Commit Graph

104 Commits

Author SHA1 Message Date
Markus Armbruster
2a6a4076e1 Clean up ill-advised or unusual header guards
Cleaned up with scripts/clean-header-guards.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-12 16:20:46 +02:00
Sergey Sorokin
b35399bb4e Fix confusing argument names in some common functions
There are functions tlb_fill(), cpu_unaligned_access() and
do_unaligned_access() that are called with access type and mmu index
arguments. But these arguments are named 'is_write' and 'is_user' in their
declarations. The patches fix the arguments to avoid a confusion.

Signed-off-by: Sergey Sorokin <afarallax@yandex.ru>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-id: 1465907177-1399402-1-git-send-email-afarallax@yandex.ru
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-07-12 13:06:08 +01:00
Emilio G. Cota
909eaac9bb tb hash: track translated blocks with qht
Having a fixed-size hash table for keeping track of all translation blocks
is suboptimal: some workloads are just too big or too small to get maximum
performance from the hash table. The MRU promotion policy helps improve
performance when the hash table is a little undersized, but it cannot
make up for severely undersized hash tables.

Furthermore, frequent MRU promotions result in writes that are a scalability
bottleneck. For scalability, lookups should only perform reads, not writes.
This is not a big deal for now, but it will become one once MTTCG matures.

The appended fixes these issues by using qht as the implementation of
the TB hash table. This solution is superior to other alternatives considered,
namely:

- master: implementation in QEMU before this patchset
- xxhash: before this patch, i.e. fixed buckets + xxhash hashing + MRU.
- xxhash-rcu: fixed buckets + xxhash + RCU list + MRU.
              MRU is implemented here by adding an intermediate struct
              that contains the u32 hash and a pointer to the TB; this
              allows us, on an MRU promotion, to copy said struct (that is not
              at the head), and put this new copy at the head. After a grace
              period, the original non-head struct can be eliminated, and
              after another grace period, freed.
- qht-fixed-nomru: fixed buckets + xxhash + qht without auto-resize +
                   no MRU for lookups; MRU for inserts.
The appended solution is the following:
- qht-dyn-nomru: dynamic number of buckets + xxhash + qht w/ auto-resize +
                 no MRU for lookups; MRU for inserts.

The plots below compare the considered solutions. The Y axis shows the
boot time (in seconds) of a debian jessie image with arm-softmmu; the X axis
sweeps the number of buckets (or initial number of buckets for qht-autoresize).
The plots in PNG format (and with errorbars) can be seen here:
  http://imgur.com/a/Awgnq

Each test runs 5 times, and the entire QEMU process is pinned to a
single core for repeatability of results.

                            Host: Intel Xeon E5-2690

  28 ++------------+-------------+-------------+-------------+------------++
     A*****        +             +             +             master **A*** +
  27 ++    *                                                 xxhash ##B###++
     |      A******A******                               xxhash-rcu $$C$$$ |
  26 C$$                  A******A******            qht-fixed-nomru*%%D%%%++
     D%%$$                              A******A******A*qht-dyn-mru A*E****A
  25 ++ %%$$                                          qht-dyn-nomru &&F&&&++
     B#####%                                                               |
  24 ++    #C$$$$$                                                        ++
     |      B###  $                                                        |
     |          ## C$$$$$$                                                 |
  23 ++           #       C$$$$$$                                         ++
     |             B######       C$$$$$$                                %%%D
  22 ++                  %B######       C$$$$$$C$$$$$$C$$$$$$C$$$$$$C$$$$$$C
     |                    D%%%%%%B######      @E@@@@@@    %%%D%%%@@@E@@@@@@E
  21 E@@@@@@E@@@@@@F&&&@@@E@@@&&&D%%%%%%B######B######B######B######B######B
     +             E@@@   F&&&   +      E@     +      F&&&   +             +
  20 ++------------+-------------+-------------+-------------+------------++
     14            16            18            20            22            24
                             log2 number of buckets

