Hexagon (target/hexagon) add A4_addp_c/A4_subp_c

Rdd32 = add(Rss32, Rtt32, Px4):carry
    Add with carry
Rdd32 = sub(Rss32, Rtt32, Px4):carry
    Sub with carry

Test cases in tests/tcg/hexagon/multi_result.c

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-22-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) add A6_vminub_RdP

Rdd32,Pe4 = vminub(Rtt32, Rss32)
    Vector min of bytes

Test cases in tests/tcg/hexagon/multi_result.c

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-21-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) add A5_ACS (vacsh)

Rxx32,Pe4 = vacsh(Rss32, Rtt32)
    Add compare and select elements of two vectors

Test cases in tests/tcg/hexagon/multi_result.c

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-20-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) add F2_sfinvsqrta

Rd32,Pe4 = sfinvsqrta(Rs32)
    Square root approx

The helper packs the 2 32-bit results into a 64-bit value,
and the fGEN_TCG override unpacks them into the proper results.

Test cases in tests/tcg/hexagon/multi_result.c
FP exception tests added to tests/tcg/hexagon/fpstuff.c

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-19-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) add F2_sfrecipa instruction

Rd32,Pe4 = sfrecipa(Rs32, Rt32)
    Recripocal approx

Test cases in tests/tcg/hexagon/multi_result.c
FP exception tests added to tests/tcg/hexagon/fpstuff.c

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-18-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) compile all debug code

Change #if HEX_DEBUG to if (HEX_DEBUG) so the debug code doesn't bit rot

Suggested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-17-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) move QEMU_GENERATE to only be on during macros.h

Suggested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-16-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) cleanup reg_field_info definition

Include size in declaration
Remove {0, 0} entry

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-15-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) cleanup ternary operators in semantics

Change  (cond ? (res = x) : (res = y)) to res = (cond ? x : y)

This makes the semnatics easier to for idef-parser to deal with

The following instructions are impacted
    C2_any8
    C2_all8
    C2_mux
    C2_muxii
    C2_muxir
    C2_muxri

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-14-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) use softfloat for float-to-int conversions

Use the proper return for helpers that convert to unsigned
Remove target/hexagon/conv_emu.[ch]

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-13-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) replace float32_mul_pow2 with float32_scalbn

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-12-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) use softfloat default NaN and tininess

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-11-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) change type of softfloat_roundingmodes

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-10-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) remove unused carry_from_add64 function

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-9-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) change variables from int to bool when appropriate

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-8-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) decide if pred has been written at TCG gen time

Multiple writes to the same preg are and'ed together.  Rather than
generating a runtime check, we can determine at TCG generation time
if the predicate has previously been written in the packet.

Test added to tests/tcg/hexagon/misc.c

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-7-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) properly generate TB end for DISAS_NORETURN

When exiting a TB, generate all the code before returning from
hexagon_tr_translate_packet so that nothing needs to be done in
hexagon_tr_tb_stop.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-6-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) use env_archcpu and env_cpu

Remove hexagon_env_get_cpu and replace with env_archcpu
Replace CPU(hexagon_env_get_cpu(env)) with env_cpu(env)

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-5-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) remove unnecessary inline directives

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-4-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) cleanup gen_log_predicated_reg_write_pair

Similar to previous cleanup of gen_log_predicated_reg_write

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-3-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Hexagon (target/hexagon) TCG generation cleanup

Simplify TCG generation of hex_reg_written

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1617930474-31979-2-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

target/hexagon: remove unnecessary semicolons

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reported-by: Richard Henderson <<richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <1615784100-26459-1-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

target/hexagon: fix typo in comment

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <1615784115-26559-1-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

target/hexagon: Change DECODE_MAPPED_REG operand name to OPNUM

Reported-by: Richard Henderson <<richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <1615784049-26215-1-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

target/hexagon: remove unnecessary checks in find_iclass_slots

Reported-by: Richard Henderson <<richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <1615784037-26129-1-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

target/hexagon: translation changes

Change cpu_ldl_code to translator_ldl.
Don't end the TB after every packet when HEX_DEBUG is on.
Make gen_check_store_width a simple call.

