If the FDT contains /chosen/rng-seed, then the Linux RNG will use it to
initialize early. Set this using the usual guest random number
generation function. This FDT node is part of the DT specification.
Cc: Chris Wulff <crwulff@gmail.com>
Cc: Marek Vasut <marex@denx.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Message-Id: <20220719120113.118034-1-Jason@zx2c4.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Depending on how the target list is sorted in by qemu, the first target
(used as the base copy of the fuzzer, to which all others are linked)
might not be a generic-fuzzer. Since we are trying to only use
generic-fuzz, on oss-fuzz, fix that, to ensure the base copy is a
generic-fuzzer.
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Message-Id: <20220720180946.2264253-1-alxndr@bu.edu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
oss-fuzz is finding possible fuzzing targets even under qemu-bundle/.../bin, but they
cannot be used because the required shared libraries are missing. Since the
fuzzing targets are already placed manually in $OUT, the bindir and libexecdir
subtrees are not needed; remove them.
Cc: Alexander Bulekov <alxndr@bu.edu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Coverity complains that there is a codepath in the query_stats()
function where it can leak the memory pointed to by stats_list. This
can only happen if the caller passes something other than
STATS_TARGET_VM or STATS_TARGET_VCPU as the 'target', which no
callsite does. Enforce this assumption using g_assert_not_reached(),
so that if we have a future bug we hit the assert rather than
silently leaking memory.
Resolves: Coverity CID 1490140
Fixes: cc01a3f4ca ("kvm: Support for querying fd-based stats")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220719134853.327059-1-peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit cf60ccc330 ("cutils: Introduce bundle mechanism") introduced
a Python script to populate a bundle directory using os.symlink() to
point to the binaries in the pc-bios directory of the source tree.
Commit 882084a04a ("datadir: Use bundle mechanism") removed previous
logic in pc-bios/meson.build to create a link/copy of pc-bios binaries
in the build tree so os.symlink() is the way to go.
However os.symlink() may fail [1] on Windows if an unprivileged Windows
user started the QEMU build process, which results in QEMU executables
generated in the build tree not able to load the default BIOS/firmware
images due to symbolic links not present in the bundle directory.
This commits updates the documentation by adding such caveats for users
who want to build QEMU on the Windows platform.
[1] https://docs.python.org/3/library/os.html#os.symlink
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Message-Id: <20220719135014.764981-1-bmeng.cn@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This replaces yesterdays pull and:
a) Fixes some test build errors without TLS
b) Reenabled the zlib acceleration on s390
now that we have Ilya's fix
Hyman's dirty page rate limit set
Ilya's fix for zlib vs migration
Peter's postcopy-preempt
Cleanup from Dan
zero-copy tidy ups from Leo
multifd doc fix from Juan
Revert disable of zlib acceleration on s390x
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
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Merge tag 'pull-migration-20220720c' of https://gitlab.com/dagrh/qemu into staging
Migration pull 2022-07-20
This replaces yesterdays pull and:
a) Fixes some test build errors without TLS
b) Reenabled the zlib acceleration on s390
now that we have Ilya's fix
Hyman's dirty page rate limit set
Ilya's fix for zlib vs migration
Peter's postcopy-preempt
Cleanup from Dan
zero-copy tidy ups from Leo
multifd doc fix from Juan
Revert disable of zlib acceleration on s390x
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
# gpg: Signature made Wed 20 Jul 2022 12:18:56 BST
# gpg: using RSA key 45F5C71B4A0CB7FB977A9FA90516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>" [full]
# Primary key fingerprint: 45F5 C71B 4A0C B7FB 977A 9FA9 0516 331E BC5B FDE7
* tag 'pull-migration-20220720c' of https://gitlab.com/dagrh/qemu: (30 commits)
Revert "gitlab: disable accelerated zlib for s390x"
migration: Avoid false-positive on non-supported scenarios for zero-copy-send
multifd: Document the locking of MultiFD{Send/Recv}Params
migration/multifd: Report to user when zerocopy not working
Add dirty-sync-missed-zero-copy migration stat
QIOChannelSocket: Fix zero-copy flush returning code 1 when nothing sent
migration: remove unreachable code after reading data
