Wire the per-cpupool admission-control switch through libxl
to xl sched-rtds, and document it.
Add -s/--schedparam to list or set pool-wide RTDS scheduler
parameters, and -a/--admission to enable or disable admission
control for a cpupool ("-c pool -s -a 0/1").
Signed-off-by: Furkan Caliskan <frn1furkan10@gmail.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@vates.tech>
Nul-terminated strings are passed in all cases, so the strlen() can very
well be invoked by the function itself. In preparation for a hypervisor
change also include the nul terminator in the size calculation.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Reviewed-by: Daniel P. Smith <dpsmith@apertussolutions.com>
More similar to other implementation.
posix_memalign was adde in NetBSD 8.0, released on July 17, 2018
and went out of support on May 4, 2024.
Signed-off-by: Frediano Ziglio <frediano.ziglio@cloud.com>
Acked-by: Anthony PERARD <anthony.perard@vates.tech>
In preparation for a hypervisor change also include the nul terminator in
the size calculations. (Note that xc_flask_getbool_byid() doesn't support
FLASK_GETBOOL's "ID being -1" variant of operation, and hence doesn't need
fiddling with.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Teddy Astie <teddy.astie@vates.tech>
Acked-by: Anthony PERARD <anthony.perard@vates.tech>
xc_report_op doesn't update errno when called with 0 operations
(even though it returns -1).
Signed-off-by: Teddy Astie <teddy.astie@vates.tech>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
It's not acceptable to hide this from the caller; the effect of doing so is to
break an atomicity expectation.
Only the caller can know what the appropriate safety action is in the case
that the claim hypercall isn't available. Ignoring it might be the right
thing to do, but xc_domain_claim_pages() cannot make this decision on behalf
of all callers.
Fixes: fc67e9dc0c ("xc: use XENMEM_claim_pages hypercall during guest creation.")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Otherwise it's not possible for device models to map IRQs of devices on
segments different than 0. Keep the same function prototype and pass the
segment in the high 16bits of the bus parameter, like it's done for the
hypercall itself.
Amends: 7620c0cf9a ("PCI multi-seg: add new physdevop-s")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
We extract cppc info from "struct xen_get_cpufreq_para", where it acts as
a member of union, and share the space with governor info.
However, it may fail in amd-cppc passive mode, in which governor info and
CPPC info could co-exist, and both need to be printed together via xenpm tool.
If we tried to still put it in "struct xen_get_cpufreq_para" (e.g. just move
out of union), "struct xen_get_cpufreq_para" will enlarge too much to further
make xen_sysctl.u exceed 128 bytes.
So we introduce a new sub-field GET_CPUFREQ_CPPC to dedicatedly acquire
CPPC-related para, and make get-cpufreq-para invoke GET_CPUFREQ_CPPC
if available.
New helpers print_cppc_para() and get_cpufreq_cppc() are introduced to
extract CPPC-related parameters process from cpufreq para.
Signed-off-by: Penny Zheng <Penny.Zheng@amd.com>
Acked-by: Jan Beulich <jbeulich@suse.com> # hypervisor
Acked-by: Anthony PERARD <anthony.perard@vates.tech>
Move xc_bitops.h to common tools location to be shared between
the toolstack and unit test code.
Adjust the guard in xen-tools/bitops.h
Correct the #include directives and comments referring to the old
xc_bitops.h in the toolstack code.
Signed-off-by: Denis Mukhin <dmukhin@ford.com>
Acked-by: Anthony PERARD <anthony.perard@vates.tech>
In `xenpm get-cpufreq-para <cpuid>`, ->freq_num and ->cpu_num checking are
tied together via variable "has_num", while ->freq_num only has non-zero value
when cpufreq driver in legacy P-states mode.
So we drop the "has_num" condition check, and mirror the ->gov_num check for
both ->freq_num and ->cpu_num in xc_get_cpufreq_para().
