The test starts two vms (vm_a, vm_b), create dirty bitmap in
the first one, do several writes to corresponding device and
then migrate vm_a to vm_b.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20180313180320.339796-13-vsementsov@virtuozzo.com
Postcopy migration of dirty bitmaps. Only named dirty bitmaps are migrated.
If destination qemu is already containing a dirty bitmap with the same name
as a migrated bitmap (for the same node), then, if their granularities are
the same the migration will be done, otherwise the error will be generated.
If destination qemu doesn't contain such bitmap it will be created.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 20180313180320.339796-12-vsementsov@virtuozzo.com
[Changed '+' to '*' as per list discussion. --js]
Signed-off-by: John Snow <jsnow@redhat.com>
Allow migrate-start-postcopy for any postcopy type
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 20180313180320.339796-11-vsementsov@virtuozzo.com
Only-postcopy savevm states (dirty-bitmap) don't need live iteration, so
to disable them and stop transporting empty sections there is a new
savevm handler.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180313180320.339796-10-vsementsov@virtuozzo.com
Add function opposite to qemu_get_counted_string.
qemu_put_counted_string puts one-byte length of the string (string
should not be longer than 255 characters), and then it puts the string,
without last zero byte.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180313180320.339796-9-vsementsov@virtuozzo.com
There would be savevm states (dirty-bitmap) which can migrate only in
postcopy stage. The corresponding pending is introduced here.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 20180313180320.339796-6-vsementsov@virtuozzo.com
Add special state, when qmp operations on the bitmap are disabled.
It is needed during bitmap migration. "Frozen" state is not
appropriate here, because it looks like bitmap is unchanged.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20180207155837.92351-5-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20180207155837.92351-4-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
Like other setters here these functions should take a lock.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20180207155837.92351-3-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180312152126.286890-9-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Simple way to have auto generated filenames with auto cleanup. Like
FilePath but without using 'with' statement and without additional
indentation of the whole test.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180312152126.286890-8-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: grammar tweak]
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180312152126.286890-7-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Minimal realization: only one extent in server answer is supported.
Flag NBD_CMD_FLAG_REQ_ONE is used to force this behavior.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180312152126.286890-6-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: grammar tweaks, fix min_block check and 32-bit cap, use -1
instead of errno on failure in nbd_negotiate_simple_meta_context,
ensure that block status makes progress on success]
Signed-off-by: Eric Blake <eblake@redhat.com>
It is ok, that fatal error hides previous not fatal, but hiding
first fatal error is a bad feature.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180312152126.286890-5-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Minimal realization: only one extent in server answer is supported.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180312152126.286890-4-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: tweak whitespace, move constant from .h to .c, improve
logic of check_meta_export_name, simplify nbd_negotiate_options
by doing more in nbd_negotiate_meta_queries]
Signed-off-by: Eric Blake <eblake@redhat.com>
Add helper to read name in format:
uint32 len (<= NBD_MAX_NAME_SIZE)
len bytes string (not 0-terminated)
The helper will be reused in following patch.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180312152126.286890-3-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: grammar fixes, actually check error]
Signed-off-by: Eric Blake <eblake@redhat.com>
NBD_REP_ERR_INVALID is often parameter to nbd_opt_drop and it would
be used more in following patches. So, let's add a helper.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180312152126.286890-2-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
This test case adds an NBD server export and then invokes
blockdev-snapshot-sync, which changes the BlockDriverState node that the
NBD server's BlockBackend points to. This is an interesting scenario to
test and exercises the code path fixed by the previous commit.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20180306204819.11266-3-stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Commit 2019ba0a01 ("block: Add AioContextNotifier functions to BB")
added blk_add/remove_aio_context_notifier() and implemented them by
passing through the bdrv_*() equivalent.
This doesn't work across bdrv_append(), which detaches child->bs and
re-attaches it to a new BlockDriverState. When
blk_remove_aio_context_notifier() is called we will access the new BDS
instead of the one where the notifier was added!
>From the point of view of the blk_*() API user, changes to the root BDS
should be transparent.
This patch maintains a list of AioContext notifiers in BlockBackend and
adds/removes them from the BlockDriverState as needed.
