When the x-blockdev-reopen was added it allowed reconfiguring the
graph by replacing backing files, but changing the 'file' option was
forbidden. Because of this restriction some operations are not
possible, notably inserting and removing block filters.
This patch adds support for replacing the 'file' option. This is
similar to replacing the backing file and the user is likewise
responsible for the correctness of the resulting graph, otherwise this
can lead to data corruption.
Signed-off-by: Alberto Garcia <berto@igalia.com>
[vsementsov: bdrv_reopen_parse_file_or_backing() is modified a lot]
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610120537.196183-9-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
It's used only in bdrv_reopen_commit(). "backing" is covered by the
loop through all children except for case when we removed backing child
during reopen.
Make it more obvious and drop extra boolean field: qdict_del will not
fail if there is no such entry.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610120537.196183-8-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add the controller identifiers list CNS 0x13, available list of ctrls
in NVM Subsystem that may or may not be attached to namespaces.
In Identify Ctrl List of the CNS 0x12 and 0x13 no endian conversion
for the nsid field.
These two CNS values shows affect when there exists a Subsystem.
Added condition if there is no Subsystem return invalid field in
command.
Signed-off-by: Gollu Appalanaidu <anaidu.gollu@samsung.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
The nvme_check_prinfo() and nvme_dif_check() functions operate on the
16 bit "control" member of the NvmeCmd. These functions do not otherwise
operate on an NvmeCmd or an NvmeRequest, so change them to expect the
actual 4 bit PRINFO field and add constants that work on this field as
well.
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Add enums for the Identify Namespace FLBAS and MC fields.
Signed-off-by: Gollu Appalanaidu <anaidu.gollu@samsung.com>
[k.jensen: squashed separate flbas/mc commits into one]
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
* Some Meson test conversions
* KVM dirty page ring buffer fix
* KVM TSC scaling support
* Fixes for SG_IO with /dev/sdX devices
* (Non)support for host devices on iOS
* -smp cleanups
# gpg: Signature made Fri 25 Jun 2021 15:16:18 BST
# gpg: using RSA key F13338574B662389866C7682BFFBD25F78C7AE83
# gpg: issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1
# Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83
* remotes/bonzini-gitlab/tags/for-upstream: (28 commits)
machine: reject -smp dies!=1 for non-PC machines
machine: pass QAPI struct to mc->smp_parse
machine: add error propagation to mc->smp_parse
machine: move common smp_parse code to caller
machine: move dies from X86MachineState to CpuTopology
file-posix: handle EINTR during ioctl
block: detect DKIOCGETBLOCKCOUNT/SIZE before use
block: try BSD disk size ioctls one after another
block: check for sys/disk.h
block: feature detection for host block support
file-posix: try BLKSECTGET on block devices too, do not round to power of 2
block: add max_hw_transfer to BlockLimits
block-backend: align max_transfer to request alignment
osdep: provide ROUND_DOWN macro
scsi-generic: pass max_segments via max_iov field in BlockLimits
file-posix: fix max_iov for /dev/sg devices
KVM: Fix dirty ring mmap incorrect size due to renaming accident
configure, meson: convert libusbredir detection to meson
configure, meson: convert libcacard detection to meson
configure, meson: convert libusb detection to meson
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
block: Make block-copy API thread-safe
# gpg: Signature made Fri 25 Jun 2021 13:40:24 BST
# gpg: using RSA key 8B9C26CDB2FD147C880E86A1561F24C1F19F79FB
# gpg: Good signature from "Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 8B9C 26CD B2FD 147C 880E 86A1 561F 24C1 F19F 79FB
* remotes/vsementsov/tags/pull-jobs-2021-06-25:
block-copy: atomic .cancelled and .finished fields in BlockCopyCallState
block-copy: add CoMutex lock
block-copy: move progress_set_remaining in block_copy_task_end
block-copy: streamline choice of copy_range vs. read/write
block-copy: small refactor in block_copy_task_entry and block_copy_common
co-shared-resource: protect with a mutex
progressmeter: protect with a mutex
blockjob: let ratelimit handle a speed of 0
block-copy: let ratelimit handle a speed of 0
ratelimit: treat zero speed as unlimited
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Third RISC-V PR for 6.1 release
- Fix MISA in the DisasContext
- Fix GDB CSR XML generation
- QOMify the SiFive UART
- Add support for the OpenTitan timer
# gpg: Signature made Thu 24 Jun 2021 13:00:26 BST
# gpg: using RSA key F6C4AC46D4934868D3B8CE8F21E10D29DF977054
# gpg: Good signature from "Alistair Francis <alistair@alistair23.me>" [full]
# Primary key fingerprint: F6C4 AC46 D493 4868 D3B8 CE8F 21E1 0D29 DF97 7054
* remotes/alistair/tags/pull-riscv-to-apply-20210624-2:
hw/riscv: OpenTitan: Connect the mtime and mtimecmp timer
hw/timer: Initial commit of Ibex Timer
hw/char/ibex_uart: Make the register layout private
hw/char: QOMify sifive_uart
hw/char: Consistent function names for sifive_uart
target/riscv: gdbstub: Fix dynamic CSR XML generation
target/riscv: Use target_ulong for the DisasContext misa
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
As part of converting -smp to a property with a QAPI type, define
the struct and use it to do the actual parsing. machine_smp_parse
takes care of doing the QemuOpts->QAPI conversion by hand, for now.
