Commit Graph

144 Commits

Author SHA1 Message Date
Alex Bennée
7dec71d5ff cputlb: ensure _cmmu helper functions follow the naming standard
We document this in docs/devel/load-stores.rst so lets follow it. The
32 bit and 64 bit access functions have historically not included the
sign so we leave those as is. We also introduce some signed helpers
which are used for loading immediate values in the translator.

Fixes: 282dffc8
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20191021150910.23216-1-alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2019-10-28 15:12:38 +00:00
Alex Bennée
235537fa73 plugins: implement helpers for resolving hwaddr
We need to keep a local per-cpu copy of the data as other threads may
be running. Currently we can provide insight as to if the access was
IO or not and give the offset into a given device (usually the main
RAMBlock). We store enough information to get details such as the
MemoryRegion which might be useful in later expansions to the API.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2019-10-28 15:12:38 +00:00
Emilio G. Cota
cfec388518 atomic_template: add inline trace/plugin helpers
In preparation for plugin support.

Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2019-10-28 15:12:38 +00:00
Emilio G. Cota
4b2190dabd cputlb: introduce get_page_addr_code_hostp
This will be used by plugins to get the host address
of instructions.

Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2019-10-28 15:12:38 +00:00
Alex Bennée
504f73f7b3 trace: add mmu_index to mem_info
We are going to re-use mem_info later for plugins and will need to
track the mmu_idx for softmmu code.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
2019-10-28 15:12:38 +00:00
Richard Henderson
7f445c8c7a cputlb: Fix tlb_vaddr_to_host
Using uintptr_t instead of target_ulong meant that, for 64-bit guest
and 32-bit host, we truncated the guest address comparator and so may
not hit the tlb when we should.

Fixes: 4811e9095c
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-10-28 10:35:23 +01:00
Alex Bennée
4cef72d042 cputlb: ensure _cmmu helper functions follow the naming standard
We document this in docs/devel/load-stores.rst so lets follow it. The
32 bit and 64 bit access functions have historically not included the
sign so we leave those as is. We also introduce some signed helpers
which are used for loading immediate values in the translator.

Fixes: 282dffc8
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20191021150910.23216-1-alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-10-28 10:26:02 +01:00
Richard Henderson
5a7c27bb8a cputlb: Pass retaddr to tb_invalidate_phys_page_fast
Rather than rely on cpu->mem_io_pc, pass retaddr down directly.

Within tb_invalidate_phys_page_range__locked, the is_cpu_write_access
parameter is non-zero exactly when retaddr would be non-zero, so that
is a simple replacement.

Recognize that current_tb_not_found is true only when mem_io_pc
(and now retaddr) are also non-zero, so remove a redundant test.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-25 10:56:28 -07:00
Richard Henderson
b56668bbe1 cputlb: Remove cpu->mem_io_vaddr
With the merge of notdirty handling into store_helper,
the last user of cpu->mem_io_vaddr was removed.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-25 10:56:28 -07:00
Richard Henderson
73bc0bd41b cputlb: Handle TLB_NOTDIRTY in probe_access
We can use notdirty_write for the write and return a valid host
pointer for this case.

Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-25 10:56:28 -07:00
Richard Henderson
707526ad86 cputlb: Merge and move memory_notdirty_write_{prepare,complete}
Since 9458a9a1df, all readers of the dirty bitmaps wait
for the rcu lock, which means that they wait until the end
of any executing TranslationBlock.

As a consequence, there is no need for the actual access
to happen in between the _prepare and _complete.  Therefore,
we can improve things by merging the two functions into
notdirty_write and dropping the NotDirtyInfo structure.

In addition, the only users of notdirty_write are in cputlb.c,
so move the merged function there.  Pass in the CPUIOTLBEntry
from which the ram_addr_t may be computed.

Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-25 10:44:29 -07:00
Richard Henderson
8f5db64153 cputlb: Partially inline memory_region_section_get_iotlb
There is only one caller, tlb_set_page_with_attrs.  We cannot
inline the entire function because the AddressSpaceDispatch
structure is private to exec.c, and cannot easily be moved to
include/exec/memory-internal.h.

