Since XSA-131 qemu-xen has defaulted to non-permissive mode and the
option was extended to cover that case in 015a373351 "tools: libxl:
allow permissive qemu-upstream pci passthrough".
Since I was rewrapping to adjust the text anyway I've split the safety
warning into a separate paragraph to make it more obvious.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Eric <epretorious@yahoo.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
(cherry picked from commit 7f25baba1c)
Section 'IGNORED FOR COMPATIBILITY WITH XM' separates 'CACHE MONITORING
TECHNOLOGY' and 'CACHE ALLOCATION TECHNOLOGY' but they really should be
put together.
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Reviewed-by: Dario Faggioli <dario.faggioli@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
(cherry picked from commit 61598449ae)
This is because the migration stream does not preserve node information.
Note this is not a regression for migration v2 vs legacy migration
because neither of them preserves node information.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- some grammar fixes to the doc and fixed a comment ]
(cherry picked from commit fa6b5490be)
And transform to POD to match our other manpages.
The content is identical, although the formatting was altered slightly
to conform to more usual manpage layout.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
And transform to POD to match our other manpages.
The content is identical (other than one correction), although the
layout differs slightly with certain indentation.
As a correction, remove the reference to xentrace_cpusplit(1) which was
removed in c/s 9b9ca98b6a, more than 10 years ago!
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
And transform to POD to match our other manpages.
The content is identical, although the layout differs slightly with
certain indentation.
In addition, adjust the MAN{1,5}SRC-y `find` runes to be more general.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
This patch introduces user configurable parameters to specify RDM
resource and according policies,
Global RDM parameter:
rdm = "strategy=host,policy=strict/relaxed"
Per-device RDM parameter:
pci = [ 'sbdf, rdm_policy=strict/relaxed' ]
Global RDM parameter, "strategy", allows user to specify reserved regions
explicitly, Currently, using 'host' to include all reserved regions reported
on this platform which is good to handle hotplug scenario. In the future
this parameter may be further extended to allow specifying random regions,
e.g. even those belonging to another platform as a preparation for live
migration with passthrough devices. By default this isn't set so we don't
check all rdms. Instead, we just check rdm specific to a given device if
you're assigning this kind of device. Note this option is not recommended
unless you can make sure any conflict does exist.
'strict/relaxed' policy decides how to handle conflict when reserving RDM
regions in pfn space. If conflict exists, 'strict' means an immediate error
so VM can't keep running, while 'relaxed' allows moving forward with a
warning message thrown out.
Default per-device RDM policy is same as default global RDM policy as being
'relaxed'. And the per-device policy would override the global policy like
others.
CC: Ian Jackson <ian.jackson@eu.citrix.com>
CC: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
CC: Ian Campbell <ian.campbell@citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Checked-by: Ian Jackson <ian.jackson@eu.citrix.com>
A platform may have a GIC compatible with previous version of the
device.
This is allow to virtualize an unmodified OS on new hardware if the GIC
is compatible with older version.
When a guest is created, the vGIC will emulate same version as the
hardware. Although, the user can specify in the configuration file the
preferred version (currently only GICv2 and GICv3 are supported).
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Usage:
hdtype=ide|ahci (default=ide)
If hdtype=ahci adds ich9 disk controller in ahci mode and uses it with
upstream qemu to emulate disks instead of ide.
It doesn't support cdroms which still using ide (cdroms will use
"-device ide-cd" as new qemu parameter)
Ahci requires new qemu parameter but for now other emulated disks cases
remains with old ones (I did it in other patch, not needed by this one)
I did it as libxl parameter disabled by default to avoid possible
problems:
- with save/restore/migration (restoring with ahci a domU that was with
ide instead)
- windows < 8 without pv drivers (a registry key change is needed for
AHCI<->IDE change FWIK to avoid possible blue screen)
- windows XP or older that many not support ahci by default.
Setting AHCI with libxl parameter and default to disabled seems the best
solution.
AHCI increase hvm domUs boot performance. On linux hvm domU I saw up to
only 20% of the previous total boot time, whereas boot time decrease a
lot on W7 domUs for most of boots I have done. Small difference in boot
time compared to ide mode on W8 and newer (probably other xen
improvements or fixes are needed not ahci related)
Signed-off-by: Fabio Fantoni <fabio.fantoni@m2r.biz>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- adjust name of LIBXL_HAVE #define as discussed on list,
fixup pod syntax in xl.cfg.pod.5 ]
Add document to introduce basic concepts and terms in PSR family
technologies and the xl interfaces.
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
This is the xc/xl changes to support Intel Cache Allocation
Technology(CAT).
'xl psr-hwinfo' is updated to show CAT info and two new commands
for CAT are introduced:
- xl psr-cat-cbm-set [-s socket] <domain> <cbm>
Set cache capacity bitmasks(CBM) for a domain.