Reported-by: Richard Henderson <<richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <1615783984-25918-1-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2021-04-30' into staging

QAPI patches patches for 2021-04-30

# gpg: Signature made Fri 30 Apr 2021 12:42:32 BST
# gpg:                using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg:                issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-qapi-2021-04-30: (25 commits)
  qapi/error.py: enable mypy checks
  qapi/error: Add type hints
  qapi/error.py: enable pylint checks
  qapi/error.py: move QAPIParseError to parser.py
  qapi/error: assert QAPISourceInfo is not None
  qapi/error: Make QAPISourceError 'col' parameter optional
  qapi/error: Use Python3-style super()
  qapi/error: Repurpose QAPIError as an abstract base exception class
  qapi/expr: Update authorship and copyright information
  qapi/expr.py: Use tuples instead of lists for static data
  qapi/expr.py: Add docstrings
  qapi/expr: Only explicitly prohibit 'Kind' nor 'List' for type names
  qapi/expr.py: enable pylint checks
  qapi/expr.py: Remove single-letter variable
  qapi/expr.py: Consolidate check_if_str calls in check_if
  qapi/expr.py: add type hint annotations
  qapi/expr.py: Modify check_keys to accept any Collection
  qapi/expr.py: Add casts in a few select cases
  qapi/expr.py: Check type of union and alternate 'data' member
  qapi/expr.py: move string check upwards in check_type
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches

- Fix permission update order problems with block graph changes
- qemu-img convert: Unshare write permission for source
- vhost-user-blk: Fail gracefully on too large queue size

# gpg: Signature made Fri 30 Apr 2021 11:27:51 BST
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (39 commits)
  vhost-user-blk: Fail gracefully on too large queue size
  qemu-img convert: Unshare write permission for source
  block: Add BDRV_O_NO_SHARE for blk_new_open()
  block: refactor bdrv_node_check_perm()
  block: rename bdrv_replace_child_safe() to bdrv_replace_child()
  block: refactor bdrv_child_set_perm_safe() transaction action
  block: inline bdrv_replace_child()
  block: inline bdrv_check_perm_common()
  block: drop unused permission update functions
  block: bdrv_reopen_multiple: refresh permissions on updated graph
  block: bdrv_reopen_multiple(): move bdrv_flush to separate pre-prepare
  block: add bdrv_set_backing_noperm() transaction action
  block: make bdrv_refresh_limits() to be a transaction action
  block: make bdrv_unset_inherits_from to be a transaction action
  block: drop ignore_children for permission update functions
  block/backup-top: drop .active
  block: introduce bdrv_drop_filter()
  block: add bdrv_remove_filter_or_cow transaction action
  block: adapt bdrv_append() for inserting filters
  block: split out bdrv_replace_node_noperm()
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

qapi/error.py: enable mypy checks

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421192233.3542904-9-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/error: Add type hints

No functional change.

Note: QAPISourceError's info parameter is Optional[] because schema.py
treats the info property of its various classes as Optional to
accommodate built-in types, which have no source. See prior commit
'qapi/error: assert QAPISourceInfo is not None'.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421192233.3542904-8-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/error.py: enable pylint checks

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421192233.3542904-7-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/error.py: move QAPIParseError to parser.py

Keeping it in error.py will create some cyclic import problems when we
add types to the QAPISchemaParser. Callers don't need to know the
details of QAPIParseError unless they are parsing or dealing directly
with the parser, so this won't create any harsh new requirements for
callers in the general case.

Update error.py with a little docstring that gives a nod to where the
error may now be found.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421192233.3542904-6-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/error: assert QAPISourceInfo is not None

Built-in stuff is not parsed from a source file, and therefore have no
QAPISourceInfo. If such None info was used for reporting an error,
built-in stuff would be broken. Programming error. Instead of reporting
a confusing error with bogus source location then, we better crash.

