Most qcow2 files are uncompressed so it is wasteful to allocate (32 + 1)
* cluster_size + 512 bytes upfront. Allocate s->cluster_cache and
s->cluster_data when the first read operation is performance on a
compressed cluster.
The buffers are freed in .bdrv_close(). .bdrv_open() no longer has any
code paths that can allocate these buffers, so remove the free functions
in the error code path.
This patch can result in significant memory savings when many qcow2
disks are attached or backing file chains are long:
Before 12.81% (1,023,193,088B)
After 5.36% (393,893,888B)
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170821135530.32344-1-stefanha@redhat.com
Cc: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Add the scripts/ directory to sys.path so Python 2.6 will be able to
import argparse.
Cc: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: John Snow <jsnow@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Message-id: 20170825155732.15665-4-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Add the scripts/ directory to sys.path so Python 2.6 will be able to
import argparse.
Cc: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: John Snow <jsnow@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Message-id: 20170825155732.15665-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The minimum Python version supported by QEMU is 2.6. The argparse
standard library module was only added in Python 2.7. Many scripts
would like to use argparse because it supports command-line
sub-commands.
This patch adds argparse. See the top of argparse.py for details.
Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: John Snow <jsnow@redhat.com>
Message-id: 20170825155732.15665-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
There's a few cases which we're passing an Error pointer to a function
only to discard it immediately afterwards without checking it. In
these cases we can simply remove the variable and pass NULL instead.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20170829120836.16091-1-berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
If QEMU is running on a system that's out of memory and mmap()
fails, QEMU aborts with no error message at all, making it hard
to debug the reason for the failure.
Add perror() calls that will print error information before
aborting.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20170829212053.6003-1-ehabkost@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
LeakyBucket.burst_length is defined as an unsigned integer but the
code never checks for overflows and it only makes sure that the value
is not 0.
In practice this means that the user can set something like
throttling.iops-total-max-length=4294967300 despite being larger than
UINT_MAX and the final value after casting to unsigned int will be 4.
This patch changes the data type to uint64_t. This does not increase
the storage size of LeakyBucket, and allows us to assign the value
directly from qemu_opt_get_number() or BlockIOThrottle and then do the
checks directly in throttle_is_valid().
The value of burst_length does not have a specific upper limit,
but since the bucket size is defined by max * burst_length we have
to prevent overflows. Instead of going for UINT64_MAX or something
similar this patch reuses THROTTLE_VALUE_MAX, which allows I/O bursts
of 1 GiB/s for 10 days in a row.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 1b2e3049803f71cafb2e1fa1be4fb47147a0d398.1503580370.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Both the throttling limits set with the throttling.iops-* and
throttling.bps-* options and their QMP equivalents defined in the
BlockIOThrottle struct are integer values.
Those limits are also reported in the BlockDeviceInfo struct and they
are integers there as well.
Therefore there's no reason to store them internally as double and do
the conversion everytime we're setting or querying them, so this patch
uses uint64_t for those types. Let's also use an unsigned type because
we don't allow negative values anyway.
LeakyBucket.level and LeakyBucket.burst_level do however remain double
because their value changes depending on the fraction of time elapsed
since the previous I/O operation.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: f29b840422767b5be2c41c2dfdbbbf6c5f8fedf8.1503580370.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The throttling code can change internally the value of bkt->max if it
hasn't been set by the user. The problem with this is that if we want
to retrieve the original value we have to undo this change first. This
is ugly and unnecessary: this patch removes the throttle_fix_bucket()
and throttle_unfix_bucket() functions completely and moves the logic
to throttle_compute_wait().
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Message-id: 5b0b9e1ac6eb208d709eddc7b09e7669a523bff3.1503580370.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Use a pointer to the bucket instead of repeating cfg->buckets[i] all
the time. This makes the code more concise and will help us expand the
checks later and save a few line breaks.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 763ffc40a26b17d54cf93f5a999e4656049fcf0c.1503580370.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The way the throttling algorithm works is that requests start being
throttled once the bucket level exceeds the burst limit. When we get
there the bucket leaks at the level set by the user (bkt->avg), and
that leak rate is what prevents guest I/O from exceeding the desired
limit.
