On 2/1/2021 3:23 PM, Alex Williamson wrote: > On Sat, 30 Jan 2021 11:54:03 -0500 > Steven Sistare <steven.sistare@xxxxxxxxxx> wrote: > >> On 1/29/2021 4:55 PM, Alex Williamson wrote: >>> On Fri, 29 Jan 2021 08:54:03 -0800 >>> Steve Sistare <steven.sistare@xxxxxxxxxx> wrote: >>> >>>> Add interfaces that allow the underlying memory object of an iova range >>>> to be mapped to a new virtual address in the host process: >>>> >>>> - VFIO_DMA_UNMAP_FLAG_VADDR for VFIO_IOMMU_UNMAP_DMA >>>> - VFIO_DMA_MAP_FLAG_VADDR flag for VFIO_IOMMU_MAP_DMA >>>> - VFIO_UPDATE_VADDR for VFIO_CHECK_EXTENSION >>>> - VFIO_DMA_UNMAP_FLAG_ALL for VFIO_IOMMU_UNMAP_DMA >>>> - VFIO_UNMAP_ALL for VFIO_CHECK_EXTENSION >>>> >>>> Unmap-vaddr invalidates the host virtual address in an iova range and blocks >>>> vfio translation of host virtual addresses, but DMA to already-mapped pages >>>> continues. Map-vaddr updates the base VA and resumes translation. The >>>> implementation supports iommu type1 and mediated devices. Unmap-all allows >>>> all ranges to be unmapped or invalidated in a single ioctl, which simplifies >>>> userland code. >>>> >>>> This functionality is necessary for live update, in which a host process >>>> such as qemu exec's an updated version of itself, while preserving its >>>> guest and vfio devices. The process blocks vfio VA translation, exec's >>>> its new self, mmap's the memory object(s) underlying vfio object, updates >>>> the VA, and unblocks translation. For a working example that uses these >>>> new interfaces, see the QEMU patch series "[PATCH V2] Live Update" at >>>> https://lore.kernel.org/qemu-devel/1609861330-129855-1-git-send-email-steven.sistare@xxxxxxxxxx >>>> >>>> Patches 1-3 define and implement the flag to unmap all ranges. >>>> Patches 4-6 define and implement the flags to update vaddr. >>>> Patches 7-9 add blocking to complete the implementation. >>> >>> Hi Steve, >>> >>> It looks pretty good to me, but I have some nit-picky comments that >>> I'll follow-up with on the individual patches. However, I've made the >>> changes I suggest in a branch that you can find here: >>> >>> git://github.com/awilliam/linux-vfio.git vaddr-v3 >>> >>> If the changes look ok, just send me an ack, I don't want to attribute >>> something to you that you don't approve of. Thanks, >> >> All changes look good, thanks! >> Do you need anything more from me on this patch series? > > Here's a new branch: > > git://github.com/awilliam/linux-vfio.git vaddr-v3.1 > > Extent of the changes are s/may not/cannot/ on patches 1 & 4 and > addition of Connie's R-b for all (rebased to rc6). If there are any > final comments, speak now. Thanks, Looks good - Steve