We currently crash only if self.col was set. Assert that self.info is
not None in order to crash reliably.

We can not yet change the type of the initializer to prove this cannot
happen at static analysis time before the remainder of the code is fully
typed.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421192233.3542904-5-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/error: Make QAPISourceError 'col' parameter optional

It's already treated as optional, with one direct caller and some
subclass callers passing 'None'. Make it officially optional, which
requires moving the position of the argument to come after all required
parameters.

QAPISemError becomes functionally identical to QAPISourceError. Keep the
name to preserve its semantic meaning and avoid code churn, but remove
the now-useless __init__ wrapper.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421192233.3542904-4-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/error: Use Python3-style super()

Missed in commit 2cae67bcb5 "qapi: Use super() now we have Python 3".

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210421192233.3542904-3-jsnow@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/error: Repurpose QAPIError as an abstract base exception class

Rename QAPIError to QAPISourceError, and then create a new QAPIError
class that serves as the basis for all of our other custom exceptions,
without specifying any class properties.

This leaves QAPIError as a package-wide error class that's suitable for
any current or future errors.

(Right now, we don't have any errors that DON'T also want to specify a
Source location, but this MAY change. In these cases, a common abstract
ancestor would be desired.)

Add docstrings to explain the intended function of each error class.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421192233.3542904-2-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr: Update authorship and copyright information

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421182032.3521476-18-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr.py: Use tuples instead of lists for static data

It is -- maybe -- possibly -- three nanoseconds faster.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20210421182032.3521476-17-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr.py: Add docstrings

Now with more :words:!

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421182032.3521476-16-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr: Only explicitly prohibit 'Kind' nor 'List' for type names

Per list review: qapi-code-gen.txt reserves suffixes Kind and
List only for type names, but the code rejects them for events and
commands, too.

It turns out we reject them earlier anyway: In check_name_upper() for
event names, and in check_name_lower() for command names.

Still, adjust the code for clarity over what precisely we are guarding
against.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421182032.3521476-15-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr.py: enable pylint checks

Signed-off-by: John Snow <jsnow@redhat.com>
Tested-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Tested-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20210421182032.3521476-14-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr.py: Remove single-letter variable

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421182032.3521476-13-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr.py: Consolidate check_if_str calls in check_if

This is a small rewrite to address some minor style nits.

Don't compare against the empty list to check for the empty condition, and
move the normalization forward to unify the check on the now-normalized
structure.

With the check unified, the local nested function isn't needed anymore
and can be brought down into the normal flow of the function. With the
nesting level changed, shuffle the error strings around a bit to get
them to fit in 79 columns.

Note: although ifcond is typed as Sequence[str] elsewhere, we *know* that
the parser will produce real, bona-fide lists. It's okay to check
isinstance(ifcond, list) here.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421182032.3521476-12-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr.py: add type hint annotations

Annotations do not change runtime behavior.
This commit *only* adds annotations.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421182032.3521476-11-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr.py: Modify check_keys to accept any Collection

This is a minor adjustment that lets parameters @required and
@optional take tuple arguments, in particular ().  Later patches will
make use of that.

(Iterable would also have worked, but Iterable also includes things like
generator expressions which are consumed upon iteration, which would
require a rewrite to make sure that each input was only traversed
once. Collection implies the "can re-iterate" property.)

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421182032.3521476-10-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr.py: Add casts in a few select cases

Casts are instructions to the type checker only, they aren't "safe" and
should probably be avoided in general. In this case, when we perform
type checking on a nested structure, the type of each field does not
"stick".

(See PEP 647 for an example of "type narrowing" that does "stick".
 It is available in Python 3.10, so we can't use it yet.)

We don't need to assert that something is a str if we've already checked
or asserted that it is -- use a cast instead for these cases.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421182032.3521476-9-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr.py: Check type of union and alternate 'data' member

Prior to this commit, specifying a non-object value here causes the QAPI
parser to crash in expr.py with a stack trace with (likely) an
AttributeError when we attempt to call that value's items() method.