If we don't allow bursts (i.e. bkt->max == 0) then we can start
throttling requests immediately. The problem with keeping the
threshold at 0 is that it only allows one request at a time, and as
soon as there's a bit of I/O from the guest every other request will
be throttled and performance will suffer considerably. That can even
make the guest unable to reach the throttle limit if that limit is
high enough, and that happens regardless of the block scheduler used
by the guest.
Increasing that threshold gives flexibility to the guest, allowing it
to perform short bursts of I/O before being throttled. Increasing the
threshold too much does not make a difference in the long run (because
it's the leak rate what defines the actual throughput) but it does
allow the guest to perform longer initial bursts and exceed the
throttle limit for a short while.
A burst value of bkt->avg / 10 allows the guest to perform 100ms'
worth of I/O at the target rate without being throttled.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 31aae6645f0d1fbf3860fb2b528b757236f0c0a7.1503580370.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The level of the burst bucket is stored in bkt.burst_level, not
bkt.burst_length.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Message-id: 49aab2711d02f285567f3b3b13a113847af33812.1503580370.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The number of queues that should be return by the admin command should:
1) Only mention the number of non-admin queues.
2) It is zero-based, meaning that '0 == one non-admin queue',
'1 == two non-admin queues', and so forth.
Because our `num_queues` means the number of queues _plus_ the admin
queue, then the right calculation for the number returned from the admin
command is `num_queues - 2`, combining the two requirements mentioned.
The issue was discovered by reducing num_queues from 64 to 8 and running
a Linux VM with an SMP parameter larger than that (e.g. 22). It tries to
utilize all queues, and therefore fails with an invalid queue number
when trying to queue I/Os on the last queue.
Signed-off-by: Dan Aloni <dan@kernelim.com>
CC: Alex Friedman <alex@e8storage.com>
CC: Keith Busch <keith.busch@intel.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The following scenario leads to an assertion failure in
qio_channel_yield():
1. Request coroutine calls qio_channel_yield() successfully when sending
would block on the socket. It is now yielded.
2. nbd_read_reply_entry() calls nbd_recv_coroutines_enter_all() because
nbd_receive_reply() failed.
3. Request coroutine is entered and returns from qio_channel_yield().
Note that the socket fd handler has not fired yet so
ioc->write_coroutine is still set.
4. Request coroutine attempts to send the request body with nbd_rwv()
but the socket would still block. qio_channel_yield() is called
again and assert(!ioc->write_coroutine) is hit.
The problem is that nbd_read_reply_entry() does not distinguish between
request coroutines that are waiting to receive a reply and those that
are not.
This patch adds a per-request bool receiving flag so
nbd_read_reply_entry() can avoid spurious aio_wake() calls.
Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20170822125113.5025-1-stefanha@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Tested-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Non-shared storage migration with NBD and drive-mirror is currently not
tested by qemu-iotests. This test case covers the basic migration
scenario.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Based-on: <20170823134242.12080-1-famz@redhat.com>
Message-Id: <20170823140506.28723-1-stefanha@redhat.com>
Tested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
In the ->inactivate() callbacks, permissions are updated, which
typically involves a recursive check of the whole graph. Setting
BDRV_O_INACTIVE right before doing that creates a state that
bdrv_is_writable() returns false, which causes permission update
failure.
Reorder them so the flag is updated after calling the function. Note
that this doesn't break the assert in bdrv_child_cb_inactivate() because
for any specific BDS, we still update its flags first before calling
->inactivate() on it one level deeper in the recursion.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170823134242.12080-5-famz@redhat.com>
Tested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
These two conditions corresponds to mirror job's source and target,
which need to be allowed as they are part of the non-shared storage
migration workflow: failing to inactivate either will result in a
failure during migration completion.