tests: Add postcopy preempt tests
tests: Add postcopy tls recovery migration test
tests: Add postcopy tls migration test
tests: Move MigrateCommon upper
migration: Respect postcopy request order in preemption mode
migration: Enable TLS for preempt channel
migration: Export tls-[creds|hostname|authz] params to cmdline too
migration: Add helpers to detect TLS capability
migration: Add property x-postcopy-preempt-break-huge
migration: Create the postcopy preempt channel asynchronously
migration: Postcopy recover with preempt enabled
migration: Postcopy preemption enablement
migration: Postcopy preemption preparation on channel creation
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Version: GnuPG v1
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Merge tag 'net-pull-request' of https://github.com/jasowang/qemu into staging
# gpg: Signature made Wed 20 Jul 2022 09:58:47 BST
# gpg: using RSA key EF04965B398D6211
# gpg: Good signature from "Jason Wang (Jason Wang on RedHat) <jasowang@redhat.com>" [marginal]
# 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: 215D 46F4 8246 689E C77F 3562 EF04 965B 398D 6211
* tag 'net-pull-request' of https://github.com/jasowang/qemu: (25 commits)
net/colo.c: fix segmentation fault when packet is not parsed correctly
net/colo.c: No need to track conn_list for filter-rewriter
net/colo: Fix a "double free" crash to clear the conn_list
softmmu/runstate.c: add RunStateTransition support form COLO to PRELAUNCH
vdpa: Add x-svq to NetdevVhostVDPAOptions
vdpa: Add device migration blocker
vdpa: Extract get features part from vhost_vdpa_get_max_queue_pairs
vdpa: Buffer CVQ support on shadow virtqueue
vdpa: manual forward CVQ buffers
vhost-net-vdpa: add stubs for when no virtio-net device is present
vdpa: Export vhost_vdpa_dma_map and unmap calls
vhost: Add svq avail_handler callback
vhost: add vhost_svq_poll
vhost: Expose vhost_svq_add
vhost: add vhost_svq_push_elem
vhost: Track number of descs in SVQDescState
vhost: Add SVQDescState
vhost: Decouple vhost_svq_add from VirtQueueElement
vhost: Check for queue full at vhost_svq_add
vhost: Move vhost_svq_kick call to vhost_svq_add
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This reverts commit 309df6acb2.
With Ilya's 'multifd: Copy pages before compressing them with zlib'
in the latest migration series, this shouldn't be a problem any more.
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Migration with zero-copy-send currently has it's limitations, as it can't
be used with TLS nor any kind of compression. In such scenarios, it should
output errors during parameter / capability setting.
But currently there are some ways of setting this not-supported scenarios
without printing the error message:
!) For 'compression' capability, it works by enabling it together with
zero-copy-send. This happens because the validity test for zero-copy uses
the helper unction migrate_use_compression(), which check for compression
presence in s->enabled_capabilities[MIGRATION_CAPABILITY_COMPRESS].
The point here is: the validity test happens before the capability gets
enabled. If all of them get enabled together, this test will not return
error.
In order to fix that, replace migrate_use_compression() by directly testing
the cap_list parameter migrate_caps_check().
2) For features enabled by parameters such as TLS & 'multifd_compression',
there was also a possibility of setting non-supported scenarios: setting
zero-copy-send first, then setting the unsupported parameter.
In order to fix that, also add a check for parameters conflicting with
zero-copy-send on migrate_params_check().
3) XBZRLE is also a compression capability, so it makes sense to also add
it to the list of capabilities which are not supported with zero-copy-send.
Fixes: 1abaec9a1b ("migration: Change zero_copy_send from migration parameter to migration capability")
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Message-Id: <20220719122345.253713-1-leobras@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reorder the structures so we can know if the fields are:
- Read only
- Their own locking (i.e. sems)
- Protected by 'mutex'
- Only for the multifd channel
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20220531104318.7494-2-quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
dgilbert: Typo fixes from Chen Zhang
Some errors, like the lack of Scatter-Gather support by the network
interface(NETIF_F_SG) may cause sendmsg(...,MSG_ZEROCOPY) to fail on using
zero-copy, which causes it to fall back to the default copying mechanism.
