Taking struct cpu_user_regs as a full object is bogus, and while what was
probably meant was to take a struct cpu_user_regs pointer, that's still wrong.
This isn't a function; its an address stored in the VMCS that the CPU resumes
from on VMExit, meaning that it doesn't conform to a normal C API/ABI.
Annotate it with `nocall`, and move the declaration into vmcs.c next to its
sole user.
Fixes: 9c3118a825 ("bitkeeper revision 1.1159.1.483 (41c0c417XYObowWqbfqU0cdLx30C9w)")
`-> "Initial Intel VMX support"
Reported-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-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>
While trying to work around a different Clang-IAS bug (parent changeset), I
stumbled onto:
In file included from arch/x86/asm-macros.c:3:
./arch/x86/include/asm/spec_ctrl_asm.h:144:19: error: \u used with
no following hex digits; treating as '\' followed by identifier [-Werror,-Wunicode]
.L\@_fill_rsb_loop\uniq:
^
It turns out that Clang -E is sensitive to the file extension of the source
file it is processing. Furthermore, C explicitly permits the use of \u
escapes in identifier names, so the diagnostic would be reasonable in
principle if we trying to compile the result.
asm-macros should really have been .S from the outset, as it is ultimately
generating assembly, not C. Rename it, which causes Clang not to complain.
We need to introduce rules for generating a .i file from .S, and substituting
c_flags for a_flags lets us drop the now-redundant -D__ASSEMBLY__.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
https://github.com/llvm/llvm-project/issues/60792
It turns out that Clang-IAS does not expand \@ uniquely in a translaition
unit, and the XSA-426 change tickles this bug:
<instantiation>:4:1: error: invalid symbol redefinition
.L1_fill_rsb_loop:
^
make[3]: *** [Rules.mk:247: arch/x86/acpi/cpu_idle.o] Error 1
Extend DO_OVERWRITE_RSB with an optional parameter so C callers can mix %= in
too, which Clang does seem to expand properly.
Fixes: 63305e5392 ("x86/spec-ctrl: Mitigate Cross-Thread Return Address Predictions")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Also print the compiler version before starting. It's not easy to find
otherwise, and does change from time to time.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
Delete the macros SVM_PAUSE{FILTER,THRESH}_INIT from svm.h and opencode
their values, since they are used in a single place and using macros is
just unnecessary obfuscation.
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
An assert failure has been observed in p2m_teardown when performing vm
forking and then destroying the forked VM (p2m-basic.c:173). The assert
checks whether the domain's shared pages counter is 0. According to the
patch that originally added the assert (7bedbbb5c3) the p2m_teardown
should only happen after mem_sharing already relinquished all shared pages.
In this patch we flip the order in which relinquish ops are called to avoid
tripping the assert. Conceptually sharing being torn down makes sense to
happen before paging is torn down.
Fixes: e7aa55c0aa ("x86/p2m: free the paging memory pool preemptively")
Signed-off-by: Tamas K Lengyel <tamas@tklengyel.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
First, apt complain that it isn't the right way to add keys anymore,
but hopefully that's just a warning.
Second, we can't install clang-8:
The following packages have unmet dependencies:
clang-8 : Depends: libstdc++-8-dev but it is not installable
Depends: libgcc-8-dev but it is not installable
Depends: libobjc-8-dev but it is not installable
Recommends: llvm-8-dev but it is not going to be installed
Recommends: libomp-8-dev but it is not going to be installed
libllvm8 : Depends: libffi7 (>= 3.3~20180313) but it is not installable
E: Unable to correct problems, you have held broken packages.
clang on Debian unstable is now version 14.0.6.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
We already have a container which track the latest CentOS 7, no need
for this one as well.
Also, 7.2 have outdated root certificate which prevent connection to
website which use Let's Encrypt.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
The attribute has no purpose here and, in the worst case, could lead to
the compiler generating worse code. In practice, however: No change to
generated code (surprisingly not even to generated debug info), at least
with gcc12 and the .config-s I've tried.
Requested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
In COVERAGE=y but DEBUG=n builds (observed by randconfig testing) gcc12
takes issue with the subtraction of 1 from __stop___pre_ex_table[],
considering this an out of bounds access. Not being able to know that
the symbol actually marks the end of an array, the compiler is kind of
right with this diagnosis. Move the subtraction into the function.
Reported-by: Anthony Perard <anthony.perard@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Both values are unconditionally overridden (to 0) in the "hvm" (i.e.
PVH) case. There's therefore no reason to punish a PVH kernel for
setting the former but not the latter.