                                 Host: Intel i7-4790K

  14.5 ++------------+------------+-------------+------------+------------++
       A**           +            +             +            master **A*** +
    14 ++ **                                                 xxhash ##B###++
  13.5 ++   **                                           xxhash-rcu $$C$$$++
       |                                            qht-fixed-nomru %%D%%% |
    13 ++     A******                                   qht-dyn-mru @@E@@@++
       |             A*****A******A******             qht-dyn-nomru &&F&&& |
  12.5 C$$                               A******A******A*****A******    ***A
    12 ++ $$                                                        A***  ++
       D%%% $$                                                             |
  11.5 ++  %%                                                             ++
       B###  %C$$$$$$                                                      |
    11 ++  ## D%%%%% C$$$$$                                               ++
       |     #      %      C$$$$$$                                         |
  10.5 F&&&&&&B######D%%%%%       C$$$$$$C$$$$$$C$$$$$$C$$$$$C$$$$$$    $$$C
    10 E@@@@@@E@@@@@@B#####B######B######E@@@@@@E@@@%%%D%%%%%D%%%###B######B
       +             F&&          D%%%%%%B######B######B#####B###@@@D%%%   +
   9.5 ++------------+------------+-------------+------------+------------++
       14            16           18            20           22            24
                              log2 number of buckets

Note that the original point before this patch series is X=15 for "master";
the little sensitivity to the increased number of buckets is due to the
poor hashing function in master.

xxhash-rcu has significant overhead due to the constant churn of allocating
and deallocating intermediate structs for implementing MRU. An alternative
would be do consider failed lookups as "maybe not there", and then
acquire the external lock (tb_lock in this case) to really confirm that
there was indeed a failed lookup. This, however, would not be enough
to implement dynamic resizing--this is more complex: see
"Resizable, Scalable, Concurrent Hash Tables via Relativistic
Programming" by Triplett, McKenney and Walpole. This solution was
discarded due to the very coarse RCU read critical sections that we have
in MTTCG; resizing requires waiting for readers after every pointer update,
and resizes require many pointer updates, so this would quickly become
prohibitive.

qht-fixed-nomru shows that MRU promotion is advisable for undersized
hash tables.

However, qht-dyn-mru shows that MRU promotion is not important if the
hash table is properly sized: there is virtually no difference in
performance between qht-dyn-nomru and qht-dyn-mru.

Before this patch, we're at X=15 on "xxhash"; after this patch, we're at
X=15 @ qht-dyn-nomru. This patch thus matches the best performance that we
can achieve with optimum sizing of the hash table, while keeping the hash
table scalable for readers.

The improvement we get before and after this patch for booting debian jessie
with arm-softmmu is:

- Intel Xeon E5-2690: 10.5% less time
- Intel i7-4790K: 5.2% less time

We could get this same improvement _for this particular workload_ by
statically increasing the size of the hash table. But this would hurt
workloads that do not need a large hash table. The dynamic (upward)
resizing allows us to start small and enlarge the hash table as needed.

A quick note on downsizing: the table is resized back to 2**15 buckets
on every tb_flush; this makes sense because it is not guaranteed that the
table will reach the same number of TBs later on (e.g. most bootup code is
thrown away after boot); it makes sense to grow the hash table as
more code blocks are translated. This also avoids the complication of
having to build downsizing hysteresis logic into qht.

Reviewed-by: Sergey Fedorov <serge.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1465412133-3029-15-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-06-11 17:11:16 -07:00
Peter Maydell
6886b98036 cpu-exec: Rename cpu_resume_from_signal() to cpu_loop_exit_noexc()
The function cpu_resume_from_signal() is now always called with a
NULL puc argument, and is rather misnamed since it is never called
from a signal handler. It is essentially forcing an exit to the
top level cpu loop but without raising any exception, so rename
it to cpu_loop_exit_noexc() and drop the useless unused argument.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Acked-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Riku Voipio <riku.voipio@linaro.org>
Message-id: 1463494687-25947-4-git-send-email-peter.maydell@linaro.org
2016-06-09 15:55:02 +01:00
Paolo Bonzini
63c915526d cpu: move exec-all.h inclusion out of cpu.h
exec-all.h contains TCG-specific definitions.  It is not needed outside
TCG-specific files such as translate.c, exec.c or *helper.c.