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170823134242.12080-3-famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[eblake: improve comment grammar]
Signed-off-by: Eric Blake <eblake@redhat.com>
The logic will be fixed (extended), move it to a separate function.
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170823134242.12080-2-famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
The 'm->numa_auto_assign_ram = numa_legacy_auto_assign_ram;' line
was supposed to be in pc_i440fx_2_9_machine_options() (see commit
3bfe5716 "numa: equally distribute memory on nodes"), but the
merge commit adb354dd ("Merge remote-tracking branch
'mst/tags/for_upstream' into staging") moved it to the
pc_i440fx_2_10_machine_options().
Move the line back to pc_i440fx_2_9_machine_options().
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-id: 20170818190943.23858-1-ehabkost@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
travis builds fail at HEAD at rc3 master with
block/nbd-client.c: In function ‘nbd_read_reply_entry’:
block/nbd-client.c:110:8: error: ‘ret’ may be used uninitialized in this function [-Werror=uninitialized]
fix it by initializing 'ret' to 0
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This is identical to the pull request from yesterday (20180822),
except that a bug in one patch is fixed so that it doesn't break TCG
on a ppc host.
Last minute ppc related fixes for qemu-2.10. I'm not sure if these
are critical enough to prompt another rc, but I'm submitting them for
consideration.
First, is Cornelia's fix for 480bc11e6 which meant "make check" would
always fail on a ppc host. Tracking that down delayed submission of
the rest of these patches, sorry.
The rest are all fairly important bugfixes for qemu crashes or guest
behaviour regression on ppc. Patches 2-4 specifically are fixes for
regressions from qemu-2.9, caused by the compatibility mode and
hotplug handling cleanups for the pseries machine type.
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Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-2.10-20170823' into staging
ppc patch queue 2017-08-23
This is identical to the pull request from yesterday (20180822),
except that a bug in one patch is fixed so that it doesn't break TCG
on a ppc host.
Last minute ppc related fixes for qemu-2.10. I'm not sure if these
are critical enough to prompt another rc, but I'm submitting them for
consideration.
First, is Cornelia's fix for 480bc11e6 which meant "make check" would
always fail on a ppc host. Tracking that down delayed submission of
the rest of these patches, sorry.
The rest are all fairly important bugfixes for qemu crashes or guest
behaviour regression on ppc. Patches 2-4 specifically are fixes for
regressions from qemu-2.9, caused by the compatibility mode and
hotplug handling cleanups for the pseries machine type.
# gpg: Signature made Wed 23 Aug 2017 01:31:47 BST
# gpg: using RSA key 0x6C38CACA20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>"
# gpg: aka "David Gibson (Red Hat) <dgibson@redhat.com>"
# gpg: aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>"
# gpg: aka "David Gibson (kernel.org) <dwg@kernel.org>"
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E 87DC 6C38 CACA 20D9 B392
* remotes/dgibson/tags/ppc-for-2.10-20170823:
hw/ppc/spapr_iommu: Fix crash when removing the "spapr-tce-table" device
hw/ppc/spapr_rtc: Mark the RTC device with user_creatable = false
hw/ppc/spapr: Fix segfault when instantiating a 'pc-dimm' without 'memdev'
spapr: Allow configure-connector to be called multiple times
ppc: fix ppc_set_compat() with KVM PR
target/ppc: 'PVR != host PVR' in KVM_SET_SREGS workaround
boot-serial-test: prefer tcg accelerator
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
QEMU currently aborts unexpectedly when the user tries to add and
remove a "spapr-tce-table" device:
$ qemu-system-ppc64 -nographic -S -nodefaults -monitor stdio
QEMU 2.9.92 monitor - type 'help' for more information
(qemu) device_add spapr-tce-table,id=x
(qemu) device_del x
**
ERROR:qemu/qdev-monitor.c:872:qdev_unplug: assertion failed: (hotplug_ctrl)
Aborted (core dumped)
The device should not be accessable for the users at all, it's just
used internally, so mark it with user_creatable = false.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
QEMU currently aborts unexpectedly when a user tries to do something
like this:
$ qemu-system-ppc64 -nographic -S -nodefaults -monitor stdio
QEMU 2.9.92 monitor - type 'help' for more information
(qemu) device_add spapr-rtc,id=spapr-rtc
(qemu) device_del spapr-rtc
**
ERROR:qemu/qdev-monitor.c:872:qdev_unplug: assertion failed: (hotplug_ctrl)
Aborted (core dumped)
The RTC device is not meant to be hot-pluggable - it's an internal
device only and it even should not be possible to create it a
second time with the "-device" parameter, so let's mark this
with "user_creatable = false".
