I believe the bs->keep_read_only flag is supposed to reflect
the initial open state of the device. If the device is initially
opened R/O, then commit operations, or reopen operations changing
to R/W, are prohibited.

Currently, the keep_read_only flag is only accurate for the active
layer, and its backing file. Subsequent images end up always having
the keep_read_only flag set.

For instance, what happens now:

[  base  ]  kro = 1, ro = 1
    |
    v
[ snap-1 ]  kro = 1, ro = 1
    |
    v
[ snap-2 ]  kro = 0, ro = 1
    |
    v
[ active ]  kro = 0, ro = 0

What we want:

[  base  ]  kro = 0, ro = 1
    |
    v
[ snap-1 ]  kro = 0, ro = 1
    |
    v
[ snap-2 ]  kro = 0, ro = 1
    |
    v
[ active ]  kro = 0, ro = 0
Signed-off-by: NJeff Cody <jcody@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

If readonly=on is given at device creation time, the ->readonly flag
needs to be set in the block driver state for this device so that
readonly-ness is preserved across media changes (qmp change command).
Similarly, to preserve the snapshot property requires ->open_flags to
be correct.
Signed-off-by: NKevin Shanahan <kmshanah@disenchant.net>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Those functions are missing in MinGW.

Some versions of MinGW-w64 include defines for gmtime_r and localtime_r.
Older versions of these macros are buggy (they return a pointer to a
static variable), therefore we don't want them. Newer versions are
similar to the code used here, but without the memset.

The implementation which is used here is not strictly reentrant,
but sufficiently good for QEMU on w32 or w64.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
[blauwirbel@gmail.com: added comment about locking]
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

smatch report:
audio/audio_template.h:416 AUD_open_out(18) warn:
 variable dereferenced before check 'as' (see line 414)

Moving the ldebug statement after the statement which checks 'as'
fixes that warning.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: Nmalc <av1474@comtv.ru>

* 'tcg-sparc' of git://repo.or.cz/qemu/rth:
  tcg-sparc: Preserve branch destinations during retranslation
  tcg-sparc: Fix and enable direct TB chaining.
  tcg-sparc: Add %g/%o registers to alloc_order
  tcg-sparc: Use defines for temporaries.
  tcg-sparc: Mask shift immediates to avoid illegal insns.
  tcg-sparc: Clean up cruft stemming from attempts to use global registers.
  tcg-sparc: Change AREG0 in generated code to %i0.
  tcg-sparc: Support GUEST_BASE.
  tcg-sparc: Fix qemu_ld/st to handle 32-bit host.
  tcg-sparc: Assume v9 cpu always, i.e. force v8plus in 32-bit mode.
  tcg-sparc: Don't MAP_FIXED on top of the program
  tcg-sparc: Fix ADDX opcode.
  tcg-sparc: Hack in qemu_ld/st64 for 32-bit.
  linux-user: Use memcpy in get_user/put_user.

In case Coprocessor Context option is enabled CPENABLE SR bits control
whether access to coprocessors is allowed or would rise one of
CoprocessorXDisabled exceptions.

See ISA, 4.4.5 for more details.

FP is coprocessor 0.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

These are comparison and conditional move opcodes.
See ISA, 4.3.10 for more details.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

These are FP to integer and integer to FP conversion opcodes.
See ISA, 4.3.10 for more details.

Note that ISA description for utrunc.s is currently incorrect and will
be fixed in future revisions.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

These are FP arithmetic opcodes.
See ISA, 4.3.10 for more details.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

These are load/store instructions for FP registers with immediate or
register index and optional base post-update.
See ISA, 4.3.10 for more details.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

There are 16 32-bit FP registers (f0 - f15), control and status user
registers (fcr, fsr).

See ISA, 4.3.10 for more details.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

NaN propagation rule: leftmost NaN in the expression gets propagated to
the result.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Architectures that don't have signaling NaNs can define
NO_SIGNALING_NANS, it will make float*_is_quiet_nan return 1 for any NaN
and float*_is_signaling_nan always return 0.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Flags passed into float{32,64}_muladd are treated as bits; assign
independent bits to float_muladd_negate_* to allow precise control over
what gets negated in float{32,64}_muladd.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

This reverts commit ad49d1f7.

This commit was not supposed to be pushed.
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Thanks to Richard Henderson
Signed-off-by: Nmalc <av1474@comtv.ru>

The TCG targets no longer need individual implementations.

Since commit 6a18ae2d,
'flags' is no longer used in tcg_target_get_call_iarg_regs_count.

The remaining tcg_target_get_call_iarg_regs_count is trivial and only
called once. Therefore the patch eliminates it completely.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

32 bit x86 hosts don't need registers for helper function arguments
because they use the default stack based calling convention.