- xl psr-cat-show <domain>
Show CAT domain information.
Examples:
[root@vmm-psr vmm]# xl psr-hwinfo --cat
Cache Allocation Technology (CAT):
Socket ID : 0
L3 Cache : 12288KB
Maximum COS : 15
CBM length : 12
Default CBM : 0xfff
[root@vmm-psr vmm]# xl psr-cat-cbm-set 0 0xff
[root@vmm-psr vmm]# xl psr-cat-show
Socket ID : 0
L3 Cache : 12288KB
Default CBM : 0xfff
ID NAME CBM
0 Domain-0 0xff
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Reviewed-by: Dario Faggioli <dario.faggioli@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Olaf reports:
[ 146s] man/xl.pod.1 around line 1529: '=item' outside of any '=over'
[ 146s] man/xl.pod.1 around line 1531: You forgot a '=back' before '=head1'
[ 146s] POD document had syntax errors at /usr/bin/pod2text line 84.
[ 146s] Makefile:167: recipe for target 'txt/man/xl.1.txt' failed
[ 146s] make[1]: *** [txt/man/xl.1.txt] Error 255
Reported-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Tested-by: Andrew Cooper <andrew.cooper3@citrix.com>
The current base directory /var/xen/dump for domU dumps will be patched
to /var/lib/xen/dump by most distros to follow FHS.
This change does three things:
- change the default from /var/xen/dump to /var/lib/xen/dump
- provide a configure option to avoid patching the source.
- update docs to refer to the new default location
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- s,/var,LOCALSTATEDIR, in help test, ran autogen.sh ]
xm migrate would do non-live migration (effectively, save, transfer
and restore) by default, unless you specified --live.
xl migrate always does live migration. Honour (by ignoring) --live
for compatibility with old callers. Document this.
(This patch should be backported as far as possible.)
Reported-by: Matthew Vernon <mcv21@cam.ac.uk>
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Matthew Vernon <mcv21@cam.ac.uk>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
The partial device tree may contains phandle. The Device Tree Compiler
tends to allocate the phandle from 1.
Reserve the ID 65000 for the GIC phandle. I think we can safely assume
that the partial device tree will never contain a such ID.
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Allow the user to pass additional nodes to the guest device tree. For
this purpose, everything in the node /passthrough from the partial
device tree will be copied into the guest device tree.
The node /aliases will be also copied to allow the user to define
aliases which can be used by the guest kernel.
A simple partial device tree will look like:
/dts-v1/;
/ {
#address-cells = <2>;
#size-cells = <2>;
passthrough {
compatible = "simple-bus";
ranges;
#address-cells = <2>;
#size-cells = <2>;
/* List of your nodes */
}
};
Note that:
* The interrupt-parent property will be added by the toolstack in
the root node
* The properties compatible, ranges, #address-cells and #size-cells
in /passthrough are mandatory.
The helpers provided by the libfdt don't perform all the necessary
security check on a given device tree. Therefore, only trusted device
tree should be used.
Note: The partial device tree code requires the presence of libfdt
functions which have been only correctly exported in libfdt 1.4.0 and
higher. All the major distributions but Debian Wheezy are using v1.4.0
or higher. It has been decided to disable partial device tree support on
OSes where libfdt doesn't meet the requirement.
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- ran autogen.sh ]
Usage:
vga="qxl"
Qxl vga support many resolutions that not supported by stdvga,
mainly the 16:9 ones and other high up to 2560x1600.
With QXL you can get improved performance and smooth video also
with high resolutions and high quality.
Require their drivers installed in the domU and spice used
otherwise act as a simple stdvga.
Signed-off-by: Fabio Fantoni <fabio.fantoni@m2r.biz>
Signed-off-by: Zhou Peng <zpengxen@gmail.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
Several users have reported that their available free memory in the
guest when they used maxmem >> memory was much smaller than when
maxmem == memory. This is the unavoidable consequence of how
ballooning works, but it's not something users expect.
Warn them of this effect in the place we tell them how to make it
happen, so they aren't surprised.
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Since b642ed6775 making docs
fail with:
man/xl.cfg.pod.5 around line 273: Unterminated B<...> sequence
POD document had syntax errors at /usr/bin/pod2text line 84.
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
instead of just list of single pCPUs or NUMA node IDs, as
it happens right now.
On the other hand, after this change, strings containing
pCPUs and NUMA node ranges is supported. The syntax is the
same one supported by the "cpus" and "cpus_soft" config
switch, i.e., "4-8" or "node:1,12-18,^14".
This make things more flexible, more consistent, and also
improves error handling, as the pCPU range parsing routine
already present in xl is more reliable than just a call
to atoi().
