With 9pfs now available in Xenstore-stubdom, there is no reason to
have distinct do_control_memreport() variants for the daemon and the
stubdom implementations.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
With 9pfs being fully available in Xenstore-stubdom now, there is no
reason to not fully support all logging capabilities in stubdom.
Open the logfile on stubdom only after the 9pfs file system has been
mounted.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Add some helpers for handling filenames which might need different
implementations between stubdom and daemon environments:
- expansion of relative filenames (those are not really defined today,
just expand them to be relative to /var/lib/xen/xenstore)
- expansion of xenstore_daemon_rundir() (used e.g. for saving the state
file in case of live update - needs to be unchanged in the daemon
case, but should result in /var/lib/xen/xenstore for stubdom)
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Mount the 9pfs device in stubdom enabling it to use files.
This has to happen in a worker thread in order to allow the main thread
handling the required Xenstore accesses in parallel.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
libxl__spawn_qdisk_backend() explicitly sets guest_config to NULL when
starting QEMU (the usual launch through libxl__spawn_local_dm() has a
guest_config though).
Bail early on a NULL guest_config/d_config. This skips the QMP queries
for chardevs and VNC, but this xenpv QEMU instance isn't expected to
provide those - only qdisk (or 9pfs backends after an upcoming change).
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
With 9pfs now available in Xenstore-stubdom, there is no reason to
have distinct do_control_memreport() variants for the daemon and the
stubdom implementations.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
With 9pfs being fully available in Xenstore-stubdom now, there is no
reason to not fully support all logging capabilities in stubdom.
Open the logfile on stubdom only after the 9pfs file system has been
mounted.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Add some helpers for handling filenames which might need different
implementations between stubdom and daemon environments:
- expansion of relative filenames (those are not really defined today,
just expand them to be relative to /var/lib/xen/xenstore)
- expansion of xenstore_daemon_rundir() (used e.g. for saving the state
file in case of live update - needs to be unchanged in the daemon
case, but should result in /var/lib/xen/xenstore for stubdom)
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Mount the 9pfs device in stubdom enabling it to use files.
This has to happen in a worker thread in order to allow the main thread
handling the required Xenstore accesses in parallel.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Add a 9pfs device to Xenstore stubdom in order to allow it to do e.g.
logging into a dom0 file.
Use the following parameters for the new device:
- tag = "Xen"
- type = "xen_9pfsd"
- path = "/var/lib/xen/xenstore"
- security-model = "none"
For now don't limit allowed file space or number of files.
Add a new libxl function for adding it similar to the function for
adding the console device.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Add support for the new 9pfs backend "xen_9pfsd". For this backend type
the tag defaults to "Xen" and the host side path to
"/var/log/xen/guests/<dom-name>".
Do most of the default settings in libxl. Unfortunately the default
path can't easily be set in libxl, as the domain name isn't available
in the related 9pfs specific function.
Settings the defaults in libxl requires to move the sanity checking
of 9pfs parameters from xl to libxl, too.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Make the backend type of 9pfs PV devices configurable. The default is
"qemu" with the related Xenstore backend-side directory being "9pfs".
Add another type "xen_9pfsd" with the related Xenstore backend-side
directory "xen_9pfs".
As additional security features it is possible to specify:
- "max-space" for limiting the maximum space consumed on the filesystem
in MBs
- "max-files" for limiting the maximum number of files in the
filesystem
- "max-open-files" for limiting the maximum number of concurrent open
files
For convenience "auto-delete" is available to let the backend delete the
oldest file of the guest in case otherwise "max-space" or "max-files"
would be violated.
The xen-9pfsd daemon will be started by libxenlight automatically when
the first "xen_9pfs" device is being created.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: George Dunlap <george.dunlap@cloud.com> # Golang bits
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Now that we no longer have a hashtable inside we can make Quota.t pure, and
push the mutable update to its callers. Store.t already had a mutable Quota.t
field.
No functional change.
Signed-off-by: Edwin Török <edwin.torok@cloud.com>
Acked-by: Christian Lindig <christian.lindig@cloud.com>
On a stress test running 1000 VMs flamegraphs have shown that
`oxenstored` spends a large amount of time in `Hashtbl.copy` and the GC.
Hashtable complexity:
* read/write: O(1) average
* copy: O(domains) -- copying the entire table
Map complexity:
* read/write: O(log n) worst case
* copy: O(1) -- a word copy
We always perform at least one 'copy' when processing each xenstore
packet (regardless whether it is a readonly operation or inside a
transaction or not), so the actual complexity per packet is:
* Hashtbl: O(domains)
* Map: O(log domains)
Maps are the clear winner, and a better fit for the immutable xenstore
tree.
Signed-off-by: Edwin Török <edwin.torok@cloud.com>
Acked-by: Christian Lindig <christian.lindig@cloud.com>
This patch addresses a behavior discrepancy in the handling of altp2m views,
where upon the creation and subsequent EPT violation, the page access
permissions were incorrectly inherited from the hostp2m instead of respecting
the altp2m default_access.