Removing the registers allows simpler code for function
tcg_target_get_call_iarg_regs_count.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

While 64 bit hosts use the first three registers which are also used
as function input parameters, 32 bit hosts use TCG_REG_EAX and
TCG_REG_EDX which are not used in parameter passing.

After defining new register macros for the registers used in L
constraint, the patch replaces most occurrences of
tcg_target_call_iarg_regs[0], tcg_target_call_iarg_regs[1] and
tcg_target_call_iarg_regs[2] by those new macros.

tcg_target_call_iarg_regs remains unchanged when it is used for input
arguments (only with 64 bit hosts) before tcg_out_calli.

A comment related to those registers was fixed, too.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
[aurel32: build fix on i386, small optimization for i386 in the prologue]
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

TCG uses 6 registers for function arguments on 64 bit Linux hosts,
but only 4 registers on W64 hosts.

Commit 2999a0b2 increased the number
of arguments for some important helper functions from 4 to 5
which triggered a bug for W64 hosts: QEMU aborts when executing
helper_lcall_real in the guest's BIOS because function
tcg_target_get_call_iarg_regs_count always returned 6.

As W64 has only 4 registers for arguments, the 5th argument must be
passed on the stack using a correct stack offset.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

See
http://lists.nongnu.org/archive/html/qemu-devel/2012-09/msg03196.html
for the whole story.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Signed-off-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Commit 25c4d9cc changed all TCGOpcode enums to be available, so we don't
need to #ifdef #endif the one that are available only on some targets.
This makes the code easier to read.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

The "op a, a, b" form is better handled on non-RISC host than the "op
a, b, a" form, so swap the arguments to this form when possible, and
when b is not a constant.

This reduces the number of generated instructions by a tiny bit.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

When both argument of brcond/movcond/setcond are the same or when one
of the two values is a constant equal to zero, it's possible to do
further optimizations.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Now that it's possible to detect copies, we can optimize the case
the "op r, a, a => movi r, 0". This helps in the computation of
overflow flags when one of the two args is 0.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Now that we can easily detect all copies, we can optimize the
"op r, a, a => mov r, a" case a bit more.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

It is possible to due copy propagation for all operations, even the one
that have side effects or clobber arguments (it only concerns input
arguments). That said, the call operation should be handled differently
due to the variable number of arguments.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

The copy propagation pass tries to keep track what is a copy of what
and what has copy of what, and in addition it keep a circular list of
of all the copies. Unfortunately this doesn't fully work: a mov from
a temp which has a state "COPY" changed it into a state "HAS_COPY".
Later when this temp is used again, it is considered has not having
copy and thus no propagation is done.

This patch fixes that by removing the hiearchy between copies, and thus
only keeping a "COPY" state both meaning "is a copy" and "has a copy".
The decision of which copy to use is deferred to the actual temp
replacement. At this stage there is not one best choice to do, but only
better choices than others. For doing the best choice the operation
would have to be parsed in reversed to know if a temp is going to be
used later or not. That what is done by the liveness analysis. At this
stage it is known that globals will be always live, that local temps
will be dead at the end of the translation block, and that the temps
will be dead at the end of the basic block. This means that this stage
should try to replace temps by local temps or globals and local temps
by globals.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

The copy propagation doesn't check the types of the temps during copy
propagation. However TCG is using the mov_i32 for the i64 to i32
conversion and thus the two are not equivalent.

With this patch tcg_opt_gen_mov() doesn't consider two temps of
different type as copies anymore.

So far it seems the optimization was not aggressive enough to trigger
this bug, but it will be triggered later in this series once the copy
propagation is improved.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

TCG_TEMP_ANY has no different meaning than TCG_TEMP_UNDEF, so use
the later instead.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

movcond operation can be implemented on MIPS32 Release 2 using the MOVN,
MOVZ, SLT and SLTU instructions.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

deposit operations can be optimized on MIPS32 Release 2 using the INS
instruction.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

rotr operations can be optimized on MIPS32 Release 2 using the ROTR and
ROTRV instructions. Also implemented rotl operations by subtracting the
shift from 32.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

bswap operations can be optimized on MIPS32 Release 2 using the ROTR,
WSBH and SEH instructions. We can't use the non-R2 code to implement the
ops due to registers constraints, so don't define the corresponding
TCG_TARGET_HAS_bswap* values.

Also bswap16* operations are supposed to be called with the 16 high bits
zeroed. This is the case everywhere (including for TCG by definition)
except when called from the store helper. Remove the AND instructions from
bswap16* and move it there.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

MIPS has some conditional branch instructions when comparing with zero.
Use them.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Use stack instead of temp_buf array in CPUState for TCG
temps.
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>