One generic function had snuck into include/exec/exec-all.h; move it to
include/qom/cpu.h.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-19 16:42:29 +02:00
Paolo Bonzini
00f6da6a1a exec: extract exec/tb-context.h
TCG backends do not need most of exec-all.h; extract what they actually
need to a separate file or move it directly to tcg.h.  The next patch
will stop including exec-all.h from everywhere.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-19 16:42:29 +02:00
Sergey Fedorov
6f789be56d tcg: Rework tb_invalidated_flag
'tb_invalidated_flag' was meant to catch two events:
 * some TB has been invalidated by tb_phys_invalidate();
 * the whole translation buffer has been flushed by tb_flush().

Then it was checked:
 * in cpu_exec() to ensure that the last executed TB can be safely
   linked to directly call the next one;
 * in cpu_exec_nocache() to decide if the original TB should be provided
   for further possible invalidation along with the temporarily
   generated TB.

It is always safe to patch an invalidated TB since it is not going to be
used anyway. It is also safe to call tb_phys_invalidate() for an already
invalidated TB. Thus, setting this flag in tb_phys_invalidate() is
simply unnecessary. Moreover, it can prevent from pretty proper linking
of TBs, if any arbitrary TB has been invalidated. So just don't touch it
in tb_phys_invalidate().

If this flag is only used to catch whether tb_flush() has been called
then rename it to 'tb_flushed'. Declare it as 'bool' and stick to using
only 'true' and 'false' to set its value. Also, instead of setting it in
tb_gen_code(), just after tb_flush() has been called, do it right inside
of tb_flush().

In cpu_exec(), this flag is used to track if tb_flush() has been called
and have made 'next_tb' (a reference to the last executed TB) invalid
for linking it to directly call the next TB. tb_flush() can be called
during the CPU execution loop from tb_gen_code(), during TB execution or
by another thread while 'tb_lock' is released. Catch for translation
buffer flush reliably by resetting this flag once before first TB lookup
and each time we find it set before trying to add a direct jump. Don't
touch in in tb_find_physical().

Each vCPU has its own execution loop in multithreaded mode and thus
should have its own copy of the flag to be able to reset it with its own
'next_tb' and don't affect any other vCPU execution thread. So make this
flag per-vCPU and move it to CPUState.

In cpu_exec_nocache(), we only need to check if tb_flush() has been
called from tb_gen_code() called by cpu_exec_nocache() itself. To do
this reliably, preserve the old value of the flag, reset it before
calling tb_gen_code(), check afterwards, and combine the saved value
back to the flag.

This patch is based on the patch "tcg: move tb_invalidated_flag to
CPUState" from Paolo Bonzini <pbonzini@redhat.com>.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:42 -10:00
Sergey Fedorov
9962c478b1 tcg: Clarify thread safety check in tb_add_jump()
The check is to make sure that another thread hasn't already done the
same while we were outside of tb_lock. Mention this in a comment.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
c37e6d7e35 tcg: Use uintptr_t type for jmp_list_{next|first} fields of TB
These fields do not contain pure pointers to a TranslationBlock
structure. So uintptr_t is the most appropriate type for them.
Also put some asserts to assure that the two least significant bits of
the pointer are always zero before assigning it to jmp_list_first.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
f309101c26 tcg: Clean up direct block chaining data fields
Briefly describe in a comment how direct block chaining is done. It
should help in understanding of the following data fields.

