Commit Graph
3155 Commits
Author SHA1 Message Date
Andrew Cooper 454239acc5 tools/libxl: Re-position CPUID handling during domain construction
CPUID handling needs to be earlier in construction.  Move it from its current
position in libxl__build_post() to libxl__build_pre() for fresh builds, and
libxl__srm_callout_callback_static_data_done() for the migration/resume case.

Later changes will make the migration/resume case conditional on whether CPUID
data was present in the migration stream, and the libxc layer took care of
restoring it.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-29 17:33:03 +01:00
Andrew Cooper c1a552ec7f tools/libxl: Provide a static_data_done callback for domain restore
This will be needed shortly to provide backwards compatiblity for migration
streams which do not have CPUID information contained within them.

No functional change yet.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-29 17:33:03 +01:00
Tamas K Lengyel 7582bbc14c tools/libxl: fix setting altp2m param broken by 1e9bc407cf
The patch 1e9bc407cf mistakenly converted the altp2m config option to a
boolean. This is incorrect and breaks external-only usecases of altp2m that
is set with a value of 2.

Signed-off-by: Tamas K Lengyel <tamas@tklengyel.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-29 17:31:12 +01:00
Juergen Gross 2ea4b9829c tools/libxl: use libxenhypfs for setting xen runtime parameters
Instead of xc_set_parameters() use xenhypfs_write() for setting
parameters of the hypervisor.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
2020-05-29 12:20:08 +02:00
George Dunlap 60db5da62a libxl: Generate golang bindings in libxl Makefile
The generated golang bindings (types.gen.go and helpers.gen.go) are
left checked in so that they can be fetched from xenbits using the
golang tooling.  This means that they must be updated whenever
libxl_types.idl (or other dependencies) are updated.  However, the
golang bindings are only built optionally; we can't assume that anyone
updating libxl_types.idl will also descend into the tools/golang tree
to re-generate the bindings.

Fix this by re-generating the golang bindings from the libxl Makefile
when the IDL dependencies are updated, so that anyone who updates
libxl_types.idl will also end up updating the golang generated files
as well.

 - Make a variable for the generated files, and a target in
   xenlight/Makefile which will only re-generate the files.

 - Add a target in libxl/Makefile to call external idl generation
   targets (currently only golang).

For ease of testing, also add a specific target in libxl/Makefile just
to check and update files generated from the IDL.

This does mean that there are two potential paths for generating the
files during a parallel build; but that shouldn't be an issue, since
tools/golang/xenlight should never be built until after tools/libxl
has completed building anyway.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>
Reviewed-by: Nick Rosbrook <rosbrookn@ainfosec.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-28 12:20:53 +01:00
Jason Andryuk e235fa2794 libxl: Check stubdomain kernel & ramdisk presence
Just out of context is the following comment for libxl__domain_make:
/* fixme: this function can leak the stubdom if it fails */

When the stubdomain kernel or ramdisk is not present, the domid and
stubdomain name will indeed be leaked.  Avoid the leak by checking the
file presence and erroring out when absent.  It doesn't fix all cases,
but it avoids a big one when using a linux device model stubdomain.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-19 16:19:15 +01:00
Marek Marczykowski-Górecki cfc47cd4e2 libxl: consider also qemu in stubdomain in libxl__dm_active check
Since qemu-xen can now run in stubdomain too, handle this case when
checking it's state too.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-19 16:19:15 +01:00
Marek Marczykowski-Górecki fa9d82825a libxl: ignore emulated IDE disks beyond the first 4
Qemu supports only 4 emulated IDE disks, when given more (or with higher
indexes), it will fail to start. Since the disks can still be accessible
using PV interface, just ignore emulated path and log a warning, instead
of rejecting the configuration altogether.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-19 16:19:15 +01:00
Marek Marczykowski-Górecki ab9ce23f5a libxl: require qemu in dom0 for multiple stubdomain consoles
Device model stubdomains (both Mini-OS + qemu-trad and linux + qemu-xen)
are always started with at least 3 consoles: log, save, and restore.
Until xenconsoled learns how to handle multiple consoles, this is needed
for save/restore support.