While there, remove a redundant error check in the legacy syntax
handling (libxl_bitmap_test() already checks the index being
within the size of the bitmap).
Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Juergen Gross <JGross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
in fact, right now, xl sub-commands 'cpupool-cpu-add' and
'cpupool-cpu-remove' only accept the specification of one
pCPU to be added or removed to/from a cpupool.
With this change, they can deal with ranges, like "4-8",
or "node:1,12-18,^14". The syntax is exactly the same one
that is supported by the 'vcpu-pin' subcommand, and
specifying just one pCPU still works, of course.
This make things more flexible, more consistent, and also
improves error handling, as the pCPU range parsing routine
already present in xl is more reliable than just a call
to atoi().
Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Juergen Gross <JGross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
This unifies the flask_enforcing and flask_enabled boot parameters into
a single parameter with additional states. Defined options are:
enforcing - require policy to be loaded at boot time and enforce it
permissive - a missing or broken policy does not panic
disabled - revert to dummy (no XSM) policy. Was flask_enabled=0
late - bootloader policy is not used; later loadpolicy is enforcing
The default mode remains "permissive" and the flask_enforcing boot
parameter is retained for compatibility. If flask_enforcing=1 is
specified and flask= is not, the bootloader policy will be loaded in
enforcing mode if present, but errors will disable access controls until
a successful loadpolicy instead of causing a panic at boot.
Suggested-by: Julien Grall <julien.grall@linaro.org>
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Add Memory Bandwidth Monitoring(MBM) for VMs. Two types of monitoring
are supported: total and local memory bandwidth monitoring. To use it,
CMT should be enabled in hypervisor.
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Usage:
spice_streaming_video=[filter|all|off]
Specifies what streaming video setting is to be used by spice (if
given),
otherwise the qemu default will be used.
Signed-off-by: Fabio Fantoni <fabio.fantoni@m2r.biz>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Usage:
spice_image_compression=[auto_glz|auto_lz|quic|glz|lz|off]
Specifies what image compression is to be used by spice (if given),
otherwise the qemu default will be used.
Signed-off-by: Fabio Fantoni <fabio.fantoni@m2r.biz>
Acked-by: Wei Liu <wei.liu2@citrix.com>
The presence of the partition reference time enlightenment persuades newer
versions of Windows to prefer the TSC as their primary time source. Hence,
if rdtsc is not being emulated and is invariant then many vmexits (for
alternative time sources such as the HPET or reference counter MSR) can
be avoided.
The implementation is not yet complete as no attempt is made to prevent
emulation of rdtsc if the enlightenment is active and guest and host
TSC frequencies differ. To do that requires invasive changes in the core
x86 time code and hence a lot more testing.
This patch avoids the issue by disabling the enlightenment if rdtsc is
being emulated, causing Windows to choose another time source. This is
safe, but may cause a big variation in performance of guests migrated
between hosts of differing TSC frequency. Thus the enlightenment is not
enabled in the default set, but may be enabled to improve guest performance
where such migrations are not a concern.
See section 15.4 of the Microsoft Hypervisor Top Level Functional
Specification v4.0a for details.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Christoph Egger <chegger@amazon.de>
If you add enough PCI devices then all mmio may not fit below 4G
which may not be the layout the user wanted. This allows you to
increase the below 4G address space that PCI devices can use and
therefore in more cases not have any mmio that is above 4G.
There are real PCI cards that do not support mmio over 4G, so if you
want to emulate them precisely, you may also need to increase the
space below 4G for them. There are drivers for these cards that also
do not work if they have their mmio space mapped above 4G.
This allows growing the MMIO hole to the size needed.
This may help with using pci passthru and HVM.
In the tools this is named mmio_hole_memkb.
Signed-off-by: Don Slutz <dslutz@verizon.com>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- fixed build error in xl_cmdimpl.c with s/%PRIu64/%ld/.
Reworded title ]
This adds support for channel declarations of the form:
channel = [ "name=...,connection=...[,path=...][,backend=...]" ]
where 'name' is a label to identify the channel to the frontend.
If 'connection = pty' then the channel is connected to a pty in the
backend domain
If 'connection = socket' then the channel is connected to a Unix domain
socket given by 'path = ...' in the backend domain.
This patch also adds the command:
xl channel-list <domain>
which allows the state of channels to be queried. In particular if
'connection=pty' this will show the path of the pty slave device.
Signed-off-by: David Scott <dave.scott@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
The commit 7471879 "tools: CMDs and APIs for Cache Monitoring Technology"
has introduced a new section but forgot to add '=back'. This will result
a build issue with newer podman:
man/xl.pod.1 around line 1443: You forgot a '=back' before '=head1'
or creating a section "POD ERRORS" with older one.
