Throttling has a weird property that throttle_get_config() does not
always return the same throttling settings that were given with
throttle_config(). In other words, the set and get functions aren't
symmetric.
If .max is 0 then the throttling code assigns a default value of .avg /
10 in throttle_config(). This is an implementation detail of the
throttling algorithm. When throttle_get_config() is called the .max
value returned should still be 0.
Users are exposed to this quirk via "info block" or "query-block"
monitor commands. This has caused confusion because it looks like a bug
when an unexpected value is reported.
This patch hides the .max value adjustment in throttle_get_config() and
updates test-throttle.c appropriately.
Reported-by: Nini Gu <ngu@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20170301115026.22621-4-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The (burst) max parameter cannot be smaller than the avg parameter.
There is a test case that uses avg = 56, max = 1 and gets away with it
because no input validation is performed by the test case.
This patch switches to valid test input parameters.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20170301115026.22621-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The disk I/O throttling options have been listed for a long time but
never explained on the QEMU man page.
Suggested-by: Nini Gu <ngu@redhat.com>
Cc: Alberto Garcia <berto@igalia.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-id: 20170301115026.22621-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
We already require gcc 4.1 or newer (for the atomic
support), so the fallback codepaths for older gcc
versions than that are now dead code and we can
just delete them.
NB: clang reports itself as gcc 4.2 (regardless of
clang version), so clang won't be using the fallbacks
either.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
* implement M profile exception return properly
* cadence GEM: fix multiqueue handling bugs
* pxa2xx.c: QOMify a device
* arm/kvm: Remove trailing newlines from error_report()
* stellaris: Don't hw_error() on bad register accesses
* Add assertion about FSC format for syndrome registers
* Move excnames[] array into arm_log_exceptions()
* exynos: minor code cleanups
* hw/arm/boot: take Linux/arm64 TEXT_OFFSET header field into account
* Fix APSR writes via M profile MSR
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=Pipo
-----END PGP SIGNATURE-----
Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20170420' into staging
target-arm queue:
* implement M profile exception return properly
* cadence GEM: fix multiqueue handling bugs
* pxa2xx.c: QOMify a device
* arm/kvm: Remove trailing newlines from error_report()
* stellaris: Don't hw_error() on bad register accesses
* Add assertion about FSC format for syndrome registers
* Move excnames[] array into arm_log_exceptions()
* exynos: minor code cleanups
* hw/arm/boot: take Linux/arm64 TEXT_OFFSET header field into account
* Fix APSR writes via M profile MSR
# gpg: Signature made Thu 20 Apr 2017 17:39:35 BST
# gpg: using RSA key 0x3C2525ED14360CDE
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>"
# gpg: aka "Peter Maydell <pmaydell@gmail.com>"
# gpg: aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>"
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83 15CF 3C25 25ED 1436 0CDE
* remotes/pmaydell/tags/pull-target-arm-20170420: (24 commits)
arm: Remove workarounds for old M-profile exception return implementation
arm: Implement M profile exception return properly
arm: Track M profile handler mode state in TB flags
arm: Abstract out "are we singlestepping" test to utility function
arm: Move condition-failed codepath generation out of if()
arm: Move gen_set_condexec() and gen_set_pc_im() up in the file
arm: Factor out "generate right kind of step exception"
arm: Thumb shift operations should not permit interworking branches
arm: Don't implement BXJ on M-profile CPUs
xlnx-zynqmp: Set the Cadence GEM revision
cadence_gem: Make the revision a property
cadence_gem: Correct the interupt logic
cadence_gem: Correct the multi-queue can rx logic
cadence_gem: Read the correct queue descriptor
hw/arm: Qomify pxa2xx.c
arm/kvm: Remove trailing newlines from error_report()
stellaris: Don't hw_error() on bad register accesses
target/arm: Add assertion about FSC format for syndrome registers
arm: Move excnames[] array into arm_log_exceptions()
target/arm: Add missing entries to excnames[] for log strings
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Now that we've rewritten M-profile exception return so that the magic
PC values are not visible to other parts of QEMU, we can delete the
special casing of them elsewhere.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 1491844419-12485-10-git-send-email-peter.maydell@linaro.org
On M profile, return from exceptions happen when code in Handler mode
executes one of the following function call return instructions:
* POP or LDM which loads the PC
* LDR to PC
* BX register
and the new PC value is 0xFFxxxxxx.