Rename some fields in TranslationBlock and TCGContext structures to
better reflect their purpose (dropping excessive 'tb_' prefix in
TranslationBlock but keeping it in TCGContext):
   tb_next_offset  =>  jmp_reset_offset
   tb_jmp_offset   =>  jmp_insn_offset
   tb_next         =>  jmp_target_addr
   jmp_next        =>  jmp_list_next
   jmp_first       =>  jmp_list_first

Avoid using a magic constant as an invalid offset which is used to
indicate that there's no n-th jump generated.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
10b4f48555 tcg: Note requirement on atomic direct jump patching
Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <1461341333-19646-12-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
7d14e0e2d6 tcg/arm: Make direct jump patching thread-safe
Ensure direct jump patching in ARM is atomic by using
atomic_read()/atomic_set() for code patching.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-8-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
ed3d51ecd7 tcg/s390: Make direct jump patching thread-safe
Ensure direct jump patching in s390 is atomic by:
 * naturally aligning a location of direct jump address;
 * using atomic_read()/atomic_set() for code patching.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-7-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
0d07abf05e tcg/i386: Make direct jump patching thread-safe
Ensure direct jump patching in i386 is atomic by:
 * naturally aligning a location of direct jump address;
 * using atomic_read()/atomic_set() for code patching.

tcg_out_nopn() implementation:
Suggested-by: Richard Henderson <rth@twiddle.net>.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-6-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:41 -10:00
Sergey Fedorov
76442a939e tci: Make direct jump patching thread-safe
Ensure direct jump patching in TCI is atomic by:
 * naturally aligning a location of direct jump address;
 * using atomic_read()/atomic_set() to load/store the address.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-4-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-05-12 14:06:40 -10:00
Emilio G. Cota
89fee74a0f tb: consistently use uint32_t for tb->flags
We are inconsistent with the type of tb->flags: usage varies loosely
between int and uint64_t. Settle to uint32_t everywhere, which is
superior to both: at least one target (aarch64) uses the most significant
bit in the u32, and uint64_t is wasteful.

Compile-tested for all targets.

Suggested-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Suggested-by: Richard Henderson <rth@twiddle.net>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1460049562-23517-1-git-send-email-cota@braap.org>
2016-05-12 14:06:40 -10:00
Alex Bennée
d977e1c2db qemu-log: dfilter-ise exec, out_asm, op and opt_op
This ensures the code generation debug code will honour -dfilter if set.
For the "exec" tracing I've added a new inline macro for efficiency's
sake.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aureL32.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1458052224-9316-8-git-send-email-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:18 +01:00
Peter Maydell
1a83063522 qemu-log: Improve the "exec" TB execution logging
Improve the TB execution logging so that it is easier to identify
what is happening from trace logs:
 * move the "Trace" logging of executed TBs into cpu_tb_exec()
   so that it is emitted if and only if we actually execute a TB,
   and for consistency for the CPU state logging
 * log when we link two TBs together via tb_add_jump()
 * log when cpu_tb_exec() returns early from a chain of TBs

The new style logging looks like this:

Trace 0x7fb7cc822ca0 [ffffffc0000dce00]
Linking TBs 0x7fb7cc822ca0 [ffffffc0000dce00] index 0 -> 0x7fb7cc823110 [ffffffc0000dce10]
Trace 0x7fb7cc823110 [ffffffc0000dce10]
Trace 0x7fb7cc823420 [ffffffc000302688]
Trace 0x7fb7cc8234a0 [ffffffc000302698]
Trace 0x7fb7cc823520 [ffffffc0003026a4]
Trace 0x7fb7cc823560 [ffffffc0000dce44]
Linking TBs 0x7fb7cc823560 [ffffffc0000dce44] index 1 -> 0x7fb7cc8235d0 [ffffffc0000dce70]
Trace 0x7fb7cc8235d0 [ffffffc0000dce70]
Stopped execution of TB chain before 0x7fb7cc8235d0 [ffffffc0000dce70]
Trace 0x7fb7cc8235d0 [ffffffc0000dce70]
Trace 0x7fb7cc822fd0 [ffffffc0000dd52c]