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
QEMU currently crashes when trying to use a 'pc-dimm' on the pseries
machine without specifying its 'memdev' property. This happens because
pc_dimm_get_memory_region() does not check whether the 'memdev' property
has properly been set by the user. Looking closer at this function, it's
also obvious that it is using &error_abort to call another function - and
this is bad in a function that is used in the hot-plugging calling chain
since this can also cause QEMU to exit unexpectedly.
So let's fix these issues in a proper way now: Add a "Error **errp"
parameter to pc_dimm_get_memory_region() which we use in case the 'memdev'
property has not been set by the user, and which we can use instead of
the &error_abort, and change the callers of get_memory_region() to make
use of this "errp" parameter for proper error checking.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
In case of in-kernel memory hot unplug, when the guest is not able
to remove all the LMBs that are requested for removal, it will add back
any LMBs that have been successfully removed. The DR Connectors of
these LMBs wouldn't have been unconfigured and hence the addition of
these LMBs will result in configure-connector call being issued on
LMB DR connectors that are already in configured state. Such
configure-connector calls will fail resulting in a DIMM which is
partially unplugged.
This however worked till recently before we overhauled the DRC
implementation in QEMU. Commit 9d4c0f4f0a71e: "spapr: Consolidate
DRC state variables" is the first commit where this problem shows up
as per git bisect.
Ideally guest shouldn't be issuing configure-connector call on an
already configured DR connector. However for now, work around this in
QEMU by allowing configure-connector to be called multiple times for
all types of DR connectors.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
[dwg: Corrected buglet that would have initialized fdt pointers ready
for reading on a device not present at reset]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
When running in KVM PR mode, kvmppc_set_compat() always fail because the
current PR implementation doesn't handle KVM_REG_PPC_ARCH_COMPAT. Now that
the machine code inconditionally calls ppc_set_compat_all() at reset time
to restore the compat mode default value (commit 66d5c492dd), it is
impossible to start a guest with PR:
qemu-system-ppc64: Unable to set CPU compatibility mode in KVM:
Invalid argument
A tentative patch [1] was recently sent by Suraj to address the issue, but
it would prevent the compat mode to be turned off on reset. And we really
don't want to explicitely check for KVM PR. During the patch's review,
David suggested that we should only call the KVM ioctl() if the compat
PVR changes. This allows at least to run with KVM PR, provided no compat
mode is requested from the command line (which should be the case when
running PR nested). This is what this patch does.
While here, we also fix the side effect where KVM would fail but we would
change the CPU state in QEMU anyway.
[1] http://patchwork.ozlabs.org/patch/782039/
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Commit d5fc133eed ("ppc: Rework CPU compatibility testing
across migration") changed the way cpu_post_load behaves with
the PVR setting, causing an unexpected bug in KVM-HV migrations
between hosts that are compatible (POWER8 and POWER8E, for example).
Even with pvr_match() returning true, the guest freezes right after
cpu_post_load. The reason is that the guest kernel can't handle a
different PVR value other that the running host in KVM_SET_SREGS.