QEMU tries to implement this by not treating the instruction
specially but then catching the attempt to execute from the magic
address value. This is not ideal, because:
* there are guest visible differences from the architecturally
specified behaviour (for instance jumping to 0xFFxxxxxx via a
different instruction should not cause an exception return but it
will in the QEMU implementation)
* we have to account for it in various places (like refusing to take
an interrupt if the PC is at a magic value, and making sure that
the MPU doesn't deny execution at the magic value addresses)
Drop these hacks, and instead implement exception return the way the
architecture specifies -- by having the relevant instructions check
for the magic value and raise the 'do an exception return' QEMU
internal exception immediately.
The effect on the generated code is minor:
bx lr, old code (and new code for Thread mode):
TCG:
mov_i32 tmp5,r14
movi_i32 tmp6,$0xfffffffffffffffe
and_i32 pc,tmp5,tmp6
movi_i32 tmp6,$0x1
and_i32 tmp5,tmp5,tmp6
st_i32 tmp5,env,$0x218
exit_tb $0x0
set_label $L0
exit_tb $0x7f2aabd61993
x86_64 generated code:
0x7f2aabe87019: mov %ebx,%ebp
0x7f2aabe8701b: and $0xfffffffffffffffe,%ebp
0x7f2aabe8701e: mov %ebp,0x3c(%r14)
0x7f2aabe87022: and $0x1,%ebx
0x7f2aabe87025: mov %ebx,0x218(%r14)
0x7f2aabe8702c: xor %eax,%eax
0x7f2aabe8702e: jmpq 0x7f2aabe7c016
bx lr, new code when in Handler mode:
TCG:
mov_i32 tmp5,r14
movi_i32 tmp6,$0xfffffffffffffffe
and_i32 pc,tmp5,tmp6
movi_i32 tmp6,$0x1
and_i32 tmp5,tmp5,tmp6
st_i32 tmp5,env,$0x218
movi_i32 tmp5,$0xffffffffff000000
brcond_i32 pc,tmp5,geu,$L1
exit_tb $0x0
set_label $L1
movi_i32 tmp5,$0x8
call exception_internal,$0x0,$0,env,tmp5
x86_64 generated code:
0x7fe8fa1264e3: mov %ebp,%ebx
0x7fe8fa1264e5: and $0xfffffffffffffffe,%ebx
0x7fe8fa1264e8: mov %ebx,0x3c(%r14)
0x7fe8fa1264ec: and $0x1,%ebp
0x7fe8fa1264ef: mov %ebp,0x218(%r14)
0x7fe8fa1264f6: cmp $0xff000000,%ebx
0x7fe8fa1264fc: jae 0x7fe8fa126509
0x7fe8fa126502: xor %eax,%eax
0x7fe8fa126504: jmpq 0x7fe8fa122016
0x7fe8fa126509: mov %r14,%rdi
0x7fe8fa12650c: mov $0x8,%esi
0x7fe8fa126511: mov $0x56095dbeccf5,%r10
0x7fe8fa12651b: callq *%r10
which is a difference of one cmp/branch-not-taken. This will
be lost in the noise of having to exit generated code and
look up the next TB anyway.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 1491844419-12485-9-git-send-email-peter.maydell@linaro.org
For M profile exception-return handling we'd like to generate different
code for some instructions depending on whether we are in Handler
mode or Thread mode. This isn't the same as "are we privileged
or user", so we need an extra bit in the TB flags to distinguish.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 1491844419-12485-8-git-send-email-peter.maydell@linaro.org
We now test for "are we singlestepping" in several places and
it's not a trivial check because we need to care about both
architectural singlestep and QEMU gdbstub singlestep. We're
also about to add another place that needs to make this check,
so pull the condition out into a function.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 1491844419-12485-7-git-send-email-peter.maydell@linaro.org
Move the code to generate the "condition failed" instruction
codepath out of the if (singlestepping) {} else {}. This
will allow adding support for handling a new is_jmp type
which can't be neatly split into "singlestepping case"
versus "not singlestepping case".
