Commit Graph

88582 Commits

Author SHA1 Message Date
Richard Henderson
7335a3d69f tcg/i386: Support bswap flags
Retain the current rorw bswap16 expansion for the zero-in/zero-out case.
Otherwise, perform a wider bswap plus a right-shift or extend.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:57 -07:00
Richard Henderson
587195bd59 tcg: Add flags argument to bswap opcodes
This will eventually simplify front-end usage, and will allow
backends to unset TCG_TARGET_HAS_MEMORY_BSWAP without loss of
optimization.

The argument is added during expansion, not currently exposed to the
front end translators.  The backends currently only support a flags
value of either TCG_BSWAP_IZ, or (TCG_BSWAP_IZ | TCG_BSWAP_OZ),
since they all require zero top bytes and leave them that way.
At the existing call sites we pass in (TCG_BSWAP_IZ | TCG_BSWAP_OZ),
except for the flags-ignored cases of a 32-bit swap of a 32-bit
value and or a 64-bit swap of a 64-bit value, where we pass 0.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:57 -07:00
Warner Losh
4f862f79ca tcg: Use correct trap number for page faults on *BSD systems
The trap number for a page fault on BSD systems is T_PAGEFLT
not 0xe -- 0xe is used by Linux and represents the intel hardware
trap vector. The BSD kernels, however, translate this to T_PAGEFLT
in their Xpage, Xtrap0e, Xtrap14, etc fault handlers. This is true
for i386 and x86_64, though the name of the trap hanlder can very
on the flavor of BSD. As far as I can tell, Linux doesn't provide
a define for this value. Invent a new one (PAGE_FAULT_TRAP) and
use it instead to avoid uglier ifdefs.

Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Signed-off-by: Juergen Lock <nox@FreeBSD.org>
[ Rework to avoid ifdefs and expand it to i386 ]
Signed-off-by: Warner Losh <imp@bsdimp.com>
Message-Id: <20210625045707.84534-3-imp@bsdimp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:57 -07:00
LIU Zhiwei
7f05d32f58 tcg: Implement tcg_gen_vec_add{sub}32_tl
Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Message-Id: <20210624105023.3852-6-zhiwei_liu@c-sky.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:57 -07:00
LIU Zhiwei
950ee59026 tcg: Add tcg_gen_vec_shl{shr}{sar}8i_i32
Implement tcg_gen_vec_shl{shr}{sar}8i_tl by adding corresponging i32 OP.

Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Message-Id: <20210624105023.3852-5-zhiwei_liu@c-sky.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:57 -07:00
LIU Zhiwei
04f2a8bbc0 tcg: Add tcg_gen_vec_shl{shr}{sar}16i_i32
Implement tcg_gen_vec_shl{shr}{sar}16i_tl by adding corresponging i32 OP.

Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Message-Id: <20210624105023.3852-4-zhiwei_liu@c-sky.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:57 -07:00
LIU Zhiwei
448e7aa28c tcg: Add tcg_gen_vec_add{sub}8_i32
Implement tcg_gen_vec_add{sub}8_tl by adding corresponging i32 OP.

Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Message-Id: <20210624105023.3852-3-zhiwei_liu@c-sky.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:57 -07:00
LIU Zhiwei
3d066e5d80 tcg: Add tcg_gen_vec_add{sub}16_i32
Implement tcg_gen_vec_add{sub}16_tl by adding corresponding i32 OP.

Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Message-Id: <20210624105023.3852-2-zhiwei_liu@c-sky.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
5f5a05cdd9 target/cris: Do not exit tb for X_FLAG changes
We always know the exact value of X, that's all that matters.
This avoids splitting the TB e.g. between "ax" and "addq".