Signed-off-by: Penny Zheng <Penny.Zheng@amd.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
xc_pm_get_pxstat() requires the caller to allocate the pt and trans_pt
buffers but then calls xc_pm_get_max_px() to determine how big they are
(and hence how much Xen will copy into them). This is susceptible to
races if xc_pm_get_max_px() changes so avoid the problem by requiring
the caller to also pass in the size of the buffers.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
The livepatch list sysctl writes metadata into a buffer provided by the
caller. The caller is expected to allocate an appropriately sized buffer
but this is racy and may result in Xen writing beyond the end of the
buffer should the metadata size change.
The name buffer is expected to be an array of elements with size
XEN_LIVEPATCH_NAME_SIZE to avoid this kind of race but the xen-livepatch
tool allocates only as many bytes as needed, therefore encountering the
same potential race condition.
Fix both these issues by requiring the caller to pass in the size of the
name and metadata buffers and then not writing beyond the allocated
size.
The sysctl interface version is bumped due to the change in semantics of
the fields.
Signed-off-by: Kevin Lampis <kevin.lampis@cloud.com>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Fixes: b145b4a39c ('livepatch: Handle arbitrary size names with the list operation')
Fixes: 5083e0ff93 ('livepatch: Add metadata runtime retrieval mechanism')
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
From their introduction all xc_hypercall_bounce_pre() uses, when they
failed, would properly cause exit from the function including cleanup,
yet without informing the caller of the failure. Purge the unlock_1
label for being both pointless and mis-named.
An earlier attempt to switch to the usual split between return value and
errno wasn't quite complete.
HWP work made the cleanup of the "available governors" array
conditional, neglecting the fact that the condition used may not be the
condition that was used to allocate the buffer (as the structure field
is updated upon getting back EAGAIN). Since cleanup can be done even if
no buffer was allocated, drop the conditional there again.
Fixes: 4513025a87 ("libxc: convert sysctl interfaces over to hypercall buffers")
Amends: 73367cf3b4 ("libxc: Fix xc_pm API calls to return negative error and stash error in errno")
Fixes: 31e264c672 ("pmstat&xenpm: Re-arrage for cpufreq union")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
It is valid for a PCI device to not have a legacy IRQ. In that case, do
not print an error to keep the logs clean.
This relies on pciback being updated to return -ENOENT for a missing
GSI.
Fixes: b93e5981d2 ("tools: Add new function to get gsi from dev")
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
... which converts binary content to hex automatically.
Update libxl to match. No API/ABI change.
This removes a latent libxl bug for cases when the buildid is longer than 4092
bytes.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
... which uses XENVER_extraversion2.
In order to do this sensibly, use manual hypercall buffer handling. Not only
does this avoid an extra bounce buffer (we need to strip the xen_varbuf_t
header anyway), it's also shorter and easlier to follow.
Update libxl and the ocaml stubs to match. No API/ABI change in either.
With this change made, `xl info` can now correctly access a >15 char
extraversion:
# xl info xen_version
4.18-unstable+REALLY LONG EXTRAVERSION
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com>
kexec-tools uses xc_version(), meaning that it is not a private API. As we're
going to extend the functionality substantially, move it to its own file.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Add a new "llc_colors" parameter that defines the LLC color assignment for
a domain. The user can specify one or more color ranges using the same
syntax used everywhere else for color config described in the
documentation.
The parameter is defined as a list of strings that represent the color
ranges.
Documentation is also added.
Golang bindings are regenerated.
Based on original work from: Luca Miccio <lucmiccio@gmail.com>
Signed-off-by: Carlo Nonato <carlo.nonato@minervasys.tech>
Signed-off-by: Marco Solieri <marco.solieri@minervasys.tech>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Instead of having to include xenctrl.h for getting definitions of cpu
barriers, add a dedicated header for that purpose.
Switch the xen-9pfsd daemon to use the new header instead of xenctrl.h.
