The logic to disallow writes to the TSC is out-of-place, and should be in
check_resource_access() rather than in resource_access().
Split the existing allow_access_msr() into two - msr_{read,write}_allowed() -
and move all permissions checks here.
Furthermore, guard access to MSR_IA32_CMT_{EVTSEL,CTR} to prohibit their use
on hardware which is lacking the QoS Monitoring feature. Introduce
cpu_has_pqe to help with the logic.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Commit cf8c4d3d13 made some preparation to have one day
variable-length-array argument, but didn't declare the array in the
function prototype the same way as in the function definition. And now
GCC 11 complains about it.
Fixes: cf8c4d3d13 ("tools/libs/foreignmemory: pull array length argument to map forward")
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
This section's contents do not represent part of actual hypervisor text,
so shouldn't be included in what is_kernel_inittext() or (while still
booting) is_active_kernel_text() report "true" for. Keep them in
.init.text though, as there's no real reason to have a separate section
for this in the final binary.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
With pt_vcpu_lock() no longer acquiring the pt_migrate lock, parties
iterating the list and acting on the timers of the list entries will no
longer be kept from entering their loops by create_periodic_time()'s
holding of that lock. Therefore at least init_timer() needs calling
ahead of list insertion, but keep this and set_timer() together.
Fixes: 8113b02f0b ("x86/vpt: do not take pt_migrate rwlock in some cases")
Reported-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
"change" command as been removed in QEMU 6.0. We can use
"blockdev-change-medium" instead.
Using `id` with "blockdev-change-medium" requires a change to the QEMU
command line, introduced by:
"libxl: Use -device for cd-rom drives"
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
`device` parameter is deprecated since QEMU 2.8.
This requires changes to the command line introduced by:
"libxl: Use -device for cd-rom drives"
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
We are going to want to check QEMU's version in other places where we
can use libxl__ev_qmp_send.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
We are supposed to read the version information only when qmp_ev is in
state "Connected" (that correspond to state==qmp_state_connected),
assert it so that the function isn't used too early.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
This allows to set an `id` on the device instead of only the drive. We
are going to need the `id` with the "eject" and
"blockdev-change-media" QMP command as using `device` parameter on
those is deprecated. (`device` is the `id` of the `-drive` on the
command line).
We set the same `id` on both -device and -drive as QEMU doesn't
complain and we can then either do "eject id=$id" or "eject
device=$id".
Using "-drive + -device" instead of only "-drive" has been
available since at least QEMU 0.15, and seems to be the preferred way as it
separates the host part (-drive which describe the disk image location
and format) from the guest part (-device which describe the emulated
device). More information in qemu.git/docs/qdev-device-use.txt .
Changing the command line during migration for the cdrom seems fine.
Also the documentation about migration in QEMU explains that the device
state ID is "been formed from a bus name and device address", so
second IDE bus and first device address on bus is still thus and
doesn't matter if written "-drive if=ide,index=2" or "-drive
ide-cd,bus=ide.1,unit=0".
See qemu.git/docs/devel/migration.rst .
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
The command "cpu-add" for CPU hotplug is deprecated and has been
removed from QEMU 6.0 (April 2021). We need to add cpus with the
command "device_add" now.
In order to find out which parameters to pass to "device_add" we first
make a call to "query-hotpluggable-cpus" which list the cpus drivers
and properties.
The algorithm to figure out which CPU to add, and by extension if any
CPU needs to be hotplugged, is in the function that adds the cpus.
Because of that, the command "query-hotpluggable-cpus" is always
called, even when not needed.
In case we are using a version of QEMU older than 2.7 (Sept 2016)
which don't have "query-hotpluggable-cpus", we fallback to using
"cpu-add".
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Short-form boolean options are deprecated in QEMU 6.0.
Upstream commit that deprecate those: ccd3b3b8112b ("qemu-option: warn
for short-form boolean options").