Reported-by: Stefano Panella <spanella@gmail.com>
Cc: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20180306204819.11266-2-stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
The NBD spec states that since trim requests can affect disk contents,
then they should allow for FUA semantics just like writes for ensuring
the disk has settled before returning. As bdrv_[co_]pdiscard() does
not support a flags argument, we can't pass FUA down the block layer
stack, and must therefore emulate it with a flush at the NBD layer.
Note that in all reality, generic well-behaved clients will never
send TRIM+FUA (in fact, qemu as a client never does, and we have no
intention to plumb flags into bdrv_pdiscard). This is because the
NBD protocol states that it is unspecified to READ a trimmed area
(you might read stale data, all zeroes, or even random unrelated
data) without first rewriting it, and even the experimental
BLOCK_STATUS extension states that TRIM need not affect reported
status. Thus, in the general case, a client cannot tell the
difference between an arbitrary server that ignores TRIM, a server
that had a power outage without flushing to disk, and a server that
actually affected the disk before returning; so waiting for the
trim actions to flush to disk makes little sense. However, for a
specific client and server pair, where the client knows the server
treats TRIM'd areas as guaranteed reads-zero, waiting for a flush
makes sense, hence why the protocol documents that FUA is valid on
trim. So, even though the NBD protocol doesn't have a way for the
server to advertise what effects (if any) TRIM will actually have,
and thus any client that relies on specific effects is probably
in error, we can at least support a client that requests TRIM+FUA.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180307225732.155835-1-eblake@redhat.com>
Split out request handling logic.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180308184636.178534-6-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: touch up blank line placement]
Signed-off-by: Eric Blake <eblake@redhat.com>
nbd_trip has difficult logic when sending replies: it tries to use one
code path for all replies. It is ok for simple replies, but is not
comfortable for structured replies. Also, two types of error (and
corresponding messages in local_err) - fatal (leading to disconnect)
and not-fatal (just to be sent to the client) are difficult to follow.
To make things a bit clearer, the following is done:
- split CMD_READ logic to separate function. It is the most difficult
command for now, and it is definitely cramped inside nbd_trip. Also,
it is difficult to follow CMD_READ logic, shared between
"case NBD_CMD_READ" and "if"s under "reply:" label.
- create separate helper function nbd_send_generic_reply() and use it
both in new nbd_do_cmd_read and for other commands in nbd_trip instead
of common code-path under "reply:" label in nbd_trip. The helper
supports an error message, so logic with local_err in nbd_trip is
simplified.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180308184636.178534-5-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: grammar tweaks and blank line placement]
Signed-off-by: Eric Blake <eblake@redhat.com>
Since the unchanged code has just set client->recv_coroutine to
NULL before calling nbd_client_receive_next_request(), we are
spawning a new coroutine unconditionally, but the first thing
that coroutine will do is check for client->closing, making it
a no-op if we have already detected that the client is going
away. Furthermore, for any error other than EIO (where we
disconnect, which itself sets client->closing), if the client
has already gone away, we'll probably encounter EIO later
in the function and attempt disconnect at that point. Logically,
as soon as we know the connection is closing, there is no need
to try a likely-to-fail a response or spawn a no-op coroutine.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180308184636.178534-4-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: squash in further reordering: hoist check before spawning
next coroutine, and document rationale in commit message]
Signed-off-by: Eric Blake <eblake@redhat.com>
In case of io error in nbd_co_send_sparse_read we should not
"goto reply:", as it was a fatal error and the common behavior
is to disconnect in this case. We should not try to send the
client an additional error reply, since we already hit a
channel-io error on our previous attempt to send one.
Fix this by handling block-status error in nbd_co_send_sparse_read,
so nbd_co_send_sparse_read fails only on io error. Then just skip
common "reply:" code path in nbd_trip.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180308184636.178534-3-vsementsov@virtuozzo.com>
[eblake: grammar tweaks]
Signed-off-by: Eric Blake <eblake@redhat.com>
To be reused in nbd_co_send_sparse_read() in the following patch.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180308184636.178534-2-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Commit afe35cde6 added additional actions to test 33, but forgot
to reset the image between tests. As a result, './check -nbd 33'
fails because the qemu-nbd process from the first half is still
occupying the port, preventing the second half from starting a
new qemu-nbd process. Worse, the failure leaves a rogue qemu-nbd
process behind even after the test fails, which causes knock-on
failures to later tests that also want to start qemu-nbd.