For Mini-OS stubdoms, this is a bug.  In practice, it works in most
cases because there is something else that triggers qemu in dom0 too:
vfb/vkb added if vnc/sdl/spice is enabled.

Additionally, Linux-based stubdomain waits for all the backends to
initialize during boot. Lack of some console backends results in
stubdomain startup timeout.

This is a temporary patch until xenconsoled will be improved.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
[Updated commit message with Marek's explanation from mailing list.]
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-19 16:19:15 +01:00
Marek Marczykowski-Górecki 83c845033d libxl: use vchan for QMP access with Linux stubdomain
Access to QMP of QEMU in Linux stubdomain is possible over vchan
connection. Handle the actual vchan connection in a separate process
(vchan-socket-proxy). This simplified integration with QMP (already
quite complex), but also allows preliminary filtering of (potentially
malicious) QMP input.
Since only one client can be connected to vchan server at the same time
and it is not enforced by the libxenvchan itself, additional client-side
locking is needed. It is implicitly implemented by vchan-socket-proxy,
as it handle only one connection at a time. Note that qemu supports only
one simultaneous client on a control socket anyway (but in UNIX socket
case, it enforce it server-side), so it doesn't add any extra
limitation.

libxl qmp client code already has locking to handle concurrent access
attempts to the same qemu qmp interface.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>

Squash in changes of regenerated autotools files.

Kill the vchan-socket-proxy so we don't leak the daemonized processes.
libxl__stubdomain_is_linux_running() works against the guest_domid, but
the xenstore path is beneath the stubdomain.  This leads to the use of
libxl_is_stubdom in addition to libxl__stubdomain_is_linux_running() so
that the stubdomain calls kill for the qmp-proxy.

Also call libxl__qmp_cleanup() to remove the unix sockets used by
vchan-socket-proxy.  vchan-socket-proxy only creates qmp-libxl-$domid,
and libxl__qmp_cleanup removes that as well as qmp-libxenstat-$domid.
However, it tolerates ENOENT, and a stray qmp-libxenstat-$domid should
not exist.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-19 16:19:15 +01:00
Jason Andryuk 379ab27086 libxl: Refactor kill_device_model to libxl__kill_xs_path
Move kill_device_model to libxl__kill_xs_path so we have a helper to
kill a process from a pid stored in xenstore.  We'll be using it to kill
vchan-qmp-proxy.

libxl__kill_xs_path takes a "what" string for use in printing error
messages.  kill_device_model is retained in libxl_dm.c to provide the
string.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-19 16:19:15 +01:00
Marek Marczykowski-Górecki 449901fc96 libxl: add save/restore support for qemu-xen in stubdomain
Rely on a wrapper script in stubdomain to attach relevant consoles to
qemu.  The save console (1) must be attached to fdset/1.  When
performing a restore, $STUBDOM_RESTORE_INCOMING_ARG must be replaced on
the qemu command line by "fd:$FD", where $FD is an open file descriptor
number to the restore console (2).

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>

Address TODO in dm_state_save_to_fdset: Only remove savefile for
non-stubdom.
Use $STUBDOM_RESTORE_INCOMING_ARG instead of fd:3 and update commit
message.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-19 16:19:15 +01:00
Marek Marczykowski-Górecki dabc571b72 libxl: write qemu arguments into separate xenstore keys
This allows using arguments with spaces, like -append, without
nominating any special "separator" character.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>

Write arguments in dm-argv directory instead of overloading mini-os's
dmargs string.

Make libxl__write_stub_dmargs vary behaviour based on the
is_linux_stubdom flag.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-19 16:19:08 +01:00
Jason Andryuk 6d721be59d libxl: Use libxl__xs_* in libxl__write_stub_dmargs
Re-work libxl__write_stub_dmargs to use libxl_xs_* functions in a loop.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-19 16:19:05 +01:00
Eric Shelton 7efd9f3d45 libxl: Handle Linux stubdomain specific QEMU options.
This patch creates an appropriate command line for the QEMU instance
running in a Linux-based stubdomain.

