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88047 commits

Author SHA1 Message Date
Peter Maydell e8cedaf779 target/arm: Split vfp_access_check() into A and M versions
vfp_access_check and its helper routine full_vfp_access_check() has
gradually grown and is now an awkward mix of A-profile only and
M-profile only pieces.  Refactor it into an A-profile only and an
M-profile only version, taking advantage of the fact that now the
only direct call to full_vfp_access_check() is in A-profile-only
code.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210618141019.10671-7-peter.maydell@linaro.org
2021-06-21 16:49:38 +01:00
Peter Maydell 95aceeeac9 target/arm: Factor FP context update code out into helper function
Factor the code in full_vfp_access_check() which updates the
ownership of the FP context and creates a new FP context
out into its own function.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210618141019.10671-6-peter.maydell@linaro.org
2021-06-21 16:49:38 +01:00
Peter Maydell e494cd0a1a target/arm: Handle writeback in VLDR/VSTR sysreg with no memory access
A few subcases of VLDR/VSTR sysreg succeed but do not perform a
memory access:
 * VSTR of VPR when unprivileged
 * VLDR to VPR when unprivileged
 * VLDR to FPCXT_NS when fpInactive

In these cases, even though we don't do the memory access we should
still update the base register and perform the stack limit check if
the insn's addressing mode specifies writeback.  Our implementation
failed to do this, because we handle these side-effects inside the
memory_to_fp_sysreg() and fp_sysreg_to_memory() callback functions,
which are only called if there's something to load or store.

Fix this by adding an extra argument to the callbacks which is set to
true to actually perform the access and false to only do side effects
like writeback, and calling the callback with do_access = false
for the three cases listed above.

This produces slightly suboptimal code for the case of a write
to FPCXT_NS when the FPU is inactive and the insn didn't have
side effects (ie no writeback, or via VMSR), in which case we'll
generate a conditional branch over an unconditional branch.
But this doesn't seem to be important enough to merit requiring
the callback to report back whether it generated any code or not.

Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210618141019.10671-5-peter.maydell@linaro.org
2021-06-21 16:49:37 +01:00
Peter Maydell fa856736b6 target/arm: Don't NOCP fault for FPCXT_NS accesses
The M-profile architecture requires that accesses to FPCXT_NS when
there is no active FP state must not take a NOCP fault even if the
FPU is disabled. We were not implementing this correctly, because
in our decode we catch the NOCP faults early in m-nocp.decode.

Fix this bug by moving all the handling of M-profile FP system
register accesses from vfp.decode into m-nocp.decode and putting
it above the NOCP blocks. This provides the correct behaviour:
 * for accesses other than FPCXT_NS the trans functions call
   vfp_access_check(), which will check for FPU disabled and
   raise a NOCP exception if necessary
 * for FPCXT_NS we have the special case code that doesn't
   call vfp_access_check()
 * when these trans functions want to raise an UNDEF they return
   false, so the decoder will fall through into the NOCP blocks.
   This means that NOCP correctly takes precedence over UNDEF
   for these insns. (This is a difference from the other insns
   handled by m-nocp.decode, where UNDEF takes precedence and
   which we implement by having those trans functions call
   unallocated_encoding() in the appropriate places.)

[Note for backport to stable: this commit has a semantic dependency
on commit 9a486856e9, which was not marked as cc-stable because
we didn't know we'd need it for a for-stable bugfix.]

Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210618141019.10671-4-peter.maydell@linaro.org
2021-06-21 16:49:37 +01:00
Peter Maydell 9931d9d84b target/arm: Handle FPU being disabled in FPCXT_NS accesses
If the guest makes an FPCXT_NS access when the FPU is disabled,
one of two things happens:
 * if there is no active FP context, then the insn behaves the
   same way as if the FPU was enabled: writes ignored, reads
   same value as FPDSCR_NS
 * if there is an active FP context, then we take a NOCP
   exception

Add code to the sysreg read/write functions which emits
code to take the NOCP exception in the latter case.

