xemu/include
David Hildenbrand 9181fb7043 hostmem: Wire up RAM_NORESERVE via "reserve" property
Let's provide a way to control the use of RAM_NORESERVE via memory
backends using the "reserve" property which defaults to true (old
behavior).

Only Linux currently supports clearing the flag (and support is checked at
runtime, depending on the setting of "/proc/sys/vm/overcommit_memory").
Windows and other POSIX systems will bail out with "reserve=false".

The target use case is virtio-mem, which dynamically exposes memory
inside a large, sparse memory area to the VM. This essentially allows
avoiding to set "/proc/sys/vm/overcommit_memory == 0") when using
virtio-mem and also supporting hugetlbfs in the future.

As really only Linux implements RAM_NORESERVE right now, let's expose
the property only with CONFIG_LINUX. Setting the property to "false"
will then only fail in corner cases -- for example on very old kernels
or when memory overcommit was completely disabled by the admin.

Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com> for memory backend and machine core
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210510114328.21835-11-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-15 20:27:38 +02:00
..
authz Prefer 'on' | 'off' over 'yes' | 'no' for bool options 2021-01-29 17:07:53 +00:00
block vl: plumb keyval-based options into -readconfig 2021-06-04 13:50:04 +02:00
chardev chardev: Fix yank with the chardev-change case 2021-04-01 15:27:44 +04:00
crypto crypto: add reload for QCryptoTLSCredsClass 2021-03-23 08:48:21 +01:00
disas Drop the deprecated lm32 target 2021-05-12 18:20:25 +02:00
exec memory: Introduce RAM_NORESERVE and wire it up in qemu_ram_mmap() 2021-06-15 20:27:38 +02:00
fpu softfloat: Convert modrem operations to FloatParts 2021-06-03 14:09:02 -07:00
hw esp: store lun coming from the MESSAGE OUT phase 2021-06-15 17:17:09 +02:00
io io: add qio_channel_readv_full_all_eof & qio_channel_readv_full_all helpers 2021-02-10 09:23:28 +00:00
libdecnumber include: Make headers more self-contained 2019-08-16 13:31:51 +02:00
migration cpu: Move CPUClass::vmsd to SysemuCPUOps 2021-05-26 15:33:59 -07:00
monitor hmp: Add "calc_dirty_rate" and "info dirty_rate" cmds 2021-06-08 20:18:26 +01:00
net vhost-vdpa: remove the unused vhost_vdpa_get_acked_features() 2021-06-11 10:30:13 +08:00
qapi vl: plumb keyval-based options into -readconfig 2021-06-04 13:50:04 +02:00
qemu util/mmap-alloc: Support RAM_NORESERVE via MAP_NORESERVE under Linux 2021-06-15 20:27:38 +02:00
qom qom: move user_creatable_add_opts logic to vl.c and QAPIfy it 2021-03-19 10:18:17 +01:00
scsi scsi: inline sg_io_sense_from_errno() into the callers. 2021-03-06 11:42:56 +01:00
semihosting semihosting: Move include/hw/semihosting/ -> include/semihosting/ 2021-03-10 15:34:12 +00:00
standard-headers headers: Add udmabuf.h 2021-05-27 12:06:37 +02:00
sysemu hostmem: Wire up RAM_NORESERVE via "reserve" property 2021-06-15 20:27:38 +02:00
tcg tcg: Fix documentation for tcg_constant_* vs tcg_temp_free_* 2021-06-13 17:42:40 -07:00
ui ui/pixman: Add qemu_pixman_to_drm_format() 2021-05-27 12:07:37 +02:00
user trace: switch position of headers to what Meson requires 2020-08-21 06:18:24 -04:00
elf.h Drop the deprecated unicore32 target 2021-05-12 18:20:52 +02:00
glib-compat.h configure: bump min required glib version to 2.56 2021-06-02 09:11:32 +02:00
qemu-common.h qemu-common.h: Update copyright string to 2021 2021-03-09 22:19:24 +01:00
qemu-io.h Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
trace-tcg.h