On Fri, Jun 5, 2026 at 3:14 PM Maxime Coquelin
<[email protected]> wrote:
>
> On Fri, Jun 5, 2026 at 1:57 AM <[email protected]> wrote:
> >
> > From: Pravin M Bathija <[email protected]>
> >
> > This is version v15 of the patchset and it incorporates the
> > recommendations made by Maxime Coquelin.
> >
> > Patch 4/5
> > - Changed VHOST_USER_REM_MEM_REG handler declaration from
> >   accepts_fd=true to accepts_fd=false, as the remove request does not
> >   expect FDs in ancillary data.
> > - Removed all close_msg_fds(ctx) calls from vhost_user_rem_mem_reg(), no
> >   longer needed since the handler is declared as not accepting FDs.
> > - Removed validate_msg_fds(dev, ctx, 0) check from
> >   vhost_user_rem_mem_reg(), as FD validation is now handled generically
> >   by the framework.
> > - Added targeted IOTLB cache invalidation in vhost_user_rem_mem_reg()
> >   using vhost_user_iotlb_cache_remove() for the removed region's GPA
> >   range, instead of the nuclear iotlb_flush_all() used by set_mem_table.
> >
> > This implementation has been extensively tested by doing Read/Write I/O
> > from multiple instances of fio + libblkio (front-end) talking to
> > spdk/dpdk (back-end) based drives. Tested with qemu front-end talking to
> > dpdk testpmd (back-end) performing add/removal of memory regions. Also
> > tested post-copy live migration after doing add_memory_region.
> >
> > Version Log:
> > Version v15 (Current version): Incorporate code review suggestions from
> > Maxime Coquelin as described above.
> >
> > Version v14: Incorporate code review suggestions from Stephen Hemminger
> > and Fengcheng Wen.
> > Changes from Fengcheng Wen review:
> > Patch 3/5
> > - Moved free_all_mem_regions() call sites in vhost_user_set_mem_table()
> >   from patch 4/5 to patch 3/5 so each commit compiles independently
> > Patch 4/5
> > - Renamed _dev_invalidate_vrings() to vhost_user_invalidate_vrings() to
> >   follow vhost naming convention
> > -  Added comment explaining *pdev propagation through
> >    translate_ring_addresses / numa_realloc()
> > - Reordered local variables in vhost_user_add_mem_reg() and
> >   vhost_user_rem_mem_reg() by descending line length
> > - Shortened overlap check variable names (current_region_guest_start/end
> >   --> cur_start/end, proposed_region_guest_start/end -> new_start/end)
> > - Fixed DMA error path in vhost_user_add_mem_reg(): added
> >   free_new_region_no_dma label so async_dma_map_region(false) is not
> >   called when the map itself failed.
> > Changes from Stephen Hemminger review:
> > Patch 4/5
> > - vhost_user_add_mem_reg() now constructs a reply with the back-end's
> >   host mapping address in userspace_addr and returns
> >   RTE_VHOST_MSG_RESULT_REPLY per the vhost-user spec
> > - Added validate_msg_fds(dev, ctx, 0) in vhost_user_rem_mem_reg() to
> >   reject malformed messages with unexpected file descriptors
> > - Dropped unnecessary (uint64_t) cast in vhost_user_get_max_mem_slots()
> >
> > Version v13: Incorporate code review suggestions from Fengcheng Wen
> > Patch 2/5
> > Renamed VhostUserSingleMemReg to VhostUserMemRegMsg and memory_single
> > to memreg
> > Patches 3/5 and 4/5
> > Relocated function remove_guest_pages from patch 3/5 to 4/5
> >
> > Version v12: Incorporate code review suggestions from Maxime Coquelin
> > and ai-code-review.
> > Patch 3/5
> > Refactored async_dma_map() to delegate to async_dma_map_region(),
> > eliminating code duplication between the two functions.
> > Restored original comments in async_dma_map_region() explaining why
> > ENODEV and EINVAL errors are ignored (these were stripped in v10)
> > Reverted unnecessary changes to vhost_user_postcopy_register() --
> > removed the host_user_addr == 0 checks and reg_msg_index indirection
> > that were added in  v10, since this function is only called from