At the moment this will never be used, because the NOCP checks in
m-nocp.decode happen first, and so the trans functions are never
called when the FPU is disabled.  The code will be needed when we
move the sysreg access insns to before the NOCP patterns in the
following commit.

Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210618141019.10671-3-peter.maydell@linaro.org
2021-06-21 16:49:37 +01:00
Peter Maydell 41b3ffc599 target/arm/translate-vfp.c: Whitespace fixes
In the code for handling VFP system register accesses there is some
stray whitespace after a unary '-' operator, and also some incorrect
indent in a couple of function prototypes.  We're about to move this
code to another file, so fix the code style issues first so
checkpatch doesn't complain about the code-movement patch.

Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210618141019.10671-2-peter.maydell@linaro.org
2021-06-21 16:49:37 +01:00
Peter Maydell 741292face docs/system/arm: Document which architecture extensions we emulate
These days the Arm architecture has a wide range of fine-grained
optional extra architectural features. We implement quite a lot
of these but by no means all of them. Document what we do implement,
so that users can find out without having to dig through back-issues
of our Changelog on the wiki.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20210617140328.28622-1-peter.maydell@linaro.org
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-21 16:49:37 +01:00
Peter Maydell 15613357ba target/arm: Use acpi_ghes_present() to see if we report ACPI memory errors
The virt_is_acpi_enabled() function is specific to the virt board, as
is the check for its 'ras' property.  Use the new acpi_ghes_present()
function to check whether we should report memory errors via
acpi_ghes_record_errors().

This avoids a link error if QEMU was built without support for the
virt board, and provides a mechanism that can be used by any future
board models that want to add ACPI memory error reporting support
(they only need to call acpi_ghes_add_fw_cfg()).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Dongjiu Geng <gengdongjiu1@gmail.com>
Message-id: 20210603171259.27962-4-peter.maydell@linaro.org
2021-06-21 16:49:37 +01:00
Peter Maydell 1c81f5735a hw/acpi: Provide function acpi_ghes_present()
Allow code elsewhere in the system to check whether the ACPI GHES
table is present, so it can determine whether it is OK to try to
record an error by calling acpi_ghes_record_errors().

(We don't need to migrate the new 'present' field in AcpiGhesState,
because it is set once at system initialization and doesn't change.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Dongjiu Geng <gengdongjiu1@gmail.com>
Message-id: 20210603171259.27962-3-peter.maydell@linaro.org
2021-06-21 16:49:37 +01:00
Peter Maydell 82faef92fb hw/acpi: Provide stub version of acpi_ghes_record_errors()
Generic code in target/arm wants to call acpi_ghes_record_errors();
provide a stub version so that we don't fail to link when
CONFIG_ACPI_APEI is not set. This requires us to add a new
ghes-stub.c file to contain it and the meson.build mechanics
to use it when appropriate.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Dongjiu Geng <gengdongjiu1@gmail.com>
Message-id: 20210603171259.27962-2-peter.maydell@linaro.org
2021-06-21 16:49:37 +01:00
Peter Maydell 53f306f316 x86 queue, 2021-06-18
Features:
 * Add ratelimit for bus locks acquired in guest (Chenyi Qiang)
 
 Documentation:
 * SEV documentation updates (Tom Lendacky)
 * Add a table showing x86-64 ABI compatibility levels (Daniel P. Berrangé)
 
 Automated changes:
 * Update Linux headers to 5.13-rc4 (Eduardo Habkost)
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Merge remote-tracking branch 'remotes/ehabkost-gl/tags/x86-next-pull-request' into staging

x86 queue, 2021-06-18

Features:
* Add ratelimit for bus locks acquired in guest (Chenyi Qiang)

Documentation:
* SEV documentation updates (Tom Lendacky)
* Add a table showing x86-64 ABI compatibility levels (Daniel P. Berrangé)

Automated changes:
* Update Linux headers to 5.13-rc4 (Eduardo Habkost)

