Re: [libvirt] [PATCH v1 10/31] schemas: Introduce disk type NVMe

There is this class of PCI devices that act like disks: NVMe. Therefore, they are both PCI devices and disks. While we already have <hostdev/> (and can assign a NVMe device to a domain successfully) we don't have disk representation. There are three problems with PCI assignment in case of a NVMe device: 1) domains with <hostdev/> can't be migrated 2) NVMe device is assigned whole, there's no way to assign only a namespace 3) Because hypervisors see <hostdev/> they don't put block layer on top of it - users don't get all the fancy features like snapshots NVMe namespaces are way of splitting one continuous NVDIMM memory

into smaller ones, effectively creating smaller NVMe-s (which can then be partitioned, LVMed, etc.) Because of all of this the following XML was chosen to model a NVMe device: <disk type='nvme' device='disk'> <driver name='qemu' type='raw'/> <source type='pci' managed='yes' namespace='1'> <address domain='0x0000' bus='0x01' slot='0x00' function='0x0'/> </source> <target dev='vda' bus='virtio'/> </disk> Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- docs/formatdomain.html.in | 45 +++++++++++++++++++++-- docs/schemas/domaincommon.rng | 32 ++++++++++++++++ tests/qemuxml2argvdata/disk-nvme.xml | 55 ++++++++++++++++++++++++++++ 3 files changed, 129 insertions(+), 3 deletions(-) create mode 100644 tests/qemuxml2argvdata/disk-nvme.xml diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index a7a6ec32a5..545578076d 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -2922,6 +2922,13 @@ &lt;/backingStore&gt; &lt;target dev='vdd' bus='virtio'/&gt; &lt;/disk&gt; + &lt;disk type='nvme' device='disk'&gt; + &lt;driver name='qemu' type='raw'/&gt; + &lt;source type='pci' managed='yes' namespace='1'&gt;

+ &lt;address domain='0x0000' bus='0x01' slot='0x00' function='0x0'/&gt; + &lt;/source&gt; + &lt;target dev='vde' bus='virtio'/&gt; + &lt;/disk&gt; &lt;/devices&gt; ...</pre>

@@ -3118,6 +3126,31 @@ <span class="since">Since 1.0.5</span> </p> </dd> + <dt><code>nvme</code></dt> + <dd> + To specify disk source for NVMe disk the <code>source</code> + element has the following attributes: + <dl> + <dt><code>type</code></dt> + <dd>The type of address specified in <code>address</code> + sub-element. Currently, only <code>pci</code> value is + accepted. + </dd> + + <dt><code>managed</code></dt> + <dd>This attribute instructs libvirt to detach NVMe + controller automatically on domain startup (<code>yes</code>) + or expect the controller to be detached by system + administrator (<code>no</code>). + </dd> + + <dt><code>namespace</code></dt> + <dd>The namespace ID which should be assigned to the domain. + According to NVMe standard, namespace numbers start from 1, + including. + </dd> + </dl> + </dd> </dl> With "file", "block", and "volume", one or more optional sub-elements <code>seclabel</code>, <a href="#seclabel">described @@ -3280,11 +3313,17 @@ initiator IQN needed to access the source via mandatory attribute <code>name</code>. </dd> + <dt><code>address</code></dt> + <dd>For disk of type <code>nvme</code> this element + specifies the PCI address of the host NVMe + controller. + <span class="since">Since 5.5.0</span> + </dd> </dl> <p> - For a "file" or "volume" disk type which represents a cdrom or floppy - (the <code>device</code> attribute), it is possible to define + For a "file", "volume" or "nvme" disk type which represents a cdrom or + floppy (the <code>device</code> attribute), it is possible to define

policy what to do with the disk if the source file is not accessible. (NB, <code>startupPolicy</code> is not valid for "volume" disk unless the specified storage volume is of "file" type). This is done by the diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index 31db599ab9..f367e8f6fd 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng

@@ -1918,6 +1919,37 @@ </optional> </define> + <define name="diskSourceNvme"> + <attribute name="type"> + <value>nvme</value> + </attribute> + <optional> + <element name="source"> + <attribute name="type"> + <value>pci</value> + </attribute> + <attribute name="namespace"> + <ref name="uint32"/> + </attribute> + <optional> + <attribute name="managed"> + <ref name="virYesNo"/> + </attribute> + </optional> + <element name="address"> + <ref name="pciaddress"/> + </element> + <ref name="diskSourceCommon"/> + <optional> + <ref name="storageStartupPolicy"/> + </optional> + <optional> + <ref name="encryption"/> + </optional> + </element> + </optional> + </define> + <define name="diskTarget"> <data type="string"> <param name="pattern">(ioemu:)?(fd|hd|sd|vd|xvd|ubd)[a-zA-Z0-9_]+</param> diff --git a/tests/qemuxml2argvdata/disk-nvme.xml b/tests/qemuxml2argvdata/disk-nvme.xml new file mode 100644 index 0000000000..0b3dbad4eb --- /dev/null +++ b/tests/qemuxml2argvdata/disk-nvme.xml @@ -0,0 +1,55 @@ +<domain type='qemu'> + <name>QEMUGuest1</name> + <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid> + <memory unit='KiB'>219136</memory> + <currentMemory unit='KiB'>219136</currentMemory> + <vcpu placement='static'>1</vcpu> + <os> + <type arch='i686' machine='pc'>hvm</type> + <boot dev='hd'/> + </os> + <clock offset='utc'/> + <on_poweroff>destroy</on_poweroff> + <on_reboot>restart</on_reboot> + <on_crash>destroy</on_crash> + <devices> + <emulator>/usr/bin/qemu-system-i686</emulator> + <disk type='nvme' device='disk'> + <driver name='qemu' type='raw'/> + <source type='pci' managed='yes' namespace='1'> + <address domain='0x0000' bus='0x01' slot='0x00' function='0x0'/> + </source> + <target dev='vda' bus='virtio'/> + </disk> + <disk type='nvme' device='disk'> + <driver name='qemu' type='raw'/> + <source type='pci' managed='yes' namespace='2'> + <address domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>

+ </source> + <target dev='vdb' bus='virtio'/> + </disk> + <disk type='nvme' device='disk'> + <driver name='qemu' type='raw'/> + <source type='pci' managed='no' namespace='1'> + <address domain='0x0000' bus='0x02' slot='0x00' function='0x0'/> + </source> + <target dev='vdc' bus='virtio'/> + </disk> + <disk type='nvme' device='disk'> + <driver name='qemu' type='raw'/> + <source type='pci' managed='no' namespace='2'> + <address domain='0x0001' bus='0x02' slot='0x00' function='0x0'/> + <encryption format='luks'> + <secret type='passphrase' uuid='0a81f5b2-8403-7b23-c8d6-21ccc2f80d6f'/> + </encryption> + </source> + <target dev='vdd' bus='virtio'/> + </disk> + <controller type='usb' index='0'/> + <controller type='pci' index='0' model='pci-root'/> + <controller type='scsi' index='0' model='virtio-scsi'/> + <input type='mouse' bus='ps2'/> + <input type='keyboard' bus='ps2'/> + <memballoon model='none'/> + </devices> +</domain>