NOTE: a number of items are not currently implemented for Linux-based
stubdomains, such as:
- save/restore
- QMP socket
- graphics output (e.g., VNC)

Signed-off-by: Eric Shelton <eshelton@pobox.com>

Simon:
 * fix disk path
 * fix cdrom path and "format"

Signed-off-by: Simon Gaiser <simon@invisiblethingslab.com>
[drop Qubes-specific parts]
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>

Allow setting stubdomain_ramdisk independently from stubdomain_kernel
Add a qemu- prefix for qemu-stubdom-linux-{kernel,rootfs} since stubdom
doesn't convey device-model.  Use qemu- since this code is qemu specific.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-18 23:23:44 +01:00
Marek Marczykowski-Górecki 46587a30d4 libxl: Allow running qemu-xen in stubdomain
Do not prohibit anymore using stubdomain with qemu-xen.
To help distingushing MiniOS and Linux stubdomain, add helper inline
functions libxl__stubdomain_is_linux() and
libxl__stubdomain_is_linux_running(). Those should be used where really
the difference is about MiniOS/Linux, not qemu-xen/qemu-xen-traditional.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-18 23:23:44 +01:00
Marek Marczykowski-Górecki 11b7f8725d libxl: fix qemu-trad cmdline for no sdl/vnc case
When qemu is running in stubdomain, any attempt to initialize vnc/sdl
there will crash it (on failed attempt to load a keymap from a file). If
vfb is present, all those cases are skipped. But since
b053f0c4c9 "libxl: do not start dom0 qemu
for stubdomain when not needed" it is possible to create a stubdomain
without vfb and contrary to the comment -vnc none do trigger VNC
initialization code (just skips exposing it externally).
Change the implicit SDL avoiding method to -nographics option, used when
none of SDL or VNC is enabled.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
2020-05-18 23:23:44 +01:00
Jan Beulich a6d1b55847 x86emul: support X{SUS,RES}LDTRK
There's nothing to be done by the emulator, as we unconditionally abort
any XBEGIN.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
2020-05-15 16:13:03 +02:00
Jan Beulich cca6bf0730 x86emul: support SERIALIZE
... enabling its use by all guest kinds at the same time.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
2020-05-15 16:09:22 +02:00
Roger Pau Monne 190c60f12d tools/libxl: disable clang indentation check for the disk parser
Clang 10 complains with:

13: error: misleading indentation; statement is not part of the previous 'if'
      [-Werror,-Wmisleading-indentation]
            if ( ! yyg->yy_state_buf )
            ^
libxlu_disk_l.c:1259:9: note: previous statement is here
        if ( ! yyg->yy_state_buf )
        ^

Due to the missing braces in single line statements and the wrong
indentation. Fix this by disabling the warning for that specific file.
I haven't found a way to force flex to add braces around single line
statements in conditional blocks.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
[ wei: regenerate output files ]
Acked-by: Wei Liu <wl@xen.org>
2020-05-10 13:02:18 +01:00
Wei Liu 4cefd87ed3 libxl: update libxlu_disk_l.[ch]
Use flex 2.6.4 that is shipped in Debian Buster.

Signed-off-by: Wei Liu <wl@xen.org>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
2020-05-10 13:00:30 +01:00
Andrew Cooper 779efdbb50 tools/libxl: Plumb a restore boolean into libxl__domain_build_state
To fix CPUID handling, libxl__build_pre() is going to have to distinguish
between a brand new VM vs one which is being migrated-in/resumed.

Transcribe dcs->restore_fd into dbs->restore in initiate_domain_create()
only (specifically avoiding the stubdom state in libxl__spawn_stub_dm()).

While tweaking initiate_domain_create(), make a new dbs alias and simplify
later code, and drop the local restore_fd alias as the new dbs->restore is
more intuitive in context.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-05-05 20:18:19 +01:00
Andrew Cooper 4803a67114 x86: Enumeration for Control-flow Enforcement Technology
The CET spec has been published and guest kernels are starting to get support.
Introduce the CPUID and MSRs, and fully block the MSRs from guest use.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wl@xen.org>
2020-04-21 16:52:03 +01:00
Ian Jackson 7e1867b121 docs etc.: https: Fix references to wiki.xen[project].org
Change the url scheme to https.  This is all in-tree references to the
Xen wiki.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
2020-03-30 15:27:06 +01:00
Olaf Hering 60d6ba1916 libxl: Fix xl shutdown for HVM without PV drivers
A return value of zero means no PV drivers. Restore a hunk which was removed.