This is in preparation of making Xenstore independent from libxenctrl.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
When dom0 is PVH, and passthrough a device to dumU, xl will
use the gsi number of device to do a pirq mapping, see
pci_add_dm_done->xc_physdev_map_pirq, but the gsi number is
got from file /sys/bus/pci/devices/<sbdf>/irq, that confuses
irq and gsi, they are in different space and are not equal,
so it will fail when mapping.
To solve this issue, to get the real gsi and add a new function
xc_physdev_map_pirq_gsi to get a free pirq for gsi.
Note: why not use current function xc_physdev_map_pirq, because
it doesn't support to allocate a free pirq, what's more, to
prevent changing it and affecting its callers, so add
xc_physdev_map_pirq_gsi.
Besides, PVH dom0 doesn't have PIRQs flag, it doesn't do
PHYSDEVOP_map_pirq for each gsi. So grant function callstack
pci_add_dm_done->XEN_DOMCTL_irq_permission will fail at function
domain_pirq_to_irq. And old hypercall XEN_DOMCTL_irq_permission
requires passing in pirq, it is not suitable for PVH dom0 that
doesn't have PIRQs to grant irq permission.
To solve this issue, use the another hypercall
XEN_DOMCTL_gsi_permission to grant the permission of irq(
translate from gsi) to dumU when dom0 has no PIRQs.
Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Chen Jiqian <Jiqian.Chen@amd.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
On PVH dom0, when passthrough a device to domU, QEMU and xl tools
want to use gsi number to do pirq mapping, see QEMU code
xen_pt_realize->xc_physdev_map_pirq, and xl code
pci_add_dm_done->xc_physdev_map_pirq, but in current codes, the gsi
number is got from file /sys/bus/pci/devices/<sbdf>/irq, that is
wrong, because irq is not equal with gsi, they are in different
spaces, so pirq mapping fails.
And in current codes, there is no method to get gsi for userspace.
For above purpose, add new function to get gsi, and the
corresponding ioctl is implemented on linux kernel side.
Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Chen Jiqian <Jiqian.Chen@amd.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Introduce a --force option to xen-ucode, in order to bypass certain checks
when applying microcode.
Update libxc's xc_microcode_update() to take an extra parameter, and to use
the new XENPF_microcode_update2 hypercall instead.
Signed-off-by: Fouad Hilly <fouad.hilly@cloud.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
With the XEN_DOMCTL_dt_overlay DOMCTL added, users should be able to
attach (in the future also detach) devices from the provided DT overlay
to domains. Support this by introducing a new "xl dt-overlay" command
and related documentation, i.e. "xl dt-overlay attach. Slightly rework
the command option parsing logic.
Signed-off-by: Henry Wang <xin.wang2@amd.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Introduce a xen-livepatch tool --force option, that's propagated into the
hyerpvisor for livepatch operations. The intention is for the option to be
used to bypass some checks that would otherwise prevent the patch from being
loaded.
Re purpose the pad field in xen_sysctl_livepatch_op to be a flags field that
applies to all livepatch operations. The flag is currently only set by the
hypercall wrappers for the XEN_SYSCTL_LIVEPATCH_UPLOAD operation, as that's so
far the only one where it will be used initially. Other uses can be added as
required.
Note that helpers would set the .pad field to 0, that's been removed since the
structure is already zero initialized at definition.
No functional usages of the new flag introduced in this patch.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
These macros were hiding that the ops are not zero-initialized by the
toolstack. This is needlessly opaque for something so simple, so this patch
removes them and replaces them with explicit zero-initialising versions.
The patch also removes PHYSDEV_OP from there, as that seems to be an old
dead macro.
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
xc_dt_overlay() sends the device tree binary overlay, size of .dtbo and overlay
operation type i.e. add or remove to xen.