# gpg: Signature made Fri 18 Jun 2021 20:51:26 BST
# gpg:                using RSA key 5A322FD5ABC4D3DBACCFD1AA2807936F984DC5A6
# gpg:                issuer "ehabkost@redhat.com"
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>" [full]
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF  D1AA 2807 936F 984D C5A6

* remotes/ehabkost-gl/tags/x86-next-pull-request:
  scripts: helper to generate x86_64 CPU ABI compat info
  docs: add a table showing x86-64 ABI compatibility levels
  docs/interop/firmware.json: Add SEV-ES support
  docs: Add SEV-ES documentation to amd-memory-encryption.txt
  doc: Fix some mistakes in the SEV documentation
  i386: Add ratelimit for bus locks acquired in guest
  Update Linux headers to 5.13-rc4

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-06-21 11:26:04 +01:00
Peter Maydell e4bfa6cd68 nbd patches for 2021-06-15
- bug fixes in coroutine aio context handling
 - rework NBD client connection logic to perform more work in coroutine
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Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2021-06-15-v2' into staging

nbd patches for 2021-06-15

- bug fixes in coroutine aio context handling
- rework NBD client connection logic to perform more work in coroutine

# gpg: Signature made Fri 18 Jun 2021 18:29:39 BST
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2021-06-15-v2: (34 commits)
  block/nbd: safer transition to receiving request
  block/nbd: add nbd_client_connected() helper
  block/nbd: reuse nbd_co_do_establish_connection() in nbd_open()
  nbd/client-connection: add option for non-blocking connection attempt
  block/nbd: split nbd_co_do_establish_connection out of nbd_reconnect_attempt
  block-coroutine-wrapper: allow non bdrv_ prefix
  nbd/client-connection: return only one io channel
  block/nbd: drop BDRVNBDState::sioc
  block/nbd: don't touch s->sioc in nbd_teardown_connection()
  block/nbd: use negotiation of NBDClientConnection
  block/nbd: split nbd_handle_updated_info out of nbd_client_handshake()
  nbd/client-connection: shutdown connection on release
  nbd/client-connection: implement connection retry
  nbd/client-connection: add possibility of negotiation
  nbd/client-connection: use QEMU_LOCK_GUARD
  nbd: move connection code from block/nbd to nbd/client-connection
  block/nbd: introduce nbd_client_connection_release()
  block/nbd: introduce nbd_client_connection_new()
  block/nbd: rename NBDConnectThread to NBDClientConnection
  block/nbd: make nbd_co_establish_connection_cancel() bs-independent
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-06-20 21:20:13 +01:00
Vladimir Sementsov-Ogievskiy bbfb7c2f35 block/nbd: safer transition to receiving request
req->receiving is a flag of request being in one concrete yield point
in nbd_co_do_receive_one_chunk().

Such kind of boolean flag is always better to unset before scheduling
the coroutine, to avoid double scheduling. So, let's be more careful.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-33-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 12:21:22 -05:00
Vladimir Sementsov-Ogievskiy 91e0998f5a block/nbd: add nbd_client_connected() helper
We already have two similar helpers for other state. Let's add another
one for convenience.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-32-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 12:21:22 -05:00
Vladimir Sementsov-Ogievskiy a71d597b98 block/nbd: reuse nbd_co_do_establish_connection() in nbd_open()
The only last step we need to reuse the function is coroutine-wrapper.
nbd_open() may be called from non-coroutine context. So, generate the
wrapper and use it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-31-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 12:21:22 -05:00
Vladimir Sementsov-Ogievskiy 97cf89259e nbd/client-connection: add option for non-blocking connection attempt
We'll need a possibility of non-blocking nbd_co_establish_connection(),
so that it returns immediately, and it returns success only if a
connections was previously established in background.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-30-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 12:21:22 -05:00
Vladimir Sementsov-Ogievskiy 51edbf537d block/nbd: split nbd_co_do_establish_connection out of nbd_reconnect_attempt
Split out the part that we want to reuse for nbd_open().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610100802.5888-29-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 12:21:21 -05:00
Vladimir Sementsov-Ogievskiy bb43694872 block-coroutine-wrapper: allow non bdrv_ prefix
We are going to reuse the script to generate a nbd_ function in
further commit. Prepare the script now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-28-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 12:21:21 -05:00
Vladimir Sementsov-Ogievskiy 43cb34dede nbd/client-connection: return only one io channel
block/nbd doesn't need underlying sioc channel anymore. So, we can
update nbd/client-connection interface to return only one top-most io
channel, which is more straight forward.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-27-vsementsov@virtuozzo.com>
[eblake: squash in Vladimir's fixes for uninit usage caught by clang]
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 12:20:53 -05:00
Vladimir Sementsov-Ogievskiy 95a078ea3e block/nbd: drop BDRVNBDState::sioc
Currently sioc pointer is used just to pass from socket-connection to
nbd negotiation. Drop the field, and use local variables instead. With
next commit we'll update nbd/client-connection.c to behave
appropriately (return only top-most ioc, not two channels).