Compute is_ram and is_romd once within tlb_set_page_with_attrs.
Fold the number of tests against these predicates.  Compute
cpu_physical_memory_is_clean outside of the tlb lock region.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-25 10:44:27 -07:00
Richard Henderson
08565552f7 cputlb: Move NOTDIRTY handling from I/O path to TLB path
Pages that we want to track for NOTDIRTY are RAM.  We do not
really need to go through the I/O path to handle them.

Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-25 10:43:22 -07:00
Richard Henderson
7b0d792ce1 cputlb: Move ROM handling from I/O path to TLB path
It does not require going through the whole I/O path
in order to discard a write.

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-25 10:42:51 -07:00
Richard Henderson
5b87b3e671 cputlb: Introduce TLB_BSWAP
Handle bswap on ram directly in load/store_helper.  This fixes a
bug with the previous implementation in that one cannot use the
I/O path for RAM.

Fixes: a26fc6f515
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-25 10:36:43 -07:00
Richard Henderson
80d9d1c678 cputlb: Split out load/store_memop
We will shortly be using these more than once.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-25 10:28:16 -07:00
Richard Henderson
86b7b9c507 cputlb: Use qemu_build_not_reached in load/store_helpers
Increase the current runtime assert to a compile-time assert.

Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-25 10:23:45 -07:00
Richard Henderson
c6b716cdc0 cputlb: Disable __always_inline__ without optimization
This forced inlining can result in missing symbols,
which makes a debugging build harder to follow.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-25 10:12:33 -07:00
David Hildenbrand
c25c283df0 tcg: Factor out probe_write() logic into probe_access()
Let's also allow to probe other access types.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20190830100959.26615-3-david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:34:18 -07:00
David Hildenbrand
fef39ccd56 tcg: Make probe_write() return a pointer to the host page
... similar to tlb_vaddr_to_host(); however, allow access to the host
page except when TLB_NOTDIRTY or TLB_MMIO is set.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20190830100959.26615-2-david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:34:18 -07:00
David Hildenbrand
ca86cf328c tcg: Enforce single page access in probe_write()
Let's enforce the interface restriction.

Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190826075112.25637-5-david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:34:18 -07:00
David Hildenbrand
03a981893c tcg: Check for watchpoints in probe_write()
Let size > 0 indicate a promise to write to those bytes.
Check for write watchpoints in the probed range.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20190823100741.9621-10-david@redhat.com>
[rth: Recompute index after tlb_fill; check TLB_WATCHPOINT.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:34:18 -07:00
Richard Henderson
50b107c5d6 cputlb: Handle watchpoints via TLB_WATCHPOINT
The raising of exceptions from check_watchpoint, buried inside
of the I/O subsystem, is fundamentally broken.  We do not have
the helper return address with which we can unwind guest state.

Replace PHYS_SECTION_WATCH and io_mem_watch with TLB_WATCHPOINT.
Move the call to cpu_check_watchpoint into the cputlb helpers
where we do have the helper return address.

This allows watchpoints on RAM to bypass the full i/o access path.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:30:39 -07:00
Richard Henderson
5787585d04 cputlb: Remove double-alignment in store_helper
We have already aligned page2 to the start of the next page.
There is no reason to do that a second time.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:30:39 -07:00
Richard Henderson
8f7cd2ad4a cputlb: Fix size operand for tlb_fill on unaligned store
We are currently passing the size of the full write to
the tlb_fill for the second page.  Instead pass the real
size of the write to that page.

This argument is unused within all tlb_fill, except to be
logged via tracing, so in practice this makes no difference.

But in a moment we'll need the value of size2 for watchpoints,
and if we've computed the value we might as well use it.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:30:39 -07:00
Richard Henderson
30d7e098d5 cputlb: Fold TLB_RECHECK into TLB_INVALID_MASK
We had two different mechanisms to force a recheck of the tlb.

Before TLB_RECHECK was introduced, we had a PAGE_WRITE_INV bit
that would immediate set TLB_INVALID_MASK, which automatically
means that a second check of the tlb entry fails.