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 1491844419-12485-6-git-send-email-peter.maydell@linaro.org
Move the utility routines gen_set_condexec() and gen_set_pc_im()
up in the file, as we will want to use them from a function
placed earlier in the file than their current location.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 1491844419-12485-5-git-send-email-peter.maydell@linaro.org
We currently have two places that do:
if (dc->ss_active) {
gen_step_complete_exception(dc);
} else {
gen_exception_internal(EXCP_DEBUG);
}
Factor this out into its own function, as we're about to add
a third place that needs the same logic.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 1491844419-12485-4-git-send-email-peter.maydell@linaro.org
In Thumb mode, the only instructions which can cause an interworking
branch by writing the PC are BLX, BX, BXJ, LDR, POP and LDM. Unlike
ARM mode, data processing instructions which target the PC do not
cause interworking branches.
When we added support for doing interworking branches on writes to
PC from data processing instructions in commit 21aeb3430c, we
accidentally changed a Thumb instruction to have interworking
branch behaviour for writes to PC. (MOV, MOVS register-shifted
register, encoding T2; this is the standard encoding for
LSL/LSR/ASR/ROR (register).)
For this encoding, behaviour with Rd == R15 is specified as
UNPREDICTABLE, so allowing an interworking branch is within
spec, but it's confusing and differs from our handling of this
class of UNPREDICTABLE for other Thumb ALU operations. Make
it perform a simple (non-interworking) branch like the others.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 1491844419-12485-3-git-send-email-peter.maydell@linaro.org
For M-profile CPUs, the BXJ instruction does not exist at all, and
the encoding should always UNDEF. We were accidentally implementing
it to behave like A-profile BXJ; correct the error.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 1491844419-12485-2-git-send-email-peter.maydell@linaro.org
Expose the Cadence GEM revision as a property.
Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 541324373cf87b50f8be0439a0cb89f5028b016f.1491947224.git.alistair.francis@xilinx.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This patch fixes two mistakes in the interrupt logic.
First we only trigger single-queue or multi-queue interrupts if the status
register is set. This logic was already used for non multi-queue interrupts
but it also applies to multi-queue interrupts.
Secondly we need to lower the interrupts if the ISR isn't set. As part
of this we can remove the other interrupt lowering logic and consolidate
it inside gem_update_int_status().
Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Message-id: 438bcc014f8f8a2f8f68f322cb6a53f4c04688c2.1491947224.git.alistair.francis@xilinx.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Correct the buffer descriptor busy logic to work correctly when using
multiple queues.
Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Message-id: 8a7e8059984e27d46a276a66299d035a0afd280f.1491947224.git.alistair.francis@xilinx.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Read the correct descriptor instead of hardcoding the first (q=0).
Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 988b183dcf951856d8b3379f7e911ec95233bbf4.1491947224.git.alistair.francis@xilinx.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Suramya Shah <shah.suramya@gmail.com>
Message-id: 20170415180316.2694-1-shah.suramya@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Current recommended style is to log a guest error on bad register
accesses, not kill the whole system with hw_error(). Change the
hw_error() calls to log as LOG_GUEST_ERROR or LOG_UNIMP or use
g_assert_not_reached() as appropriate.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 1491486314-25823-1-git-send-email-peter.maydell@linaro.org
In tlb_fill() we construct a syndrome register value from a
fault status register value which is filled in by arm_tlb_fill().
arm_tlb_fill() returns FSR values which might be in the format
used with short-format page descriptors, or the format used
with long-format (LPAE) descriptors. The syndrome register
always uses LPAE-format FSR status codes.