In [1] it was discussed the possibility of a new KVM capability
that would indicate that the guest kernel can handle a different
PVR in KVM_SET_SREGS. Even if such feature is implemented, there is
still the problem with older kernels that will not have this capability
and will fail to migrate.
This patch implements a workaround for that scenario. If running
with KVM, check if the guest kernel does not have the capability
(named here as 'cap_ppc_pvr_compat'). If it doesn't, calls
kvmppc_is_pr() to see if the guest is running in KVM-HV. If all this
happens, set env->spr[SPR_PVR] to the same value as the current
host PVR. This ensures that we allow migrations with 'close enough'
PVRs to still work in KVM-HV but also makes the code ready for
this new KVM capability when it is done.
A new function called 'kvmppc_pvr_workaround_required' was created
to encapsulate the conditions said above and to avoid calling too
many kvm.c internals inside cpu_post_load.
[1] https://lists.gnu.org/archive/html/qemu-ppc/2017-06/msg00503.html
Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
[dwg: Fix for the case of using TCG on a PPC host]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Prefer to use the tcg accelarator if it is available: This is our only
real smoke test for tcg, and fast enough to use it for that.
Fixes: 480bc11e6 ("boot-serial-test: fallback to kvm accelerator")
Reported-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The mmio-interface device is not something we want to allow
users to create on the command line:
* it is intended as an implementation detail of the memory
subsystem, which gets created and deleted by that
subsystem on demand; it makes no sense to create it
by hand on the command line
* it uses a pointer property 'host_ptr' which can't be
set on the command line
Mark the device as not user_creatable to avoid confusion.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1502807418-9994-1-git-send-email-peter.maydell@linaro.org
Reviewed-by: Thomas Huth <thuth@redhat.com>
According to the ARM ARM exclusive loads require the same alignment as
exclusive stores. Let's update the memops used for the load to match
that of the store. This adds the alignment requirement to the memops.
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20170815145714.17635-4-richard.henderson@linaro.org
[rth: Require 16-byte alignment for 64-bit LDXP.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We are not providing the required single-copy atomic semantics for
the 64-bit operation that is the 32-bit paired load.
At the same time, leave the entire 64-bit value in cpu_exclusive_val
and stop writing to cpu_exclusive_high. This means that we do not
have to re-assemble the 64-bit quantity when it comes time to store.
At the same time, drop a redundant temporary and perform all loads
directly into the cpu_exclusive_* globals.
Tested-by: Alistair Francis <alistair.francis@xilinx.com>
Reviewed-by: Alistair Francis <alistair.francis@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20170815145714.17635-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
When we perform the atomic_cmpxchg operation we want to perform the
operation on a pair of 32-bit registers. Previously we were just passing
the register size in which was set to MO_32. This would result in the
high register to be ignored. To fix this issue we hardcode the size to
be 64-bits long when operating on 32-bit pairs.
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Portia Stephens <portia.stephens@xilinx.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20170815145714.17635-2-richard.henderson@linaro.org
Message-Id: <bc18dddca56e8c2ea4a3def48d33ceb5d21d1fff.1502488636.git.alistair.francis@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
When we switched NBD to use coroutines for qemu 2.9 (in particular,
commit a12a712a), we introduced a regression: if a server sends us
garbage (such as a corrupted magic number), we quit the read loop
but do not stop sending further queued commands, resulting in the
client hanging when it never reads the response to those additional
commands. In qemu 2.8, we properly detected that the server is no
longer reliable, and cancelled all existing pending commands with
EIO, then tore down the socket so that all further command attempts
get EPIPE.
Restore the proper behavior of quitting (almost) all communication
with a broken server: Once we know we are out of sync or otherwise
can't trust the server, we must assume that any further incoming
data is unreliable and therefore end all pending commands with EIO,
and quit trying to send any further commands. As an exception, we
still (try to) send NBD_CMD_DISC to let the server know we are going
away (in part, because it is easier to do that than to further
refactor nbd_teardown_connection, and in part because it is the
only command where we do not have to wait for a reply).