After each full dirty-bitmap scan there should be a zero-copy flush
happening, which checks for errors each of the previous calls to
sendmsg(...,MSG_ZEROCOPY). If all of them failed to use zero-copy, then
increment dirty_sync_missed_zero_copy migration stat to let the user know
about it.
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220711211112.18951-4-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220711211112.18951-3-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
If flush is called when no buffer was sent with MSG_ZEROCOPY, it currently
returns 1. This return code should be used only when Linux fails to use
MSG_ZEROCOPY on a lot of sendmsg().
Fix this by returning early from flush if no sendmsg(...,MSG_ZEROCOPY)
was attempted.
Fixes: 2bc58ffc29 ("QIOChannelSocket: Implement io_writev zero copy flag & io_flush for CONFIG_LINUX")
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220711211112.18951-2-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
The code calls qio_channel_read() in a loop when it reports
QIO_CHANNEL_ERR_BLOCK. This code is reported when errno==EAGAIN.
As such the later block of code will always hit the 'errno != EAGAIN'
condition, making the final 'else' unreachable.
Fixes: Coverity CID 1490203
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220627135318.156121-1-berrange@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Four tests are added for preempt mode:
- Postcopy plain
- Postcopy recovery
- Postcopy tls
- Postcopy tls+recovery
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185530.27801-1-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
dgilbert: Manual merge
It's easy to build this upon the postcopy tls test. Rename the old
postcopy recovery test to postcopy/recovery/plain.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185527.27747-1-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
dgilbert: Manual merge
We just added TLS tests for precopy but not postcopy. Add the
corresponding test for vanilla postcopy.
Rename the vanilla postcopy to "postcopy/plain" because all postcopy tests
will only use unix sockets as channel.
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185525.27692-1-peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
dgilbert: Manual merge
So that it can be used in postcopy tests too soon.
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185522.27638-1-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
With preemption mode on, when we see a postcopy request that was requesting
for exactly the page that we have preempted before (so we've partially sent
the page already via PRECOPY channel and it got preempted by another
postcopy request), currently we drop the request so that after all the
other postcopy requests are serviced then we'll go back to precopy stream
and start to handle that.
We dropped the request because we can't send it via postcopy channel since
the precopy channel already contains partial of the data, and we can only
send a huge page via one channel as a whole. We can't split a huge page
into two channels.
That's a very corner case and that works, but there's a change on the order
of postcopy requests that we handle since we're postponing this (unlucky)
postcopy request to be later than the other queued postcopy requests. The
problem is there's a possibility that when the guest was very busy, the
postcopy queue can be always non-empty, it means this dropped request will
never be handled until the end of postcopy migration. So, there's a chance
that there's one dest QEMU vcpu thread waiting for a page fault for an
extremely long time just because it's unluckily accessing the specific page
that was preempted before.
The worst case time it needs can be as long as the whole postcopy migration
procedure. It's extremely unlikely to happen, but when it happens it's not
good.
The root cause of this problem is because we treat pss->postcopy_requested
variable as with two meanings bound together, as the variable shows:
1. Whether this page request is urgent, and,
2. Which channel we should use for this page request.
With the old code, when we set postcopy_requested it means either both (1)
and (2) are true, or both (1) and (2) are false. We can never have (1)
and (2) to have different values.
However it doesn't necessarily need to be like that. It's very legal that
there's one request that has (1) very high urgency, but (2) we'd like to
use the precopy channel. Just like the corner case we were discussing
above.
To differenciate the two meanings better, introduce a new field called
postcopy_target_channel, showing which channel we should use for this page
request, so as to cover the old meaning (2) only. Then we leave the
postcopy_requested variable to stand only for meaning (1), which is the
urgency of this page request.
With this change, we can easily boost priority of a preempted precopy page
as long as we know that page is also requested as a postcopy page. So with
the new approach in get_queued_page() instead of dropping that request, we
send it right away with the precopy channel so we get back the ordering of
the page faults just like how they're requested on dest.