We can use the same mechanism to handle small pages.
Conserve TLB_* bits by removing TLB_RECHECK.

Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:30:39 -07:00
Tony Nguyen
a26fc6f515 cputlb: Byte swap memory transaction attribute
Notice new attribute, byte swap, and force the transaction through the
memory slow path.

Required by architectures that can invert endianness of memory
transaction, e.g. SPARC64 has the Invert Endian TTE bit.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <2a10a1f1c00a894af1212c8f68ef09c2966023c1.1566466906.git.tony.nguyen@bt.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:30:39 -07:00
Tony Nguyen
9bf825bf3d memory: Single byte swap along the I/O path
Now that MemOp has been pushed down into the memory API, and
callers are encoding endianness, we can collapse byte swaps
along the I/O path into the accelerator and target independent
adjust_endianness.

Collapsing byte swaps along the I/O path enables additional endian
inversion logic, e.g. SPARC64 Invert Endian TTE bit, with redundant
byte swaps cancelling out.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
Message-Id: <911ff31af11922a9afba9b7ce128af8b8b80f316.1566466906.git.tony.nguyen@bt.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:30:39 -07:00
Tony Nguyen
be5c4787e9 cputlb: Replace size and endian operands for MemOp
Preparation for collapsing the two byte swaps adjust_endianness and
handle_bswap into the former.

Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <755b7104410956b743e1f1e9c34ab87db113360f.1566466906.git.tony.nguyen@bt.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:30:39 -07:00
Tony Nguyen
d5d680cacc memory: Access MemoryRegion with endianness
Preparation for collapsing the two byte swaps adjust_endianness and
handle_bswap into the former.

Call memory_region_dispatch_{read|write} with endianness encoded into
the "MemOp op" operand.

This patch does not change any behaviour as
memory_region_dispatch_{read|write} is yet to handle the endianness.

Once it does handle endianness, callers with byte swaps can collapse
them into adjust_endianness.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
Message-Id: <8066ab3eb037c0388dfadfe53c5118429dd1de3a.1566466906.git.tony.nguyen@bt.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:30:39 -07:00
Tony Nguyen
4cbb198eef cputlb: Access MemoryRegion with MemOp
The memory_region_dispatch_{read|write} operand "unsigned size" is
being converted into a "MemOp op".

Convert interfaces by using no-op size_memop.

After all interfaces are converted, size_memop will be implemented
and the memory_region_dispatch_{read|write} operand "unsigned size"
will be converted into a "MemOp op".

As size_memop is a no-op, this patch does not change any behaviour.

Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <c4571c76467ade83660970f7ef9d7292297f1908.1566466906.git.tony.nguyen@bt.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:30:38 -07:00
Tony Nguyen
14776ab5a1 tcg: TCGMemOp is now accelerator independent MemOp
Preparation for collapsing the two byte swaps, adjust_endianness and
handle_bswap, along the I/O path.

Target dependant attributes are conditionalized upon NEED_CPU_H.

Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <81d9cd7d7f5aaadfa772d6c48ecee834e9cf7882.1566466906.git.tony.nguyen@bt.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-09-03 08:30:38 -07:00
Alex Bennée
ab7a2009df cputlb: cast size_t to target_ulong before using for address masks
While size_t is defined to happily access the biggest host object this
isn't the case when generating masks for 64 bit guests on 32 bit
hosts. Otherwise we end up truncating the address when we fall back to
our unaligned helper.

Fixes: https://bugs.launchpad.net/qemu/+bug/1831545

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Andrew Randrianasulu <randrianasulu@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-06-12 17:53:23 +01:00
Alex Bennée
8c79b28851 cputlb: use uint64_t for interim values for unaligned load
When running on 32 bit TCG backends a wide unaligned load ends up
truncating data before returning to the guest. We specifically have
the return type as uint64_t to avoid any premature truncation so we
should use the same for the interim types.