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
We use the deprecated QMP command "query-cpus" which is removed in the
QEMU 6.0 release. There's a replacement which is "query-cpus-fast",
and have been available since QEMU 2.12 (April 2018).
This patch try the new command first and when the command isn't
available, it fall back to the deprecated one so libxl still works
with older QEMU versions.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
This confuses disassemblers, at the very least. Move
.altinstr_replacement to .init.text. The previously redundant ALIGN()
now gets converted to page alignment, such that the hypervisor mapping
won't have this as executable (it'll instead get mapped r/w, which I'm
told is intended to be adjusted at some point).
Note that for the actual patching logic's purposes this part of
.init.text _has_ to live after _einittext (or before _sinittext), or
else branch_insn_requires_update() would produce wrong results.
Also, to have .altinstr_replacement have consistent attributes in the
object files, add "x" to the one instance where it was missing.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
The section .proc.info lives in .rodata as it doesn't contain any
executable code. However, the section is still marked as executable
as the consequence .rodata will also be marked executable.
Xen doesn't use the ELF permissions to decide the page-table mapping
permission. However, this will confuse disassemblers.
'#execinstr' is now removed on all the pushsection dealing with
.proc.info
Signed-off-by: Jan Beulich <jbeulich@suse.com>
[julieng: Rework the commit message]
Acked-by: Julien Grall <jgrall@amazon.com>
I have touched most of the Xen libraries in the past, and there is a
clear lack of reviewer band width in the tools area.
Add myself as a tools/libs reviewer for that reason.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
The reasoning for commit 7bd8989ab7 ("tools/libs/guest: fix max_pfn
setting in map_p2m()") was wrong.
The max_pfn field in shared_info is misnamed, it has the semantics of
num_pfns, which is hidden at least partially in Linux, as the kernel is
(wrongly) treating it like the highest used pfn in some places.
So revert above commit.
Fixes: 7bd8989ab7 ("tools/libs/guest: fix max_pfn setting in map_p2m()")
Signed-off-by: Juergen Gross <jgross@suse.com>
Since XSA-228 (commit 02cbeeb620 "gnttab: split maptrack lock
to make it fulfill its purpose again"), v->maptrack_head,
v->maptrack_tail and the content of the freelist are accessed with
the lock v->maptrack_freelist_lock held.
Therefore it is not necessary to update the fields using cmpxchg()
and also read them atomically.
Note that there are two cases where v->maptrack_tail is accessed without
the lock. They both happen in get_maptrack_handle() when initializing
the free list of the current vCPU. Therefore there is no possible race.
The code is now reworked to remove any use of cmpxch() and read_atomic()
when accessing the fields v->maptrack_{head, tail} as wel as the
freelist.
Take the opportunity to add a comment on top of the lock definition
and explain what it protects.
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The Arm ARM's description of MSR (ARM DDI 0406C.d section B9.3.12)
doesn't even allow for plain "SPSR" here, and while gas accepts this, it
takes it to mean SPSR_cf. Yet surely all of SPSR wants updating on this
path, not just the lowest and highest 8 bits.
Fixes: dfcffb128b ("xen/arm32: SPSR_hyp/SPSR")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
There are some internals in the libxenstore interface which should be
removed.
Move those functions into xs_lib.c and the related definitions into
xs_lib.h. Remove the functions from the mapfile. Add xs_lib.o to
xenstore_client as some of the internal functions are needed there.
Bump the libxenstore version to 4.0 as the change is incompatible.
Note that the removed functions should not result in any problem as
they ought to be used by xenstored or xenstore_client only.