Reported-by: Manish Mishra <manish.mishra@nutanix.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Manish Mishra <manish.mishra@nutanix.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185520.27583-1-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This patch is based on the async preempt channel creation. It continues
wiring up the new channel with TLS handshake to destionation when enabled.
Note that only the src QEMU needs such operation; the dest QEMU does not
need any change for TLS support due to the fact that all channels are
established synchronously there, so all the TLS magic is already properly
handled by migration_tls_channel_process_incoming().
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185518.27529-1-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
It's useful for specifying tls credentials all in the cmdline (along with
the -object tls-creds-*), especially for debugging purpose.
The trick here is we must remember to not free these fields again in the
finalize() function of migration object, otherwise it'll cause double-free.
The thing is when destroying an object, we'll first destroy the properties
that bound to the object, then the object itself. To be explicit, when
destroy the object in object_finalize() we have such sequence of
operations:
object_property_del_all(obj);
object_deinit(obj, ti);
So after this change the two fields are properly released already even
before reaching the finalize() function but in object_property_del_all(),
hence we don't need to free them anymore in finalize() or it's double-free.
This also fixes a trivial memory leak for tls-authz as we forgot to free it
before this patch.
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185515.27475-1-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Add migrate_channel_requires_tls() to detect whether the specific channel
requires TLS, leveraging the recently introduced migrate_use_tls(). No
functional change intended.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185513.27421-1-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Add a property field that can conditionally disable the "break sending huge
page" behavior in postcopy preemption. By default it's enabled.
It should only be used for debugging purposes, and we should never remove
the "x-" prefix.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Manish Mishra <manish.mishra@nutanix.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185511.27366-1-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This patch allows the postcopy preempt channel to be created
asynchronously. The benefit is that when the connection is slow, we won't
take the BQL (and potentially block all things like QMP) for a long time
without releasing.
A function postcopy_preempt_wait_channel() is introduced, allowing the
migration thread to be able to wait on the channel creation. The channel
is always created by the main thread, in which we'll kick a new semaphore
to tell the migration thread that the channel has created.
We'll need to wait for the new channel in two places: (1) when there's a
new postcopy migration that is starting, or (2) when there's a postcopy
migration to resume.
For the start of migration, we don't need to wait for this channel until
when we want to start postcopy, aka, postcopy_start(). We'll fail the
migration if we found that the channel creation failed (which should
probably not happen at all in 99% of the cases, because the main channel is
using the same network topology).
For a postcopy recovery, we'll need to wait in postcopy_pause(). In that
case if the channel creation failed, we can't fail the migration or we'll
crash the VM, instead we keep in PAUSED state, waiting for yet another
recovery.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Manish Mishra <manish.mishra@nutanix.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185509.27311-1-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
To allow postcopy recovery, the ram fast load (preempt-only) dest QEMU thread
needs similar handling on fault tolerance. When ram_load_postcopy() fails,
instead of stopping the thread it halts with a semaphore, preparing to be
kicked again when recovery is detected.
A mutex is introduced to make sure there's no concurrent operation upon the
socket. To make it simple, the fast ram load thread will take the mutex during
its whole procedure, and only release it if it's paused. The fast-path socket
will be properly released by the main loading thread safely when there's
network failures during postcopy with that mutex held.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185506.27257-1-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This patch enables postcopy-preempt feature.
It contains two major changes to the migration logic:
(1) Postcopy requests are now sent via a different socket from precopy
background migration stream, so as to be isolated from very high page
request delays.
(2) For huge page enabled hosts: when there's postcopy requests, they can now
intercept a partial sending of huge host pages on src QEMU.
After this patch, we'll live migrate a VM with two channels for postcopy: (1)
PRECOPY channel, which is the default channel that transfers background pages;
and (2) POSTCOPY channel, which only transfers requested pages.
There's no strict rule of which channel to use, e.g., if a requested page is
already being transferred on precopy channel, then we will keep using the same
precopy channel to transfer the page even if it's explicitly requested. In 99%
of the cases we'll prioritize the channels so we send requested page via the
postcopy channel as long as possible.