Fixes commit b183e180bc

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Wei Liu <wl@xen.org>
2020-03-21 16:44:15 +00:00
Paul Durrant f18f8d9d63 libxl: make creation of xenstore 'suspend event channel' node optional...
... and, if it is not created, make the top level 'device' node in
xenstore writable by the guest instead.

The purpose and semantics of the suspend event channel node are explained
in xenstore-paths.pandoc [1]. It was originally introduced in xend by
commit 17636f47a4 "Teach xc_save to use event-channel-based domain
suspend if available.". Note that, because, the top-level frontend
'device' node was created writable by the guest in xend, there was no
need to explicitly create the 'suspend-event-channel' node as a writable
node.

However, libxl creates the 'device' node as read-only by the guest and so
explicit creation of the 'suspend-event-channel' node is necessary to make
it usable. This unfortunately has the side-effect of making some old
Windows PV drivers [2] cease to function. This is because they scan the top
level 'device' node, find the 'suspend' node and expect it to contain the
usual sub-nodes describing a PV frontend. When this is found not to be the
case, enumeration ceases and (because the 'suspend' node is observed before
the 'vbd' node) no system disk is enumerated. Windows will then crash with
bugcheck code 0x7B (missing system disk).

This patch adds a boolean 'xend_suspend_evtchn_compat' field into
libxl_create_info and a similarly named option in xl.cfg to set it.
If the value is true then the xenstore node is not created. Instead the
old xend behaviour of making top level device node writable by the guest is
re-instated. If the value is false (the default) then the current libxl
behaviour persists.

xenstore-paths.pandoc is also modified to say that the suspend event
channel node may not exist and, if it does not exist, then the guest may
create it. A note is also added concerning the writability of the top
level device node.

[1] https://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/misc/xenstore-paths.pandoc;hb=HEAD#l177
[2] https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/5/html/para-virtualized_windows_drivers_guide/sect-para-virtualized_windows_drivers_guide-installing_and_configuring_the_para_virtualized_drivers-installing_the_para_virtualized_drivers

NOTE: While adding the new LIBXL_HAVE_CREATEINFO_... definition into
      libxl.h, this patch corrects the previous stanza which erroneously
      implies libxl_domain_create_info is a function.

Signed-off-by: Paul Durrant <paul@xen.org>
Reviewed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-03-19 15:56:54 +00:00
Paul Durrant 1f706eace3 libxl: create domain 'error' node in xenstore
Several PV drivers (both historically and currently [1]) report errors
by writing text into /local/domain/$DOMID/error. This patch creates the
node in libxl and makes it writable by the domain, and also adds some
text into xenstore-paths.pandoc to state what the node is for.

[1] https://xenbits.xen.org/gitweb/?p=pvdrivers/win/xenvif.git;a=blob;f=src/xenvif/frontend.c;hb=HEAD#l459

Signed-off-by: Paul Durrant <paul@xen.org>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-03-19 15:56:00 +00:00
Paweł Marczewski d094e95fb7 libxl: fix cleanup bug in initiate_domain_create()
In case of errors, we immediately call domcreate_complete()
which cleans up the console_xswait object. Make sure it is initialized
before we start cleanup.

Signed-off-by: Paweł Marczewski <pawel@invisiblethingslab.com>
Reviewed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-03-13 11:33:40 +00:00
Paweł Marczewski 0d99c909d7 libxl: wait for console path before firing console_available
If the path doesn't become available after LIBXL_INIT_TIMEOUT
seconds, fail the domain creation.

If we skip the bootloader, the TTY path will be set by xenconsoled.
However, there is no guarantee that this will happen by the time we
want to call the console_available callback, so we have to wait.