Fixes: https://bugs.launchpad.net/qemu/+bug/1830872
Fixes: eed5664238

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Igor Mammedov <imammedo@redhat.com>
2019-06-12 17:53:22 +01:00
Richard Henderson
29a0af618d cpu: Replace ENV_GET_CPU with env_cpu
Now that we have both ArchCPU and CPUArchState, we can define
this generically instead of via macro in each target's cpu.h.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-06-10 07:03:34 -07:00
Richard Henderson
a40ec84ee2 tcg: Create struct CPUTLB
Move all softmmu tlb data into this structure.  Arrange the
members so that we are able to place mask+table together and
at a smaller absolute offset from ENV.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-06-10 07:03:34 -07:00
Richard Henderson
79e4208506 tcg: Fold CPUTLBWindow into CPUTLBDesc
Both structures are allocated once per mmu_idx.
There is no reason for them to be separate.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-06-10 07:03:34 -07:00
Peter Maydell
d8276573da Add CPUClass::tlb_fill.
Improve tlb_vaddr_to_host for use by ARM SVE no-fault loads.
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Merge remote-tracking branch 'remotes/rth/tags/pull-tcg-20190510' into staging

Add CPUClass::tlb_fill.
Improve tlb_vaddr_to_host for use by ARM SVE no-fault loads.

# gpg: Signature made Fri 10 May 2019 19:48:37 BST
# gpg:                using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg:                issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A  05C0 64DF 38E8 AF7E 215F

* remotes/rth/tags/pull-tcg-20190510: (27 commits)
  tcg: Use tlb_fill probe from tlb_vaddr_to_host
  tcg: Remove CPUClass::handle_mmu_fault
  tcg: Use CPUClass::tlb_fill in cputlb.c
  target/xtensa: Convert to CPUClass::tlb_fill
  target/unicore32: Convert to CPUClass::tlb_fill
  target/tricore: Convert to CPUClass::tlb_fill
  target/tilegx: Convert to CPUClass::tlb_fill
  target/sparc: Convert to CPUClass::tlb_fill
  target/sh4: Convert to CPUClass::tlb_fill
  target/s390x: Convert to CPUClass::tlb_fill
  target/riscv: Convert to CPUClass::tlb_fill
  target/ppc: Convert to CPUClass::tlb_fill
  target/openrisc: Convert to CPUClass::tlb_fill
  target/nios2: Convert to CPUClass::tlb_fill
  target/moxie: Convert to CPUClass::tlb_fill
  target/mips: Convert to CPUClass::tlb_fill
  target/mips: Tidy control flow in mips_cpu_handle_mmu_fault
  target/mips: Pass a valid error to raise_mmu_exception for user-only
  target/microblaze: Convert to CPUClass::tlb_fill
  target/m68k: Convert to CPUClass::tlb_fill
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-05-16 13:15:08 +01:00
Richard Henderson
4601f8d10d cputlb: Do unaligned store recursion to outermost function
This is less tricky than for loads, because we always fall
back to single byte stores to implement unaligned stores.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
2019-05-10 20:23:21 +01:00
Richard Henderson
2dd9260678 cputlb: Do unaligned load recursion to outermost function
If we attempt to recurse from load_helper back to load_helper,
even via intermediary, we do not get all of the constants
expanded away as desired.

But if we recurse back to the original helper (or a shim that
has a consistent function signature), the operands are folded
away as desired.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
2019-05-10 20:23:21 +01:00
Richard Henderson
fc1bc77791 cputlb: Drop attribute flatten
Going to approach this problem via __attribute__((always_inline))
instead, but full conversion will take several steps.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
2019-05-10 20:23:21 +01:00
Richard Henderson
f1be36969d cputlb: Move TLB_RECHECK handling into load/store_helper
Having this in io_readx/io_writex meant that we forgot to
re-compute index after tlb_fill.  It also means we can use
the normal aligned memory load path.  It also fixes a bug
in that we had cached a use of index across a tlb_fill.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
2019-05-10 20:23:21 +01:00
Alex Bennée
eed5664238 accel/tcg: demacro cputlb
Instead of expanding a series of macros to generate the load/store
helpers we move stuff into common functions and rely on the compiler
to eliminate the dead code for each variant.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
2019-05-10 20:23:06 +01:00
Richard Henderson
4811e9095c tcg: Use tlb_fill probe from tlb_vaddr_to_host
Most of the existing users would continue around a loop which
would fault the tlb entry in via a normal load/store.