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210617155308.928754-10-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In order to make SMP configuration a Machine property, we need a getter as
well as a setter. To simplify the implementation put everything that the
getter needs in the CpuTopology struct.
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210617155308.928754-7-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
By adding acquire/release pairs, we ensure that .ret and .error_is_read
fields are written by block_copy_dirty_clusters before .finished is true,
and that they are read by API user after .finished is true.
The atomic here are necessary because the fields are concurrently modified
in coroutines, and read outside.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20210624072043.180494-6-eesposit@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
co-shared-resource is currently not thread-safe, as also reported
in co-shared-resource.h. Add a QemuMutex because co_try_get_from_shres
can also be invoked from non-coroutine context.
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20210614081130.22134-6-eesposit@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Progressmeter is protected by the AioContext mutex, which
is taken by the block jobs and their caller (like blockdev).
We would like to remove the dependency of block layer code on the
AioContext mutex, since most drivers and the core I/O code are already
not relying on it.
Create a new C file to implement the ProgressMeter API, but keep the
struct as public, to avoid forcing allocation on the heap.
Also add a mutex to be able to provide an accurate snapshot of the
progress values to the caller.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20210614081130.22134-5-eesposit@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Both users of RateLimit, block-copy.c and blockjob.c, treat
a speed of zero as unlimited, while RateLimit treats it as
"as slow as possible". The latter is nicer from the code
point of view but pretty useless, so disable rate limiting
if a speed of zero is provided.
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20210614081130.22134-2-eesposit@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
A few miscellaneous fixes
- tweak tcg/kvm based GIC tests
- add header to MTTCG docs
- cleanup checkpatch handling
- GitLab feature and bug request templates
- symbol resolution helper for plugin API
- skip hppa/s390x signals test until fixes arrive
# gpg: Signature made Fri 25 Jun 2021 10:10:57 BST
# gpg: using RSA key 6685AE99E75167BCAFC8DF35FBD0DB095A9E2A44
# gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>" [full]
# Primary key fingerprint: 6685 AE99 E751 67BC AFC8 DF35 FBD0 DB09 5A9E 2A44
* remotes/stsquad/tags/pull-testing-updates-250621-1:
plugins/api: expose symbol lookup to plugins
tests/tcg: skip the signals test for hppa/s390x for now
GitLab: Add "Feature Request" issue template.
GitLab: Add "Bug" issue reporting template
scripts/checkpatch: roll diff tweaking into checkpatch itself
docs/devel: Add a single top-level header to MTTCG's doc
tests/acceptance: tweak the tcg/kvm tests for virt
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
For block host devices, I/O can happen through either the kernel file
descriptor I/O system calls (preadv/pwritev, io_submit, io_uring)
or the SCSI passthrough ioctl SG_IO.
In the latter case, the size of each transfer can be limited by the
HBA, while for file descriptor I/O the kernel is able to split and
merge I/O in smaller pieces as needed. Applying the HBA limits to
file descriptor I/O results in more system calls and suboptimal
performance, so this patch splits the max_transfer limit in two:
max_transfer remains valid and is used in general, while max_hw_transfer
is limited to the maximum hardware size. max_hw_transfer can then be
included by the scsi-generic driver in the block limits page, to ensure
that the stricter hardware limit is used.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
osdep.h provides a ROUND_UP macro to hide bitwise operations for the
purpose of rounding a number up to a power of two; add a ROUND_DOWN
macro that does the same with truncation towards zero.
