MachineClass::no_sdcard is initialized as false by default.
To catch all uses, convert it to a tri-state, having the
current default (false) becoming AUTO.
No logical change intended.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20250204200934.65279-2-philmd@linaro.org>
Locking the memory without MCL_ONFAULT instantly prefaults any mmaped
anonymous memory with a write-fault, which introduces a lot of extra
overhead in terms of memory usage when all you want to do is to prevent
kcompactd from migrating and compacting QEMU pages. Add an option to
only lock pages lazily as they're faulted by the process by using
MCL_ONFAULT if asked.
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Link: https://lore.kernel.org/r/20250212143920.1269754-5-d-tatianin@yandex-team.ru
Signed-off-by: Peter Xu <peterx@redhat.com>
Repair poisoned memory location(s), calling ram_block_discard_range():
punching a hole in the backend file when necessary and regenerating
a usable memory.
If the kernel doesn't support the madvise calls used by this function
and we are dealing with anonymous memory, fall back to remapping the
location(s).
Signed-off-by: William Roche <william.roche@oracle.com>
Acked-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20250211212707.302391-3-william.roche@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Right now, we only allow for writing to memory regions that allow direct
access using memcpy etc; all other writes are simply ignored. This
implies that debugging guests will not work as expected when writing
to MMIO device regions.
Let's extend cpu_memory_rw_debug() to write to more memory regions,
including MMIO device regions. Reshuffle the condition in
memory_access_is_direct() to make it easier to read and add a comment.
While this change implies that debug access can now also write to MMIO
devices, we now are also permit ELF image loads and similar users of
cpu_memory_rw_debug() to write to MMIO devices; currently we ignore
these writes.
Peter assumes [1] that there's probably a class of guest images, which
will start writing junk (likely zeroes) into device model registers; we
previously would silently ignore any such bogus ELF sections. Likely
these images are of questionable correctness and this can be ignored. If
ever a problem, we could make these cases use address_space_write_rom()
instead, which is left unchanged for now.
This patch is based on previous work by Stefan Zabka.
[1] https://lore.kernel.org/all/CAFEAcA_2CEJKFyjvbwmpt=on=GgMVamQ5hiiVt+zUr6AY3X=Xg@mail.gmail.com/
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/213
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20250210084648.33798-8-david@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
As documented in commit 4a2e242bbb ("memory: Don't use memcpy for
ram_device regions"), we disallow direct access to RAM DEVICE regions.
This change implies that address_space_write_rom() and
cpu_memory_rw_debug() won't be able to write to RAM DEVICE regions. It
will also affect cpu_flush_icache_range(), but it's only used by
hw/core/loader.c after writing to ROM, so it is expected to not apply
here with RAM DEVICE.
This fixes direct access to these regions where we don't want direct
access. We'll extend cpu_memory_rw_debug() next to also be able to write to
these (and IO) regions.
This is a preparation for further changes.
Cc: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20250210084648.33798-5-david@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
testing and gdbstub updates:
- add a check-rust test to docker builds
- re-factor the qtest logic to be cleaner
- fix tests to not clock_step when no timers enabled
- roll-up log prefix into qtest_send
- cleaner error reporting when qtest_clock_set fails
- revert old deadlock fix now tests are updated
- only run full set of migration tests under HW acceleration
- support late attachment to user-mode gdbstubs
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# gpg: Signature made Mon 10 Feb 2025 08:54:51 EST
# gpg: using RSA key 6685AE99E75167BCAFC8DF35FBD0DB095A9E2A44
# gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
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* tag 'pull-10.0-testing-and-gdstub-updates-100225-1' of https://gitlab.com/stsquad/qemu:
tests/tcg: Add late gdbstub attach test
docs/user: Document the %d placeholder and suspend=n QEMU_GDB features
gdbstub: Allow late attachment
osdep: Introduce qemu_kill_thread()
user: Introduce host_interrupt_signal
user: Introduce user/signal.h
gdbstub: Try unlinking the unix socket before binding
gdbstub: Allow the %d placeholder in the socket path
tests/qtest/migration: Pick smoke tests
tests/qtest/migration: Add --full option
Revert "util/timer: avoid deadlock when shutting down"
tests/qtest: tighten up the checks on clock_step
tests/qtest: rename qtest_send_prefix and roll-up into qtest_send
tests/qtest: simplify qtest_process_inbuf
tests/qtest: don't step clock at start of npcm7xx periodic IRQ test
tests/qtest: don't attempt to clock_step while waiting for virtio ISR
tests/docker: replicate the check-rust-tools-nightly CI job
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The general expectation is that header files should follow the same
file/path naming scheme as the corresponding source file. There are
various historical exceptions to this practice in QEMU, with one of
the most notable being the include/qapi/qmp/ directory.