Based on a patch by Vladimir Sementsov-Ogievskiy.
A malicious server can be created with the following hack,
followed by setting NBD_SERVER_DEBUG to a non-zero value in the
environment when running qemu-nbd:
| --- a/nbd/server.c
| +++ b/nbd/server.c
| @@ -919,6 +919,17 @@ static int nbd_send_reply(QIOChannel *ioc, NBDReply *reply, Error **errp)
| stl_be_p(buf + 4, reply->error);
| stq_be_p(buf + 8, reply->handle);
|
| + static int debug;
| + static int count;
| + if (!count++) {
| + const char *str = getenv("NBD_SERVER_DEBUG");
| + if (str) {
| + debug = atoi(str);
| + }
| + }
| + if (debug && !(count % debug)) {
| + buf[0] = 0;
| + }
| return nbd_write(ioc, buf, sizeof(buf), errp);
| }
Reported-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170814213426.24681-1-eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
As in the case of nbd_export_new(), bdrv_invalidate_cache() can be
called when migration is still in progress. In this case we are not
ready to tighten the shared permissions fenced by blk->disable_perm.
Defer to a VM state change handler.
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170815130740.31229-4-famz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
The "inactive" state of BDS affects whether the permissions can be
granted, we must call bdrv_invalidate_cache before bdrv_set_perm to
support "-incoming defer" case.
Reported-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170815130740.31229-3-famz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
They will be used by BlockBackend code in block-obj-y, which doesn't
always get linked with common-obj-y. Add stubs to keep ld happy.
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170815130740.31229-2-famz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
The 093 throttling test submits twice as many requests as the throttle
limit in order to ensure that we reach the limit. The remaining
requests are left in-flight at the end of each test iteration.
Commit 452589b6b4 ("vl.c/exit: pause cpus
before closing block devices") exposed a hang in 093. This happens
because requests are still in flight when QEMU terminates but
QEMU_CLOCK_VIRTUAL time is frozen. bdrv_drain_all() hangs forever since
throttled requests cannot complete.
Step the clock at the end of each test iteration so in-flight requests
actually finish. This solves the hang and is cleaner than leaving tests
in-flight.
Note that this could also be "fixed" by disabling throttling when drives
are closed in QEMU. That approach has two issues:
1. We must drain requests before disabling throttling, so the hang
cannot be easily avoided!
2. Any time QEMU disables throttling internally there is a chance that
malicious users can abuse the code path to bypass throttling limits.
Therefore it makes more sense to fix the test case than to modify QEMU.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20170815130502.8736-1-stefanha@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
NBD_CMD_DISC is a disconnect request, not a data discard request.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170811015749.20365-1-eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
The simpletrace.py script can pretty-print flight recorder ring buffers.
These are not full simpletrace binary trace files but just the end of a
trace file. There is no header and the event ID mapping information is
often unavailable since the ring buffer may have filled up and discarded
event ID mapping records.
The simpletrace.stp script that generates ring buffer traces uses the
same trace-events-all input file as simpletrace.py. Therefore both
scripts have the same global ordering of trace events. A dynamic event
ID mapping isn't necessary: just use the trace-events-all file as the
reference for how event IDs are numbered.
It is now possible to analyze simpletrace.stp ring buffers again using:
$ ./simpletrace.py trace-events-all path/to/ring-buffer
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170815084430.7128-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This is a partial revert of commit
7f1b588f20 ("trace: emit name <-> ID
mapping in simpletrace header"), which broke the SystemTap flight
recorder because event mapping records may not be present in the ring
buffer when the trace is analyzed. This means simpletrace.py
--no-header does not know the event ID mapping needed to pretty-print
the trace.
Instead of numbering events dynamically, use a static event ID mapping
as dictated by the event order in the trace-events-all file.
The simpletrace.py script also uses trace-events-all so the next patch
will fix the simpletrace.py --no-header option to take advantage of this
knowledge.
Cc: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170815084430.7128-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
