Added 2 ioctls to achieve this. > > v7 -> v8: > - Updated comments for KABI > - Added BAR address validation check during PCI device's config space load > as suggested by Dr. David Alan Gilbert. > - Changed vfio_migration_set_state() to set or clear device state flags. > - Some nit fixes. > > v6 -> v7: > - Fix build failures. > > v5 -> v6: > - Fix build failure. > > v4 -> v5: > - Added decriptive comment about the sequence of access of members of > structure vfio_device_migration_info to be followed based on Alex's > suggestion > - Updated get dirty pages sequence. > - As per Cornelia Huck's suggestion, added callbacks to VFIODeviceOps to > get_object, save_config and load_config. > - Fixed multiple nit picks. > - Tested live migration with multiple vfio device assigned to a VM. > > v3 -> v4: > - Added one more bit for _RESUMING flag to be set explicitly. > - data_offset field is read-only for user space application. > - data_size is read for every iteration before reading data from migration, > that is removed assumption that data will be till end of migration > region. > - If vendor driver supports mappable sparsed region, map those region > during setup state of save/load, similarly unmap those from cleanup > routines. > - Handles race condition that causes data corruption in migration region > during save device state by adding mutex and serialiaing save_buffer and > get_dirty_pages routines. > - Skip called get_dirty_pages routine for mapped MMIO region of device. > - Added trace events. > - Split into multiple functional patches. > > v2 -> v3: > - Removed enum of VFIO device states. Defined VFIO device state with 2 > bits. > - Re-structured vfio_device_migration_info to keep it minimal and defined > action on read and write access on its members. > > v1 -> v2: > - Defined MIGRATION region type and sub-type which should be used with > region type capability. > - Re-structured vfio_device_migration_info. This structure will be placed > at 0th offset of migration region. > - Replaced ioctl with read/write for trapped part of migration region. > - Added both type of access support, trapped or mmapped, for data section > of the region. > - Moved PCI device functions to pci file. > - Added iteration to get dirty page bitmap until bitmap for all requested > pages are copied. > > Thanks, > Kirti > > > Kirti Wankhede (8): > vfio: UAPI for migration interface for device state > vfio iommu: Remove atomicity of ref_count of pinned pages > vfio iommu: Cache pgsize_bitmap in struct vfio_iommu > vfio iommu: Add ioctl definition for dirty pages tracking > vfio iommu: Implementation of ioctl for dirty pages tracking > vfio iommu: Update UNMAP_DMA ioctl to get dirty bitmap before unmap > vfio iommu: Add migration capability to report supported features > vfio: Selective dirty page tracking if IOMMU backed device pins pages > > drivers/vfio/vfio.c | 13 +- > drivers/vfio/vfio_iommu_type1.c | 571 ++++++++++++++++++++++++++++++++++++---- > include/linux/vfio.h | 4 +- > include/uapi/linux/vfio.h | 318 ++++++++++++++++++++++ > 4 files changed, 847 insertions(+), 59 deletions(-) > > -- > 2.7.0 >
On 5/28/2020 10:17 AM, Yan Zhao wrote: > > The whole series works for us in general: > Reviewed-by: Yan Zhao <yan.y.zhao@intel.com> Thanks. Kirti > > On Wed, May 20, 2020 at 11:38:00PM +0530, Kirti Wankhede wrote: >> Hi, >> >> This patch set adds: >> * IOCTL VFIO_IOMMU_DIRTY_PAGES to get dirty pages bitmap with >> respect to IOMMU container rather than per device. All pages pinned by >> vendor driver through vfio_pin_pages external API has to be marked as >> dirty during migration. When IOMMU capable device is present in the >> container and all pages are pinned and mapped, then all pages are marked >> dirty. >> When there are CPU writes, CPU dirty page tracking can identify dirtied >> pages, but any page pinned by vendor driver can also be written by >> device. As of now there is no device which has hardware support for >> dirty page tracking. So all pages which are pinned should be considered >> as dirty. >> This ioctl is also used to start/stop dirty pages tracking for pinned and >> unpinned pages while migration is active. >> >> * Updated IOCTL VFIO_IOMMU_UNMAP_DMA to get dirty pages bitmap before >> unmapping IO virtual address range. >> With vIOMMU, during pre-copy phase of migration, while CPUs are still >> running, IO virtual address unmap can happen while device still keeping >> reference of guest pfns. Those pages should be reported as dirty before >> unmap, so that VFIO user space application can copy content of those >> pages from source to destination. >> >> * Patch 8 detect if IOMMU capable device driver is smart to report pages >> to be marked dirty by pinning pages using vfio_pin_pages() API. >> >> >> Yet TODO: >> Since there is no device which has hardware support for system memmory >> dirty bitmap tracking, right now there is no other API from vendor driver >> to VFIO IOMMU module to report dirty pages. In future, when such hardware >> support will be implemented, an API will be required such that vendor >> driver could report dirty pages to VFIO module during migration phases. >> >> v22 -> v23 >> - Fixed issue reported by Yan >> https://lore.kernel.org/kvm/97977ede-3c5b-c5a5-7858-7eecd7dd531c@nvidia.com/ >> - Fixed nit picks suggested by Cornelia >> >> v21 -> v22 >> - Fixed issue raised by Alex : >> https://lore.kernel.org/kvm/20200515163307.72951dd2@w520.home/ >> >> v20 -> v21 >> - Added checkin for GET_BITMAP ioctl for vfio_dma boundaries. >> - Updated unmap ioctl function - as suggested by Alex. >> - Updated comments in DIRTY_TRACKING ioctl definition - as suggested by >> Cornelia. >> >> v19 -> v20 >> - Fixed ioctl to get dirty bitmap to get bitmap of multiple vfio_dmas >> - Fixed unmap ioctl to get dirty bitmap of multiple vfio_dmas. >> - Removed flag definition from migration capability. >> >> v18 -> v19 >> - Updated migration capability with supported page sizes bitmap for dirty >> page tracking and maximum bitmap size supported by kernel module. >> - Added patch to calculate and cache pgsize_bitmap when iommu->domain_list >> is updated. >> - Removed extra buffers added in previous version for bitmap manipulation >> and optimised the code. >> >> v17 -> v18 >> - Add migration capability to the capability chain for VFIO_IOMMU_GET_INFO >> ioctl >> - Updated UMAP_DMA ioctl to return bitmap of multiple vfio_dma >> >> v16 -> v17 >> - Fixed errors reported by kbuild test robot <lkp@intel.com> on i386 >> >> v15 -> v16 >> - Minor edits and nit picks (Auger Eric) >> - On copying bitmap to user, re-populated bitmap only for pinned pages, >> excluding unmapped pages and CPU dirtied pages. >> - Patches are on tag: next-20200318 and 1-3 patches from Yan's series >> https://lkml.org/lkml/2020/3/12/1255 >> >> v14 -> v15 >> - Minor edits and nit picks. >> - In the verification of user allocated bitmap memory, added check of >> maximum size. >> - Patches are on tag: next-20200318 and 1-3 patches from Yan's series >> https://lkml.org/lkml/2020/3/12/1255 >> >> v13 -> v14 >> - Added struct vfio_bitmap to kabi. updated structure >> vfio_iommu_type1_dirty_bitmap_get and vfio_iommu_type1_dma_unmap. >> - All small changes suggested by Alex. >> - Patches are on tag: next-20200318 and 1-3 patches from Yan's series >> https://lkml.org/lkml/2020/3/12/1255 >> >> v12 -> v13 >> - Changed bitmap allocation in vfio_iommu_type1 to per vfio_dma >> - Changed VFIO_IOMMU_DIRTY_PAGES ioctl behaviour to be per vfio_dma range. >> - Changed vfio_iommu_type1_dirty_bitmap structure to have separate data >> field. >> >> v11 -> v12 >> - Changed bitmap allocation in vfio_iommu_type1. >> - Remove atomicity of ref_count. >> - Updated comments for migration device state structure about error >> reporting. >> - Nit picks from v11 reviews >> >> v10 -> v11 >> - Fix pin pages API to free vpfn if it is marked as unpinned tracking page. >> - Added