Signed-off-by: Vikram Garhwal <vikram.garhwal@amd.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
The full structures cannot match in layout, as soon as a 32-bit tool
stack build comes into play. But it also doesn't need to; the part of
the layouts that needs to match is merely the union that we memcpy()
from the sysctl structure to the xc one. Keep (in adjusted form) only
the relevant ones.
Since the whole block needs touching anyway, move it closer to the
respective memcpy() and use a wrapper macro to limit verbosity. Also
tidy the full-size-check there.
Fixes: 2381dfab08 ("xen/sysctl: Nest cpufreq scaling options")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Add xc_set_cpufreq_cppc to allow calling xen_systctl_pm_op
SET_CPUFREQ_CPPC.
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Rearrange code now that xen_sysctl_pm_op's get_para fields has the
nested union and struct. In particular, the scaling governor
information like scaling_available_governors is inside the union, so it
is not always available. Move those fields (op->u.get_para.u.s.u.*)
together as well as the common fields (ones outside the union like
op->u.get_para.turbo_enabled).
With that, gov_num may be 0, so bounce buffer handling needs
to be modified.
scaling_governor and other fields inside op->u.get_para.u.s.u.* won't be
used for hwp, so this will simplify the change when hwp support is
introduced and re-indents these lines all together.
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Add a union and struct so that most of the scaling variables of struct
xen_get_cpufreq_para are within in a binary-compatible layout. This
allows cppc_para to live in the larger union and use uint32_ts - struct
xen_cppc_para will be 10 uint32_t's.
The new scaling struct is 3 * uint32_t + 16 bytes CPUFREQ_NAME_LEN + 4 *
uint32_t for xen_ondemand = 11 uint32_t. That means the old size is
retained, int32_t turbo_enabled doesn't move and it's binary compatible.
The out-of-context memcpy() in xc_get_cpufreq_para() now handles the
copying of the fields removed there.
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
It previously mimicked the getdomaininfo sysctl semantics by returning
the first domid higher than the requested domid that does exist. This
unintuitive behaviour causes quite a few mistakes and makes the call
needlessly slow in its error path.
This patch removes the fallback search, returning -ESRCH if the requested
domain doesn't exist. Domain discovery can still be done through the sysctl
interface as that performs a linear search on the list of domains.
With this modification the xc_domain_getinfo() function is deprecated and
removed to make sure it's not mistakenly used expecting the old behaviour.
The new xc wrapper is xc_domain_getinfo_single().
All previous callers of xc_domain_getinfo() have been updated to use
xc_domain_getinfo_single() or xc_domain_getinfolist() instead. This also
means xc_dominfo_t is no longer used by anything and can be purged.
Resolves: xen-project/xen#105
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Currently it's hard to get CPU's microcode revision from Xen after late
loading without looking into Xen logs, which is not always convenient.
Add a new platform op in order to get the required data from Xen and
provide a wrapper for libxenctrl.
Signed-off-by: Sergey Dyasli <sergey.dyasli@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
It's a stricter version of xc_domain_getinfo() where the returned domid
always matches the requested domid or the error code shows an error instead.
A few patches ahead usages of xc_domain_getinfo() are removed until only
xc_domain_getinfo_single() and xc_domain_getinfolist() remain.
Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
In order to better reflect the contents of the header and to make it
more appropriate to use it for different runtime environments like
programs, libraries, and firmware, rename the libs.h include file to
common-macros.h. Additionally add a comment pointing out the need to be
self-contained.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> # tools/python/xen/lowlevel/xc/xc.c
Acked-by: Christian Lindig <christian.lindig@cloud.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Replace PKG_CONFIG variable name with PKG_CONFIG_FILE for the name of
the pkg-config file.
This is preventing a conflict in some build systems where PKG_CONFIG
actually contains the path to the pkg-config executable to use, as the
default assignment in libs.mk is using a weak assignment (?=).
This problem has been found when trying to build the latest version of
Xen tools using buildroot.