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
0ce97a315f target/cris: Remove dc->flagx_known
Ever since 2a44f7f173, flagx_known is always true.
Fold away all of the tests against the flag.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
3a1a80cc05 target/cris: Improve JMP_INDIRECT
Use movcond instead of brcond to set env_pc.
Discard the btarget and btaken variables to improve
register allocation and avoid unnecessary writeback.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
e0a4620c1f target/cris: Use tcg_gen_lookup_and_goto_ptr
We can use this in gen_goto_tb and for DISAS_JUMP
to indirectly chain to the next TB.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
3173715195 target/cris: Add DISAS_DBRANCH
Move delayed branch handling to tb_stop, where we can re-use other
end-of-tb code, e.g. the evaluation of flags.  Honor single stepping.
Validate that we aren't losing state by overwriting is_jmp.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
c96747521c target/cris: Add DISAS_UPDATE_NEXT
Move this pc update into tb_stop.
We will be able to re-use this code shortly.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
9e9f5ba071 target/cris: Set cpustate_changed for rfe/rfn
These insns set DISAS_UPDATE without cpustate_changed,
which isn't quite right.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
afd5a3310c target/cris: Fold unhandled X_FLAG changes into cpustate_changed
We really do this already, by including them into the same test.
This just hoists the expression up a bit.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
5899ce683e target/cris: Mark static arrays const
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
71fc4615c6 target/cris: Mark helper_raise_exception noreturn
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
330ca14bce target/cris: Convert to TranslatorOps
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
06188c8981 target/cris: Fix use_goto_tb
Do not skip the page check for user-only -- mmap/mprotect can
still change page mappings.  Only check dc->base.pc_first, not
dc->ppc -- the start page is the only one that's relevant.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
1dd09c47f6 target/cris: Mark exceptions as DISAS_NORETURN
After we've raised the exception, we have left the TB.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
a67f11b1d9 target/cris: Replace DISAS_TB_JUMP with DISAS_NORETURN
The only semantic of DISAS_TB_JUMP is that we've done goto_tb,
which is the same as DISAS_NORETURN -- we've exited the tb.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
6abfa161aa target/cris: Remove DISAS_SWI
This value is unused.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
67f69c4c15 target/cris: Add DisasContextBase to DisasContext
Migrate the is_jmp, tb and singlestep_enabled fields
from DisasContext into the base.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
3fbd28d88f target/avr: Convert to TranslatorOps
Tested-by: Michael Rolnik <mrolnik@gmail.com>
Reviewed-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
bcef6d7601 target/avr: Change ctx to DisasContext* in gen_intermediate_code
Prepare for receiving it as a pointer input.

Tested-by: Michael Rolnik <mrolnik@gmail.com>
Reviewed-by: Michael Rolnik <mrolnik@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
93d4d5e485 target/avr: Add DisasContextBase to DisasContext
Migrate the bstate, tb and singlestep_enabled fields
from DisasContext into the base.

Tested-by: Michael Rolnik <mrolnik@gmail.com>
Reviewed-by: Michael Rolnik <mrolnik@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:04:56 -07:00
Richard Henderson
77b42a2d53 target/nios2: Use pc_next for pc + 4
We have pre-computed the next instruction address into
dc->base.pc_next, so we might as well use it.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:03:11 -07:00
Richard Henderson
1ff375d743 target/nios2: Inline handle_instruction
Move handle_instruction into nios2_tr_translate_insn
as the only caller.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:02:58 -07:00
Richard Henderson
a5f919d19c target/nios2: Clean up goto in handle_instruction
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:02:49 -07:00
Richard Henderson
50e1a0cd3c target/nios2: Remove assignment to env in handle_instruction
Direct assignments to env during translation do not work.

As it happens, the only way we can get here is if env->pc
is already set to dc->pc.  We will trap on the first insn
we execute anywhere on the page.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:02:32 -07:00
Richard Henderson
d67cbd9321 target/nios2: Convert to TranslatorOps
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 10:02:05 -07:00
Richard Henderson
e9150ea523 target/nios2: Add DisasContextBase to DisasContext
Migrate the is_jmp, tb and singlestep_enabled fields from
DisasContext into the base.  Use pc_first instead of tb->pc.
Increment pc_next prior to decode, leaving the address of
the current insn in dc->pc.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 09:58:42 -07:00
Richard Henderson
438aabed0a target/nios2: Use global cpu_R
We do not need to copy this into DisasContext.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 09:57:14 -07:00
Richard Henderson
12f9387f5c target/nios2: Use global cpu_env
We do not need to copy this into DisasContext.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 09:57:14 -07:00
Richard Henderson
1cf134f1e8 target/nios2: Replace DISAS_TB_JUMP with DISAS_NORETURN
The only semantic of DISAS_TB_JUMP is that we've done goto_tb,
which is the same as DISAS_NORETURN -- we've exited the tb.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-06-29 09:57:14 -07:00
Taylor Simpson
fb858fb76b Hexagon (target/hexagon) remove unused TCG variables
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1622589584-22571-5-git-send-email-tsimpson@quicinc.com>
2021-06-29 11:32:50 -05:00
Taylor Simpson
8872533671 Hexagon (target/hexagon) cleanup gen_store_conditional[48] functions
Previously the store-conditional code was writing to hex_pred[prednum].
Then, the fGEN_TCG override was reading from there to the destination
variable so that the packet commit logic would handle it properly.

The correct implementation is to write to the destination variable
and don't have the extra read in the override.

Remove the unused arguments from gen_store_conditional[48]

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1622589584-22571-4-git-send-email-tsimpson@quicinc.com>
2021-06-29 11:32:50 -05:00
Taylor Simpson
a5a8d98c85 Hexagon (target/hexagon) fix l2fetch instructions
Y4_l2fetch == l2fetch(Rs32, Rt32)
Y5_l2fetch == l2fetch(Rs32, Rtt32)

The semantics for these instructions are present, but the encodings
are missing.