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-26-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:54 -05:00
Vladimir Sementsov-Ogievskiy c2405af0e4 block/nbd: don't touch s->sioc in nbd_teardown_connection()
Negotiation during reconnect is now done in a thread, and s->sioc is
not available during negotiation. Negotiation in thread will be
cancelled by nbd_client_connection_release() called from
nbd_clear_bdrvstate().  So, we don't need this code chunk anymore.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-25-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:54 -05:00
Vladimir Sementsov-Ogievskiy 6d2b0332d3 block/nbd: use negotiation of NBDClientConnection
Now that we can opt in to negotiation as part of the client connection
thread, use that to simplify connection_co.  This is another step on
the way to moving all reconnect code into NBDClientConnection.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-24-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:54 -05:00
Vladimir Sementsov-Ogievskiy e9ba7788b0 block/nbd: split nbd_handle_updated_info out of nbd_client_handshake()
To be reused in the following patch.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Roman Kagan <rvkagan@yandex-team.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-23-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:54 -05:00
Vladimir Sementsov-Ogievskiy f58b2dfe3e nbd/client-connection: shutdown connection on release
Now, when a thread can do negotiation and retry, it may run relatively
long. We need a mechanism to stop it, when the user is not interested
in a result any more. So, on nbd_client_connection_release() let's
shutdown the socket, and do not retry connection if thread is detached.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610100802.5888-22-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy e0e67cbe58 nbd/client-connection: implement connection retry
Add an option for a thread to retry connecting until it succeeds. We'll
use nbd/client-connection both for reconnect and for initial connection
in nbd_open(), so we need a possibility to use same NBDClientConnection
instance to connect once in nbd_open() and then use retry semantics for
reconnect.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610100802.5888-21-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: grammar tweak]
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy 130d49baa5 nbd/client-connection: add possibility of negotiation
Add arguments and logic to support nbd negotiation in the same thread
after successful connection.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610100802.5888-20-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy e70da5ff64 nbd/client-connection: use QEMU_LOCK_GUARD
We don't update connect_thread_func() to use QEMU_LOCK_GUARD, as it
will get more complex critical sections logic in further commit, where
QEMU_LOCK_GUARD doesn't help.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610100802.5888-19-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy 5276c87c12 nbd: move connection code from block/nbd to nbd/client-connection
We now have bs-independent connection API, which consists of four
functions:

  nbd_client_connection_new()
  nbd_client_connection_release()
  nbd_co_establish_connection()
  nbd_co_establish_connection_cancel()

Move them to a separate file together with NBDClientConnection
structure which becomes private to the new API.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-18-vsementsov@virtuozzo.com>
[eblake: comment tweaks]
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy 248d470198 block/nbd: introduce nbd_client_connection_release()
This is a last step of creating bs-independent nbd connection
interface. With next commit we can finally move it to separate file.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610100802.5888-17-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy f68729747d block/nbd: introduce nbd_client_connection_new()
This is a step of creating bs-independent nbd connection interface.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Roman Kagan <rvkagan@yandex-team.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-16-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy 90ddc64fb2 block/nbd: rename NBDConnectThread to NBDClientConnection
We are going to move the connection code to its own file, and want
clear names and APIs first.