Fixes: 632cbaf124 ("libelf: improve PVH elfnote parsing")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
This is the only file left with a use of an __s<N> type coming from
Linux. Since the file has been using an apparently random mix of all
three classes of fixed-width types (__{s,u}<N>, {s,u}<N>, and
{,u}int<N>_t), consolidate this to use exclusively standard types.
No functional change intended.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
It is easier just to make the functions void and let the compiler do the (not
very) hard work.
Passing regs is a bit weird for HVM guests anyway, because the resulting
pointer is invariant (this isn't native exception handling where the regs
pointers *are* important), and all functions calculate current themselves
which is another invariant.
Finally, the compiler can merge the get_cpu_info() calculation which is common
to both current and guest_cpu_user_regs(), meaning the delta in C really is
just one LEA, and not any more expensive than MOV's in ASM anyway.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Consolidate this to use exclusively standard types, and change
indentation style to Xen's there at the same time (the file already had
a mix of styles).
While there
- switch boolean fields to use bool,
- drop the notion of big-endian bitfields being a thing on x86,
- drop the names for reserved fields,
- adjust the comment on "dest32".
No functional change intended.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
The original issue has been reported on AMD Bulldozer-based CPUs where
ucode loading loses the LWP feature bit in order to gain the IBPB bit.
LWP disabling is per-SMT/CMT core modification and needs to happen on
each sibling thread despite the shared microcode engine. Otherwise,
logical CPUs will end up with different cpuid capabilities.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216211
Guests running under Xen happen to be not affected because of levelling
logic for the feature masking/override MSRs which causes the LWP bit to
fall out and hides the issue. The latest recommendation from AMD, after
discussing this bug, is to load ucode on every logical CPU.
In Linux kernel this issue has been addressed by e7ad18d1169c
("x86/microcode/AMD: Apply the patch early on every logical thread").
Follow the same approach in Xen.
Introduce SAME_UCODE match result and use it for early AMD ucode
loading. Take this opportunity and move opt_ucode_allow_same out of
compare_revisions() to the relevant callers and also modify the warning
message based on it. Intel's side of things is modified for consistency
but provides no functional change.
Signed-off-by: Sergey Dyasli <sergey.dyasli@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Consolidate this to use exclusively standard types, and change oprofile
code (apparently trying to mirror those types) at the same time. Where
sensible actually drop local variables.
No functional change intended.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Do not include the headers:
xen/irq.h
asm/hvm/svm/intr.h
asm/io.h
asm/mem_sharing.h
asm/regs.h
because none of the declarations and macro definitions in them is used.
Sort the rest of the headers alphabetically.
Remove the forward declaration of svm_function_table and place start_svm()
after the svm_function_table's definition.
Replace double new lines with one.
No functional change intended.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
The checklist requires to have access to several accounts on both
xenbits and osstest. List those accounts at the beginning of the file
so it is easier to check if one has the permissions before starting
the branching process.
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Henry Wang <Henry.Wang@arm.com>
----
Changes in v2:
- Add Henry's reviewed-by
Make clear the patchbot is accessible from the user "xen" on xenbits.
Signed-off-by: Julien Grall <jgrall@amazon.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>
Reviewed-by: Henry Wang <Henry.Wang@arm.com>
----
Changes in v2:
- Add Henry's reviewed-by
- Add George's acked-by
The cambridge colo was internal to Citrix (now Cloud) and hasn't been used
by the community for a while.
So remove the section.
Signed-off-by: Julien Grall <jgrall@amazon.com>
Acked-by: George Dunlap <george.dunlap@cloud.com>
Reviewed-by: Henry Wang <Henry.Wang@arm.com>
----
Changes in v2:
- Add George's acked-by
- Add Henry's reviewed-by
Since at least Xen 4.12, the revision for external trees don't contain
the word "unstable". So explicitly list the *_REVISION variables that
need to be updated as part of the branching process.
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Henry Wang <Henry.Wang@arm.com>
----
Changes in v2:
* Explain what should be the tag format for each variables
Clang-15 (as seen in the FreeBSD 14 tests) complains:
xg_main.c:1248 error: a function declaration without a
prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
xg_init()
^
void
The error message is a bit confusing but appears to new as part of
-Wdeprecated-non-prototype which is part of supporting C2x which formally
removes K&R syntax.
Either way, fix the identified function.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Clang-15 (as seen in the FreeBSD 14 tests) complains:
arch/x86/time.c:1364:20: error: a function declaration without a
prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
s_time_t get_s_time()
^
void
The error message is a bit confusing but appears to new as part of
-Wdeprecated-non-prototype which is part of supporting C2x which formally
removes K&R syntax.