It isn't actually possible to end up delivering a syndrome
register value to the guest for a fault which is reported
with a short-format FSR (that kind of stage 1 fault will only
happen for an AArch32 translation regime which doesn't have
a syndrome register, and can never be redirected to an AArch64
or Hyp exception level). Add an assertion which checks this,
and adjust the code so that we construct a syndrome with
an invalid status code, rather than allowing set bits in
the FSR input to randomly corrupt other fields in the syndrome.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 1491486152-24304-1-git-send-email-peter.maydell@linaro.org
The excnames[] array is defined in internals.h because we used
to use it from two different source files for handling logging
of AArch32 and AArch64 exception entry. Refactoring means that
it's now used only in arm_log_exception() in helper.c, so move
the array into that function.
Suggested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 1491821097-5647-1-git-send-email-peter.maydell@linaro.org
Recent changes have added new EXCP_ values to ARM but forgot
to update the excnames[] array which is used to provide
human-readable strings when printing information about the
exception for debug logging. Add the missing entries, and
add a comment to the list of #defines to help avoid the mistake
being repeated in future.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 1491486340-25988-1-git-send-email-peter.maydell@linaro.org
Short declaration of 'i' was in the middle of declarations with
assignments. Make it a little bit more readable. Additionally switch
from "unsigned" to "unsigned int" as this pattern is more widely used.
No functional change.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20170313184750.429-4-krzk@kernel.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The static array exynos4210_uart_regs with register values is not
modified so it can be made const.
Few other functions accept driver or uart state as an argument but they
do not change it and do not cast it so this can be made const for code
safeness.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Message-id: 20170313184750.429-3-krzk@kernel.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
qemu_log_mask() and error_report() are preferred over fprintf() for
logging errors. Also remove square brackets [] and additional new line
characters in printed messages.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20170313184750.429-2-krzk@kernel.org
[PMM: wrapped long line]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The arm64 boot protocol stipulates that the kernel must be loaded
TEXT_OFFSET bytes beyond a 2 MB aligned base address, where TEXT_OFFSET
could be any 4 KB multiple between 0 and 2 MB, and whose value can be
found in the header of the Image file.
So after attempts to load the arm64 kernel image as an ELF file or as a
U-Boot image have failed (both of which have their own way of specifying
the load offset), try to determine the TEXT_OFFSET from the image after
loading it but before mapping it as a ROM mapping into the guest address
space.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1489414630-21609-1-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Version: GnuPG v2
iQEtBAABCAAXBQJY9imYEBxmYW16QHJlZGhhdC5jb20ACgkQyjViTGqRccYulQf/
aMygBnFxgH/YJ9TkoSlXmss1M+nyjXsckJ4GD5hecSmDefEDvlbhzMANe4b/Rcma
Q6ibxvgnxUEKGSsQx71UzDo64vLPZxsyLkPjbp03ojkiq+1I8rVdBKJmsH8W3RPv
cFL8FmfGJh+PjhrPXZ50fwcQclCLzXkeP4Nlxi0PgyvJAzzpNFRP+DxLgFqOfJCf
rB8ziO8XXdSbaLO3e5GwWqJiLvEZ9l91Gt+S5MW4yB7zjjjd/ODrFcslExL7fLEX
skXjCBIGUNlRVhYKLdRoK8Q+zQhn+72wq1HTd5RRvJp7qXocqm8xNIiIBaUwobhd
LeT97Cmr8gOGIwr5Q4HNVw==
=6F+u
-----END PGP SIGNATURE-----
Merge remote-tracking branch 'remotes/famz/tags/block-pull-request' into staging
# gpg: Signature made Tue 18 Apr 2017 15:58:32 BST
# gpg: using RSA key 0xCA35624C6A9171C6
# gpg: Good signature from "Fam Zheng <famz@redhat.com>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg: It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 5003 7CB7 9706 0F76 F021 AD56 CA35 624C 6A91 71C6
* remotes/famz/tags/block-pull-request:
block: Drain BH in bdrv_drained_begin
block: Walk bs->children carefully in bdrv_drain_recurse
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
During block job completion, nothing is preventing
block_job_defer_to_main_loop_bh from being called in a nested
aio_poll(), which is a trouble, such as in this code path:
qmp_block_commit
commit_active_start
bdrv_reopen
bdrv_reopen_multiple
bdrv_reopen_prepare
bdrv_flush
aio_poll
aio_bh_poll
aio_bh_call
block_job_defer_to_main_loop_bh
stream_complete
bdrv_reopen
block_job_defer_to_main_loop_bh is the last step of the stream job,
which should have been "paused" by the bdrv_drained_begin/end in
bdrv_reopen_multiple, but it is not done because it's in the form of a
main loop BH.