The structure is shared between user and (possibly) several runs of
connect-thread. So it's wrong to call it "thread". Let's rename to
something more generic.

Appropriately rename connect_thread and thr variables to conn.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Roman Kagan <rvkagan@yandex-team.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-15-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy c3e7730485 block/nbd: make nbd_co_establish_connection_cancel() bs-independent
nbd_co_establish_connection_cancel() actually needs only pointer to
NBDConnectThread. So, make it clean.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Roman Kagan <rvkagan@yandex-team.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-14-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy d33833d7af block/nbd: bs-independent interface for nbd_co_establish_connection()
We are going to split connection code to a separate file. Now we are
ready to give nbd_co_establish_connection() clean and bs-independent
interface.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Roman Kagan <rvkagan@yandex-team.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-13-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy b8e8a3d116 block/nbd: drop thr->state
We don't need all these states. The code refactored to use two boolean
variables looks simpler.

While moving the comment in nbd_co_establish_connection() rework it to
give better information. Also, we are going to move the connection code
to separate file and mentioning drained section would be confusing.

Improve also the comment in NBDConnectThread, while dropping removed
state names from it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610100802.5888-12-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: comment tweak]
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy 08ea55d068 block/nbd: simplify waking of nbd_co_establish_connection()
Instead of managing connect_bh, bh_ctx, and wait_connect fields, we
can use a single link to the waiting coroutine with proper mutex
protection.

So new logic is:

nbd_co_establish_connection() sets wait_co under the mutex, releases
the mutex, then yield()s.  Note that wait_co may be scheduled by the
thread immediately after unlocking the mutex.  Still, the main thread
(or iothread) will not reach the code for entering the coroutine until
the yield(), so we are safe.

connect_thread_func() and nbd_co_establish_connection_cancel() do
the following to handle wait_co:

Under the mutex, if thr->wait_co is not NULL, make it NULL and
schedule it. This way, we avoid scheduling the coroutine twice.

Still scheduling is a bit different:

In connect_thread_func() we can just call aio_co_wake under mutex,
after commit
   [async: the main AioContext is only "current" if under the BQL]
we are sure that aio_co_wake() will not try to acquire the aio context
and do qemu_aio_coroutine_enter() but simply schedule the coroutine by
aio_co_schedule().

nbd_co_establish_connection_cancel() will be called from non-coroutine
context in further patch and will be able to go through
qemu_aio_coroutine_enter() path of aio_co_wake(). So keep current
behavior of waking the coroutine after the critical section.

Also, this commit reduces the dependence of
nbd_co_establish_connection() on the internals of bs (we now use a
generic pointer to the coroutine, instead of direct use of
s->connection_co).  This is a step towards splitting the connection
API out of nbd.c.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610100802.5888-11-vsementsov@virtuozzo.com>
Reviewied-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy 2def3edb4b block/nbd: BDRVNBDState: drop unused connect_err and connect_status
These fields are write-only. Drop them.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Roman Kagan <rvkagan@yandex-team.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-10-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy 2a25def4be block/nbd: nbd_client_handshake(): fix leak of s->ioc
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Roman Kagan <rvkagan@yandex-team.ru>
Message-Id: <20210610100802.5888-9-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Roman Kagan e8b35bf5dc block/nbd: ensure ->connection_thread is always valid
Simplify lifetime management of BDRVNBDState->connect_thread by
delaying the possible cleanup of it until the BDRVNBDState itself goes
away.

This also reverts
 0267101af6 "block/nbd: fix possible use after free of s->connect_thread"
as now s->connect_thread can't be cleared until the very end.

Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru>
 [vsementsov: rebase, revert 0267101af6 changes]
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
 [eblake: tweak comment]
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-8-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy 6cc702beac block/nbd: call socket_address_parse_named_fd() in advance
Detecting monitor by current coroutine works bad when we are not in
coroutine context. And that's exactly so in nbd reconnect code, where
qio_channel_socket_connect_sync() is called from thread.

Monitor is needed only to parse named file descriptor. So, let's just
parse it during nbd_open(), so that all further users of s->saddr don't
need to access monitor.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610100802.5888-7-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy c542370418 qemu-sockets: introduce socket_address_parse_named_fd()
Add function that transforms named fd inside SocketAddress structure
into number representation. This way it may be then used in a context
where current monitor is not available.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610100802.5888-6-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: comment tweak]
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy fb392b548e block/nbd: connect_thread_func(): do qio_channel_set_delay(false)
nbd_open() does it (through nbd_establish_connection()).
Actually we lost that call on reconnect path in 1dc4718d84
"block/nbd: use non-blocking connect: fix vm hang on connect()"
when we have introduced reconnect thread.

Fixes: 1dc4718d84
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610100802.5888-5-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Vladimir Sementsov-Ogievskiy bbba1c376b block/nbd: fix how state is cleared on nbd_open() failure paths
We have two "return error" paths in nbd_open() after
nbd_process_options(). Actually we should call nbd_clear_bdrvstate()
on these paths. Interesting that nbd_process_options() calls
nbd_clear_bdrvstate() by itself.

Let's fix leaks and refactor things to be more obvious:

- intialize yank at top of nbd_open()
- move yank cleanup to nbd_clear_bdrvstate()
- refactor nbd_open() so that all failure paths except for
  yank-register goes through nbd_clear_bdrvstate()

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Roman Kagan <rvkagan@yandex-team.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-4-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:53 -05:00
Roman Kagan 3687ad4903 block/nbd: fix channel object leak
nbd_free_connect_thread leaks the channel object if it hasn't been
stolen.

Unref it and fix the leak.

Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210610100802.5888-3-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:52 -05:00
Vladimir Sementsov-Ogievskiy 0e70260b65 co-queue: drop extra coroutine_fn marks
qemu_co_queue_next() and qemu_co_queue_restart_all() just call
aio_co_wake() which works well in non-coroutine context. So these
functions can be called from non-coroutine context as well. And
actually qemu_co_queue_restart_all() is called from
nbd_cancel_in_flight(), which is called from non-coroutine context.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610100802.5888-2-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:52 -05:00
Paolo Bonzini 55159c34b8 tests: cover aio_co_enter from a worker thread without BQL taken
Add a testcase for the test fixed by commit 'async: the main AioContext
is only "current" if under the BQL.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210614110214.726722-1-pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:52 -05:00
Paolo Bonzini 5f50be9b58 async: the main AioContext is only "current" if under the BQL
If we want to wake up a coroutine from a worker thread, aio_co_wake()
currently does not work.  In that scenario, aio_co_wake() calls
aio_co_enter(), but there is no current AioContext and therefore
qemu_get_current_aio_context() returns the main thread.  aio_co_wake()
then attempts to call aio_context_acquire() instead of going through
aio_co_schedule().

The default case of qemu_get_current_aio_context() was added to cover
synchronous I/O started from the vCPU thread, but the main and vCPU
threads are quite different.  The main thread is an I/O thread itself,
only running a more complicated event loop; the vCPU thread instead
is essentially a worker thread that occasionally calls
qemu_mutex_lock_iothread().  It is only in those critical sections
that it acts as if it were the home thread of the main AioContext.

Therefore, this patch detaches qemu_get_current_aio_context() from
iothreads, which is a useless complication.  The AioContext pointer
is stored directly in the thread-local variable, including for the
main loop.  Worker threads (including vCPU threads) optionally behave
as temporary home threads if they have taken the big QEMU lock,
but if that is not the case they will always schedule coroutines
on remote threads via aio_co_schedule().