Either way, fix the identified functions.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Unfortunatly, --default-symver doesn't work with LLVM's LD, LLD.
Instead, we will generate a temporary version-script.
In order to allow regenerating the script, we'll have a different
filename. In order to check if the content is up-to-date, we'll always
generated it and compare.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Fixes: 98d95437ed ("libs: Fix auto-generation of version-script for unstable libs")
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
The lock is not meant to be modified by _rw_is{,_write}_locked(). So
constify it.
This is helpful to be able to assert if the lock is taken when the
underlying structure is const.
Requested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
The lock is not meant to be modified by _spin_is_locked(). So constify
it.
This is helpful to be able to assert the locked is taken when the
underlying structure is const.
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Henry Wang <Henry.Wang@arm.com>
Tested-by: Henry Wang <Henry.Wang@arm.com> #Arm
APIC virtualization support is currently implemented only for Intel VT-x.
To aid future work on separating AMD-V from Intel VT-x code, instead of
calling directly vmx_vlapic_msr_changed() from common hvm code, add a stub
to the hvm_function_table, named update_vlapic_mode, and create a wrapper
function, called hvm_vlapic_mode(), to be used by common hvm code.
After the change above, do not include header asm/hvm/vmx/vmx.h as it is
not required anymore and resolve subsequent build errors for implicit
declaration of functions ‘TRACE_2_LONG_3D’ and ‘TRC_PAR_LONG’ by including
missing asm/hvm/trace.h header.
No functional change intended.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Consolidate cper.h to use exclusively standard types.
No functional change intended.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
This might be helpful in providing additional debugging information (in
most cases, at least to distinguish -EINVAL from -ENOMEM), so modify the
code to include printing return code in panic message. In create_dom0,
move the call to alloc_dom0_vcpu0() to a separate condition and call a
meaningful panic message.
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Add a new test job qemu-smoke-dom0less-arm32-gcc-without-dom0 in debug
and non-debug variant that will execute qemu-smoke-dom0less-arm32.sh
script to test dom0less domU boot without dom0 (i.e. true dom0less
configuration).
By passing "without-dom0" as a test variant, the test will clear the
dom0 prompt that we grep for as a last step and remove all the DOM0
related options in ImageBuilder configuration.
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Xen supports booting gzip compressed kernels, therefore add a new test
job qemu-smoke-dom0less-arm32-gcc-gzip in debug and non-debug variant
that will execute qemu-smoke-dom0less-arm32.sh script to test booting
a domU with a gzip compressed kernel image (in our case zImage).
By passing "gzip" as a test variant, the test will call gzip command
to compress kernel image and use it in ImageBuilder configuration for
domU1. No need for a specific check to be executed from domU. Being able
to see a test message from a boot log is sufficient to mark a test as
passed.
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Add a new test job qemu-smoke-dom0less-arm32-gcc-staticmem in debug
and non-debug variant that will execute qemu-smoke-dom0less-arm32.sh
script to test static memory allocation feature. The test case itself
is directly taken from dom0less arm64 testing.
Populate build jobs to compile Xen with config options necessary to
enable static memory feature. Populate test jobs passing "static-mem"
as a test variant. The test configures domU with a static memory region
(direct-mapped) and adds a check using /proc/iomem to determine the
memory region marked as "System RAM".
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
At the moment, we only perform a single arm32 test in our CI, checking
whether dom0 boots successfully or not. This is mostly because we do not
have any arm32 runners and we only execute a hypervisor only build.
In order not to leave the arm32 testing in such a poor state, add a
script qemu-smoke-dom0less-arm32.sh to start testing dom0less
configuration, while keeping dom0 to make the test more interesting.
The script is mostly based on the one used for dom0 arm32 testing as well
as the one used for dom0less arm64 testing. We obtain Debian Bullseye
kernel and Alpine Linux busybox-based rootfs. Depending on the test
variant, we prepare a test case contained within domU_check variable,
that will be executed as part of /init script from domU rootfs.
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Due to the limited x86 CI resources slowing down the whole pipeline,
switch the arm32 cross builds to be executed on arm64 which is much more
capable. For that, rename the existing debian container dockerfile
from unstable-arm32-gcc to unstable-arm64v8-arm32-gcc and use
arm64v8/debian:unstable as an image. Note, that we cannot use the same
container name as we have to keep the backwards compatibility.
Take the opportunity to remove extra empty line at the end of a file.
Modify the tag of .arm32-cross-build-tmpl to arm64 and update the build
jobs accordingly.