While at it, change the formatting of some comments.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* Documentation updates
* Remove leading underscores from header guards
* Display hexadecimal value with '0x' prefix
# gpg: Signature made Mon 21 Jun 2021 11:33:53 BST
# gpg: using RSA key 27B88847EEE0250118F3EAB92ED9D774FE702DB5
# gpg: issuer "thuth@redhat.com"
# gpg: Good signature from "Thomas Huth <th.huth@gmx.de>" [full]
# gpg: aka "Thomas Huth <thuth@redhat.com>" [full]
# gpg: aka "Thomas Huth <huth@tuxfamily.org>" [full]
# gpg: aka "Thomas Huth <th.huth@posteo.de>" [unknown]
# Primary key fingerprint: 27B8 8847 EEE0 2501 18F3 EAB9 2ED9 D774 FE70 2DB5
* remotes/thuth-gitlab/tags/pull-request-2021-06-21:
MAINTAINERS: Add qtest/arm-cpu-features.c to ARM TCG CPUs section
fuzz: Display hexadecimal value with '0x' prefix
Remove leading underscores from QEMU defines
Update documentation to refer to new location for issues
docs/tools/virtiofsd: Fix bad rst syntax
docs/tools/virtiofsd.rst: Do not hard-code the QEMU binary name
docs/interop/live-block-operations: Do not hard-code the QEMU binary name
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
s390x update:
- tcg: implement the vector enhancements facility and bump the
'qemu' cpu model to a stripped-down z14 GA2
- fix psw.mask handling in signals
- fix vfio-ccw sense data handling
# gpg: Signature made Mon 21 Jun 2021 10:53:00 BST
# gpg: using RSA key C3D0D66DC3624FF6A8C018CEDECF6B93C6F02FAF
# gpg: issuer "cohuck@redhat.com"
# gpg: Good signature from "Cornelia Huck <conny@cornelia-huck.de>" [unknown]
# gpg: aka "Cornelia Huck <huckc@linux.vnet.ibm.com>" [full]
# gpg: aka "Cornelia Huck <cornelia.huck@de.ibm.com>" [full]
# gpg: aka "Cornelia Huck <cohuck@kernel.org>" [unknown]
# gpg: aka "Cornelia Huck <cohuck@redhat.com>" [unknown]
# Primary key fingerprint: C3D0 D66D C362 4FF6 A8C0 18CE DECF 6B93 C6F0 2FAF
* remotes/cohuck-gitlab/tags/s390x-20210621: (37 commits)
s390x/css: Add passthrough IRB
s390x/css: Refactor IRB construction
s390x/css: Split out the IRB sense data
s390x/css: Introduce an ESW struct
linux-user/s390x: Save and restore psw.mask properly
target/s390x: Use s390_cpu_{set_psw, get_psw_mask} in gdbstub
target/s390x: Improve s390_cpu_dump_state vs cc_op
target/s390x: Do not modify cpu state in s390_cpu_get_psw_mask
target/s390x: Expose load_psw and get_psw_mask to cpu.h
configure: Check whether we can compile the s390-ccw bios with -msoft-float
s390x/cpumodel: Bump up QEMU model to a stripped-down IBM z14 GA2
s390x/tcg: We support Vector enhancements facility
linux-user: elf: s390x: Prepare for Vector enhancements facility
s390x/tcg: Implement VECTOR FP (MAXIMUM|MINIMUM)
s390x/tcg: Implement VECTOR FP NEGATIVE MULTIPLY AND (ADD|SUBTRACT)
s390x/tcg: Implement 32/128 bit for VECTOR FP MULTIPLY AND (ADD|SUBTRACT)
s390x/tcg: Implement 32/128 bit for VECTOR FP TEST DATA CLASS IMMEDIATE
s390x/tcg: Implement 32/128 bit for VECTOR FP PERFORM SIGN OPERATION
s390x/tcg: Implement 128 bit for VECTOR FP LOAD ROUNDED
s390x/tcg: Implement 64 bit for VECTOR FP LOAD LENGTHENED
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The Arm MVE VDUP implementation would like to be able to emit code to
duplicate a byte or halfword value into an i32. We have code to do
this already in tcg-op-gvec.c, so all we need to do is make the
functions global.
For consistency with other functions made available to the frontends:
* we rename to tcg_gen_dup_*
* we expose both the _i32 and _i64 forms
* we provide the #define for a _tl form
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20210617121628.20116-10-peter.maydell@linaro.org
Allow code elsewhere in the system to check whether the ACPI GHES
table is present, so it can determine whether it is OK to try to
record an error by calling acpi_ghes_record_errors().
