The virtio-mem is paravirtualized mechanism of adding/removing
memory to/from a VM. A virtio-mem-pci device is split into blocks
of equal size which are then exposed (all or only a requested
portion of them) to the guest kernel to use as regular memory.
Therefore, the device has two important attributes:
1) block-size, which defines the size of a block
2) requested-size, which defines how much memory (in bytes)
is the device requested to expose to the guest.
The 'block-size' is configured on command line and immutable
throughout device's lifetime. The 'requested-size' can be set on
the command line too, but also is adjustable via monitor. In
fact, that is how management software places its requests to
change the memory allocation. If it wants to give more memory to
the guest it changes 'requested-size' to a bigger value, and if it
wants to shrink guest memory it changes the 'requested-size' to a
smaller value. Note, value of zero means that guest should
release all memory offered by the device. Of course, guest has to
cooperate. Therefore, there is a third attribute 'size' which is
read only and reflects how much memory the guest still has. This
can be different to 'requested-size', obviously. Because of name
clash, I've named it 'current' and it is dealt with in future
commits (it is a runtime information anyway).
In the backend, memory for virtio-mem is backed by usual objects:
memory-backend-{ram,file,memfd} and their size puts the cap on
the amount of memory that a virtio-mem device can offer to a
guest. But we are already able to express this info using <size/>
under <target/>.
Therefore, we need only two more elements to cover 'block-size'
and 'requested-size' attributes. This is the XML I've came up
with:
<memory model='virtio-mem'>
<source>
<nodemask>1-3</nodemask>
<pagesize unit='KiB'>2048</pagesize>
</source>
<target>
<size unit='KiB'>2097152</size>
<node>0</node>
<block unit='KiB'>2048</block>
<requested unit='KiB'>1048576</requested>
</target>
<address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
</memory>
I hope by now it is obvious that:
1) 'requested-size' must be an integer multiple of
'block-size', and
2) virtio-mem-pci device goes onto PCI bus and thus needs PCI
address.
Then there is a limitation that the minimal 'block-size' is
transparent huge page size (I'll leave this without explanation).
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The value of zero is valid <unique_id/> (see
virNodeDeviceGetSCSIHostCaps()) but our RNG does not think so.
Switching the type to 'unsignedInt' does allow value of zero.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
A nodedev can have 'scsi_generic' capabilities but corresponding
RNG is missing. Fortunately, it's very simple - there's only one
mandatory child element <char/>.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The <type/> element for <capability type='scsi'> part of nodedev
XML is optional (see udevProcessSCSIDevice()) and as such might
not be formatted into nodedev XML (see
virNodeDeviceCapSCSIDefFormat()). Reflect this in our RNG.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The option "queue-size" for virtio-blk was added in qemu-2.12.0, and
default value increased from qemu-5.0.0.
However, increasing this value may lead to drop of random access
performance.
Signed-off-by: Hiroki Narukawa <hnarukaw@yahoo-corp.jp>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Add up-to-date information about creating and defining mediated devices
in libvirt.
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Bring the documentation for nodedev-list up to date with the latest
code, especially documenting the --active and -all options.
Also add documentation for the nodedev-define, nodedev-undefine, and
nodedev-start commands.
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
When documenting our public API in some places we use '@' to
refer to the variable. For instance:
* This API tries to set guest time to the given value. The time
* to set (@seconds and @nseconds) should be in seconds relative
* to the Epoch of 1970-01-01 00:00:00 in UTC.
However, when generating HTML documentation these tokens are
copied verbatim. What we can do is drop the '@' character and
wrap the variable in <code/> so that it is formatted properly.
Due to the way we 'parse' docs a token might actually be slightly
more than just '@variable'. For instance in the example above we
will have the following tokens: '(@seconds' and '@nseconds)'.
Thus we need to handle possible substring before and after
variable.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
This is currently the only way to view the 'autostart' property for a
node device in virsh.
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Add ability to set node devices to autostart on boot or parent device
availability.