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
[AJB: reword patch title, Abandoned->Stopped]
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1458052224-9316-6-git-send-email-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:18 +01:00
Peter Maydell
651a5bc037 exec.c: Add cpu_get_address_space()
Add a function to return the AddressSpace for a CPU based on
its numerical index. (Callers outside exec.c don't have access
to the CPUAddressSpace struct so can't just fish it out of the
CPUState struct directly.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2016-01-21 14:15:05 +00:00
Peter Maydell
a54c87b68a exec.c: Pass MemTxAttrs to iotlb_to_region so it uses the right AS
Pass the MemTxAttrs for the memory access to iotlb_to_region(); this
allows it to determine the correct AddressSpace to use for the lookup.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2016-01-21 14:15:05 +00:00
Peter Maydell
d7898cda81 cputlb.c: Use correct address space when looking up MemoryRegionSection
When looking up the MemoryRegionSection for the new TLB entry in
tlb_set_page_with_attrs(), use cpu_asidx_from_attrs() to determine
the correct address space index for the lookup, and pass it into
address_space_translate_for_iotlb().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2016-01-21 14:15:05 +00:00
Peter Maydell
1787cc8ee5 exec-all.h: Document tlb_set_page_with_attrs, tlb_set_page
Add documentation comments for tlb_set_page_with_attrs()
and tlb_set_page().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2016-01-21 14:15:04 +00:00
Peter Maydell
12ebc9a76d exec.c: Allow target CPUs to define multiple AddressSpaces
Allow multiple calls to cpu_address_space_init(); each
call adds an entry to the cpu->ases array at the specified
index. It is up to the target-specific CPU code to actually use
these extra address spaces.

Since this multiple AddressSpace support won't work with
KVM, add an assertion to avoid confusing failures.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2016-01-21 14:15:04 +00:00
Peter Maydell
56943e8cc1 exec.c: Don't set cpu->as until cpu_address_space_init
Rather than setting cpu->as unconditionally in cpu_exec_init
(and then having target-i386 override this later), don't set
it until the first call to cpu_address_space_init.

This requires us to initialise the address space for
both TCG and KVM (KVM doesn't need the AS listener but
it does require cpu->as to be set).

For target CPUs which don't set up any address spaces (currently
everything except i386), add the default address_space_memory
in qemu_init_vcpu().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2016-01-21 14:15:04 +00:00
Dr. David Alan Gilbert
87f50caa30 Move page_size_init earlier
The HOST_PAGE_ALIGN macros don't work until the page size variables
have been set up; later in postcopy I use those macros in the RAM
code, and it can be triggered using -object.

Fix this by initialising page_size_init() earlier - it's currently
initialised inside the accelerators, move it up into vl.c.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 14:51:48 +01:00
Pavel Dovgalyuk
56c0269a9e cpu-exec: allow temporary disabling icount
This patch is required for deterministic replay to generate an exception
by trying executing an instruction without changing icount.
It adds new flag to TB for disabling icount while translating it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162359.8676.77011.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-05 12:19:09 +01:00
Paolo Bonzini
88401cbc5b exec: remove non-TCG stuff from exec-all.h header.
The header is included from basically everywhere, thanks to cpu.h.
It should be moved to the (TCG only) files that actually need it.
As a start, remove non-TCG stuff.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-12 18:29:26 +02:00
Peter Maydell
32857f4d5e exec.c: Collect AddressSpace related fields into a CPUAddressSpace struct
Gather up all the fields currently in CPUState which deal with the CPU's
AddressSpace into a separate CPUAddressSpace struct. This paves the way
for allowing the CPU to know about more than one AddressSpace.

The rearrangement also allows us to make the MemoryListener a directly
embedded object in the CPUAddressSpace (it could not be embedded in
CPUState because 'struct MemoryListener' isn't defined for the user-only
builds). This allows us to resolve the FIXME in tcg_commit() by going
directly from the MemoryListener to the CPUAddressSpace.

