From c7cddce1f7eb4b6d1ae979349f3dacb130a37814 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 28 Nov 2017 16:15:28 +0000 Subject: qemu-options: document missing memory-backend-file options This patch adds undocumented memory-backend-file options to the documentation. Signed-off-by: Stefan Hajnoczi Message-Id: <20171128161529.3025-2-stefanha@redhat.com> Reviewed-by: Eric Blake Reviewed-by: Eduardo Habkost Signed-off-by: Eduardo Habkost --- qemu-options.hx | 48 +++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 41 insertions(+), 7 deletions(-) (limited to 'qemu-options.hx') diff --git a/qemu-options.hx b/qemu-options.hx index 678181c599..fe8c04f644 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -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 -- cgit v1.2.3