At the same time, capitalize the title of the section to match the coding
style used within the files.
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Introduced some new xl commands to enable/disable Cache Monitoring
Technology(CMT) feature.
The following two commands is to attach/detach the CMT feature
to/from a certain domain.
$ xl psr-cmt-attach domid
$ xl psr-cmt-detach domid
This command is to display the CMT information, such as L3 cache
occupancy.
$ xl psr-cmt-show cache_occupancy <domid>
Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Disk replication is enabled by default. This patch adds a cmdline
switch to 'xl remus' command to explicitly disable disk replication.
A new boolean field 'diskbuf' is added to the libxl_domain_remus_info
structure to represent this configuration option inside libxl.
Note: Disabling disk replication requires enabling unsafe mode.
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Add two members in libxl_domain_remus_info:
netbuf: whether netbuf is enabled
netbufscript: the path of the script which will be run to setup
and tear down the guest's interface.
Add cmdline switches to 'xl remus' command to enable or disable
network buffering and a domain-specific hotplug script to setup
network buffering.
Add a new config var 'remus.default.netbufscript' to xl.conf, that
allows the user to override the default global script used to
setup network buffering.
Note: Network buffering is enabled by default. Disabling network
buffering requires enabling unsafe mode.
Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: Wen Congyang <wency@cn.fujitsu.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
By default, network buffering and disk replication are enabled;
checkpoints are replicated to another standby VM.
This patch allows the user to disable any of these features by
explicitly specifying a 'run in unsafe mode' switch when invoking
the 'xl remus' command. While running Remus in an unsafe mode
makes little sense under normal circumstances, it is useful to be
able to disable one or more features mentioned above for
testing/debugging/profiling purposes.
Unless this option is enabled, it will not be possible to
replicate memory checkpoints to /dev/null (blackhole replication),
disable network buffering or disk replication.
As a starter, the use of blackhole replication now requires that
the unsafe mode be enabled. Subsequent patches will add support
for disabling network buffering and disk replication in a similar
manner.
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This patch optionally re-instates support for the partition time reference
counter that was previously introduced by commit
e36cd2cdc9 and reverted by commit
1cd4fab14c. The previous implementation was
non-optional and flawed.
This implementation uses the tsc of vcpu0, which is preserved across
save/restore as part of the architectural state, and then converts that
to a 100ns tick using the domain's tsc_khz.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Keir Fraser <keir@xen.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Christoph Egger <chegger@amazon.de>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
The following commits introduced the time reference counter MSR and
TSC/APIC frequency MSRs into the viridian feature set respectively:
e36cd2cdc984657efd91
The time reference counter MSR feature was then reverted by commit
1cd4fab14c
because a flaw in the implementation meant the counter was reset on
migration.
All of these changes were made without any addtional options being
added to the VM configuration, or any compatibility checks being made
in the domain save/restore code. Hence setting the single boolean
'viridian' option in the VM configuration yields a different set of
features depending on which version of Xen the VM is started on, and the
feature set can change across migration (so new MSRs can magically appear).
This patch grandfathers in the current viridian features set and calls them
the 'base' and 'freq' feature sets. HVM_PARAM_VIRIDIAN is re-purposed as
a feature mask. The hypervisor has only ever allowed it ot be set to 0
or 1, so the presence of the base and freq sets are indicated by setting
bit 0. The freq set can then be turned off by setting bit 1, thus
restoring the pre-Xen-4.4 base set. Newly implemented viridian features
can be optionally enabled in future by setting further bits.
The viridian option in xl.cfg(5) has also been changed to a list so
that the sets can be individually enabled or disabled. For compatibility,
if the option is specified as a boolean, then a true (1) value will enable
the base and freq sets and a false (0) value will not enable any
enlightenments.
This patch also alters the allowed write accesses to HVM_PARAM_VIRIDIAN.
Currently there is nothing to stop the guest writing this value (which,
while harmless to anything else, should not happen) and nothing to
stop a toolstack from setting the value back to zero whilst the guest is
running, causing CPUID leaves to disappear and MSR accesses to start
causing GPFs in the guest. Both of these possibilities are now disallowed:
Once the parameter is set to a non-zero value it may not be modified (only
re-written with the same value), and guests no longer have any write
access.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Keir Fraser <keir@xen.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: David Scott <dave.scott@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Ian Campbell
Chao Peng
Wei Liu
Andrew Cooper
Ed White
Tiejun Chen
Julien Grall
Fabio Fantoni
Dario Faggioli
Olaf Hering
Ian Jackson
Julien Grall
Giuseppe Mazzotta
George Dunlap
Riku Voipio
Daniel De Graaf
Paul Durrant
Don Slutz
David Scott
Yang Hongyang
Meng Xu