Message ID | 20210510114328.21835-1-david@redhat.com |
---|---|
Headers | show |
Series | RAM_NORESERVE, MAP_NORESERVE and hostmem "reserve" property | expand |
On 10/05/21 13:43, David Hildenbrand wrote: > Based-on: 20210406080126.24010-1-david@redhat.com Queued both the dependent series and this one, thanks. Sorry for the delay. Paolo > Some cleanups previously sent in other context (resizeable allocations), > followed by RAM_NORESERVE, implementing it under Linux using MAP_NORESERVE, > and letting users configure it for memory backens using the "reserve" > property (default: true). > > MAP_NORESERVE under Linux has in the context of QEMU an effect on > 1) Private/shared anonymous memory > -> memory-backend-ram,id=mem0,size=10G > 2) Private fd-based mappings > -> memory-backend-file,id=mem0,size=10G,mem-path=/dev/shm/0 > -> memory-backend-memfd,id=mem0,size=10G > 3) Private/shared hugetlb mappings > -> memory-backend-memfd,id=mem0,size=10G,hugetlb=on,hugetlbsize=2M > > With MAP_NORESERVE/"reserve=off", we won't be reserving swap space (1/2) or > huge pages (3) for the whole memory region. > > The target use case is virtio-mem, which dynamically exposes memory > inside a large, sparse memory area to the VM. MAP_NORESERVE tells the OS > "this mapping might be very sparse". This essentially allows > avoiding having to set "/proc/sys/vm/overcommit_memory == 1") when using > virtio-mem and also supporting hugetlbfs in the future. > > Later, upper layers are expected to specify "reserve=off" only for > memory backends assigned to virtio-mem devices, not all VM memory. To make > mistakes by users less severe, we're, for example, working on preallocation > of memory in virtio-mem itself, to be upstreamed later. > > > v7 -> v8: > - "hostmem: Wire up RAM_NORESERVE via "reserve" property" > -- Make the "reserve" property depend on CONFIG_LINUX > -- Add missing (since 6.1) to qom json > - "qmp: Include "reserve" property of memory backends" > -- Make the "reserve" value optional, depending on availability of the > "reserve" property > - "hmp: Print "reserve" property of memory backends with "info memdev"" > -- Print only with "has_reserve" > > v6 -> v7: > - Collected ACKs and RBs > - "hostmem: Wire up RAM_NORESERVE via "reserve" property" > -- Extended qapi/qom.json documentation > - "qmp: Include "reserve" property of memory backends" > -- Extended property description > > v5 -> v6: > - "softmmu/memory: Pass ram_flags to memory_region_init ..." > -- Split up into two patches > ---> "softmmu/memory: Pass ram_flags to memory_region.." > ---> "softmmu/memory: Pass ram_flags to qemu_ram_alloc() ..." > -- Also set RAM_PREALLOC from qemu_ram_alloc_from_ptr() > - Collected acks/rbs > > v4 -> v5: > - Sent out shared anonymous RAM fixes separately > - Rebased > - "hostmem: Wire up RAM_NORESERVE via "reserve" property" > -- Adjusted/simplified description of new "reserve" property > -- Properly add it to qapi/qom.json > - "qmp: Clarify memory backend properties returned via query-memdev" > -- Added > - "qmp: Include "share" property of memory backends" > -- Added > - "hmp: Print "share" property of memory backends with "info memdev"" > - Added > - "qmp: Include "reserve" property of memory backends" > -- Adjust description of new "reserve" property > > v3 -> v4: > - Minor comment/description updates > - "softmmu/physmem: Fix ram_block_discard_range() to handle shared ..." > -- Extended description > - "util/mmap-alloc: Pass flags instead of separate bools to ..." > -- Move flags to include/qemu/osdep.h and rename to "QEMU_MAP_*" > - "memory: Introduce RAM_NORESERVE and wire it up in qemu_ram_mmap()" > -- Adjust to new flags. Handle errors in mmap_activate() for now. > - "util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE under Linux" > -- Restrict support to Linux only for now > - "qmp: Include "reserve" property of memory backends" > -- Added > - "hmp: Print "reserve" property of memory backends with ..." > -- Added > > v2 -> v3: > - Renamed "softmmu/physmem: Drop "shared" parameter from ram_block_add()" > to "softmmu/physmem: Mark shared anonymous memory RAM_SHARED" and > adjusted the description > - Added "softmmu/physmem: Fix ram_block_discard_range() to handle shared > anonymous memory" > - Added "softmmu/physmem: Fix qemu_ram_remap() to handle shared anonymous > memory" > - Added "util/mmap-alloc: Pass flags instead of separate bools to > qemu_ram_mmap()" > - "util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE" > -- Further tweak code comments > -- Handle shared anonymous memory > > v1 -> v2: > - Rebased to upstream and phs_mem_alloc simplifications > -- Upsteam added the "map_offset" parameter to many RAM allocation > interfaces. > - "softmmu/physmem: Drop "shared" parameter from ram_block_add()" > -- Use local variable "shared" > - "memory: introduce RAM_NORESERVE and wire it up in qemu_ram_mmap()" > -- Simplify due to phs_mem_alloc changes > - "util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE" > -- Add a whole bunch of comments. > -- Exclude shared anonymous memory that QEMU doesn't use > -- Special-case readonly mappings > > Cc: Peter Xu <peterx@redhat.com> > Cc: "Michael S. Tsirkin" <mst@redhat.com> > Cc: Eduardo Habkost <ehabkost@redhat.com> > Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > Cc: Richard Henderson <richard.henderson@linaro.org> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Igor Mammedov <imammedo@redhat.com> > Cc: "Philippe Mathieu-Daudé" <philmd@redhat.com> > Cc: Stefan Hajnoczi <stefanha@redhat.com> > Cc: Murilo Opsfelder Araujo <muriloo@linux.ibm.com> > Cc: Greg Kurz <groug@kaod.org> > Cc: Liam Merwick <liam.merwick@oracle.com> > Cc: Marcel Apfelbaum <mapfelba@redhat.com> > Cc: Daniel P. Berrangé <berrange@redhat.com> > Cc: Michal Privoznik <mprivozn@redhat.com> > Cc: Marek Kedzierski <mkedzier@redhat.com> > > David Hildenbrand (15): > util/mmap-alloc: Factor out calculation of the pagesize for the guard > page > util/mmap-alloc: Factor out reserving of a memory region to > mmap_reserve() > util/mmap-alloc: Factor out activating of memory to mmap_activate() > softmmu/memory: Pass ram_flags to qemu_ram_alloc_from_fd() > softmmu/memory: Pass ram_flags to > memory_region_init_ram_shared_nomigrate() > softmmu/memory: Pass ram_flags to qemu_ram_alloc() and > qemu_ram_alloc_internal() > util/mmap-alloc: Pass flags instead of separate bools to > qemu_ram_mmap() > memory: Introduce RAM_NORESERVE and wire it up in qemu_ram_mmap() > util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE under Linux > hostmem: Wire up RAM_NORESERVE via "reserve" property > qmp: Clarify memory backend properties returned via query-memdev > qmp: Include "share" property of memory backends > hmp: Print "share" property of memory backends with "info memdev" > qmp: Include "reserve" property of memory backends > hmp: Print "reserve" property of memory backends with "info memdev" > > backends/hostmem-file.c | 11 +- > backends/hostmem-memfd.c | 8 +- > backends/hostmem-ram.c | 7 +- > backends/hostmem.c | 36 +++ > hw/core/machine-hmp-cmds.c | 6 + > hw/core/machine-qmp-cmds.c | 8 + > hw/m68k/next-cube.c | 4 +- > hw/misc/ivshmem.c | 5 +- > include/exec/cpu-common.h | 1 + > include/exec/memory.h | 42 ++-- > include/exec/ram_addr.h | 9 +- > include/qemu/mmap-alloc.h | 16 +- > include/qemu/osdep.h | 30 ++- > include/sysemu/hostmem.h | 2 +- > migration/ram.c | 3 +- > qapi/machine.json | 16 +- > qapi/qom.json | 10 + > .../memory-region-housekeeping.cocci | 8 +- > softmmu/memory.c | 27 ++- > softmmu/physmem.c | 51 +++-- > util/mmap-alloc.c | 212 +++++++++++++----- > util/oslib-posix.c | 7 +- > util/oslib-win32.c | 13 +- > 23 files changed, 374 insertions(+), 158 deletions(-) >
On 11.06.21 15:34, Paolo Bonzini wrote: > On 10/05/21 13:43, David Hildenbrand wrote: >> Based-on: 20210406080126.24010-1-david@redhat.com > > Queued both the dependent series and this one, thanks. Sorry for the delay. > No worries Paolo, I know that we're all super busy -- thanks!