Previously, when a new altp2m view was established with restrictive
default_access permissions and activated via xc_altp2m_switch_to_view(),
it failed to trigger an event on the first access violation. This behavior
diverged from the intended mechanism, where the altp2m's default_access
should dictate the initial permissions, ensuring proper event triggering on
access violations.
The correction involves modifying the handling mechanism to respect the
altp2m view's default_access upon its activation, eliminating the need for
setting memory access permissions for the entire altp2m range (e.g. within
xen-access.c). This change not only aligns the behavior with the expected
access control logic but also results in a significant performance improvement
by reducing the overhead associated with setting memory access permissions
across the altp2m range.
Signed-off-by: Petr Beneš <w1benny@gmail.com>
Acked-by: Tamas K Lengyel <tamas@tklengyel.com>
When re-working library call wrapping the sed invocation didn't account
for all sources living in the parent directory when building the 32-bit
harness binary.
Fixes: 6fba45ca3b ("x86emul: rework wrapping of libc functions in test and fuzzing harnesses")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
In xen-9pfsd fill_data() va_end() needs to be called before returning.
Coverity Id CID 1592145
Fixes: bcec59cf7f ("tools/xen-9pfsd: add 9pfs version request support")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
According to comments (and experiments) qemu-xen cannot handle memory
reolcation done by hvmloader. The code was already disabled when running
qemu-xen in dom0 (see libxl__spawn_local_dm()), but it was missed when
adding qemu-xen support to stubdomain. Adjust libxl__spawn_stub_dm() to
be consistent in this regard.
Reported-by: Neowutran <xen@neowutran.ovh>
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Allow administrators to control whether Xen grant mappings for
the virtio disk devices should be used. By default (when new
parameter is not specified), the existing behavior is retained
(we enable grants if backend-domid != 0).
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Add the attach request of the 9pfs protocol. This introduces the "fid"
scheme of the 9pfs protocol.
As this will be needed later, use a dedicated memory allocation
function in alloc_fid() and prepare a fid reference count.
For filling the qid data take the approach from the qemu 9pfs backend
implementation.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Add the version request of the 9pfs protocol. For the version use the
"9P2000.u" variant, as it is supported by Mini-OS and Linux.
For the request parsing add all format items needed even in future in
order to avoid code churn for those additions later.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Add support for generation a 9pfs protocol response via a format based
approach.
Strings are stored in a per device string buffer and they are
referenced via their offset in this buffer. This allows to avoid
having to dynamically allocate memory for each single string.
As a first user of the response handling add a generic p9_error()
function which will be used to return any error to the client.
Add all format parsing variants in order to avoid additional code churn
later when adding the users of those variants. Prepare a special case
for the "read" case already (format character 'D'): in order to avoid
adding another buffer for read data support doing the read I/O directly
into the response buffer.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Add the transport layer of 9pfs. This is basically the infrastructure
to receive requests from the frontend and to send the related answers
via the rings.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Add "xen-9pfsd", a new 9pfs daemon meant to support infrastructure
domains (e.g. xenstore-stubdom) to access files in dom0.
For now only add the code needed for starting the daemon and
registering it with Xenstore via a new "libxl/xen-9pfs/state" node by
writing the "running" state to it.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
It's located in libxl_domain_build_info, not libxl_domain_create_info.
Fixes: 45ba9a7d76 ("tools/[lib]xl: Add vmtrace_buf_size parameter")
Signed-off-by: Petr Beneš <w1benny@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Add a command line option to xentop to be able to display dom0 first, on top of the list.
This is unconditional, so sorting domains with the S option will also ignore dom0.
Signed-off-by: Cyril Rébert (zithro) <slack@rabbit.lu>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
A Linux HVM domain ignores PV block devices with type cdrom. The
Windows PV drivers also ignore device-type != "disk". Therefore QEMU's
emulated CD-ROM support is used. This allows ejection and other CD-ROM
features to work.
With a stubdom, QEMU is running in the stubdom. A PV disk is still
connected into the stubdom, and then QEMU can emulate the CD-ROM into
the guest. Phy support has been enhanced to provide a placeholder file
forempty disks, so it is usable as a CDROM backend as well. Allow Phy
to pass the check as well.
(Bypassing just for a linux-based stubdom doesn't work because
libxl__device_disk_setdefault() gets called early in domain creation
before xenstore is populated with relevant information for the stubdom
type. The build information isn't readily available and won't exist in
some call trees, so it isn't usable either.)
Let disk_try_backend() allow format empty for Phy cdrom drives.
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
With a device model stubdom, dom0 exports a PV disk to the stubdom.
Inside the stubdom, QEMU emulates a cdrom to the guest with a
host_device pointing at the PV frontend (/dev/xvdc)
An empty cdrom drive causes problems booting the stubdom. The PV disk
protocol isn't designed to support no media. That can be partially
hacked around, but the stubdom kernel waits for all block devices to
transition to Connected. Since the backend never connects empty media,
stubdom launch times out and it is destroyed.