With this change, the stub qemu_mutex_iothread_locked() must be changed
from true to false.  The previous value of true was needed because the
main thread did not have an AioContext in the thread-local variable,
but now it does have one.

Reported-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210609122234.544153-1-pbonzini@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Tested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[eblake: tweak commit message per Vladimir's review]
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-06-18 10:59:52 -05:00
Peter Maydell 8f521741e1 VFIO update 2021-06-18
* VFIO migration documentation (Tarun Gupta)
 
  * Fix SaveVMHandler de-registration (Kunkun Jiang)
 
  * Fix vmstate change transition (Kirti Wankhede)
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Merge remote-tracking branch 'remotes/awilliam/tags/vfio-update-20210618.0' into staging

VFIO update 2021-06-18

 * VFIO migration documentation (Tarun Gupta)

 * Fix SaveVMHandler de-registration (Kunkun Jiang)

 * Fix vmstate change transition (Kirti Wankhede)

# gpg: Signature made Fri 18 Jun 2021 16:20:34 BST
# gpg:                using RSA key 42F6C04E540BD1A99E7B8A90239B9B6E3BB08B22
# gpg:                issuer "alex.williamson@redhat.com"
# gpg: Good signature from "Alex Williamson <alex.williamson@redhat.com>" [full]
# gpg:                 aka "Alex Williamson <alex@shazbot.org>" [full]
# gpg:                 aka "Alex Williamson <alwillia@redhat.com>" [full]
# gpg:                 aka "Alex Williamson <alex.l.williamson@gmail.com>" [full]
# Primary key fingerprint: 42F6 C04E 540B D1A9 9E7B  8A90 239B 9B6E 3BB0 8B22

* remotes/awilliam/tags/vfio-update-20210618.0:
  vfio/migration: Correct device state from vmstate change for savevm case
  vfio: Fix unregister SaveVMHandler in vfio_migration_finalize
  docs/devel: Add VFIO device migration documentation

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-06-18 16:42:25 +01:00
Kirti Wankhede d742d064c1 vfio/migration: Correct device state from vmstate change for savevm case
Set _SAVING flag for device state from vmstate change handler when it
gets called from savevm.

Currently State transition savevm/suspend is seen as:
    _RUNNING -> _STOP -> Stop-and-copy -> _STOP

State transition savevm/suspend should be:
    _RUNNING -> Stop-and-copy -> _STOP

State transition from _RUNNING to _STOP occurs from
vfio_vmstate_change() where when vmstate changes from running to
!running, _RUNNING flag is reset but at the same time when
vfio_vmstate_change() is called for RUN_STATE_SAVE_VM, _SAVING bit
should be set.

Reported by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Message-Id: <1623177441-27496-1-git-send-email-kwankhede@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-06-18 09:10:35 -06:00
Kunkun Jiang 22fca190e2 vfio: Fix unregister SaveVMHandler in vfio_migration_finalize
In the vfio_migration_init(), the SaveVMHandler is registered for
VFIO device. But it lacks the operation of 'unregister'. It will
lead to 'Segmentation fault (core dumped)' in
qemu_savevm_state_setup(), if performing live migration after a
VFIO device is hot deleted.

Fixes: 7c2f5f75f9 (vfio: Register SaveVMHandlers for VFIO device)
Reported-by: Qixin Gan <ganqixin@huawei.com>
Signed-off-by: Kunkun Jiang <jiangkunkun@huawei.com>
Message-Id: <20210527123101.289-1-jiangkunkun@huawei.com>
Reviewed by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-06-18 08:38:04 -06:00
Tarun Gupta 2a5781331a docs/devel: Add VFIO device migration documentation
Document interfaces used for VFIO device migration. Added flow
of state changes during live migration with VFIO device.

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Co-developed-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Tarun Gupta <targupta@nvidia.com>
Message-Id: <20210418122251.88809-1-targupta@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-06-18 08:38:04 -06:00