This patch extracts the actual update of the cached dispatch pointer
from cpu_reload_memory_map() (which is renamed accordingly to
cpu_reloading_memory_map() as it is only responsible for breaking
cpu-exec.c's RCU critical section now). This lets us keep the definition
of the CPUAddressSpace struct private to exec.c.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <1443709790-25180-4-git-send-email-peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-12 18:29:26 +02:00
Richard Henderson
126d89e8cd tcg: Adjust CODE_GEN_AVG_BLOCK_SIZE
At present, the "average" guestimate of TB size is way too small, leading
to many unused entries in the pre-allocated TB array.  For a guest with 1GB
ram, we're currently allocating 256MB for the array.

Survey arm, alpha, aarch64, ppc, sparc, i686, x86_64 guests running on
x86_64 and ppc64 hosts and select a new average.  The size of the array
drops to 81MB with no more flushing than before.

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2015-10-07 20:40:00 +11:00
Richard Henderson
b125f9dc7b tcg: Check for overflow via highwater mark
We currently pre-compute an worst case code size for any TB, which
works out to be 122kB.  Since the average TB size is near 1kB, this
wastes quite a lot of storage.

Instead, check for overflow in between generating code for each opcode.
The overhead of the check isn't measurable and wastage is minimized.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2015-10-07 20:36:53 +11:00
Richard Henderson
4e5e121515 tcg: Remove gen_intermediate_code_pc
It is no longer used, so tidy up everything reached by it.
This includes the gen_opc_* arrays, the search_pc parameter
and the inline gen_intermediate_code_internal functions.

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2015-10-07 20:36:52 +11:00
Richard Henderson
fca8a500d5 tcg: Save insn data and use it in cpu_restore_state_from_tb
We can now restore state without retranslation.

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2015-10-07 20:36:51 +11:00
Richard Henderson
bad729e272 tcg: Pass data argument to restore_state_to_opc
The gen_opc_* arrays are already redundant with the data stored in
the insn_start arguments.  Transition restore_state_to_opc to use
data from the latter.

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2015-10-07 20:36:51 +11:00
Richard Henderson
fec88f64bd tcg: Merge cpu_gen_code into tb_gen_code
As it's only caller, this tidies things a bit.

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2015-10-07 20:36:49 +11:00
Peter Crosthwaite
dfccc76023 include/exec: Move cputlb exec.c defs out
Move the architecture agnostic function prototypes for exec.c out of
cputlb.h to exec-all.h. This allows hiding of the arch specific
cputlb.h from exec.c which should be getting close to having no
architecture specifics. Prepares support for multi-arch, which will have
a minimal cpu.h that services exec.c but not cputlb.h.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Message-Id: <b4fe754c58c860315e35d44430c26b1c967ce2c9.1441614289.git.crosthwaite.peter@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-16 17:33:33 +02:00
Peter Maydell
a2aa09e181 * Support for jemalloc
* qemu_mutex_lock_iothread "No such process" fix
 * cutils: qemu_strto* wrappers
 * iohandler.c simplification
 * Many other fixes and misc patches.
 
 And some MTTCG work (with Emilio's fixes squashed):
 * Signal-free TCG kick
 * Removing spinlock in favor of QemuMutex
 * User-mode emulation multi-threading fixes/docs
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Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* Support for jemalloc
* qemu_mutex_lock_iothread "No such process" fix
* cutils: qemu_strto* wrappers
* iohandler.c simplification
* Many other fixes and misc patches.