Similar to why block jobs should be paused between drained_begin and
drained_end, BHs they schedule must be excluded as well. To achieve
this, this patch forces draining the BH in BDRV_POLL_WHILE.
As a side effect this fixes a hang in block_job_detach_aio_context
during system_reset when a block job is ready:
#0 0x0000555555aa79f3 in bdrv_drain_recurse
#1 0x0000555555aa825d in bdrv_drained_begin
#2 0x0000555555aa8449 in bdrv_drain
#3 0x0000555555a9c356 in blk_drain
#4 0x0000555555aa3cfd in mirror_drain
#5 0x0000555555a66e11 in block_job_detach_aio_context
#6 0x0000555555a62f4d in bdrv_detach_aio_context
#7 0x0000555555a63116 in bdrv_set_aio_context
#8 0x0000555555a9d326 in blk_set_aio_context
#9 0x00005555557e38da in virtio_blk_data_plane_stop
#10 0x00005555559f9d5f in virtio_bus_stop_ioeventfd
#11 0x00005555559fa49b in virtio_bus_stop_ioeventfd
#12 0x00005555559f6a18 in virtio_pci_stop_ioeventfd
#13 0x00005555559f6a18 in virtio_pci_reset
#14 0x00005555559139a9 in qdev_reset_one
#15 0x0000555555916738 in qbus_walk_children
#16 0x0000555555913318 in qdev_walk_children
#17 0x0000555555916738 in qbus_walk_children
#18 0x00005555559168ca in qemu_devices_reset
#19 0x000055555581fcbb in pc_machine_reset
#20 0x00005555558a4d96 in qemu_system_reset
#21 0x000055555577157a in main_loop_should_exit
#22 0x000055555577157a in main_loop
#23 0x000055555577157a in main
The rationale is that the loop in block_job_detach_aio_context cannot
make any progress in pausing/completing the job, because bs->in_flight
is 0, so bdrv_drain doesn't process the block_job_defer_to_main_loop
BH. With this patch, it does.
Reported-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170418143044.12187-3-famz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Tested-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
The recursive bdrv_drain_recurse may run a block job completion BH that
drops nodes. The coming changes will make that more likely and use-after-free
would happen without this patch
Stash the bs pointer and use bdrv_ref/bdrv_unref in addition to
QLIST_FOREACH_SAFE to prevent such a case from happening.
Since bdrv_unref accesses global state that is not protected by the AioContext
lock, we cannot use bdrv_ref/bdrv_unref unconditionally. Fortunately the
protection is not needed in IOThread because only main loop can modify a graph
with the AioContext lock held.
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170418143044.12187-2-famz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Tested-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
The local backend was recently converted to using "at*()" syscalls in order
to ensure all accesses happen below the shared directory. This requires that
we only pass relative paths, otherwise the dirfd argument to the "at*()"
syscalls is ignored and the path is treated as an absolute path in the host.
This is actually the case for paths in all fids, with the notable exception
of the root fid, whose path is "/". This causes the following backend ops to
act on the "/" directory of the host instead of the virtfs shared directory
when the export root is involved:
- lstat
- chmod
- chown
- utimensat
ie, chmod /9p_mount_point in the guest will be converted to chmod / in the
host for example. This could cause security issues with a privileged QEMU.
All "*at()" syscalls are being passed an open file descriptor. In the case
of the export root, this file descriptor points to the path in the host that
was passed to -fsdev.
The fix is thus as simple as changing the path of the export root fid to be
"." instead of "/".
This is CVE-2017-7471.
