Jeff Cody [Thu, 20 Sep 2012 19:13:19 +0000 (15:13 -0400)]
block: Framework for reopening files safely
This is based on Supriya Kannery's bdrv_reopen() patch series.
This provides a transactional method to reopen multiple
images files safely.
Image files are queue for reopen via bdrv_reopen_queue(), and the
reopen occurs when bdrv_reopen_multiple() is called. Changes are
staged in bdrv_reopen_prepare() and in the equivalent driver level
functions. If any of the staged images fails a prepare, then all
of the images left untouched, and the staged changes for each image
abandoned.
Block drivers are passed a reopen state structure, that contains:
* BDS to reopen
* flags for the reopen
* opaque pointer for any driver-specific data that needs to be
persistent from _prepare to _commit/_abort
* reopen queue pointer, if the driver needs to queue additional
BDS for a reopen
Jeff Cody [Thu, 20 Sep 2012 19:13:18 +0000 (15:13 -0400)]
block: make bdrv_set_enable_write_cache() modify open_flags
bdrv_set_enable_write_cache() sets the bs->enable_write_cache flag,
but without the flag recorded in bs->open_flags, then next time
a reopen() is performed the enable_write_cache setting may be
inadvertently lost.
This will set the flag in open_flags, so it is preserved across
reopens.
Jeff Cody [Thu, 20 Sep 2012 19:13:17 +0000 (15:13 -0400)]
block: correctly set the keep_read_only flag
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
Kevin Shanahan [Thu, 20 Sep 2012 23:20:22 +0000 (08:50 +0930)]
blockdev: preserve readonly and snapshot states across media changes
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.
Stefan Weil [Sat, 22 Sep 2012 20:26:19 +0000 (22:26 +0200)]
w32: Add implementation of gmtime_r, localtime_r
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.
Blue Swirl [Sat, 22 Sep 2012 17:59:15 +0000 (17:59 +0000)]
Merge branch 'tcg-sparc' of git://repo.or.cz/qemu/rth
* '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.
Max Filippov [Wed, 19 Sep 2012 00:23:51 +0000 (04:23 +0400)]
softfloat: add NO_SIGNALING_NANS
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.
Max Filippov [Wed, 19 Sep 2012 00:23:50 +0000 (04:23 +0400)]
softfloat: make float_muladd_negate_* flags independent
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.
Stefan Weil [Thu, 13 Sep 2012 17:37:44 +0000 (19:37 +0200)]
tcg/i386: Add shortcuts for registers used in L constraint
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: Stefan Weil <[email protected]>
[aurel32: build fix on i386, small optimization for i386 in the prologue] Signed-off-by: Aurelien Jarno <[email protected]>
Stefan Weil [Thu, 13 Sep 2012 17:37:43 +0000 (19:37 +0200)]
w64: Fix TCG helper functions with 5 arguments
TCG uses 6 registers for function arguments on 64 bit Linux hosts,
but only 4 registers on W64 hosts.
Commit 2999a0b20074a7e4a58f56572bb1436749368f59 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.
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.
tcg/optimize: prefer the "op a, a, b" form for commutative ops
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.
tcg/optimize: further optimize brcond/movcond/setcond
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.
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.
tcg/optimize: do copy propagation for all operations
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.
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.
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.
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.
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.
Instead of int, use the correct TCGArg and TCGReg type: TCGReg when
representing a TCG target register, TCGArg when representing the latter
or a constant.
The 'Z' constraint has been introduced to map the zero register. However
when the op also accept a constant, there is no point to accept the zero
register in addition.
tcg-sparc: Mask shift immediates to avoid illegal insns.
The xtensa-test image generates a sra_i32 with count 0x40.
Whether this is accident of tcg constant propagation or
originating directly from the instruction stream is immaterial.
At the same time, split out the tlb load logic to a new function.
Fixes the cases of two data registers and two address registers.
Fixes the signature of, and adds missing, qemu_ld/st opcodes.
tcg-sparc: Assume v9 cpu always, i.e. force v8plus in 32-bit mode.
Current code doesn't actually work in 32-bit mode at all. Since
no one really noticed, drop the complication of v7 and v8 cpus.