Empty media and the PV disks not connecting is fine at runtime since the
stubdom keeps running irrespective of the disk state.
Empty media can be worked around my providing an empty file to the
stubdom for the PV disk source. This works as the disk is exposed as a
zero-size disk. Dynamically create the empty file as needed and remove
in the stubdom cleanup.
libxl__device_disk_set_backend() needs to allow through these "empty"
disks with a pdev_path.
Fixup the params writing since scripts have trouble with an empty params
field.
This works for non-stubdom HVMs as well.
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
This patch re-introduces blktap support to libxl. Unlike earlier
versions, it does not link against any blktap library. libxl changes
are needed to write to the vbd3 backend XenStore nodes.
blktap has three components. tapdisk is a daemon implementing the disk
IO, NBD (Network Block Device), and Xen PV interfaces. tap-ctl is a
tool to control tapdisks - creating, starting, stopping and freeing.
tapback manages the XenStore operations and instructs tapdisk to
connect.
It is notable that tapdisk performs the grant and event channel ops, but
doesn't interact with XenStore. tapback performs XenStore operations
and notifies tapdisks of values and changes.
The flow is: libxl writes to the "vbd3" XenStore nodes and runs the
block-tap script. The block-tap script runs tap-ctl to create a tapdisk
instance as the physical device. tapback then sees the tapdisk and
instructs the tapdisk to connect up the PV blkif interface.
This is expected to work without the kernel blktap driver, so the
block-tap script is modified accordingly to write the UNIX NBD path.
backendtype=tap was not fully removed previously, but it would never
succeed since it would hit the hardcoded error in disk_try_backend().
It is reused now.
An example command to attach a vhd:
xl block-attach vm 'vdev=xvdf,backendtype=tap,format=vhd,target=/srv/target.vhd'
Format raw also works to run an "aio:" tapdisk.
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Add the missing `vmtrace_buf_kb` field to the OCaml bindings to match the
vm.cfg configuration, correcting an oversight from its initial introduction.
Signed-off-by: Petr Beneš <w1benny@gmail.com>
Acked-by: Christian Lindig <christian.lindig@cloud.com>
same_vm is broken when the two main domains do not have targets. otvm
and targetvm are both missing, which means they get set to -1 and then
converted to empty strings:
++10697+ local targetvm=-1
++10697+ local otvm=-1
++10697+ otvm=
++10697+ othervm=/vm/cc97bc2f-3a91-43f7-8fbc-4cb92f90b4e4
++10697+ targetvm=
++10697+ local frontend_uuid=/vm/844dea4e-44f8-4e3e-8145-325132a31ca5
The final comparison returns true since the two empty strings match:
++10697+ '[' /vm/844dea4e-44f8-4e3e-8145-325132a31ca5 = /vm/cc97bc2f-3a91-43f7-8fbc-4cb92f90b4e4 -o '' = /vm/cc97bc2f-3a91-43f7-8fbc-4cb92f90b4e4 -o /vm/844dea4e-44f8-4e3e-8145-325132a31ca5 = '' -o '' = '' ']'
Replace -1 with distinct strings indicating the lack of a value and
remove the collescing to empty stings. The strings themselves will no
longer match, and that is correct.
++12364+ '[' /vm/844dea4e-44f8-4e3e-8145-325132a31ca5 = /vm/cc97bc2f-3a91-43f7-8fbc-4cb92f90b4e4 -o 'No target' = /vm/cc97bc2f-3a91-43f7-8fbc-4cb92f90b4e4 -o /vm/844dea4e-44f8-4e3e-8145-325132a31ca5 = 'No other target' -o 'No target' = 'No other target' ']'
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
When running as stubdom, map the stubdom's Xenstore ring page in order
to support using the 9pfs frontend.
Use the same pattern as in dom0_init() when running as daemon in dom0
(introduce the own domain, then send an event to the client side to
signal Xenstore is ready to communicate).
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Today domain_init() is called either just before calling dom0_init()
in case no live update is being performed, or it is called after
reading the global state from read_state_global(), as the event
channel fd is needed.
Split up domain_init() into a preparation part which can be called
unconditionally, and in a part setting up the event channel handle.
Note that there is no chance that chk_domain_generation() can be
called now before xc_handle has been setup, so there is no need for
the related special case anymore.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
When [un]mapping the ring page of a Xenstore client, different actions
are required for "normal" guests and dom0. Today this distinction is
made at call site.
Move this distinction into [un]map_interface() instead, avoiding code
duplication and preparing special handling for [un]mapping the stub
domain's ring page.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
All of the socket handling is needed only when running as daemon.
Move it into posix.c, allowing to remove the NO_SOCKETS macro.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
All of the log-pipe handling is needed only when running as daemon.
Move it into posix.c. This requires to have a service function in the
main event loop for handling the related requests and one for setting
the fds[] array, which is renamed to poll_fds to have a more specific
name. Use a generic name for those functions, as socket handling can
be added to them later, too.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Move systemd handling to a new late_init() function in posix.c.
This prepares a future removal of the NO_SOCKETS macro.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Juergen Gross