Cc: qemu-stable@nongnu.org
Reported-by: Léo Gaspard <leo@gaspard.io>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
In case of block migration, there may be writes to BlockBackends that do
not have the write permission taken. Before this issue is fixed (which
is not going to happen in 2.9), we therefore cannot assert that this is
the case.
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20170411145050.31290-1-mreitz@redhat.com
Tested-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This fixes a regression introduced in commit 9d456654.
aio_co_wake() can only be used to reenter a coroutine that was already
previously entered, otherwise co->ctx is uninitialised and we access
garbage. Using it immediately after qemu_coroutine_create() like in
co_read_response() is wrong and causes segfaults.
Replace the call with aio_co_enter(), which gets an explicit AioContext
parameter and works even for new coroutines.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Kashyap Chamarthy <kchamart@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1491919733-21065-1-git-send-email-kwolf@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Since d5895fcb (iscsi: Split URL into individual options), creating
qcow2 image on an iscsi LUN fails:
qemu-img create -f qcow2 iscsi://$SERVER/$IQN/0 1G
qemu-img: iscsi://$SERVER/$IQN/0: Could not create image: Invalid
argument
The problem is iscsi_open now expects that transport_name, portal and
target are already parsed into structured options by
iscsi_parse_filename, but it is not called in iscsi_create.
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 20170410075451.21329-1-famz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
[mreitz: Dropped now superfluous
qdict_put(bs_options, "filename", ...)]
Signed-off-by: Max Reitz <mreitz@redhat.com>
When a block device that is part of a throttle group is hot-unplugged,
we forgot to remove it from the throttle group. This leaves stale
memory around, and causes an easily reproducible crash:
$ ./x86_64-softmmu/qemu-system-x86_64 -nodefaults -nographic -qmp stdio \
-device virtio-scsi-pci,bus=pci.0 -drive \
id=drive_image2,if=none,format=raw,file=file2,bps=512000,iops=100,group=foo \
-device scsi-hd,id=image2,drive=drive_image2 -drive \
id=drive_image3,if=none,format=raw,file=file3,bps=512000,iops=100,group=foo \
-device scsi-hd,id=image3,drive=drive_image3
{'execute':'qmp_capabilities'}
{'execute':'device_del','arguments':{'id':'image3'}}
{'execute':'system_reset'}
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1428810
Suggested-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20170406190847.29347-1-eblake@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
raw_open() expects the caller always passing in the right actual
@options parameter. But when trying to applying snapshot on a RBD
image, bdrv_snapshot_goto() calls raw_open() (by calling the
bdrv_open callback on the BlockDriver) with a NULL @options, and
that will result in a Segmentation fault.
For the other non-raw format drivers, it also makes sense to passing
in the actual options, althought they don't trigger the problem so
far.
Let's prepare a @options by adding the "file" key-value pair to a
copy of the actual options that were given for the node (i.e.
bs->options), and pass it to the callback.
BlockDriver.bdrv_open() expects bs->file to be NULL and just
overwrites it with the result from bdrv_open_child(). That means we
should actually make sure it's NULL because otherwise the child BDS
will have a reference count that is 1 too high. So we unconditionally
invoke bdrv_unref_child() before calling BlockDriver.bdrv_open(), and
we wrap everything in bdrv_ref()/bdrv_unref() so the BDS isn't
deleted in the meantime.
Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-id: 20170405091909.36357-2-bjsdjshi@linux.vnet.ibm.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Version: GnuPG v2
iQEtBAABCAAXBQJY7MfPEBxmYW16QHJlZGhhdC5jb20ACgkQyjViTGqRccbnCgf+
N6q6oHpcO6LsisYNPxpJ5p/Vnah/DKNgGhCnwCOHXkhv17KJHCIKqHo+07zcRJUk
kO9Yc2g9PaWkgM61NsecnbTc4YE8G5SGrBCRj0o3f5Re8X3OnEi2Or8etaa9o/ZF
qIkRk5SMYE2aQFRzn7Hw7LZ/9cta5DPI6+vCzs//S4mnx06p/068Ai21lAWC4Mxy
8dLbz+0GCXEdr9XRweoQKYTYH5HE+gLpRtzlD4QtbfbGN2qkUtR/DLnHTFCUqJ10
F+GBi440L4A7ZXzHIGKVWSH4wO67X65lnWhEFUhIyXHZqkuZzTwsEfIqR005sMub
hViMFGYv6sEbf+A9sBz1Xw==
=BCcn
-----END PGP SIGNATURE-----
Merge remote-tracking branch 'remotes/famz/tags/block-pull-request' into staging
# gpg: Signature made Tue 11 Apr 2017 13:10:55 BST
# gpg: using RSA key 0xCA35624C6A9171C6
# gpg: Good signature from "Fam Zheng <famz@redhat.com>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg: It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 5003 7CB7 9706 0F76 F021 AD56 CA35 624C 6A91 71C6
* remotes/famz/tags/block-pull-request:
sheepdog: Use bdrv_coroutine_enter before BDRV_POLL_WHILE
block: Fix bdrv_co_flush early return
block: Use bdrv_coroutine_enter to start I/O coroutines
qemu-io-cmds: Use bdrv_coroutine_enter
blockjob: Use bdrv_coroutine_enter to start coroutine
block: Introduce bdrv_coroutine_enter
async: Introduce aio_co_enter
coroutine: Extract qemu_aio_coroutine_enter
tests/block-job-txn: Don't start block job before adding to txn
block: Quiesce old aio context during bdrv_set_aio_context
block: Make bdrv_parent_drained_begin/end public
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
When called from main thread, the coroutine should run in the context of
bs. Use bdrv_coroutine_enter to ensure that.
Signed-off-by: Fam Zheng <famz@redhat.com>
bdrv_inc_in_flight and bdrv_dec_in_flight are mandatory for
BDRV_POLL_WHILE to work, even for the shortcut case where flush is
unnecessary. Move the if block to below bdrv_dec_in_flight, and BTW fix
the variable declaration position.
Signed-off-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
BDRV_POLL_WHILE waits for the started I/O by releasing bs's ctx then polling
the main context, which relies on the yielded coroutine continuing on bs->ctx
before notifying qemu_aio_context with bdrv_wakeup().
Thus, using qemu_coroutine_enter to start I/O is wrong because if the coroutine
is entered from main loop, co->ctx will be qemu_aio_context, as a result of the
"release, poll, acquire" loop of BDRV_POLL_WHILE, race conditions happen when
both main thread and the iothread access the same BDS:
main loop iothread
-----------------------------------------------------------------------
blockdev_snapshot
aio_context_acquire(bs->ctx)
virtio_scsi_data_plane_handle_cmd
bdrv_drained_begin(bs->ctx)
bdrv_flush(bs)
bdrv_co_flush(bs) aio_context_acquire(bs->ctx).enter
...
qemu_coroutine_yield(co)
BDRV_POLL_WHILE()
aio_context_release(bs->ctx)
aio_context_acquire(bs->ctx).return
...
aio_co_wake(co)
aio_poll(qemu_aio_context) ...
co_schedule_bh_cb() ...
qemu_coroutine_enter(co) ...
/* (A) bdrv_co_flush(bs) /* (B) I/O on bs */
continues... */
aio_context_release(bs->ctx)
aio_context_acquire(bs->ctx)
Note that in above case, bdrv_drained_begin() doesn't do the "release,
poll, acquire" in BDRV_POLL_WHILE, because bs->in_flight == 0.
Fix this by using bdrv_coroutine_enter and enter coroutine in the right
context.
iotests 109 output is updated because the coroutine reenter flow during
mirror job complete is different (now through co_queue_wakeup, instead
of the unconditional qemu_coroutine_switch before), making the end job
len different.
Signed-off-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
qemu_coroutine_create associates @co to qemu_aio_context but we poll
blk's context below. If the coroutine yields, it may never get resumed
again.
Use bdrv_coroutine_enter to make sure we are starting the I/O on the
right context.
Signed-off-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Resuming and especially starting of the block job coroutine, could be issued in
the main thread. However the coroutine's "home" ctx should be set to the same
context as job->blk. Use bdrv_coroutine_enter to ensure that.
Signed-off-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
