This patch documents XML elements used for support of shmem devices. Considering there could be other shared memory related devices, this patch introduces a general device model, called shmem device. Currenly "ivshmem" is the only shared memory model supported. About ivshmem, please see the following documentation: http://git.qemu.org/?p=qemu.git;a=blob;f=docs/specs/ivshmem_device_spec.txt (Ivshmem documentation for qemu will be updated soon: http://lists.gnu.org/archive/html/qemu-devel/2014-08/msg01244.html) In the devices section in the domain XML users may specify: - For ivshmem device using an ivshmem server: <shmem name='shmem0' model='ivshmem'> <source file='/tmp/socket-ivshmem0'/> <size unit='M'>32</size> <msi vectors='32' ioeventfd='on'/> </shmem> - For ivshmem device not using an ivshmem server: <shmem name='ivshmem1' model='ivshmem'> <size unit='M'>32</size> </shmem> Signed-off-by: Maxime Leroy <maxime.leroy@xxxxxxxxx> --- docs/formatdomain.html.in | 68 +++++++++++++++++++++++++++++++++++++++++++ docs/schemas/domaincommon.rng | 49 +++++++++++++++++++++++++++++++ 2 files changed, 117 insertions(+) diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index ed17389..c7644bc 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -5422,6 +5422,74 @@ qemu-kvm -net nic,model=? /dev/null </dd> </dl> + <h4><a name="elementsShmem">Shmem device</a></h4> + + <p> + A shmem (i.e. shared memory) device allows to share a memory + region between different virtual machines and the host. + </p> + +<pre> + ... + <devices> + <shmem name='shmem0' model='ivshmem'/> + <shmem name='shmem1' model='ivshmem'/> + </devices> + ...</pre> + + <dl> + <dt><code>shmem</code></dt> + <dd> + The <code>shmem</code> element has one mandatory attribute, + <code>name</code> to identify the shared memory. The optional element + <code>model</code> specify the type of shared memory. Only one mode of + shared-memory is currently supported: <code>ivshmem</code>. + </dd> + </dl> + + <h5><a name="elementsIvshmem">Ivshmem model</a></h5> + + <p> + An ivshmem (i.e. Inter-VM shared memory) device allows to share a memory + region (created on the host via the POSIX shared memory API) between + multiple QEMU processes running different guests. + For more information, please see the + <a href="http://git.qemu.org/?p=qemu.git;a=blob;f=docs/specs/ivshmem_device_spec.txt";> + ivshmem documentation of qemu</a>. + </p> + +<pre> + ... + <devices> + <shmem name='shmem0' model='ivshmem'> + <server path='/tmp/socket-shmem0'/> + <size unit='M'>32</size> + <msi vectors='32' ioeventfd='on'/> + </shmem> + <shmem name='shmem1' model='ivshmem'> + <size unit='M'>32</size> + </shmem> + </devices> + ...</pre> + + <dl> + <dt><code>server</code></dt> + <dd>The optional <code>server</code> element can be used to configure an + ivshmem device connected to the ivshmem server via a unix socket. The + <code>path</code> attribute specifies the path to the unix socket. + </dd> + <dt><code>size</code></dt> + <dd>The optional <code>size</code> element specifies the size of the shared memory. + </dd> + <dt><code>msi</code></dt> + <dd>The optional <code>msi</code> element allows to enable MSI interrupts. + This option can only be used with the <code>server</code> attribute. + The <code>vectors</code> attribute can be used to specify the number of + interrupt vectors. The <code>ioeventd</code> attribute allows to enable + ioeventfd. + </dd> + </dl> + <h3><a name="seclabel">Security label</a></h3> <p> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index 033f2f6..64abf2b 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -3221,6 +3221,54 @@ </optional> </element> </define> + + <define name="shmem"> + <element name="shmem"> + <attribute name="name"/> + <optional> + <ref name="ivshmem"/> + </optional> + <optional> + <ref name="alias"/> + </optional> + <optional> + <ref name="address"/> + </optional> + </element> + </define> + + <define name="ivshmem"> + <group> + <attribute name="model"> + <value>ivshmem</value> + </attribute> + <interleave> + <optional> + <element name="server"> + <attribute name="path"/> + </element> + </optional> + <optional> + <element name="msi"> + <optional> + <ref name="ioeventfd"/> + </optional> + <optional> + <attribute name="vectors"> + <ref name="unsignedInt"/> + </attribute> + </optional> + </element> + </optional> + <optional> + <element name="size"> + <ref name="scaledInteger"/> + </element> + </optional> + </interleave> + </group> + </define> + <define name="memballoon"> <element name="memballoon"> <attribute name="model"> @@ -3807,6 +3855,7 @@ <ref name="redirfilter"/> <ref name="rng"/> <ref name="tpm"/> + <ref name="shmem"/> </choice> </zeroOrMore> <optional> -- 1.9.3 -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list