This member needs to be an object (Dict), and not anything else. Add a
check for this with a nicer error message, and formalize that check with
new test cases that exercise that error.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421182032.3521476-8-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr.py: move string check upwards in check_type

For readability purposes only, shimmy the early return upwards to the
top of the function, so cases proceed in order from least to most
complex.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20210421182032.3521476-7-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr.py: Add assertion for union type 'check_dict'

mypy isn't fond of allowing you to check for bool membership in a
collection of str elements. Guard this lookup for precisely when we were
given a name.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20210421182032.3521476-6-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr.py: constrain incoming expression types

mypy does not know the types of values stored in Dicts that masquerade
as objects. Help the type checker out by constraining the type.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421182032.3521476-5-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr.py: Check for dict instead of OrderedDict

OrderedDict is a subtype of dict, so we can check for a more general
form. These functions do not themselves depend on it being any
particular type.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20210421182032.3521476-4-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr.py: Remove 'info' argument from nested check_if_str

The function can just use the argument from the scope above. Otherwise,
we get shadowed argument errors because the parameter name clashes with
the name of a variable already in-scope.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20210421182032.3521476-3-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/expr: Comment cleanup

The linter yaps after 0825f62c842. Fix this trivial issue to restore the
linter baseline.

(Yes, ideally -- and soon -- the linter will be part of CI so we don't
clutter up the log with fixups. For now, though, the baseline is useful
for testing intermediate commits as types are added to the QAPI
library.)

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20210421182032.3521476-2-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20210430' into staging

target-arm queue:
 * hw/pci-host/gpex: Don't fault for unmapped parts of MMIO and PIO windows
 * hw: add compat machines for 6.1
 * Fault misaligned accesses where the architecture requires it
 * Fix some corner cases of MTE faults (notably with misaligned accesses)
 * Make Thumb store insns UNDEF for Rn==1111
 * hw/arm/smmuv3: Support 16K translation granule

# gpg: Signature made Fri 30 Apr 2021 11:33:45 BST
# gpg:                using RSA key E1A5C593CD419DE28E8315CF3C2525ED14360CDE
# gpg:                issuer "peter.maydell@linaro.org"
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>" [ultimate]
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>" [ultimate]
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>" [ultimate]
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83  15CF 3C25 25ED 1436 0CDE

* remotes/pmaydell/tags/pull-target-arm-20210430: (43 commits)
  hw/pci-host/gpex: Don't fault for unmapped parts of MMIO and PIO windows
  hw: add compat machines for 6.1
  target/arm: Enforce alignment for sve LD1R
  target/arm: Enforce alignment for aa64 vector LDn/STn (single)
  target/arm: Enforce alignment for aa64 vector LDn/STn (multiple)
  target/arm: Use MemOp for size + endian in aa64 vector ld/st
  target/arm: Enforce alignment for aa64 load-acq/store-rel
  target/arm: Use finalize_memop for aa64 fpr load/store
  target/arm: Use finalize_memop for aa64 gpr load/store
  target/arm: Enforce alignment for VLDn/VSTn (single)
  target/arm: Enforce alignment for VLDn/VSTn (multiple)
  target/arm: Enforce alignment for VLDn (all lanes)
  target/arm: Enforce alignment for VLDR/VSTR
  target/arm: Enforce alignment for VLDM/VSTM
  target/arm: Enforce alignment for SRS
  target/arm: Enforce alignment for RFE
  target/arm: Enforce alignment for LDM/STM
  target/arm: Enforce alignment for LDA/LDAH/STL/STLH
  target/arm: Enforce word alignment for LDRD/STRD
  target/arm: Adjust gen_aa32_{ld, st}_i64 for align+endianness
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

vhost-user-blk: Fail gracefully on too large queue size

virtio_add_queue() aborts when queue_size > VIRTQUEUE_MAX_SIZE, so
vhost_user_blk_device_realize() should check this before calling it.