include/qapi/qmp/dispatch.h corresponds mostly to qapi/qmp-registry.c.
Move and rename it to include/qapi/qmp-registry.h.
Now just qerror.h is left in include/qapi/qmp/. Since it's deprecated
& (slowly) getting eliminated anyway, it isn't worth moving.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20241118151235.2665921-3-armbru@redhat.com>
The general expectation is that header files should follow the same
file/path naming scheme as the corresponding source file. There are
various historical exceptions to this practice in QEMU, with one of
the most notable being the include/qapi/qmp/ directory. Most of the
headers there correspond to source files in qobject/.
This patch corrects most of that inconsistency by creating
include/qobject/ and moving the headers for qobject/ there.
This also fixes MAINTAINERS for include/qapi/qmp/dispatch.h:
scripts/get_maintainer.pl now reports "QAPI" instead of "No
maintainers found".
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com> #s390x
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20241118151235.2665921-2-armbru@redhat.com>
[Rebased]
qtest_send_prefix never actually sent something over the chardev, all
it does is print the timestamp to the QTEST_LOG when enabled. So
rename the function, make it static, remove the unused CharDev and
simplify all the call sites by handling that directly with
qtest_send (and qtest_log_send).
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20250207153112.3939799-6-alex.bennee@linaro.org>
The '-old-param' command line option is specific to Arm targets; it
is very briefly documented as "old param mode". What this option
actually does is change the behaviour when directly booting a guest
kernel, so that command line arguments are passed to the kernel using
the extremely old "param_struct" ABI, rather than the newer ATAGS or
even newer DTB mechanisms.
This support was added back in 2007 to support an old vendor kernel
on the akita/terrier board types:
https://mail.gnu.org/archive/html/qemu-devel/2007-07/msg00344.html
Even then, it was an out-of-date mechanism from the kernel's
point of view -- the kernel has had a comment since 2001 marking
it as deprecated. As of mid-2024, the kernel only retained
param_struct support for the RiscPC and Footbridge platforms:
https://lore.kernel.org/linux-arm-kernel/2831c5a6-cfbf-4fe0-b51c-0396e5b0aeb7@app.fastmail.com/
None of the board types QEMU supports need param_struct support;
mark this option as deprecated.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20250127123113.2947620-1-peter.maydell@linaro.org
qemu_ram_alloc_from_fd allocates space if file_size == 0. If non-zero,
it uses the existing space and verifies it is large enough, but the
verification was broken when the offset parameter was introduced. As
a result, a file smaller than offset passes the verification and causes
errors later. Fix that, and update the error message to include offset.