Eliminate the --sparc_cpu configure option and standardize macro
testing on TCG_TARGET_REG_BITS / HOST_LONG_BITS
The address we pick in sparc64.ld is also 0x60000000, so doing a fixed map
on top of that is guaranteed to blow up. Choosing 0x40000000 is exactly
right for the max of code_gen_buffer_size set below.
No need to ever use MAP_FIXED. While getting our desired address helps
optimize the generated code, we won't fail if we don't get it.
When host and target have differing alignment rules, using a cast
and direct memory operation can result in SIGBUS. Use memcpy instead,
which the compiler will happily optimize when alignment is satisfied.
Merge branch 'usb.65' of git://git.kraxel.org/qemu
* 'usb.65' of git://git.kraxel.org/qemu:
uhci: Don't queue up packets after one with the SPD flag set
usb-redir: Revert usb-redir part of commit 93bfef4c
usb-redir: Add chardev open / close debug logging
usb-redir: Add support for migration
usb-redir: Store max_packet_size in endp_data
usb-redir: Add an already_in_flight packet-id queue
usb-redir: Change cancelled packet code into a generic packet-id queue
ehci: Walk async schedule before and after migration
ehci: Don't set seen to 0 when removing unseen queue-heads
configure: usbredir fixes
ehci: Don't process too much frames in 1 timer tick (v2)
ehci: Fix interrupts stopping when Interrupt Threshold Control is 8
ehci: switch to new-style memory ops
usb-host: allow emulated (non-async) control requests without USBPacket
gdbstub/sh4: fix build with USE_SOFTFLOAT_STRUCT_TYPES
We have to use different type to access float values when
USE_SOFTFLOAT_STRUCT_TYPES is defined.
Rework SH4 version of cpu_gdb_{read,write}_register() using
a single case, and fixing the coding style. Use ldll_p() and
stfl_p() to access float values.
Since commit fd4bab102 PC is restored in case of exception through code
retranslation. While it is clearly the thing to do in case it is not
not known if an helper is going to trigger an exception or not
(e.g. for load/store, FPU, etc.), it just make things slower when the
exception is already known at translation time.
Partially revert this commit and save PC in the TCG code. Set bstate to
BS_BRANCH to not generate TCG exit code. Micro-optimize the sleep
helper. Make all the exception helpers to call raise_exception and mark
it as noreturn.
It's possible swap the two 16-bit words of a 32-bit register using a
rotation. If the TCG target doesn't implement rotation, the replacement
code is similar to the previously implemented code.
The register being 32 bit long, after a shift to the right by 16 bits,
the upper 16 bit are already cleared. There is no need to call ext16u
to clear them.
addv and subv helpers implementation is directly copied from the SH4
manual and looks quite complex. It is however possible to explain it
without branches, and is therefore possible to implement it with TCG.
Max Filippov [Thu, 20 Sep 2012 22:59:50 +0000 (02:59 +0400)]
target-xtensa: don't emit extra tcg_gen_goto_tb
Unconditional gen_check_loop_end at the end of disas_xtensa_insn
can emit tcg_gen_goto_tb with slot id already used in the TB (e.g. when
TB ends at LEND with a branch).
The real problem is that the all temps states should be reset at the end
of a basic block. This was done by adding such operations in the switch,
but brcond2 was forgotten (that's why the crash was only observed on 32-bit
hosts).
Fix that by looking at the TCG_OPF_BB_END instead. We need to keep the case
for op_set_label as temps might be modified through another path.
pflash_cfi01 announces a version number of 1.1, which implies
"Protection Register Information" and "Burst Read information"
sections, which are not provided.
Decrease the version number to 1.0 so that only the "Protection
Register Information" section is needed.
Set the number of protection fields (0x3f) to 0x01, as 0x00 means 256
protections field, which makes the CFI table bigger than the current
implementation, causing some kernels to fail to read it.
set_label is effectively the end of a basic block, as no optimization
can be made accross it. It was treated as such in the liveness analysis
code, but as a special case.
Mark it with TCG_OPF_BB_END flag so that this information can be used
by other parts of the TCG code, and remove the special case in the liveness
analysis code.
Peter Maydell [Wed, 19 Sep 2012 13:51:38 +0000 (14:51 +0100)]
arch_init.c: Improve '-soundhw help' for non-HAS_AUDIO_CHOICE archs
For architectures which don't set HAS_AUDIO_CHOICE, improve the
'-soundhw help' message so that it doesn't simply print an empty
list, implying no sound support at all.
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