On the source QEMU, when we found a postcopy request, we'll interrupt the
PRECOPY channel sending process and quickly switch to the POSTCOPY channel.
After we serviced all the high priority postcopy pages, we'll switch back to
PRECOPY channel so that we'll continue to send the interrupted huge page again.
There's no new thread introduced on src QEMU.
On the destination QEMU, one new thread is introduced to receive page data from
the postcopy specific socket (done in the preparation patch).
This patch has a side effect: after sending postcopy pages, previously we'll
assume the guest will access follow up pages so we'll keep sending from there.
Now it's changed. Instead of going on with a postcopy requested page, we'll go
back and continue sending the precopy huge page (which can be intercepted by a
postcopy request so the huge page can be sent partially before).
Whether that's a problem is debatable, because "assuming the guest will
continue to access the next page" may not really suite when huge pages are
used, especially if the huge page is large (e.g. 1GB pages). So that locality
hint is much meaningless if huge pages are used.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185504.27203-1-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Create a new socket for postcopy to be prepared to send postcopy requested
pages via this specific channel, so as to not get blocked by precopy pages.
A new thread is also created on dest qemu to receive data from this new channel
based on the ram_load_postcopy() routine.
The ram_load_postcopy(POSTCOPY) branch and the thread has not started to
function, and that'll be done in follow up patches.
Cleanup the new sockets on both src/dst QEMUs, meanwhile look after the new
thread too to make sure it'll be recycled properly.
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185502.27149-1-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
dgilbert: With Peter's fix to quieten compiler warning on
start_migration
Firstly, postcopy already preempts precopy due to the fact that we do
unqueue_page() first before looking into dirty bits.
However that's not enough, e.g., when there're host huge page enabled, when
sending a precopy huge page, a postcopy request needs to wait until the whole
huge page that is sending to finish. That could introduce quite some delay,
the bigger the huge page is the larger delay it'll bring.
This patch adds a new capability to allow postcopy requests to preempt existing
precopy page during sending a huge page, so that postcopy requests can be
serviced even faster.
Meanwhile to send it even faster, bypass the precopy stream by providing a
standalone postcopy socket for sending requested pages.
Since the new behavior will not be compatible with the old behavior, this will
not be the default, it's enabled only when the new capability is set on both
src/dst QEMUs.
This patch only adds the capability itself, the logic will be added in follow
up patches.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185342.26794-2-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
zlib_send_prepare() compresses pages of a running VM. zlib does not
make any thread-safety guarantees with respect to changing deflate()
input concurrently with deflate() [1].
One can observe problems due to this with the IBM zEnterprise Data
Compression accelerator capable zlib [2]. When the hardware
acceleration is enabled, migration/multifd/tcp/plain/zlib test fails
intermittently [3] due to sliding window corruption. The accelerator's
architecture explicitly discourages concurrent accesses [4]:
Page 26-57, "Other Conditions":
As observed by this CPU, other CPUs, and channel
programs, references to the parameter block, first,
second, and third operands may be multiple-access
references, accesses to these storage locations are
not necessarily block-concurrent, and the sequence
of these accesses or references is undefined.
Mark Adler pointed out that vanilla zlib performs double fetches under
certain circumstances as well [5], therefore we need to copy data
before passing it to deflate().
[1] https://zlib.net/manual.html
[2] https://github.com/madler/zlib/pull/410
[3] https://lists.nongnu.org/archive/html/qemu-devel/2022-03/msg03988.html
[4] http://publibfp.dhe.ibm.com/epubs/pdf/a227832c.pdf
[5] https://lists.gnu.org/archive/html/qemu-devel/2022-07/msg00889.html
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20220705203559.2960949-1-iii@linux.ibm.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Add dirty page rate limit test if kernel support dirty ring,
The following qmp commands are covered by this test case:
"calc-dirty-rate", "query-dirty-rate", "set-vcpu-dirty-limit",
"cancel-vcpu-dirty-limit" and "query-vcpu-dirty-limit".
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Acked-by: Peter Xu <peterx@redhat.com>
Message-Id: <eed5b847a6ef0a9c02a36383dbdd7db367dd1e7e.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Implement dirtyrate calculation periodically basing on
dirty-ring and throttle virtual CPU until it reachs the quota
dirty page rate given by user.