And some MTTCG work (with Emilio's fixes squashed):
* Signal-free TCG kick
* Removing spinlock in favor of QemuMutex
* User-mode emulation multi-threading fixes/docs

# gpg: Signature made Thu 10 Sep 2015 09:03:07 BST using RSA key ID 78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>"

* remotes/bonzini/tags/for-upstream: (44 commits)
  cutils: work around platform differences in strto{l,ul,ll,ull}
  cpu-exec: fix lock hierarchy for user-mode emulation
  exec: make mmap_lock/mmap_unlock globally available
  tcg: comment on which functions have to be called with mmap_lock held
  tcg: add memory barriers in page_find_alloc accesses
  remove unused spinlock.
  replace spinlock by QemuMutex.
  cpus: remove tcg_halt_cond and tcg_cpu_thread globals
  cpus: protect work list with work_mutex
  scripts/dump-guest-memory.py: fix after RAMBlock change
  configure: Add support for jemalloc
  add macro file for coccinelle
  configure: factor out adding disas configure
  vhost-scsi: fix wrong vhost-scsi firmware path
  checkpatch: remove tests that are not relevant outside the kernel
  checkpatch: adapt some tests to QEMU
  CODING_STYLE: update mixed declaration rules
  qmp: Add example usage of strto*l() qemu wrapper
  cutils: Add qemu_strtoull() wrapper
  cutils: Add qemu_strtoll() wrapper
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2015-09-14 16:13:16 +01:00
Pavel Dovgalyuk
1c3c8af1fb cpu-exec: introduce loop exit with restore function
This patch introduces loop exit function, which also
restores guest CPU state according to the value of host
program counter.

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150710095702.13280.97477.stgit@PASHA-ISP>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2015-09-11 08:16:16 -07:00
Paolo Bonzini
8fd19e6cfd exec: make mmap_lock/mmap_unlock globally available
There is some iffy lock hierarchy going on in translate-all.c.  To
fix it, we need to take the mmap_lock in cpu-exec.c.  Make the
functions globally available.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-09 15:34:56 +02:00
KONRAD Frederic
677ef6230b replace spinlock by QemuMutex.
spinlock is only used in two cases:
  * cpu-exec.c: to protect TranslationBlock
  * mem_helper.c: for lock helper in target-i386 (which seems broken).

It's a pthread_mutex_t in user-mode, so we can use QemuMutex directly,
with an #ifdef.  The #ifdef will be removed when multithreaded TCG
will need the mutex as well.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Message-Id: <1439220437-23957-5-git-send-email-fred.konrad@greensocs.com>
Signed-off-by: Emilio G. Cota <cota@braap.org>
[Merge Emilio G. Cota's patch to remove volatile. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-09 15:34:55 +02:00
Paolo Bonzini
e0c382113f tcg: signal-free qemu_cpu_kick
Signals are slow and do not exist on Win32.  The previous patches
have done most of the legwork to introduce memory barriers (some
of them were even there already for the sake of Windows!) and
we can now set the flags directly in the iothread.

qemu_cpu_kick_thread is not used anymore on TCG, since the TCG thread is
never outside usermode while the CPU is running (not halted).  Instead run
the content of the signal handler (now in qemu_cpu_kick_no_halt) directly.
qemu_cpu_kick_no_halt is also used in qemu_mutex_lock_iothread to avoid
the overhead of qemu_cond_broadcast.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-09 15:34:54 +02:00
Paolo Bonzini
9373e63297 tcg: introduce tcg_current_cpu
This is already useful on Windows in order to remove tls.h, because
accesses to current_cpu are done from a different thread on that
platform.  It will be used on POSIX platforms as soon TCG stops using
signals to interrupt the execution of translated code.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-09 15:34:53 +02:00
Peter Crosthwaite
a17d448274 exec-all: Translate TCI return addresses backwards too
This subtraction of return addresses applies directly to TCI as well as
host-TCG. This fixes Linux boots for at least Microblaze, CRIS, ARM and
SH4 when using TCI.