Avoid an enum as part of a structure as the size of an enum is
compiler implementation dependent.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
Clang 10 reports
domain.c:1328:10: error: variable 'cr3_mfn' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
if ( !compat )
^~~~~~~
domain.c:1334:34: note: uninitialized use occurs here
cr3_page = get_page_from_mfn(cr3_mfn, d);
^~~~~~~
domain.c:1328:5: note: remove the 'if' if its condition is always true
if ( !compat )
^~~~~~~~~~~~~~
domain.c:1042:18: note: initialize the variable 'cr3_mfn' to silence this warning
mfn_t cr3_mfn;
^
= 0
domain.c:1189:14: error: variable 'fail' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
if ( !compat )
^~~~~~~
domain.c:1211:9: note: uninitialized use occurs here
fail |= v->arch.pv.gdt_ents != c(gdt_ents);
^~~~
domain.c:1189:9: note: remove the 'if' if its condition is always true
if ( !compat )
^~~~~~~~~~~~~~
domain.c:1187:18: note: initialize the variable 'fail' to silence this warning
bool fail;
^
= false
despite this being a build with -O2 in effect, and despite "compat"
being constant "false" when CONFIG_COMPAT (and hence CONFIG_PV32) is not
defined, as it gets set at the top of the function from the result of
is_pv_32bit_domain().
Re-arrange the two "offending" if()s such that when COMPAT=n the
respective variables will be seen as unconditionally initialized. The
original aim was to have the !compat cases first, though.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
SPSR_hyp is not meant to be accessed from Hyp mode (EL2); accesses
trigger UNPREDICTABLE behaviour. Xen should read/write SPSR instead.
See: ARM DDI 0487D.b page G8-5993.
This fixes booting Xen/arm32 on QEMU.
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
The June 2021 microcode is formally de-featuring TSX on the older Skylake
client CPUs. The workaround from the March 2019 microcode is being dropped,
and replaced with additions to MSR_TSX_FORCE_ABORT to hide the HLE/RTM CPUID
bits.
With this microcode in place, TSX is disabled by default on these CPUs.
Backwards compatibility is provided in the same way as for TAA - RTM force
aborts, rather than suffering #UD, and the CPUID bits can be hidden to recover
performance.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Add arch-specific makefiles and configs needed to build for
riscv. Also add a minimal head.S that is a simple infinite loop.
head.o can be built with
$ make XEN_TARGET_ARCH=riscv64 SUBSYSTEMS=xen -C xen tiny64_defconfig
$ make XEN_TARGET_ARCH=riscv64 SUBSYSTEMS=xen -C xen TARGET=riscv64/head.o
No other TARGET is supported at the moment.
Signed-off-by: Connor Davis <connojdavis@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Acked-by: Bobby Eshleman <bobbyeshleman@gmail.com>
Defaulting to yes only for X86 and ARM reduces the requirements
for a minimal build when porting new architectures.
Signed-off-by: Connor Davis <connojdavis@gmail.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Better reflect reality: Andrew and Jan are active maintainers
and I review patches. Keep myself as a reviewer so I can help
with historical context &c.
Signed-off-by: Tim Deegan <tim@xen.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
First and foremost - such timeouts were not signaled to callers, making
them believe they're fine to e.g. free previously unmapped pages.
Mirror VT-d's behavior: A fixed number of loop iterations is not a
suitable way to detect timeouts in an environment (CPU and bus speeds)
independent manner anyway. Furthermore, leaving an in-progress operation
pending when it appears to take too long is problematic: If a command
completed later, the signaling of its completion may instead be
understood to signal a subsequently started command's completion.
Log excessively long processing times (with a progressive threshold) to
have some indication of problems in this area. Allow callers to specify
a non-default timeout bias for this logging, using the same values as
VT-d does, which in particular means a (by default) much larger value
for device IO TLB invalidation.
This is part of XSA-373 / CVE-2021-28692.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
No caller cared about send_iommu_command() indicating unavailability of
a slot. Hence if a sufficient number prior commands timed out, we did
blindly assume that the requested command was submitted to the IOMMU
when really it wasn't. This could mean both a hanging system (waiting
for a command to complete that was never seen by the IOMMU) or blindly
propagating success back to callers, making them believe they're fine
to e.g. free previously unmapped pages.
Fold the three involved functions into one, add spin waiting for an
available slot along the lines of VT-d's qinval_next_index(), and as a
consequence drop all error indicator return types/values.