Signed-off-by: Paweł Marczewski <pawel@invisiblethingslab.com>
Reviewed-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
2020-03-04 10:15:45 +00:00
Andrew Cooper fedd1f6f41 tools/libxl: Simplify callback handling in libxl-save-helper
The {save,restore}_callback helpers can have their scope reduced vastly, and
helper_setcallbacks_{save,restore}() doesn't need to use a ternary operator to
write 0 (meaning NULL) into an already zeroed structure.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-02-27 18:56:24 +00:00
Jan Beulich 5f29f34981 libxl/PCI: align reserved device memory boundary for HAP guests
As the code comment says, this will allow use of a 2Mb super page
mapping at the end of "low" memory.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wl@xen.org>
2020-02-27 15:45:31 +01:00
Jan Beulich fc7b56510d libxl/PCI: pass correct "hotplug" argument to libxl__device_pci_setdefault()
Uniformly passing "false" can't be right, but has been benign because of
the function not using this parameter.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wl@xen.org>
2020-02-27 15:45:05 +01:00
Jan Beulich df04e202c9 libxl/PCI: make "rdm=" parsing comply with documentation
Documentation says "<RDM_RESERVATION_STRING> is a comma separated list
of <KEY=VALUE> settings, from the following list". There's no mention
of a specific order, yet so far the parsing logic did accept only
strategy, then policy (and neither of the two omitted). Make "state"
move
- back to STATE_TYPE when finding a comma after having parsed the
  <VALUE> part of a setting,
- to STATE_TERMINAL otherwise.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wl@xen.org>
2020-02-27 15:44:41 +01:00
Jan Beulich 6fdb8eef87 libxl/PCI: establish per-device reserved memory policy earlier
Reserved device memory region processing as well as E820 table creation
happen earlier than the adding of (PCI) devices, yet they consume the
policy (e.g. to decide whether to add entries to the E820 table). But so
far it was only at the stage of PCI device addition that the final
policy was established (i.e. if not explicitly specified by the guest
config file).

Note that I couldn't find the domain ID to be available in
libxl__domain_device_construct_rdm(), but observing that
libxl__device_pci_setdefault() also doesn't use it, for the time being
DOMID_INVALID gets passed. An obvious alternative would be to drop the
unused parameter/argument, yet at that time the question would be
whether to also drop other unused ones.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wl@xen.org>
2020-02-27 15:44:17 +01:00
Jan Beulich 3bdb073643 libxl/PCI: honor multiple per-device reserved memory regions
While in "host" strategy all regions get processed, of the per-device
ones only the first entry has been consumed so far.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wl@xen.org>
2020-02-27 15:43:55 +01:00
Paul Durrant d7d751bfdb libxl: add initializers for libxl__domid_history
This patch fixes Coverity issue CID 1459006 (Insecure data handling
(INTEGER_OVERFLOW)).

The problem is that the error paths for libxl__mark_domid_recent() and
libxl__is_domid_recent() check the 'f' field in struct libxl__domid_history
when it may not have been initialized.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Wei Liu <wl@xen.org>
2020-02-26 21:48:39 +00:00
Paul Durrant 37a5b5f673 libxl: fix build with older glibc
Commit 2b02882ebb "libxl: add infrastructure to track and query
'recent' domids" added a call to clock_gettime() into libxl. The man-
page for this states:

"Link with -lrt (only for glibc versions before 2.17)."

Unfortunately Centos 6 does have an glibc prior to that version, and the
libxl Makefile was not updated to add '-lrt' so the build will fail in
that environment.

This patch simply adds '-lrt' to LIBXL_LIBS unconditionally, as it does
no harm in newer environments.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Fixes: 2b02882ebb ("libxl: add infrastructure to track and query 'recent' domids")
Acked-by: Wei Liu <wl@xen.org>
2020-02-25 14:28:59 +00:00
Paul Durrant 4a3a25678d libxl: allow creation of domains with a specified or random domid
This patch adds a 'domid' field to libxl_domain_create_info and then
modifies libxl__domain_make() to have Xen use that value if it is valid.
If the domid value is invalid then Xen will choose the domid, as before,
unless the value is the new special RANDOM_DOMID value added to the API.
This value instructs libxl__domain_make() to choose a random domid value
for Xen to use.