Note that these are treated as nops in qemu, so we add overrides.

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

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1622589584-22571-3-git-send-email-tsimpson@quicinc.com>
2021-06-29 11:32:50 -05:00
Taylor Simpson
07c0f65385 Hexagon (target/hexagon) fix bug in fLSBNEW*
Change fLSBNEW/fLSBNEW0/fLSBNEW1 from copy to "x & 1"
Remove gen_logical_not function
Clean up fLSBNEWNOT to use andi-1 followed by xori-1

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

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1622589584-22571-2-git-send-email-tsimpson@quicinc.com>
2021-06-29 11:32:50 -05:00
Vladimir Sementsov-Ogievskiy
7170170866 block/commit: use QEMU_AUTO_VFREE
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210628121133.193984-3-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29 16:51:21 +02:00
Vladimir Sementsov-Ogievskiy
4d324c0bf6 introduce QEMU_AUTO_VFREE
Introduce a convenient macro, that works for qemu_memalign() like
g_autofree works with g_malloc.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210628121133.193984-2-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29 16:51:21 +02:00
Alberto Garcia
4c5393f169 iotests: Test replacing files with x-blockdev-reopen
This patch adds new tests in which we use x-blockdev-reopen to change
bs->file

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20210610120537.196183-10-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29 16:51:00 +02:00
Alberto Garcia
ecd30d2d97 block: Allow changing bs->file on reopen
When the x-blockdev-reopen was added it allowed reconfiguring the
graph by replacing backing files, but changing the 'file' option was
forbidden. Because of this restriction some operations are not
possible, notably inserting and removing block filters.

This patch adds support for replacing the 'file' option. This is
similar to replacing the backing file and the user is likewise
responsible for the correctness of the resulting graph, otherwise this
can lead to data corruption.

Signed-off-by: Alberto Garcia <berto@igalia.com>
 [vsementsov: bdrv_reopen_parse_file_or_backing() is modified a lot]
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610120537.196183-9-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29 16:51:00 +02:00
Vladimir Sementsov-Ogievskiy
3d0e8743f0 block: BDRVReopenState: drop replace_backing_bs field
It's used only in bdrv_reopen_commit(). "backing" is covered by the
loop through all children except for case when we removed backing child
during reopen.

Make it more obvious and drop extra boolean field: qdict_del will not
fail if there is no such entry.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610120537.196183-8-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29 16:51:00 +02:00
Vladimir Sementsov-Ogievskiy
25f78d9e2d block: move supports_backing check to bdrv_set_file_or_backing_noperm()
Move supports_backing check of bdrv_reopen_parse_backing to called
(through bdrv_set_backing_noperm()) bdrv_set_file_or_backing_noperm()
function. The check applies to general case, so it's appropriate for
bdrv_set_file_or_backing_noperm().

We have to declare backing support for two test drivers, otherwise new
check fails.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610120537.196183-7-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29 16:51:00 +02:00
Vladimir Sementsov-Ogievskiy
cbfdb98ce2 block: bdrv_reopen_parse_backing(): simplify handling implicit filters
The logic around finding overlay here is not obvious. Actually it does
two simple things:

1. If new bs is already in backing chain, split from parent bs by
   several implicit filters we are done, do nothing.

2. Otherwise, don't try to replace implicit filter.

Let's rewrite this in more obvious way.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610120537.196183-6-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29 16:51:00 +02:00
Vladimir Sementsov-Ogievskiy
bfae052a57 block: bdrv_reopen_parse_backing(): don't check frozen child
bdrv_set_backing_noperm() takes care of it (actual check is in
bdrv_set_file_or_backing_noperm()), so we don't need to check it here.

While being here, improve error message a bit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610120537.196183-5-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29 16:51:00 +02:00
Vladimir Sementsov-Ogievskiy
fd26b8a089 block: bdrv_reopen_parse_backing(): don't check aio context
We don't need this check: bdrv_set_backing_noperm() will do it anyway
(actually in bdrv_attach_child_common()).

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610120537.196183-4-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29 16:51:00 +02:00
Vladimir Sementsov-Ogievskiy
e9238278c2 block: introduce bdrv_set_file_or_backing_noperm()
To be used for reopen in future commit.

Notes:
 - It seems OK to update inherits_from if new bs is recursively inherits
 from parent bs. Let's just not check for backing_chain_contains, to
 support file child of non-filters.

 - Simply check child->frozen instead of
   bdrv_is_backing_chain_frozen(), as we really interested only in this
   one child.

 - Role determination of new child is a bit more complex: it remains
   the same for backing child, it's obvious for filter driver. But for
   non-filter file child let's for now restrict to only replacing
   existing child (and keeping its role).

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210610120537.196183-3-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29 16:51:00 +02:00