This is part of XSA-373 / CVE-2021-28692.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
The user chosen setting for MSR_TSX_CTRL needs restoring after S3.
All APs get the correct setting via start_secondary(), but the BSP was missed
out.
This is XSA-377 / CVE-2021-28690.
Fixes: 8c4330818f ("x86/spec-ctrl: Mitigate the TSX Asynchronous Abort sidechannel")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Modern x86 processors have far-better-than-architecturally-guaranteed self
modifying code detection. Typically, when a write hits an instruction in
flight, a Machine Clear occurs to flush stale content in the frontend and
backend.
For self modifying code, before a write which hits an instruction in flight
retires, the frontend can speculatively decode and execute the old instruction
stream. Speculation of this form can suffer from type confusion in registers,
and potentially leak data.
Furthermore, updates are typically byte-wise, rather than atomic. Depending
on timing, speculation can race ahead multiple times between individual
writes, and execute the transiently-malformed instruction stream.
Xen has stubs which are used in certain cases for emulation purposes. Inhibit
speculation between updating the stub and executing it.
This is XSA-375 / CVE-2021-0089.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Leaving an in-progress operation pending when it appears to take too
long is problematic: If e.g. a QI command completed later, the write to
the "poll slot" may instead be understood to signal a subsequently
started command's completion. Also our accounting of the timeout period
was actually wrong: We included the time it took for the command to
actually make it to the front of the queue, which could be heavily
affected by guests other than the one for which the flush is being
performed.
Do away with all timeout detection on all flush related code paths.
Log excessively long processing times (with a progressive threshold) to
have some indication of problems in this area.
Additionally log (once) if qinval_next_index() didn't immediately find
an available slot. Together with the earlier change sizing the queue(s)
dynamically, we should now have a guarantee that with our fully
synchronous model any demand for slots can actually be satisfied.
This is part of XSA-373 / CVE-2021-28692.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
With the present synchronous model, we need two slots for every
operation (the operation itself and a wait command). There can be one
such pair of commands pending per CPU. To ensure that under all normal
circumstances a slot is always available when one is requested, size the
command ring according to the number of present CPUs.
This is part of XSA-373 / CVE-2021-28692.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
With the present synchronous model, we need two slots for every
operation (the operation itself and a wait descriptor). There can be
one such pair of requests pending per CPU. To ensure that under all
normal circumstances a slot is always available when one is requested,
size the queue ring according to the number of present CPUs.
This is part of XSA-373 / CVE-2021-28692.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Paul Durrant <paul@xen.org>
The function to initialize the pages (see init_heap_pages()) will request
scrub when the admin request idle bootscrub (default) and state ==
SYS_STATE_active. When bootscrub=on, Xen will scrub any free pages in
heap_init_late().
Currently, the boot modules (e.g. kernels, initramfs) will be discarded/
freed after heap_init_late() is called and system_state switched to
SYS_STATE_active. This means the pages associated with the boot modules
will not get scrubbed before getting re-purposed.
If the memory is assigned to an untrusted domU, it may be able to
retrieve secrets from the modules.
This is part of XSA-372 / CVE-2021-28693.
Fixes: 1774e9b1df ("xen/arm: introduce create_domUs")
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
In a follow-up patch we will need to unallocate the boot modules
before heap_init_late() is called.
The modules will contain the domUs kernel and initramfs. Therefore Xen
will need to create extra domUs (used by dom0less) before heap_init_late().
This has two consequences on dom0less:
1) Domains will not be unpaused as soon as they are created but
once all have been created. However, Xen doesn't guarantee an order
to unpause, so this is not something one could rely on.
2) The memory allocated for a domU will not be scrubbed anymore when an
admin select bootscrub=on. This is not something we advertised, but if
this is a concern we can introduce either force scrub for all domUs or
a per-domain flag in the DT. The behavior for bootscrub=off and
bootscrub=idle (default) has not changed.