> > vhost_user_set_mem_table() where regions are always contiguous.
> >
> > Version v11: Incorporate code review suggestions from Stephen Hemminger.
> > Patch 4/5
> > Fix incomplete cleanup in vhost_user_add_mem_reg() when
> > vhost_user_mmap_region() fails after the mmap succeeds (e.g.
> > add_guest_pages() realloc failure) realloc failure). The error path now
> > calls remove_guest_pages() and free_mem_region() to undo the mapping
> > and stale guest-page entries, preventing a leaked mmap and slot reuse
> > corruption. The plain close(fd) path is kept for pre-mmap failures.
> >
> > Version v10: Incorporate code review suggestions from Stephen Hemminger.
> > Patch 4/5
> > Moved dev_invalidate_vrings after free_mem_region, array compaction, and
> > nregions decrement. This ensures translate_ring_addresses only sees
> > surviving memory regions, preventing vring pointers from resolving into
> > a region that is about to be unmapped.
> >
> > Version v9: Incorporate code review suggestions from Stephen Hemminger.
> > Patch 3/5
> > Restored max_guest_pages initial value to hardcoded 8 instead of
> > VHOST_MEMORY_MAX_NREGIONS, matching upstream semantics.
> > Patch 4/5
> > Added close(reg->fd) and reg->fd = -1 before goto close_msg_fds in the
> > mmap failure path to fix fd leak after fd was moved from ctx->fds[0].
> > Converted dev_invalidate_vrings from a plain function to a macro +
> > implementation function pair, accepting message ID as a parameter so
> > the static_assert reports the correct handler at each call site.
> > Updated dev_invalidate_vrings call in add_mem_reg to pass
> > VHOST_USER_ADD_MEM_REG as message ID.
> > Updated dev_invalidate_vrings call in rem_mem_reg to pass
> > VHOST_USER_REM_MEM_REG as message ID.
> >
> > Version v8:  Incorporate code review suggestions from Stephen Hemminger.
> > rewrite async_dma_map_region function to iterate guest pages by host
> > address range matching
> > change function dev_invalidate_vrings to accept a double pointer to
> > propagate pointer updates
> > new function remove_guest_pages was added
> > add_mem_reg error path was narrowed to only clean up the single failed
> > region instead of destroting all existing regions
> >
> > Version v7: Incorporate code review suggestions from Maxime Coquelin.
> > Add debug messages to vhost_postcopy_register function.
> >
> > Version v6: Added the enablement of this feature as a final patch in
> > this patch-set and other code optimizations as suggested by Maxime
> > Coquelin.
> >
> > Version v5: removed the patch that increased the number of memory regions
> > from 8 to 128. This will be submitted as a separate feature at a later
> > point after incorporating additional optimizations. Also includes code
> > optimizations as suggested by Feng Cheng Wen.
> >
> > Version v4: code optimizations as suggested by Feng Cheng Wen.
> >
> > Version v3: code optimizations as suggested by Maxime Coquelin
> > and Thomas Monjalon.
> >
> > Version v2: code optimizations as suggested by Maxime Coquelin.
> >
> > Version v1: Initial patch set.
> >
> > Pravin M Bathija (5):
> >   vhost: add user to mailmap and define to vhost hdr
> >   vhost: header defines for add/rem mem region
> >   vhost: refactor memory helper functions
> >   vhost: add mem region add/remove handlers
> >   vhost: enable configure memory slots
> >
> >  .mailmap               |   1 +
> >  lib/vhost/rte_vhost.h  |   4 +
> >  lib/vhost/vhost_user.c | 425 +++++++++++++++++++++++++++++++++++------
> >  lib/vhost/vhost_user.h |  10 +
> >  4 files changed, 378 insertions(+), 62 deletions(-)
> >
> > --
> > 2.43.0
> >
>
> Applied to next-virtio/for-next-net.

Given a new version has been posted and Thomas did not pull it yet,
I dropped this series from my pull request.

>
> Thanks,
> Maxime

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