Commit c7cddce1 authored by Stefan Hajnoczi's avatar Stefan Hajnoczi Committed by Eduardo Habkost
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qemu-options: document missing memory-backend-file options 



This patch adds undocumented memory-backend-file options to the
documentation.

Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20171128161529.3025-2-stefanha@redhat.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Reviewed-by: default avatarEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
parent e3ab04de

qemu-options.hx

+41 −7
Original line number Diff line number Diff line
@@ -3972,18 +3972,24 @@ property must be set. These objects are placed in the 


@table @option



@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off},discard-data=@var{on|off}

@item -object memory-backend-file,id=@var{id},size=@var{size},mem-path=@var{dir},share=@var{on|off},discard-data=@var{on|off},merge=@var{on|off},dump=@var{on|off},prealloc=@var{on|off},host-nodes=@var{host-nodes},policy=@var{default|preferred|bind|interleave}



Creates a memory file backend object, which can be used to back

the guest RAM with huge pages. The @option{id} parameter is a

unique ID that will be used to reference this memory region

when configuring the @option{-numa} argument. The @option{size}

option provides the size of the memory region, and accepts

common suffixes, eg @option{500M}. The @option{mem-path} provides

the path to either a shared memory or huge page filesystem mount.

the guest RAM with huge pages.



The @option{id} parameter is a unique ID that will be used to reference this

memory region when configuring the @option{-numa} argument.



The @option{size} option provides the size of the memory region, and accepts

common suffixes, eg @option{500M}.



The @option{mem-path} provides the path to either a shared memory or huge page

filesystem mount.



The @option{share} boolean option determines whether the memory

region is marked as private to QEMU, or shared. The latter allows

a co-operating external process to access the QEMU memory region.



Setting the @option{discard-data} boolean option to @var{on}

indicates that file contents can be destroyed when QEMU exits,

to avoid unnecessarily flushing data to the backing file.  Note
@@ -3991,6 +3997,34 @@ that @option{discard-data} is only an optimization, and QEMU 
might not discard file contents if it aborts unexpectedly or is

terminated using SIGKILL.



The @option{merge} boolean option enables memory merge, also known as

MADV_MERGEABLE, so that Kernel Samepage Merging will consider the pages for

memory deduplication.



Setting the @option{dump} boolean option to @var{off} excludes the memory from

core dumps. This feature is also known as MADV_DONTDUMP.



The @option{prealloc} boolean option enables memory preallocation.



The @option{host-nodes} option binds the memory range to a list of NUMA host

nodes.



The @option{policy} option sets the NUMA policy to one of the following values:



@table @option

@item @var{default}

default host policy



@item @var{preferred}

prefer the given host node list for allocation



@item @var{bind}

restrict memory allocation to the given host node list



@item @var{interleave}

interleave memory allocations across the given host node list

@end table



@item -object rng-random,id=@var{id},filename=@var{/dev/random}



Creates a random number generator backend which obtains entropy from