Reported-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180312211156.452139-1-eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Enabling bitmap successor is necessary to enable successors of bitmaps
being migrated before target vm start.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180207155837.92351-2-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
target_msync is not used, remove its declaration and implementation.
Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
target_mprotect/target_munmap return value goes through get_errno at the
call site, thus the functions must either set errno to host error code
and return -1 or return negative guest error code. Do the latter.
Cc: qemu-stable@nongnu.org
Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
In linux-user QEMU that runs for a target with TARGET_ABI_BITS bigger
than L1_MAP_ADDR_SPACE_BITS an assertion in page_set_flags fires when
mmap, munmap, mprotect, mremap or shmat is called for an address outside
the guest address space. mmap and mprotect should return ENOMEM in such
case.
Change definition of GUEST_ADDR_MAX to always be the last valid guest
address. Account for this change in open_self_maps.
Add macro guest_addr_valid that verifies if the guest address is valid.
Add function guest_range_valid that verifies if address range is within
guest address space and does not wrap around. Use that macro in
mmap/munmap/mprotect/mremap/shmat for error checking.
Cc: qemu-stable@nongnu.org
Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
- emit TCG barriers for MEMW, EXTW, S32RI and L32AI;
- do atomic_cmpxchg_i32 for S32C1I.
Cc: Emilio G. Cota <cota@braap.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
System emulation should provide access to all registers, userspace
emulation should only provide access to unprivileged registers.
Record register flags from GDB register map definition, calculate both
num_regs and num_core_regs if either is zero. Use num_regs in system
emulation, num_core_regs in userspace emulation gdbstub.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Add arrows that mark beginning of register windows and position of the
current window in the windowed register file.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa_cpu_dump_state outputs CPU physical registers as is, without
synchronization from current window. That may result in different values
printed for the current window and corresponding physical registers.
Synchronize physical registers from window before dumping.
Cc: qemu-stable@nongnu.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
When starting QEMU management apps will usually setup a monitor socket, and
then open it immediately after startup. If not using QEMU's own -daemonize
arg, this process can be troublesome to handle correctly. The mgmt app will
need to repeatedly call connect() until it succeeds, because it does not
know when QEMU has created the listener socket. If can't retry connect()
forever though, because an error might have caused QEMU to exit before it
even creates the monitor.
The obvious way to fix this kind of problem is to just pass in a pre-opened
socket file descriptor for the QEMU monitor to listen on. The management
app can now immediately call connect() just once. If connect() fails it
knows that QEMU has exited with an error.
The SocketAddress(Legacy) structs allow for FD passing via the monitor, and
now via inherited file descriptors from the process that spawned QEMU. The
final missing piece is adding a 'fd' parameter in the socket chardev
options.
This allows both HMP usage, pass any FD number with SCM_RIGHTS, then
running HMP commands:
getfd myfd
chardev-add socket,fd=myfd
Note that numeric FDs cannot be referenced directly in HMP, only named FDs.
And also CLI usage, by leak FD 3 from parent by clearing O_CLOEXEC, then
spawning QEMU with
-chardev socket,fd=3,id=mon
-mon chardev=mon,mode=control
Note that named FDs cannot be referenced in CLI args, only numeric FDs.
We do not wire this up in the legacy chardev syntax, so you cannot use FD
passing with '-qmp', you must use the modern '-mon' + '-chardev' pair.
When passing pre-opened FDs there is a restriction on use of TLS encryption.
It can be used on a server socket chardev, but cannot be used for a client
socket chardev. This is because when validating a server's certificate, the
client needs to have a hostname available to match against the certificate
identity.
An illustrative example of usage is:
#!/usr/bin/perl
use IO::Socket::UNIX;
use Fcntl;
unlink "/tmp/qmp";
my $srv = IO::Socket::UNIX->new(
Type => SOCK_STREAM(),
Local => "/tmp/qmp",
Listen => 1,
);
my $flags = fcntl $srv, F_GETFD, 0;
fcntl $srv, F_SETFD, $flags & ~FD_CLOEXEC;
my $fd = $srv->fileno();
exec "qemu-system-x86_64", \
"-chardev", "socket,fd=$fd,server,nowait,id=mon", \
"-mon", "chardev=mon,mode=control";
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
To prepare for handling more address types, refactor the parsing of
socket address information to make it more robust and extensible.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The SocketAddress 'fd' kind accepts the name of a file descriptor passed
to the monitor with the 'getfd' command. This makes it impossible to use
the 'fd' kind in cases where a monitor is not available. This can apply in
handling command line argv at startup, or simply if internal code wants to
use SocketAddress and pass a numeric FD it has acquired from elsewhere.