(We don't need to migrate the new 'present' field in AcpiGhesState,
because it is set once at system initialization and doesn't change.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Dongjiu Geng <gengdongjiu1@gmail.com>
Message-id: 20210603171259.27962-3-peter.maydell@linaro.org
x86 queue, 2021-06-18
Features:
* Add ratelimit for bus locks acquired in guest (Chenyi Qiang)
Documentation:
* SEV documentation updates (Tom Lendacky)
* Add a table showing x86-64 ABI compatibility levels (Daniel P. Berrangé)
Automated changes:
* Update Linux headers to 5.13-rc4 (Eduardo Habkost)
# gpg: Signature made Fri 18 Jun 2021 20:51:26 BST
# gpg: using RSA key 5A322FD5ABC4D3DBACCFD1AA2807936F984DC5A6
# gpg: issuer "ehabkost@redhat.com"
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>" [full]
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF D1AA 2807 936F 984D C5A6
* remotes/ehabkost-gl/tags/x86-next-pull-request:
scripts: helper to generate x86_64 CPU ABI compat info
docs: add a table showing x86-64 ABI compatibility levels
docs/interop/firmware.json: Add SEV-ES support
docs: Add SEV-ES documentation to amd-memory-encryption.txt
doc: Fix some mistakes in the SEV documentation
i386: Add ratelimit for bus locks acquired in guest
Update Linux headers to 5.13-rc4
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Wire in the subchannel callback for building the IRB
ESW and ECW space for passthrough devices, and copy
the hardware's ESW into the IRB we are building.
If the hardware presented concurrent sense, then copy
that sense data into the IRB's ECW space.
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20210617232537.1337506-5-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Currently, all subchannel types have "sense data" copied into
the IRB.ECW space, and a couple flags enabled in the IRB.SCSW
and IRB.ESW. But for passthrough (vfio-ccw) subchannels,
this data isn't populated in the first place, so enabling
those flags leads to unexpected behavior if the guest tries to
process the sense data (zeros) in the IRB.ECW.
Let's add a subchannel callback that builds these portions of
the IRB, and move the existing code into a routine for those
virtual subchannels. The passthrough subchannels will be able
to piggy-back onto this later.
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20210617232537.1337506-4-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
The Interrupt Response Block is comprised of several other
structures concatenated together, but only the 12-byte
Subchannel-Status Word (SCSW) is defined as a proper struct.
Everything else is a simple array of 32-bit words.
Let's define a proper struct for the 20-byte Extended-Status
Word (ESW) so that we can make good decisions about the sense
data that would go into the ECW area for virtual vs
passthrough devices.
[CH: adapted ESW definition to build with mingw, as discussed]
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20210617232537.1337506-2-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
This removes all of the problems with unaligned accesses
to the bytecode stream.
With an 8-bit opcode at the bottom, we have 24 bits remaining,
which are generally split into 6 4-bit slots. This fits well
with the maximum length opcodes, e.g. INDEX_op_add2_i32, which
have 6 register operands.
We have, in previous patches, rearranged things such that there
are no operations with a label which have more than one other
operand. Which leaves us with a 20-bit field in which to encode
a label, giving us a maximum TB size of 512k -- easily large.
Change the INDEX_op_tci_movi_{i32,i64} opcodes to tci_mov[il].
The former puts the immediate in the upper 20 bits of the insn,
like we do for the label displacement. The later uses a label
to reference an entry in the constant pool. Thus, in the worst
case we still have a single memory reference for any constant,
but now the constants are out-of-line of the bytecode and can
be shared between different moves saving space.
Change INDEX_op_call to use a label to reference a pair of
pointers in the constant pool. This removes the only slightly
dodgy link with the layout of struct TCGHelperInfo.
The re-encode cannot be done in pieces.
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This requires adjusting where arguments are stored.
Place them on the stack at left-aligned positions.
Adjust the stack frame to be at entirely positive offsets.
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
As noted by qemu-plugins.h, enum qemu_plugin_cb_flags is
currently unused -- plugins can neither read nor write
guest registers.
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We will shortly be interested in distinguishing pointers
from integers in the helper's declaration, as well as a
true void return. We currently have two parallel 1 bit
fields; merge them and expand to a 3 bit field.
Our current maximum is 7 helper arguments, plus the return
makes 8 * 3 = 24 bits used within the uint32_t typemask.
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
block/nbd doesn't need underlying sioc channel anymore. So, we can
update nbd/client-connection interface to return only one top-most io
channel, which is more straight forward.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-27-vsementsov@virtuozzo.com>
[eblake: squash in Vladimir's fixes for uninit usage caught by clang]
Signed-off-by: Eric Blake <eblake@redhat.com>
Add an option for a thread to retry connecting until it succeeds. We'll
use nbd/client-connection both for reconnect and for initial connection
in nbd_open(), so we need a possibility to use same NBDClientConnection
instance to connect once in nbd_open() and then use retry semantics for
reconnect.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610100802.5888-21-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: grammar tweak]
Signed-off-by: Eric Blake <eblake@redhat.com>
We now have bs-independent connection API, which consists of four
functions:
nbd_client_connection_new()
nbd_client_connection_release()
nbd_co_establish_connection()
nbd_co_establish_connection_cancel()
Move them to a separate file together with NBDClientConnection
structure which becomes private to the new API.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-18-vsementsov@virtuozzo.com>
[eblake: comment tweaks]
Signed-off-by: Eric Blake <eblake@redhat.com>
