xemu/qapi
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
..
acpi.json qapi: Extract ACPI commands to 'acpi.json' 2020-09-29 15:41:36 +02:00
audio.json sdlaudio: add -audiodev sdl,out.buffer-count option 2021-01-15 11:25:22 +01:00
authz.json qapi/qom: Add ObjectOptions for authz-* 2021-03-19 10:17:13 +01:00
block-core.json block: Drop the sheepdog block driver 2021-05-12 17:42:23 +02:00
block-export.json fuse: Allow growable exports 2020-12-11 17:52:40 +01:00
block.json qapi: Normalize version references x.y.0 to just x.y 2020-12-10 17:16:44 +01:00
char.json ui/vdagent: add clipboard support 2021-05-21 09:42:44 +02:00
common.json qapi/qom: Add ObjectOptions for input-* 2021-03-19 10:17:14 +01:00
compat.json qapi: New -compat deprecated-input=crash 2021-03-19 16:05:11 +01:00
control.json monitor: remove 'query-events' QMP command 2021-03-18 09:22:55 +00:00
crypto.json qapi/qom: Add ObjectOptions for tls-*, deprecate 'loaded' 2021-03-19 10:17:13 +01:00
dump.json schemas: Add vim modeline 2020-08-03 08:28:08 +02:00
error.json schemas: Add vim modeline 2020-08-03 08:28:08 +02:00
introspect.json monitor: Drop query-qmp-schema 'gen': false hack 2021-03-19 16:05:09 +01:00
job.json migration: introduce snapshot-{save, load, delete} QMP commands 2021-02-08 11:19:52 +00:00
machine-target.json qapi: Normalize version references x.y.0 to just x.y 2020-12-10 17:16:44 +01:00
machine.json Drop the deprecated unicore32 target 2021-05-12 18:20:52 +02:00
meson.build Revert "hmp: Use QAPI NetdevInfo in hmp_info_network" 2021-04-08 17:33:59 +08:00
migration.json migration/dirtyrate: make sample page count configurable 2021-06-08 20:18:25 +01:00
misc-target.json target/i386/sev: add support to query the attestation report 2021-06-01 09:32:23 -04:00
misc.json qmp: remove deprecated "change" command 2021-01-23 15:55:07 -05:00
net.json netdev: add more commands to preconfig mode 2021-06-11 10:30:13 +08:00
opts-visitor.c qapi, qemu-options: make all parsing visitors parse boolean options the same 2020-11-04 12:00:40 -05:00
pci.json qapi: Normalize version references x.y.0 to just x.y 2020-12-10 17:16:44 +01:00
pragma.json block: Remove monitor command block_passwd 2021-03-23 22:31:56 +01:00
qapi-clone-visitor.c qapi: Make visitor functions taking Error ** return bool, not void 2020-07-10 15:18:08 +02:00
qapi-dealloc-visitor.c qapi: Make visitor functions taking Error ** return bool, not void 2020-07-10 15:18:08 +02:00
qapi-schema.json qemu-options: New -compat to set policy for deprecated interfaces 2021-03-19 15:43:33 +01:00
qapi-util.c qapi, qemu-options: make all parsing visitors parse boolean options the same 2020-11-04 12:00:40 -05:00
qapi-visit-core.c qapi: Implement deprecated-input=reject for QMP command arguments 2021-03-19 16:05:11 +01:00
qdev.json qapi: Normalize version references x.y.0 to just x.y 2020-12-10 17:16:44 +01:00
qmp-dispatch.c qapi: New -compat deprecated-input=crash 2021-03-19 16:05:11 +01:00
qmp-event.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
qmp-registry.c qga: return a more explicit error on why a command is disabled 2021-03-16 20:21:47 -05:00
qobject-input-visitor.c qapi: New -compat deprecated-input=crash 2021-03-19 16:05:11 +01:00
qobject-output-visitor.c qapi: Implement deprecated-output=hide for QMP command results 2021-03-19 15:43:33 +01:00
qom.json hostmem: Wire up RAM_NORESERVE via "reserve" property 2021-06-15 20:27:38 +02:00
rdma.json schemas: Add vim modeline 2020-08-03 08:28:08 +02:00
replay.json replay: implement replay-seek command 2020-10-06 08:34:49 +02:00
rocker.json schemas: Add vim modeline 2020-08-03 08:28:08 +02:00
run-state.json runstate: cleanup reboot and panic actions 2021-01-21 13:00:41 +01:00
sockets.json sockets: Support multipath TCP 2021-06-08 19:36:22 +01:00
string-input-visitor.c qapi, qemu-options: make all parsing visitors parse boolean options the same 2020-11-04 12:00:40 -05:00
string-output-visitor.c string-output-visitor: Fix to use sufficient precision 2020-12-19 10:37:16 +01:00
tpm.json schemas: Add vim modeline 2020-08-03 08:28:08 +02:00
trace-events docs: fix references to docs/devel/tracing.rst 2021-06-02 06:51:09 +02:00
trace.h trace: switch position of headers to what Meson requires 2020-08-21 06:18:24 -04:00
trace.json qapi: Add blank lines before bulleted lists 2020-02-15 11:41:50 +01:00
transaction.json block: Drop the sheepdog block driver 2021-05-12 17:42:23 +02:00
ui.json qmp: add new qmp display-reload 2021-03-23 08:48:21 +01:00
yank.json Introduce yank feature 2021-01-13 10:21:17 +01:00