Simple reproducer:

qemu-system-x86_64 \
    -chardev null,id=foo \
    -device vhost-user-blk-pci,queue-size=4096,chardev=foo

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1935014
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210413165654.50810-1-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

qemu-img convert: Unshare write permission for source

For a successful conversion of an image, we must make sure that its
content doesn't change during the conversion.

A special case of this is using the same image file both as the source
and as the destination. If both input and output format are raw, the
operation would just be useless work, with other formats it is a sure
way to destroy the image. This will now fail because the image file
can't be opened a second time for the output when opening it for the
input has already acquired file locks to unshare BLK_PERM_WRITE.

Nevertheless, if there is some reason in a special case why it is
actually okay to allow writes to the image while it is being converted,
-U can still be used to force sharing all permissions.

Note that for most image formats, BLK_PERM_WRITE would already be
unshared by the format driver, so this only really makes a difference
for raw source images (but any output format).

Reported-by: Xueqiang Wei <xuwei@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210422164344.283389-3-kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: Add BDRV_O_NO_SHARE for blk_new_open()

Normally, blk_new_open() just shares all permissions. This was fine
originally when permissions only protected against uses in the same
process because no other part of the code would actually get to access
the block nodes opened with blk_new_open(). However, since we use it for
file locking now, unsharing permissions becomes desirable.

Add a new BDRV_O_NO_SHARE flag that is used in blk_new_open() to unshare
any permissions that can be unshared.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210422164344.283389-2-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: refactor bdrv_node_check_perm()

Now, bdrv_node_check_perm() is called only with fresh cumulative
permissions, so its actually "refresh_perm".

Move permission calculation to the function. Also, drop unreachable
error message and rewrite the remaining one to be more generic (as now
we don't know which node is added and which was already here).

Add also Virtuozzo copyright, as big work is done at this point.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-37-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: rename bdrv_replace_child_safe() to bdrv_replace_child()

We don't have bdrv_replace_child(), so it's time for
bdrv_replace_child_safe() to take its place.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-36-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: refactor bdrv_child_set_perm_safe() transaction action

Old interfaces dropped, nobody directly calls
bdrv_child_set_perm_abort() and bdrv_child_set_perm_commit(), so we can
use personal state structure for the action and stop exploiting
BdrvChild structure. Also, drop "_safe" suffix which is redundant now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-35-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: inline bdrv_replace_child()

bdrv_replace_child() has only one caller, the second argument is
unused. Inline it now. This triggers deletion of some more unused
interfaces.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-34-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: inline bdrv_check_perm_common()

bdrv_check_perm_common() has only one caller, so no more sense in
"common".

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-33-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: drop unused permission update functions

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-32-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: bdrv_reopen_multiple: refresh permissions on updated graph

Move bdrv_reopen_multiple to new paradigm of permission update:
first update graph relations, then do refresh the permissions.

We have to modify reopen process in file-posix driver: with new scheme
we don't have prepared permissions in raw_reopen_prepare(), so we
should reconfigure fd in raw_check_perm(). Still this seems more native
and simple anyway.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-31-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: bdrv_reopen_multiple(): move bdrv_flush to separate pre-prepare

During reopen we may add backing bs from other aio context, which may
lead to changing original context of top bs.

We are going to move graph modification to prepare stage. So, it will
be possible that bdrv_flush() in bdrv_reopen_prepare called on bs in
non-original aio context, which we didn't aquire which leads to crash.

To avoid this problem move bdrv_flush() to be a separate reopen stage
before bdrv_reopen_prepare().

This doesn't seem correct to acquire only one aio context and not all
contexts participating in reopen. But it's not obvious how to do it
correctly, keeping in mind:

 1. rules of bdrv_set_aio_context_ignore() that requires new_context
    lock not being held

 2. possible deadlocks because of holding all (or several?) AioContext
    locks

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-30-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: add bdrv_set_backing_noperm() transaction action

Split out no-perm part of bdrv_set_backing_hd() as a separate
transaction action. Note the in case of existing BdrvChild we reuse it,
not recreate, just to do less actions.