[sw: Removed indentation for preprocessor statement]
[sw: The patch also fixes Linux boot for x86_64]

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
2015-08-26 20:50:46 +02:00
Peter Maydell
d7a74a9d4a cputlb: Add functions for flushing TLB for a single MMU index
Guest CPU TLB maintenance operations may be sufficiently
specialized to only need to flush TLB entries corresponding
to a particular MMU index. Implement cputlb functions for
this, to avoid the inefficiency of flushing TLB entries
which we don't need to.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 1439548879-1972-2-git-send-email-peter.maydell@linaro.org
2015-08-25 16:18:33 +01:00
Paolo Bonzini
414b15c909 exec: drop cpu_can_do_io, just read cpu->can_do_io
After commit 626cf8f (icount: set can_do_io outside TB execution,
2014-12-08), can_do_io is set to 1 if not executing code.  It is
no longer necessary to make this assumption in cpu_can_do_io.

It is also possible to remove the use_icount test, simply by
never setting cpu->can_do_io to 0 unless use_icount is true.

With these changes cpu_can_do_io boils down to a read of
cpu->can_do_io.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-14 23:40:32 +02:00
Sergey Fedorov
02d57ea115 cpu-exec: Do not invalidate original TB in cpu_exec_nocache()
Instead of invalidating an original TB in cpu_exec_nocache()
prematurely, just save a link to it in the temporary generated TB. If
cpu_io_recompile() is raised subsequently from the temporary TB,
invalidate the original one as well. That allows reusing the original TB
each time cpu_exec_nocache() is called to handle expired instruction
counter in icount mode.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Message-Id: <1435656909-29116-1-git-send-email-serge.fdrv@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-08-06 12:04:08 +02:00
Peter Crosthwaite
4bad9e392e cpu: Change cpu_exec_init() arg to cpu, not env
The callers (most of them in target-foo/cpu.c) to this function all
have the cpu pointer handy. Just pass it to avoid an ENV_GET_CPU() from
core code (in exec.c).

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Michael Walle <michael@walle.cc>
Cc: Leon Alrae <leon.alrae@imgtec.com>
Cc: Anthony Green <green@moxielogic.com>
Cc: Jia Liu <proljc@gmail.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Blue Swirl <blauwirbel@gmail.com>
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Cc: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2015-07-09 15:20:40 +02:00
Peter Crosthwaite
bbd77c180d translate-all: Change tb_flush() env argument to cpu
All of the core-code usages of this API have the cpu pointer handy so
pass it in. There are only 3 architecture specific usages (2 of which
are commented out) which can just use ENV_GET_CPU() locally to get the
cpu pointer. The reduces core code usage of the CPU env, which brings
us closer to common-obj'ing these core files.

Cc: Riku Voipio <riku.voipio@iki.fi>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2015-07-09 15:20:40 +02:00
Bharata B Rao
5a790cc4b9 cpu: Add Error argument to cpu_exec_init()
Add an Error argument to cpu_exec_init() to let users collect the
error. This is in preparation to change the CPU enumeration logic
in cpu_exec_init(). With the new enumeration logic, cpu_exec_init()
can fail if cpu_index values corresponding to max_cpus have already
been handed out.

Since all current callers of cpu_exec_init() are from instance_init,
use error_abort Error argument to abort in case of an error.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
2015-07-09 15:20:40 +02:00
Li Zhijian
dd63169766 migration: extend migration_bitmap
Prevously, if we hotplug a device(e.g. device_add e1000) during
migration is processing in source side, qemu will add a new ram
block but migration_bitmap is not extended.
In this case, migration_bitmap will overflow and lead qemu abort
unexpectedly.

Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-07-07 14:54:56 +02:00
Peter Crosthwaite
e1b89321ba include/exec: Move tb hash functions out
This is one of very few things in exec-all with a genuine CPU
architecture dependency. Move these hashing helpers to a new
header to trim exec-all.h down to a near architecture-agnostic
header.

The defs are only used by cpu-exec and translate-all which are both
arch-obj's so the new tb-hash.h has no core code usage.

Reviewed-by: Richard Henderson <rth@redhat.com>
Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Message-Id: <9d048b96f7cfa64a4d9c0b88e0dd2877fac51d41.1433052532.git.crosthwaite.peter@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-06-26 16:00:51 +02:00