Introduce qmp commands "set-vcpu-dirty-limit",
"cancel-vcpu-dirty-limit", "query-vcpu-dirty-limit"
to enable, disable, query dirty page limit for virtual CPU.
Meanwhile, introduce corresponding hmp commands
"set_vcpu_dirty_limit", "cancel_vcpu_dirty_limit",
"info vcpu_dirty_limit" so the feature can be more usable.
"query-vcpu-dirty-limit" success depends on enabling dirty
page rate limit, so just add it to the list of skipped
command to ensure qmp-cmd-test run successfully.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <4143f26706d413dd29db0b672fe58b3d3fbe34bc.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Setup a negative feedback system when vCPU thread
handling KVM_EXIT_DIRTY_RING_FULL exit by introducing
throttle_us_per_full field in struct CPUState. Sleep
throttle_us_per_full microseconds to throttle vCPU
if dirtylimit is in service.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <977e808e03a1cef5151cae75984658b6821be618.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Introduce kvm_dirty_ring_size util function to help calculate
dirty ring ful time.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Acked-by: Peter Xu <peterx@redhat.com>
Message-Id: <f9ce1f550bfc0e3a1f711e17b1dbc8f701700e56.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Introduce the third method GLOBAL_DIRTY_LIMIT of dirty
tracking for calculate dirtyrate periodly for dirty page
rate limit.
Add dirtylimit.c to implement dirtyrate calculation periodly,
which will be used for dirty page rate limit.
Add dirtylimit.h to export util functions for dirty page rate
limit implementation.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <5d0d641bffcb9b1c4cc3e323b6dfecb36050d948.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
abstract out dirty log change logic into function
global_dirty_log_change.
abstract out dirty page rate calculation logic via
dirty-ring into function vcpu_calculate_dirtyrate.
abstract out mathematical dirty page rate calculation
into do_calculate_dirtyrate, decouple it from DirtyStat.
rename set_sample_page_period to dirty_stat_wait, which
is well-understood and will be reused in dirtylimit.
handle cpu hotplug/unplug scenario during measurement of
dirty page rate.
export util functions outside migration.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <7b6f6f4748d5b3d017b31a0429e630229ae97538.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Introduce cpu_list_generation_id to track cpu list generation so
that cpu hotplug/unplug can be detected during measurement of
dirty page rate.
cpu_list_generation_id could be used to detect changes of cpu
list, which is prepared for dirty page rate measurement.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <06e1f1362b2501a471dce796abb065b04f320fa5.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Add a non-required argument 'CPUState' to kvm_dirty_ring_reap so
that it can cover single vcpu dirty-ring-reaping scenario.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <c32001242875e83b0d9f78f396fe2dcd380ba9e8.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
store effectively happens before the load. There are two bug fixes
in this series.
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Merge tag 'pull-hex-20220719-1' of https://github.com/quic/qemu into staging
Recall that the semantics of a Hexagon mem_noshuf packet are that the
store effectively happens before the load. There are two bug fixes
in this series.
# gpg: Signature made Tue 19 Jul 2022 22:25:19 BST
# gpg: using RSA key 3635C788CE62B91FD4C59AB47B0244FB12DE4422
# gpg: Good signature from "Taylor Simpson (Rock on) <tsimpson@quicinc.com>" [undefined]
# 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: 3635 C788 CE62 B91F D4C5 9AB4 7B02 44FB 12DE 4422
* tag 'pull-hex-20220719-1' of https://github.com/quic/qemu:
Hexagon (target/hexagon) fix bug in mem_noshuf load exception
Hexagon (target/hexagon) fix store w/mem_noshuf & predicated load
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
When COLO use only one vnet_hdr_support parameter between
filter-redirector and filter-mirror(or colo-compare), COLO will crash
with segmentation fault. Back track as follow:
Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x0000555555cb200b in eth_get_l2_hdr_length (p=0x0)
at /home/tao/project/COLO/colo-qemu/include/net/eth.h:296
296 uint16_t proto = be16_to_cpu(PKT_GET_ETH_HDR(p)->h_proto);
(gdb) bt
0 0x0000555555cb200b in eth_get_l2_hdr_length (p=0x0)
at /home/tao/project/COLO/colo-qemu/include/net/eth.h:296
1 0x0000555555cb22b4 in parse_packet_early (pkt=0x555556a44840) at
net/colo.c:49
2 0x0000555555cb2b91 in is_tcp_packet (pkt=0x555556a44840) at
net/filter-rewriter.c:63
So wrong vnet_hdr_len will cause pkt->data become NULL. Add check to
raise error and add trace-events to track vnet_hdr_len.