Peter provides this concise reproducer:
$ touch ramfile
$ truncate -s 64M ramfile
$ ./qemu-system-x86_64 -object memory-backend-file,mem-path=./ramfile,offset=128M,size=128M,id=mem1,prealloc=on
qemu-system-x86_64: qemu_prealloc_mem: preallocating memory failed: Bad address
With the fix, the error message is:
qemu-system-x86_64: mem1 backing store size 0x4000000 is too small for 'size' option 0x8000000 plus 'offset' option 0x8000000
Cc: qemu-stable@nongnu.org
Fixes: 4b870dc4d0 ("hostmem-file: add offset option")
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/1736967650-129648-3-git-send-email-steven.sistare@oracle.com
Signed-off-by: Fabiano Rosas <farosas@suse.de>
(cherry picked from commit 719168fba7)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Add the cpr-transfer migration mode, which allows the user to transfer
a guest to a new QEMU instance on the same host with minimal guest pause
time, by preserving guest RAM in place, albeit with new virtual addresses
in new QEMU, and by preserving device file descriptors. Pages that were
locked in memory for DMA in old QEMU remain locked in new QEMU, because the
descriptor of the device that locked them remains open.
cpr-transfer preserves memory and devices descriptors by sending them to
new QEMU over a unix domain socket using SCM_RIGHTS. Such CPR state cannot
be sent over the normal migration channel, because devices and backends
are created prior to reading the channel, so this mode sends CPR state
over a second "cpr" migration channel. New QEMU reads the cpr channel
prior to creating devices or backends. The user specifies the cpr channel
in the channel arguments on the outgoing side, and in a second -incoming
command-line parameter on the incoming side.
The user must start old QEMU with the the '-machine aux-ram-share=on' option,
which allows anonymous memory to be transferred in place to the new process
by transferring a memory descriptor for each ram block. Memory-backend
objects must have the share=on attribute, but memory-backend-epc is not
supported.
The user starts new QEMU on the same host as old QEMU, with command-line
arguments to create the same machine, plus the -incoming option for the
main migration channel, like normal live migration. In addition, the user
adds a second -incoming option with channel type "cpr". This CPR channel
must support file descriptor transfer with SCM_RIGHTS, i.e. it must be a
UNIX domain socket.
To initiate CPR, the user issues a migrate command to old QEMU, adding
a second migration channel of type "cpr" in the channels argument.
Old QEMU stops the VM, saves state to the migration channels, and enters
the postmigrate state. New QEMU mmap's memory descriptors, and execution
resumes.
The implementation splits qmp_migrate into start and finish functions.
Start sends CPR state to new QEMU, which responds by closing the CPR
channel. Old QEMU detects the HUP then calls finish, which connects the
main migration channel.
In summary, the usage is:
qemu-system-$arch -machine aux-ram-share=on ...
start new QEMU with "-incoming <main-uri> -incoming <cpr-channel>"
Issue commands to old QEMU:
migrate_set_parameter mode cpr-transfer
{"execute": "migrate", ...
{"channel-type": "main"...}, {"channel-type": "cpr"...} ... }
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Link: https://lore.kernel.org/r/1736967650-129648-17-git-send-email-steven.sistare@oracle.com
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Save the memfd for ramblocks in CPR state, along with a name that
uniquely identifies it. The block's idstr is not yet set, so it
cannot be used for this purpose. Find the saved memfd in new QEMU when
creating a block. If size of a resizable block is larger in new QEMU,
extend it via the file_ram_alloc truncate parameter, and the extra space
will be usable after a guest reset.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/1736967650-129648-9-git-send-email-steven.sistare@oracle.com
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Allocate auxilliary guest RAM as an anonymous file that is shareable
with an external process. This option applies to memory allocated as
a side effect of creating various devices. It does not apply to
memory-backend-objects, whether explicitly specified on the command
line, or implicitly created by the -m command line option.
This option is intended to support new migration modes, in which the
memory region can be transferred in place to a new QEMU process, by sending
the memfd file descriptor to the process. Memory contents are preserved,
and if the mode also transfers device descriptors, then pages that are
locked in memory for DMA remain locked. This behavior is a pre-requisite
for supporting vfio, vdpa, and iommufd devices with the new modes.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/1736967650-129648-7-git-send-email-steven.sistare@oracle.com
Signed-off-by: Fabiano Rosas <farosas@suse.de>