proposal to detect if IOMMU capable device calls external pin pages >> API to mark pages dirty. >> - Nit picks from v10 reviews >> >> v9 -> v10: >> - Updated existing VFIO_IOMMU_UNMAP_DMA ioctl to get dirty pages bitmap >> during unmap while migration is active >> - Added flag in VFIO_IOMMU_GET_INFO to indicate driver support dirty page >> tracking. >> - If iommu_mapped, mark all pages dirty. >> - Added unpinned pages tracking while migration is active. >> - Updated comments for migration device state structure with bit >> combination table and state transition details. >> >> v8 -> v9: >> - Split patch set in 2 sets, Kernel and QEMU. >> - Dirty pages bitmap is queried from IOMMU container rather than from >> vendor driver for per device. Added 2 ioctls to achieve this. >> >> v7 -> v8: >> - Updated comments for KABI >> - Added BAR address validation check during PCI device's config space load >> as suggested by Dr. David Alan Gilbert. >> - Changed vfio_migration_set_state() to set or clear device state flags. >> - Some nit fixes. >> >> v6 -> v7: >> - Fix build failures. >> >> v5 -> v6: >> - Fix build failure. >> >> v4 -> v5: >> - Added decriptive comment about the sequence of access of members of >> structure vfio_device_migration_info to be followed based on Alex's >> suggestion >> - Updated get dirty pages sequence. >> - As per Cornelia Huck's suggestion, added callbacks to VFIODeviceOps to >> get_object, save_config and load_config. >> - Fixed multiple nit picks. >> - Tested live migration with multiple vfio device assigned to a VM. >> >> v3 -> v4: >> - Added one more bit for _RESUMING flag to be set explicitly. >> - data_offset field is read-only for user space application. >> - data_size is read for every iteration before reading data from migration, >> that is removed assumption that data will be till end of migration >> region. >> - If vendor driver supports mappable sparsed region, map those region >> during setup state of save/load, similarly unmap those from cleanup >> routines. >> - Handles race condition that causes data corruption in migration region >> during save device state by adding mutex and serialiaing save_buffer and >> get_dirty_pages routines. >> - Skip called get_dirty_pages routine for mapped MMIO region of device. >> - Added trace events. >> - Split into multiple functional patches. >> >> v2 -> v3: >> - Removed enum of VFIO device states. Defined VFIO device state with 2 >> bits. >> - Re-structured vfio_device_migration_info to keep it minimal and defined >> action on read and write access on its members. >> >> v1 -> v2: >> - Defined MIGRATION region type and sub-type which should be used with >> region type capability. >> - Re-structured vfio_device_migration_info. This structure will be placed >> at 0th offset of migration region. >> - Replaced ioctl with read/write for trapped part of migration region. >> - Added both type of access support, trapped or mmapped, for data section >> of the region. >> - Moved PCI device functions to pci file. >> - Added iteration to get dirty page bitmap until bitmap for all requested >> pages are copied. >> >> Thanks, >> Kirti >> >> >> Kirti Wankhede (8): >> vfio: UAPI for migration interface for device state >> vfio iommu: Remove atomicity of ref_count of pinned pages >> vfio iommu: Cache pgsize_bitmap in struct vfio_iommu >> vfio iommu: Add ioctl definition for dirty pages tracking >> vfio iommu: Implementation of ioctl for dirty pages tracking >> vfio iommu: Update UNMAP_DMA ioctl to get dirty bitmap before unmap >> vfio iommu: Add migration capability to report supported features >> vfio: Selective dirty page tracking if IOMMU backed device pins pages >> >> drivers/vfio/vfio.c | 13 +- >> drivers/vfio/vfio_iommu_type1.c | 571 ++++++++++++++++++++++++++++++++++++---- >> include/linux/vfio.h | 4 +- >> include/uapi/linux/vfio.h | 318 ++++++++++++++++++++++ >> 4 files changed, 847 insertions(+), 59 deletions(-) >> >> -- >> 2.7.0 >>