Signed-off-by: Tao Xu <tao3.xu@intel.com>
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Filter-rewriter no need to track connection in conn_list.
This patch fix the glib g_queue_is_empty assertion when COLO guest
keep a lot of network connection.
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
We notice the QEMU may crash when the guest has too many
incoming network connections with the following log:
15197@1593578622.668573:colo_proxy_main : colo proxy connection hashtable full, clear it
free(): invalid pointer
[1] 15195 abort (core dumped) qemu-system-x86_64 ....
This is because we create the s->connection_track_table with
g_hash_table_new_full() which is defined as:
GHashTable * g_hash_table_new_full (GHashFunc hash_func,
GEqualFunc key_equal_func,
GDestroyNotify key_destroy_func,
GDestroyNotify value_destroy_func);
The fourth parameter connection_destroy() will be called to free the
memory allocated for all 'Connection' values in the hashtable when
we call g_hash_table_remove_all() in the connection_hashtable_reset().
But both connection_track_table and conn_list reference to the same
conn instance. It will trigger double free in conn_list clear. So this
patch remove free action on hash table side to avoid double free the
conn.
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
If the checkpoint occurs when the guest finishes restarting
but has not started running, the runstate_set() may reject
the transition from COLO to PRELAUNCH with the crash log:
{"timestamp": {"seconds": 1593484591, "microseconds": 26605},\
"event": "RESET", "data": {"guest": true, "reason": "guest-reset"}}
qemu-system-x86_64: invalid runstate transition: 'colo' -> 'prelaunch'
Long-term testing says that it's pretty safe.
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Finally offering the possibility to enable SVQ from the command line.
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Since the vhost-vdpa device is exposing _F_LOG, adding a migration blocker if
it uses CVQ.
However, qemu is able to migrate simple devices with no CVQ as long as
they use SVQ. To allow it, add a placeholder error to vhost_vdpa, and
only add to vhost_dev when used. vhost_dev machinery place the migration
blocker if needed.
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
To know the device features is needed for CVQ SVQ, so SVQ knows if it
can handle all commands or not. Extract from
vhost_vdpa_get_max_queue_pairs so we can reuse it.
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Introduce the control virtqueue support for vDPA shadow virtqueue. This
is needed for advanced networking features like rx filtering.
Virtio-net control VQ copies the descriptors to qemu's VA, so we avoid
TOCTOU with the guest's or device's memory every time there is a device
model change. Otherwise, the guest could change the memory content in
the time between qemu and the device read it.
To demonstrate command handling, VIRTIO_NET_F_CTRL_MACADDR is
implemented. If the virtio-net driver changes MAC the virtio-net device
model will be updated with the new one, and a rx filtering change event
will be raised.
More cvq commands could be added here straightforwardly but they have
not been tested.
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Do a simple forwarding of CVQ buffers, the same work SVQ could do but
through callbacks. No functional change intended.
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
net/vhost-vdpa.c will need functions that are declared in
vhost-shadow-virtqueue.c, that needs functions of virtio-net.c.
Copy the vhost-vdpa-stub.c code so
only the constructor net_init_vhost_vdpa needs to be defined.
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Jason A. Donenfeld
Alexander Bulekov
Paolo Bonzini
Peter Maydell
Bin Meng
Dr. David Alan Gilbert
Leonardo Bras
Juan Quintela
Daniel P. Berrangé
Peter Xu
Ilya Leoshkevich
Hyman Huang(黄勇)
Zhang Chen
Eugenio Pérez