We don't need to create extra reference to backing_hd as we don't lose
it in bdrv_attach_child().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-29-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: make bdrv_refresh_limits() to be a transaction action

To be used in further commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-28-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: make bdrv_unset_inherits_from to be a transaction action

To be used in the further commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-27-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: drop ignore_children for permission update functions

This argument is always NULL. Drop it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-26-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/backup-top: drop .active

We don't need this workaround anymore: bdrv_append is already smart
enough and we can use new bdrv_drop_filter().

This commit efficiently reverts also recent 705dde27c6c53b73, which
checked .active on io path. Still it said that the problem should be
theoretical. And the logic of filter removement is changed anyway.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-25-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: introduce bdrv_drop_filter()

Using bdrv_replace_node() for removing filter is not good enough: it
keeps child reference of the filter, which may conflict with original
top node during permission update.

Instead let's create new interface, which will do all graph
modifications first and then update permissions.

Let's modify bdrv_replace_node_common(), allowing it additionally drop
backing chain child link pointing to new node. This is quite
appropriate for bdrv_drop_intermediate() and makes possible to add
new bdrv_drop_filter() as a simple wrapper.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-24-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: add bdrv_remove_filter_or_cow transaction action

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-23-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: adapt bdrv_append() for inserting filters

bdrv_append is not very good for inserting filters: it does extra
permission update as part of bdrv_set_backing_hd(). During this update
filter may conflict with other parents of top_bs.

Instead, let's first do all graph modifications and after it update
permissions.

append-greedy-filter test-case in test-bdrv-graph-mod is now works, so
move it out of debug option.

Note: bdrv_append() is still only works for backing-child based
filters. It's something to improve later.

Note2: we use the fact that bdrv_append() is used to append new nodes,
without backing child, so we don't need frozen check and inherits_from
logic from bdrv_set_backing_hd().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-22-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: split out bdrv_replace_node_noperm()

Split part of bdrv_replace_node_common() to be used separately.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-21-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: add bdrv_attach_child_noperm() transaction action

Split no-perm part of bdrv_attach_child as separate transaction action.
It will be used in later commits.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-20-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: add bdrv_attach_child_common() transaction action

Split out no-perm part of bdrv_root_attach_child() into separate
transaction action. bdrv_root_attach_child() now moves to new
permission update paradigm: first update graph relations then update
permissions.

qsd-jobs test output updated. Seems now permission update goes in
another order. Still, the test comment say that we only want to check
that command doesn't crash, and it's still so.

Error message is a bit misleading as it looks like job was added first.
But actually in new paradigm of graph update we can't distinguish such
things. We should update the error message, but let's not do it now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210428151804.439460-19-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: fix bdrv_replace_node_common

inore_children thing doesn't help to track all propagated permissions
of children we want to ignore. The simplest way to correctly update
permissions is update graph first and then do permission update. In
this case we just referesh permissions for the whole subgraph (in
topological-sort defined order) and everything is correctly calculated
automatically without any ignore_children.

So, refactor bdrv_replace_node_common to first do graph update and then
refresh the permissions.

Test test_parallel_exclusive_write() now pass, so move it out of
debugging "if".

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-18-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: add bdrv_replace_child_safe() transaction action

To be used in the following commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-17-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: add bdrv_list_* permission update functions

Add new interface, allowing use of existing node list. It will be used
to fix bdrv_replace_node() in the further commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-16-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: add bdrv_drv_set_perm transaction action

Refactor calling driver callbacks to a separate transaction action to
be used later.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-15-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: use topological sort for permission update

Rewrite bdrv_check_perm(), bdrv_abort_perm_update() and bdrv_set_perm()
to update nodes in topological sort order instead of simple DFS. With
topologically sorted nodes, we update a node only when all its parents
already updated. With DFS it's not so.

Consider the following example:

    A -+
    |  |
    |  v
    |  B
    |  |
    v  |
    C<-+

A is parent for B and C, B is parent for C.