Fortunately the 'getfd' command mandated that the FD names must not start
with a leading digit. We can thus safely extend semantics of the
SocketAddress 'fd' kind, to allow a purely numeric name to reference an
file descriptor that QEMU already has open. There will be restrictions on
when each kind can be used.
In codepaths where we are handling a monitor command (ie cur_mon != NULL),
we will only support use of named file descriptors as before. Use of FD
numbers is still not permitted for monitor commands.
In codepaths where we are not handling a monitor command (ie cur_mon ==
NULL), we will not support named file descriptors. Instead we can reference
FD numers explicitly. This allows the app spawning QEMU to intentionally
"leak" a pre-opened socket to QEMU and reference that in a SocketAddress
definition, or for code inside QEMU to pass pre-opened FDs around.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The SocketAddress struct has an "fd" type, which references the name of a
file descriptor passed over the monitor using the "getfd" command. We
currently blindly assume the FD is a socket, which can lead to hard to
diagnose errors later. This adds an explicit check that the FD is actually
a socket to improve the error diagnosis.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The fd_is_socket() helper method is useful in a few places, so put it in
the common sockets code. Make the code more compact while moving it.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Instead of just checking whether it is possible to bind() on a socket, also
check that we can successfully connect() to the socket we bound to. This
more closely replicates the level of functionality that tests will actually
use.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The test-io-channel-socket.c file has some useful helper functions for
checking if a specific IP protocol is available. Other tests need to
perform similar kinds of checks to avoid running tests that will fail
due to missing IP protocols.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
There are qemu_strtoNN functions for various sized integers. This adds two
more for plain int & unsigned int types, with suitable range checking.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This adds a possibility for the platform to tell VFIO not to emulate MSIX
so MMIO memory regions do not get split into chunks in flatview and
the entire page can be registered as a KVM memory slot and make direct
MMIO access possible for the guest.
This enables the entire MSIX BAR mapping to the guest for the pseries
platform in order to achieve the maximum MMIO preformance for certain
devices.
Tested on:
LSI Logic / Symbios Logic SAS3008 PCI-Express Fusion-MPT SAS-3 (rev 02)
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
At the moment we unconditionally avoid mapping MSIX data of a BAR and
emulate MSIX table in QEMU. However it is 1) not always necessary as
a platform may provide a paravirt interface for MSIX configuration;
2) can affect the speed of MMIO access by emulating them in QEMU when
frequently accessed registers share same system page with MSIX data,
this is particularly a problem for systems with the page size bigger
than 4KB.
A new capability - VFIO_REGION_INFO_CAP_MSIX_MAPPABLE - has been added
to the kernel [1] which tells the userspace that mapping of the MSIX data
is possible now. This makes use of it so from now on QEMU tries mapping
the entire BAR as a whole and emulate MSIX on top of that.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a32295c612c57990d17fb0f41e7134394b2f35f6
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
At the moment if vfio_memory_listener is registered in the system memory
address space, it maps/unmaps every RAM memory region for DMA.
It expects system page size aligned memory sections so vfio_dma_map
would not fail and so far this has been the case. A mapping failure
would be fatal. A side effect of such behavior is that some MMIO pages
would not be mapped silently.
However we are going to change MSIX BAR handling so we will end having
non-aligned sections in vfio_memory_listener (more details is in
the next patch) and vfio_dma_map will exit QEMU.
In order to avoid fatal failures on what previously was not a failure and
was just silently ignored, this checks the section alignment to
the smallest supported IOMMU page size and prints an error if not aligned;
it also prints an error if vfio_dma_map failed despite the page size check.
Both errors are not fatal; only MMIO RAM regions are checked
(aka "RAM device" regions).
If the amount of errors printed is overwhelming, the MSIX relocation
could be used to avoid excessive error output.
This is unlikely to cause any behavioral change.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[aw: Fix Int128 bit ops]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