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
In the example for <memory model='dimm'/> we show how to
configure hugepages as backend. In the example we show 4MiB
hugepages which are non-standard and thus at the first glance may
mislead users thinking that a regular sized pages (4K) will be
used. Use 2MiB as the value instead.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
The virtiofs project started off using "virtio-fs" but later switched to
the "virtiofs" spelling because it matches the spelling of the mount -t
virtiofs command-line. Update the kbase article with the new spelling so
it matches the virtiofs website.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
A number of legacy issues make the virtiofs kbase article hard to
understand. Most users don't need to configure NUMA or a memory backend
other than memfd. Move that information to the bottom of the article so
the recommended syntax is most prominent.
Suggested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
We simply terminate qemu instead of issuing a reset as the semantics of
the setting dictate.
Fix it by handling it identically to 'fake reboot'.
We need to forbid the combination of 'onReboot' -> 'destroy' and
'onPoweroff' -> reboot though as the handling would be hairy and it
honetly makes no sense.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
The qemu driver didn't ever implement any meaningful handling for the
'preserve' action.
Forbid the flag in the qemu def validator and update the documentation
to be factual.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
The qemu driver didn't ever implement any meaningful handling for the
'rename-restart' action.
At this point the following handling would take place:
'on_reboot' set to 'rename-restart' is ignored on guest-initiated
reboots, the guest simply reboots.
For on_poweroff set to 'rename-restart' the following happens:
guest initiated shutdown -> 'destroy'
libvirt initiated shutdown -> 'reboot'
In addition when 'on_reboot' is 'destroy' in addition to 'on_poweroff'
being 'rename-restart' the guest is able to execute instructions after
issuing a reset before libvirt terminates it. This will be addressed
separately later.
Forbid the flag in the qemu def validator and update the documentation
to be factual.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Recently, I wanted to attach an vhost-user interface but found
out that attach-interface command doesn't support it.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Note that it's for internal testing use and remove the manpage entry.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
There is no need to error out for empty <partition></partition> element
as we can just simply ignore it. This allows to simplify the function
and prepare it for new sub-elements of <resource>.
It makes the <partition> element optional so we need to reflect the
change in schema as well.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
This is the preferred way to do it, but there were a few
instances in which some of the path components had embedded
slashes instead.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Commit 12967c3e13 incorrectly made the target optional.
The validation was re-introduced by commit e8863b91f (which
put it into FSDefValidate instead of the parser), but
it did not amend the schema to make it mandatory again.
https://bugzilla.redhat.com/show_bug.cgi?id=1969232
Fixes: e8863b91fb98f077d4c44a11bd7ea84c5e6b29ef
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
This function add halt polling time interface in domstats. So that
we can use command 'virsh domstats VM' to get the data if system
support.
Signed-off-by: Yang Fei <yangfei85@huawei.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Add support for customizable grabToggle key combinations with
<input type='evdev'>.
Signed-off-by: Justin Gatzen <justin.gatzen@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Adding availability of s390-pv in domain capabilities and adjust tests.
Signed-off-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Add documentation for launch security type s390-pv.
Signed-off-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Add launch security type 's390-pv' as well as some tests.
Signed-off-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Change launch security to make it reusable for other types.
Signed-off-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Even though 'id' attribute is output-only, we should accept xml
files containing it.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1941594
Signed-off-by: Kristina Hanicova <khanicov@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Enabling core dumps is a reasonably straightforward task, but is not
documented clearly. This page provides as easy link to point users
to when they need to debug QEMU.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
We need to report via domcapabilities if specifying shared memory
is supported without hugepages or numa config in order to find
out if domain has suitable setup to make virtiofs work.
The solution is to report source types of memory backing to
determine if memfd is a valid option.
Signed-off-by: Kristina Hanicova <khanicov@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Turns out, when introducing HMAT support in v6.6.0-rc1~249
I've forgot to allow "cache" attribute for <bandwidth/> element
in RNG. It's parsed and formatted, but schema does not allow it.
Fixes: a89bbbac86383a10be0cec5a93feb7ed820871eb
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1980162
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
The gitlab.com repos are the primary source, with libvirt.org just a
read-only mirror.
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