If Xen determines that a domid specified to or chosen by
libxl__domain_make() co-incides with an existing domain then the create
operation will fail. In this case, if RANDOM_DOMID was specified to
libxl__domain_make() then a new random value will be chosen and the create
operation will be re-tried, otherwise libxl__domain_make() will fail.

After Xen has successfully created a new domain, libxl__domain_make() will
check whether its domid matches any recently used domid values. If it does
then the domain will be destroyed. If the domid used in creation was
specified to libxl__domain_make() then it will fail at this point,
otherwise the create operation will be re-tried with either a new random
or Xen-selected domid value.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-02-24 17:17:35 +00:00
Paul Durrant 2b02882ebb libxl: add infrastructure to track and query 'recent' domids
A domid is considered recent if the domain it represents was destroyed
less than a specified number of seconds ago. For debugging and/or testing
purposes the number can be set using the environment variable
LIBXL_DOMID_REUSE_TIMEOUT. If the variable does not exist then a default
value of 60s is used.

Whenever a domain is destroyed, a time-stamped record will be written into
a history file (/var/run/xen/domid-history). To avoid the history file
growing too large, any records with time-stamps that indicate that the
age of a domid has exceeded the re-use timeout will also be purged.

A new utility function, libxl__is_recent_domid(), has been added. This
function reads the same history file checking whether a specified domid
has a record that does not exceed the re-use timeout. Since this utility
function does not write to the file, no records are actually purged by it.

NOTE: The history file is purged on boot to it is safe to use
      CLOCK_MONOTONIC as a time source.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-02-24 17:17:35 +00:00
Andrew Cooper 1a16fee21c xen/public: Obsolete HVM_PARAM_PAE_ENABLED
Xen has never acted upon the value of HVM_PARAM_PAE_ENABLED, contrary perhaps
to expectations based on how other boolean fields work.

It was only ever used as a non-standard calling convention for
xc_cpuid_apply_policy() but that has been fixed now.

Purge its use, and any possible confusion over its behaviour, by having Xen
reject any attempts to use it.  Forgo setting it up in libxl's
hvm_set_conf_params().  The only backwards compatibility necessary is to have
the HVM restore stream discard it if found.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-02-21 15:28:40 +00:00
Andrew Cooper 744807bdb0 x86/splitlock: CPUID and MSR details
A splitlock is an atomic operation which crosses a cache line boundary.  It
serialises operations in the cache coherency fabric and comes with a
multi-thousand cycle stall.

Intel Tremont CPUs introduce MSR_CORE_CAPS to enumerate various core-specific
features, and MSR_TEST_CTRL to adjust the behaviour in the case of a
splitlock.

Virtualising this for guests is distinctly tricky owing to the fact that
MSR_TEST_CTRL has core rather than thread scope.  In the meantime however,
prevent the MSR values leaking into guests.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Wei Liu <wl@xen.org>
2020-02-21 13:50:00 +00:00
Paul Durrant c733b9e25c libxl: modify libxl__logv() to only log valid domid values
Some code-paths use values other than INVALID_DOMID to indicate an invalid
domain id. Specifically, xl will pass a value of 0 when creating/restoring
a domain. Therefore modify libxl__logv() to use libxl_domid_valid_guest()
as a validity test.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Wei Liu <wl@xen.org>
2020-02-21 12:05:41 +00:00
Andrew Cooper 8171e07965 tools/libx[cl]: Don't use HVM_PARAM_PAE_ENABLED as a function parameter
HVM_PARAM_PAE_ENABLED is set and consumed by the toolstack only.  It is in
practice a complicated and non-standard way of passing a boolean parameter
into xc_cpuid_apply_policy().

This is silly.  Pass PAE as a regular parameter instead.

In libxl__cpuid_legacy(), leave a rather better explaination of why only HVM
guests have a choice in PAE setting.