Obviously, to update permissions, we should go in order A B C, so, when
we update C, all parent permissions already updated. But with current
approach (simple recursion) we can update in sequence A C B C (C is
updated twice). On first update of C, we consider old B permissions, so
doing wrong thing. If it succeed, all is OK, on second C update we will
finish with correct graph. But if the wrong thing failed, we break the
whole process for no reason (it's possible that updated B permission
will be less strict, but we will never check it).

Also new approach gives a way to simultaneously and correctly update
several nodes, we just need to run bdrv_topological_dfs() several times
to add all nodes and their subtrees into one topologically sorted list
(next patch will update bdrv_replace_node() in this manner).

Test test_parallel_perm_update() is now passing, so move it out of
debugging "if".

We also need to support ignore_children in
bdrv_parent_perms_conflict()

For test 283 order of conflicting parents check is changed.

Note also that in bdrv_check_perm() we don't check for parents conflict
at root bs, as we may be in the middle of permission update in
bdrv_reopen_multiple(). bdrv_reopen_multiple() will be updated soon.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-14-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: inline bdrv_child_*() permission functions calls

Each of them has only one caller. Open-coding simplifies further
pemission-update system changes.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-13-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: rewrite bdrv_child_try_set_perm() using bdrv_refresh_perms()

We are going to drop recursive bdrv_child_* functions, so stop use them
in bdrv_child_try_set_perm() as a first step.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-12-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: refactor bdrv_child* permission functions

Split out non-recursive parts, and refactor as block graph transaction
action.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-11-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: bdrv_refresh_perms: check for parents permissions conflict

Add additional check that node parents do not interfere with each
other. This should not hurt existing callers and allows in further
patch use bdrv_refresh_perms() to update a subtree of changed
BdrvChild (check that change is correct).

New check will substitute bdrv_check_update_perm() in following
permissions refactoring, so keep error messages the same to avoid
unit test result changes.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-10-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

util: add transactions.c

Add simple transaction API to use in further update of block graph
operations.

Supposed usage is:

- "prepare" is main function of the action and it should make the main
  effect of the action to be visible for the following actions, keeping
  possibility of roll-back, saving necessary things in action state,
  which is prepended to the action list (to do that, prepare func
  should call tran_add()). So, driver struct doesn't include "prepare"
  field, as it is supposed to be called directly.

- commit/rollback is supposed to be called for the list of action
  states, to commit/rollback all the actions in reverse order

- When possible "commit" should not make visible effect for other
  actions, which make possible transparent logical interaction between
  actions.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-9-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: make bdrv_reopen_{prepare,commit,abort} private

These functions are called only from bdrv_reopen_multiple() in block.c.
No reason to publish them.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-8-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: drop ctx argument from bdrv_root_attach_child

Passing parent aio context is redundant, as child_class and parent
opaque pointer are enough to retrieve it. Drop the argument and use new
bdrv_child_get_parent_aio_context() interface.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-7-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: BdrvChildClass: add .get_parent_aio_context handler

Add new handler to get aio context and implement it in all child
classes. Add corresponding public interface to be used soon.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-6-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block: bdrv_append(): don't consume reference

We have too much comments for this feature. It seems better just don't
do it. Most of real users (tests don't count) have to create additional
reference.

Drop also comment in external_snapshot_prepare:
 - bdrv_append doesn't "remove" old bs in common sense, it sounds
   strange
 - the fact that bdrv_append can fail is obvious from the context
 - the fact that we must rollback all changes in transaction abort is
   known (it's the direct role of abort)

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-5-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

tests/test-bdrv-graph-mod: add test_append_greedy_filter

bdrv_append() is not quite good for inserting filters: it does extra
permission update in intermediate state, where filter get it filtered
child but is not yet replace it in a backing chain.

Some filters (for example backup-top) may want permissions even when
have no parents. And described intermediate state becomes invalid.

That's (half a) reason, why we need "inactive" state for backup-top
filter.

bdrv_append() will be improved later, now let's add a unit test.