Fixes: d400dc5729 ("tools: tweak tools/libs/libs.mk for being able to support libxenctrl")
Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
When there isn't a version-script for a shared library (like for
unstable libs), we create one based on the current Xen version. But
that version-script became out-of-date as soon as Xen's version
changes and make as no way to regenerate the version-script on
rebuild.
For unstable libs, we only needs the symver to be different from a
previous release of Xen. There's an option "--default-symver" which
allow to use the soname as symver and as the soname have the Xen
release version, it will be different for every release. With
--default-symver we don't need to generate a version-script.
But we also need to know if there's already an existing version script
, for that we introduce $(version-script) to be used to point to the
path of the existing script. (Guessing if a version script exist for a
stable library with for example $(wildcard) won't work as a file will
exist when building the library without this patch.)
We don't need the version-script unless we are making the shared
library so it is removed from the "all" target.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
The existing XEN_DOMCTL_SHADOW_OP_{GET,SET}_ALLOCATION have problems:
* All set_allocation() flavours have an overflow-before-widen bug when
calculating "sc->mb << (20 - PAGE_SHIFT)".
* All flavours have a granularity of 1M. This was tolerable when the size of
the pool could only be set at the same granularity, but is broken now that
ARM has a 16-page stopgap allocation in use.
* All get_allocation() flavours round up, and in particular turn 0 into 1,
meaning the get op returns junk before a successful set op.
* The x86 flavours reject the hypercalls before the VM has vCPUs allocated,
despite the pool size being a domain property.
* Even the hypercall names are long-obsolete.
Implement a better interface, which can be first used to unit test the
behaviour, and subsequently correct a broken implementation. The old
interface will be retired in due course.
The unit of bytes (as opposed pages) is a deliberate API/ABI improvement to
more easily support multiple page granularities.
This is part of XSA-409 / CVE-2022-33747.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
This new "Makefile.common" is intended to be used by both tools/ and
stubdom/ build system without stubdom needed to use tools/ build
system.
It should contain the necessary list of objects and CFLAGS needed to
build a static library.
Change stubdom/ to check Makefile.common, for the linkfarm.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
The only thing done thing done with $(SRCS-y) is to replace ".c" by
".o". It is more useful to collect which object we want to build as
make will figure out how to build it and from which source file.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
There is no need for an extra "cleanlocal" target, we can use
double-colon rules instead.
Generated headers are now in tools/include/, so remove those file
there.
Remove -f flag as it's already in $(RM).
libs.mk:
- don't try to remove "*.rpm" anymore.
libs/light:
- "_paths.*.tmp" isn't created anymore.
- clean "libxenlight_test.so" and "libxl_test_*.opic".
libs/stat:
- don't remove $(DEPS_RM) from here as it is already done in
"libs.mk".
libs/util:
- fix clean of version-script file.
include/xen-foreign:
- remove __pycache__
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Make the do_memory_op function accessible to tools linking with libxc.
Similar functions are already available for both domctl and sysctl. As part
of this patch we also change the input 'cmd' to be unsigned int to accurately
reflect what the hypervisor expects.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@intel.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Add monitor event that hooks the vmexit handler allowing for both sync and
async monitoring of events. With async monitoring an event is placed on the
monitor ring for each exit and the rest of the vmexit handler resumes normally.
If there are additional monitor events configured those will also place their
respective events on the monitor ring.
With the sync version an event is placed on the monitor ring but the handler
does not get resumed, thus the sync version is only useful when the VM is not
expected to resume normally after the vmexit. Our use-case is primarily with
the sync version with VM forks where the fork gets reset after sync vmexit
event, thus the rest of the vmexit handler can be safely skipped. This is
very useful when we want to avoid Xen crashing the VM under any circumstance,
for example during fuzzing. Collecting all vmexit information regardless of
the root cause makes it easier to reason about the state of the VM on the
monitor side, hence we opt to receive all events, even for external interrupt
and NMI exits and let the monitor agent decide how to proceed.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@intel.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Furkan Caliskan