No change in how a guest is constructed.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-02-17 19:10:55 +00:00
Wei Liu ad1d3db985 libxl: mark parameters in stub functions as unused
Hopefully this can fix issues like:

In file included from ../../src/libxl/xen_xl.c:24:0:
/home/osstest/build.147035.build-amd64-libvirt/xendist/usr/local/include/libxl.h: In function 'libxl_cpuid_apply_policy':
/home/osstest/build.147035.build-amd64-libvirt/xendist/usr/local/include/libxl.h:2345:56: error: unused parameter 'ctx' [-Werror=unused-parameter]
 static inline void libxl_cpuid_apply_policy(libxl_ctx *ctx, uint32_t domid) {}

Fixes: dacb80f9 ("tools/libxl: Remove libxl_cpuid_{set,apply_policy}() from the API")
Signed-off-by: Wei Liu <wl@xen.org>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-02-14 11:08:53 +00:00
Wei Liu d3cec8e1f2 libxl: fix libxl__cpuid_legacy in libxl_nocpuid.c
Its last parameter should be libxl_domain_build_info.

Fixes: 1b3cec69 ("tools/libxl: Combine legacy CPUID handling logic")
Signed-off-by: Wei Liu <wl@xen.org>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
2020-02-13 15:31:18 +00:00
Andrew Cooper 1b3cec69bf tools/libxl: Combine legacy CPUID handling logic
While we are in the process of overhauling boot time CPUID/MSR handling, the
existing logic is going to have to remain in roughly this form for backwards
compatibility.

Fold libxl__cpuid_apply_policy() and libxl__cpuid_set() together into a single
libxl__cpuid_legacy() to reduce the complexity for callers.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-02-11 18:26:52 +00:00
Andrew Cooper dacb80f975 tools/libxl: Remove libxl_cpuid_{set,apply_policy}() from the API
These functions should never have been exposed.  They don't have external
users, and can't usefully be used for several reasons.

Move libxl_cpuid_{set,apply_policy}() to being internal functions, and leave
an equivalent of the nop stubs in the API for caller compatibility.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-02-11 18:26:52 +00:00
Paul Durrant d00377890a libxl: fix assertion failure in stub domain creation
An assertion in libxl__domain_make():

'soft_reset || *domid == INVALID_DOMID'

does not hold true for stub domain creation, where soft_reset is false
but the passed in domid == 0. This is easily fixed by changing the
initializer in libxl__spawn_stub_dm().

NOTE: The comment for XEN_DOMCTL_createdomain in domctl.h is changed to
      reflect reality.

Fixes: 75259239d8 ("libxl_create: make 'soft reset' explicit")
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Wei Liu <wl@xen.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
2020-02-05 11:56:27 +00:00
Paul Durrant 1d224ce698 libxl: generalise libxl__domain_userdata_lock()
This function implements a file-based lock with a file name generated
from a domid.

This patch splits it into two, generalising the core of the locking code
into a new libxl__lock_file() function which operates on a specified file,
leaving just the file name generation in libxl__domain_userdata_lock().

This patch also generalises libxl__unlock_domain_userdata() to
libxl__unlock_file() and modifies all call-sites.

Suggested-by: Ian Jackson <ian.jackson@eu.citrix.com>
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-01-31 16:10:46 +00:00
Paul Durrant 75259239d8 libxl_create: make 'soft reset' explicit
The 'soft reset' code path in libxl__domain_make() is currently taken if a
valid domid is passed into the function. A subsequent patch will enable
higher levels of the toolstack to determine the domid of newly created or
restored domains and therefore this criteria for choosing 'soft reset'
will no longer be usable.

This patch adds an extra boolean option to libxl__domain_make() to specify
whether it is being invoked in soft reset context and appropriately
modifies callers to choose the right value. To facilitate this, a new
'soft_reset' boolean field is added to struct libxl__domain_create_state
and the 'domid_soft_reset' field is renamed to 'domid' in anticipation of
its wider remit. For the moment do_domain_create() will always set
domid to INVALID_DOMID and hence we can add an assertion into
libxl__domain_create() that, if it is not called in soft reset context,
the passed in domid is exactly that value.

Whilst in the neighbourhood, some checks of 'restore_fd > -1' have been
replaced by 'restore_fd >= 0' to be more conventional and consistent with
checks of 'restore_fd < 0'.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2020-01-31 16:10:46 +00:00