This is part of XSA-372 / CVE-2021-28693.
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
xen-cpuid does print out the list of special features, and this is helpful to
keep.
Fixes: ba6950fb070 ("x86/cpuid: Drop special_features[]")
Reported-by: Jan Beulich <JBeulich@suse.com>
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
First of all avoid "long" when "int" suffices, i.e. in particular when
merely conveying error codes. 32-bit values are slightly cheaper to
deal with on x86, and their processing is at least no more expensive on
Arm. Where possible use evtchn_port_t for port numbers and unsigned int
for other unsigned quantities in adjacent code. In evtchn_set_priority()
eliminate a local variable altogether instead of changing its type.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
The combination is pretty common, so adding a simple local helper seems
worthwhile. Make it const- and type-correct, in turn requiring the
two called function to also be const-correct (and at this occasion also
make them type-correct).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
port_is_valid() and evtchn_from_port() are fine to use without holding
any locks. Accordingly acquire the per-domain lock slightly later in
evtchn_close() and evtchn_bind_vcpu(). Especially for the use by the
former (but there are pre-existing uses) add a comment about
port_is_valid()'s guarantees.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Julien Grall <julien@xen.org>
A platform introduced in EDK II named OvmfXen is now the one to use for
Xen instead of OvmfX64. It comes with PVH support.
Also, the Xen support in OvmfX64 is deprecated,
"deprecation notice: *dynamic* multi-VMM (QEMU vs. Xen) support in OvmfPkg"
https://edk2.groups.io/g/devel/message/75498
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
After 32-bit PV-guests have been security de-supported when not running
under PV-shim, the hypervisor will no longer be configured to support
those domains per default when not being built as PV-shim.
Unfortunately libxenguest will fail saving or restoring a PV domain
due to this restriction, as it is trying to get the compat MFN list
even for 64 bit guests.
Fix that by obtaining the compat MFN list only for 32-bit PV guests.
Fixes: 1a0f2fe229 ("SUPPORT.md: Un-shimmed 32-bit PV guests are no longer supported")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
While the ! annotation is useful to indicate that something special is
happening, an array of bits is not. Drop it, to prevent mistakes.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
For reasons which are my fault, but I don't recall why, the
FDP_EXCP_ONLY/NO_FPU_SEL adjustment uses the whole special_features[] array
element, not the two relevant bits.
HLE and RTM were recently added to the list of special features, causing them
to be always set in guest view, irrespective of the toolstacks choice on the
matter.
Rewrite the logic to refer to the features specifically, rather than relying
on the contents of the special_features[] array.
Fixes: 8fe24090d9 ("x86/cpuid: Rework HLE and RTM handling")
Reported-by: Edwin Török <edvin.torok@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Our releases look to flip-flop between keeping or discarding the date
and title of the referenced qemu-trad commit. I think with the hash
replaced by a tag, the commit's date and title would better also be
purged.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
If we schedule, and the current vCPU continues to run, its statistical
load is not properly updated, resulting in something like this, even if
all the 8 vCPUs are 100% busy:
(XEN) Runqueue 0:
(XEN) [...]
(XEN) aveload = 2097152 (~800%)
(XEN) [...]
(XEN) Domain: 0 w 256 c 0 v 8
(XEN) 1: [0.0] flags=2 cpu=4 credit=9996885 [w=256] load=35 (~0%)
(XEN) 2: [0.1] flags=2 cpu=2 credit=9993725 [w=256] load=796 (~0%)
(XEN) 3: [0.2] flags=2 cpu=1 credit=9995885 [w=256] load=883 (~0%)
(XEN) 4: [0.3] flags=2 cpu=5 credit=9998833 [w=256] load=487 (~0%)
(XEN) 5: [0.4] flags=2 cpu=6 credit=9998942 [w=256] load=1595 (~0%)
(XEN) 6: [0.5] flags=2 cpu=0 credit=9994669 [w=256] load=22 (~0%)
(XEN) 7: [0.6] flags=2 cpu=7 credit=9997706 [w=256] load=0 (~0%)
(XEN) 8: [0.7] flags=2 cpu=3 credit=9992440 [w=256] load=0 (~0%)
As we can see, the average load of the runqueue as a whole is, instead,
computed properly.