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
The FILE symbols in out-of-tree builds may be either a relative path to
the object dir or an absolute path depending on how the build is
invoked. Fix the paths for C files so that they are consistent with
in-tree builds - the path is relative to the "xen" directory (e.g.
common/irq.c).
This fixes livepatch builds when the original Xen build was out-of-tree
since livepatch-build always does in-tree builds. Note that this doesn't
fix the behaviour for Clang < 6 which always embeds full paths.
Fixes: 7115fa562f ("build: adding out-of-tree support to the xen build")
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Documentation for credit2_runqueue=all says it should create one queue
for all pCPUs on the host. But since introduction
sched_credit2_max_cpus_runqueue, it actually created separate runqueue
per socket, even if the CPUs count is below
sched_credit2_max_cpus_runqueue.
Adjust the condition to skip syblink check in case of
credit2_runqueue=all.
Fixes: 8e2aa76dc1 ("xen: credit2: limit the max number of CPUs in a runqueue")
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Provide the user with configuration control over the IOMMU support by making
AMD_IOMMU and INTEL_IOMMU options user selectable and able to be turned off.
However, there are cases where the IOMMU support is required, for instance for
a system with more than 254 CPUs. In order to prevent users from unknowingly
disabling it and ending up with a broken hypervisor, make the support user
selectable only if EXPERT is enabled.
To preserve the current default configuration of an x86 system, both options
depend on X86 and default to Y.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
The function hvm_dpci_isairq_eoi() has no dependencies on VT-d driver code
and can be moved from xen/drivers/passthrough/vtd/x86/hvm.c to
xen/drivers/passthrough/x86/hvm.c, along with the corresponding copyrights.
Remove the now empty xen/drivers/passthrough/vtd/x86/hvm.c.
Since the function is used only in this file, declare it static.
No functional change intended.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Posted interrupt support in Xen is currently implemented only for the
Intel platforms. Instead of calling directly pi_update_irte() from the
common hvm code, add a pi_update_irte callback to the hvm_function_table.
Then, create a wrapper function hvm_pi_update_irte() to be used by the
common hvm code.
In the pi_update_irte callback prototype, pass the vcpu as first parameter
instead of the posted-interrupt descriptor that is platform specific, and
remove the const qualifier from the parameter gvec since it is not needed
and because it does not compile with the alternative code patching in use.
Since the posted interrupt descriptor is Intel VT-x specific while
msi_msg_write_remap_rte is iommu specific, open code pi_update_irte() inside
vmx_pi_update_irte() but replace msi_msg_write_remap_rte() with generic
iommu_update_ire_from_msi(). That way vmx_pi_update_irte() is not bound to
Intel VT-d anymore.
Remove the now unused pi_update_irte() implementation.
No functional change intended.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
The variable untrusted_msi indicates whether the system is vulnerable to
CVE-2011-1898 due to the absence of interrupt remapping support.
Although AMD iommus with interrupt remapping disabled are also affected,
this case is not handled yet. Given that the issue is not VT-d specific,
and to accommodate future use of the flag for covering also the AMD iommu
case, move the definition of the flag out of the VT-d specific code to the
common x86 iommu code.
Also, since the current implementation assumes that only PV guests are prone
to this attack, take the opportunity to define untrusted_msi only when PV is
enabled.
No functional change intended.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
The AMD-Vi driver forces coherent accesses by hardwiring the FC bit to 1.
Therefore, given that iommu_snoop is used only when the iommu is enabled,
when Xen is configured with only the AMD iommu enabled, iommu_snoop can be
reduced to a #define to true.
No functional change intended.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
First of all the variable is meaningful only when an IOMMU is in use for
a guest. Qualify the check accordingly, like done elsewhere. Furthermore
the controlling command line option is supposed to take effect on VT-d
only. Since command line parsing happens before we know whether we're
going to use VT-d, force the variable back to set when instead running
with AMD IOMMU(s).
Since it may end up misleading, also remove the clearing of the flag in
iommu_setup() and vtd_setup()'s error path. The variable simply is
meaningless with IOMMU(s) disabled, so there's no point touching it
there.
Finally also correct a relevant nearby comment.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
It's imo helping readability as well as uses a little if properly
arranging for sufficiently late macro expansion is part of the macro
itself, rather than all (applicable) instances of its users.
No functional change intended.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
The documented connection sequence in xen/include/public/io/9pfs.h has
a bug: the frontend needs to wait for the backend to have published its
features before being able to allocate its rings and event-channels.
While correcting that, make it clear that there might be multiple
rings and event-channels by adding "(s)".
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Andrew Cooper