Now test fails, so it runs only with -d flag. To run do

  ./test-bdrv-graph-mod -d -p /bdrv-graph-mod/append-greedy-filter

from <build-directory>/tests.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-4-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

tests/test-bdrv-graph-mod: add test_parallel_perm_update

Add test to show that simple DFS recursion order is not correct for
permission update. Correct order is topological-sort order, which will
be introduced later.

Consider the block driver which has two filter children: one active
with exclusive write access and one inactive with no specific
permissions.

And, these two children has a common base child, like this:

┌─────┐     ┌──────┐
│ fl2 │ ◀── │ top  │
└─────┘     └──────┘
  │           │
  │           │ w
  │           ▼
  │         ┌──────┐
  │         │ fl1  │
  │         └──────┘
  │           │
  │           │ w
  │           ▼
  │         ┌──────┐
  └───────▶ │ base │
            └──────┘

So, exclusive write is propagated.

Assume, we want to make fl2 active instead of fl1.
So, we set some option for top driver and do permission update.

If permission update (remember, it's DFS) goes first through
top->fl1->base branch it will succeed: it firstly drop exclusive write
permissions and than apply them for another BdrvChildren.
But if permission update goes first through top->fl2->base branch it
will fail, as when we try to update fl2->base child, old not yet
updated fl1->base child will be in conflict.

Now test fails, so it runs only with -d flag. To run do

  ./test-bdrv-graph-mod -d -p /bdrv-graph-mod/parallel-perm-update

from <build-directory>/tests.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-3-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

tests/test-bdrv-graph-mod: add test_parallel_exclusive_write

Add the test that shows that concept of ignore_children is incomplete.
Actually, when we want to update something, ignoring permission of some
existing BdrvChild, we should ignore also the propagated effect of this
child to the other children. But that's not done. Better approach
(update permissions on already updated graph) will be implemented
later.

Now the test fails, so it's added with -d argument to not break make
check.

Test fails with

 "Conflicts with use by fl1 as 'backing', which does not allow 'write' on base"

because when updating permissions we can ignore original top->fl1
BdrvChild. But we don't ignore exclusive write permission in fl1->base
BdrvChild, which is propagated. Correct thing to do is make graph
change first and then do permission update from the top node.

To run test do

  ./test-bdrv-graph-mod -d -p /bdrv-graph-mod/parallel-exclusive-write

from <build-directory>/tests.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-2-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

hw/pci-host/gpex: Don't fault for unmapped parts of MMIO and PIO windows

Currently the gpex PCI controller implements no special behaviour for
guest accesses to areas of the PIO and MMIO where it has not mapped
any PCI devices, which means that for Arm you end up with a CPU
exception due to a data abort.

Most host OSes expect "like an x86 PC" behaviour, where bad accesses
like this return -1 for reads and ignore writes.  In the interests of
not being surprising, make host CPU accesses to these windows behave
as -1/discard where there's no mapped PCI device.

The old behaviour generally didn't cause any problems, because
almost always the guest OS will map the PCI devices and then only
access where it has mapped them. One corner case where you will see
this kind of access is if Linux attempts to probe legacy ISA
devices via a PIO window access. So far the only case where we've
seen this has been via the syzkaller fuzzer.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Message-id: 20210325163315.27724-1-peter.maydell@linaro.org
Fixes: https://bugs.launchpad.net/qemu/+bug/1918917
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw: add compat machines for 6.1

Add 6.1 machine types for arm/i440fx/q35/s390x/spapr.

Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Greg Kurz <groug@kaod.org>
Message-id: 20210331111900.118274-1-cohuck@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm: Enforce alignment for sve LD1R

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-32-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm: Enforce alignment for aa64 vector LDn/STn (single)

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-31-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm: Enforce alignment for aa64 vector LDn/STn (multiple)

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-30-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm: Use MemOp for size + endian in aa64 vector ld/st

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-29-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm: Enforce alignment for aa64 load-acq/store-rel

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-28-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>