This issue would, in theory, potentially affect Credit2 load balancing
logic. In practice, however, the problem only manifests (at least with
these characteristics) when there is only 1 runqueue active in the
cpupool, which also means there is no need to do any load-balancing.
Hence its real impact is pretty much limited to wrong per-vCPU load
percentages, when looking at the output of the 'r' debug-key.
With this patch, the load is updated and displayed correctly:
(XEN) Runqueue 0:
(XEN) [...]
(XEN) aveload = 2097152 (~800%)
(XEN) [...]
(XEN) Domain info:
(XEN) Domain: 0 w 256 c 0 v 8
(XEN) 1: [0.0] flags=2 cpu=4 credit=9995584 [w=256] load=262144 (~100%)
(XEN) 2: [0.1] flags=2 cpu=6 credit=9992992 [w=256] load=262144 (~100%)
(XEN) 3: [0.2] flags=2 cpu=3 credit=9998918 [w=256] load=262118 (~99%)
(XEN) 4: [0.3] flags=2 cpu=5 credit=9996867 [w=256] load=262144 (~100%)
(XEN) 5: [0.4] flags=2 cpu=1 credit=9998912 [w=256] load=262144 (~100%)
(XEN) 6: [0.5] flags=2 cpu=2 credit=9997842 [w=256] load=262144 (~100%)
(XEN) 7: [0.6] flags=2 cpu=7 credit=9994623 [w=256] load=262144 (~100%)
(XEN) 8: [0.7] flags=2 cpu=0 credit=9991815 [w=256] load=262144 (~100%)
Signed-off-by: Dario Faggioli <dfaggioli@suse.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
A !runnable unit (temporarily) present in the runq may cause us to
stop scanning the runq itself too early. Of course, we don't run any
non-runnable vCPUs, but we end the scan and we fallback to picking
the idle unit. In other word, this prevent us to find there and pick
the actual unit that we're meant to start running (which might be
further ahead in the runq).
Depending on the vCPU pinning configuration, this may lead to such
unit to be stuck in the runq for long time, causing malfunctioning
inside the guest.
Fix this by checking runnable/non-runnable status up-front, in the runq
scanning function.
Reported-by: Michał Leszczyński <michal.leszczynski@cert.pl>
Reported-by: Dion Kant <g.w.kant@hunenet.nl>
Signed-off-by: Dario Faggioli <dfaggioli@suse.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
There are some definitions which are used in libxenguest only now.
Move them from libxenctrl over to libxenguest.
Remove an unused macro.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
The functionality in xc_core* should be part of libxenguest instead
of libxenctrl. Users are already either in libxenguest, or in xl.
There is one single exception: xc_core_arch_auto_translated_physmap()
is being used by xc_domain_memory_mapping(), which is used by qemu.
So leave the xc_core_arch_auto_translated_physmap() functionality in
libxenctrl.
This will make it easier to merge common functionality of xc_core*
and xg_sr_save*.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
The guest suspend functionality is already part of libxenguest. Move
the resume functionality from libxenctrl to libxenguest, too.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wl@xen.org>
Instead of open coding the mapping of the p2m list use the already
existing xc_core_arch_map_p2m() call, especially as the current code
does not support guests with the linear p2m map. It should be noted
that this code is needed for colo/remus only.
Switching to xc_core_arch_map_p2m() drops the need to bail out for
bitness of tool stack and guest differing.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
Acked-by: Wei Liu <wl@xen.org>
Andrew Cooper
Anthony PERARD
Jan Beulich
Juergen Gross
Julien Grall
Stefano Stabellini
Connor Davis
Tim Deegan
Dario Faggioli