This series has been successfully tested by QE. Start the qemu-storage-daemon in the background with a rhel 9.5 image and vhost-user-blk. After that, boot up a VM with virtio-mem and vhost-user-blk-pci. Check with the HMP command 'info mtree' that virtio-mem is making use of multiple memslots.
On Wed, Feb 14, 2024 at 4:18 PM David Hildenbrand <da...@redhat.com> wrote: > > This series adds support for more memslots (509) to libvhost-user, to > make it fully compatible with virtio-mem that uses up to 256 memslots > accross all memory devices in "dynamic-memslot" mode (more details > in patch #2). > > With that in place, this series optimizes and extends memory region > handling in libvhost-user: > * Heavily deduplicate and clean up the memory region handling code > * Speeds up GPA->VA translation with many memslots using binary search > * Optimize mmap_offset handling to use it as fd_offset for mmap() > * Avoid ring remapping when adding a single memory region > * Avoid dumping all guest memory, possibly allocating memory in sparse > memory mappings when the process crashes > > I'm being very careful to not break some weird corner case that modern > QEMU might no longer trigger, but older one could have triggered or some > other frontend might trigger. > > The only thing where I am not careful is to forbid memory regions that > overlap in GPA space: it doesn't make any sense. > > With this series, virtio-mem (with dynamic-memslots=on) + > qemu-storage-daemon works flawlessly and as expected in my tests. > > v1 -> v2: > * Drop "libvhost-user: Fix msg_region->userspace_addr computation" > -> Not actually required > * "libvhost-user: Factor out adding a memory region" > -> Make debug output more consistent (add missing ":") > * "libvhost-user: Use most of mmap_offset as fd_offset" > -> get_fd_pagesize -> get_fd_hugepagesize; remove getpagesize() > -> "mmap_offset:" to "old mmap_offset:" in debug message > -> "adj mmap_offset:" to "new mmap_offset:" in debug message > -> Use "(unsigned int)fs.f_type"; the man page of fstatfs() calls out > that the type of f_type can vary depending on the architecture. > "unsigned int" is sufficient here. > -> Updated patch description > * Added RBs+ACKs > * Did a Gitlab CI run, seems to be happy reagrding libvhost-user > > Cc: Michael S. Tsirkin <m...@redhat.com> > Cc: Jason Wang <jasow...@redhat.com> > Cc: Stefan Hajnoczi <stefa...@redhat.com> > Cc: Stefano Garzarella <sgarz...@redhat.com> > Cc: Germano Veit Michel <germ...@redhat.com> > Cc: Raphael Norwitz <raphael.norw...@nutanix.com> > > David Hildenbrand (14): > libvhost-user: Dynamically allocate memory for memory slots > libvhost-user: Bump up VHOST_USER_MAX_RAM_SLOTS to 509 > libvhost-user: Factor out removing all mem regions > libvhost-user: Merge vu_set_mem_table_exec_postcopy() into > vu_set_mem_table_exec() > libvhost-user: Factor out adding a memory region > libvhost-user: No need to check for NULL when unmapping > libvhost-user: Don't zero out memory for memory regions > libvhost-user: Don't search for duplicates when removing memory > regions > libvhost-user: Factor out search for memory region by GPA and simplify > libvhost-user: Speedup gpa_to_mem_region() and vu_gpa_to_va() > libvhost-user: Use most of mmap_offset as fd_offset > libvhost-user: Factor out vq usability check > libvhost-user: Dynamically remap rings after (temporarily?) removing > memory regions > libvhost-user: Mark mmap'ed region memory as MADV_DONTDUMP > > subprojects/libvhost-user/libvhost-user.c | 595 ++++++++++++---------- > subprojects/libvhost-user/libvhost-user.h | 10 +- > 2 files changed, 334 insertions(+), 271 deletions(-) > > -- > 2.43.0 > >