But for AArch64 SVE we have an existing emulation bug wherein we
would mark the first element of a no-fault vector load as faulted
(within the FFR, not via exception) just because we did not have
its address in the TLB.  Now we can properly only mark it as faulted
if there really is no valid, readable translation, while still not
raising an exception.  (Note that beyond the first element of the
vector, the hardware may report a fault for any reason whatsoever;
with at least one element loaded, forward progress is guaranteed.)

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-05-10 11:12:50 -07:00
Richard Henderson
c319dc1357 tcg: Use CPUClass::tlb_fill in cputlb.c
We can now use the CPUClass hook instead of a named function.

Create a static tlb_fill function to avoid other changes within
cputlb.c.  This also isolates the asserts within.  Remove the
named tlb_fill function from all of the targets.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-05-10 11:12:50 -07:00
Shahab Vahedi
ef5dae6805 cputlb: Fix io_readx() to respect the access_type
This change adapts io_readx() to its input access_type. Currently
io_readx() treats any memory access as a read, although it has an
input argument "MMUAccessType access_type". This results in:

1) Calling the tlb_fill() only with MMU_DATA_LOAD
2) Considering only entry->addr_read as the tlb_addr

Buglink: https://bugs.launchpad.net/qemu/+bug/1825359
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Shahab Vahedi <shahab.vahedi@gmail.com>
Message-Id: <20190420072236.12347-1-shahab.vahedi@gmail.com>
[rth: Remove assert; fix expression formatting.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-04-25 10:40:06 -07:00
Emilio G. Cota
6d967cb86d cputlb: update TLB entry/index after tlb_fill
We are failing to take into account that tlb_fill() can cause a
TLB resize, which renders prior TLB entry pointers/indices stale.
Fix it by re-doing the TLB entry lookups immediately after tlb_fill.

Fixes: 86e1eff8bc ("tcg: introduce dynamic TLB sizing", 2019-01-28)
Reported-by: Max Filippov <jcmvbkbc@gmail.com>
Tested-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20190209162745.12668-3-cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-02-11 08:52:44 -08:00
Thomas Huth
fb0343d5b4 tcg: Fix LGPL version number
It's either "GNU *Library* General Public version 2" or "GNU Lesser
General Public version *2.1*", but there was no "version 2.0" of the
"Lesser" library. So assume that version 2.1 is meant here.

Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1548252536-6242-5-git-send-email-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2019-01-30 11:01:52 +01:00
Richard Henderson
e77c89fb08 cputlb: Remove static tlb sizing
Now that all tcg backends support TCG_TARGET_IMPLEMENTS_DYN_TLB,
remove the define and the old code.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-01-28 07:04:35 -08:00
Emilio G. Cota
86e1eff8bc tcg: introduce dynamic TLB sizing
Disabled in all TCG backends for now.

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20190116170114.26802-3-cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-01-28 07:03:34 -08:00
Emilio G. Cota
3cea94bbc9 cputlb: do not evict empty entries to the vtlb
Currently we evict an entry to the victim TLB when it doesn't match
the current address. But it could be that there's no match because
the current entry is empty (i.e. all -1's, for instance via tlb_flush).
Do not evict the entry to the vtlb in that case.

This change will help us keep track of the TLB's use rate, which
we'll use to implement a policy for dynamic TLB sizing.

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20190116170114.26802-2-cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2019-01-28 07:03:34 -08:00
Richard Henderson
ab65110530 cputlb: Remove tlb_c.pending_flushes
This is essentially redundant with tlb_c.dirty.

Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31 12:16:39 +00:00
Richard Henderson
3d1523ced6 cputlb: Filter flushes on already clean tlbs
Especially for guests with large numbers of tlbs, like ARM or PPC,
we may well not use all of them in between flush operations.
Remember which tlbs have been used since the last flush, and
avoid any useless flushing.

Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31 12:16:35 +00:00
Richard Henderson
e09de0a20d cputlb: Count "partial" and "elided" tlb flushes
Our only statistic so far was "full" tlb flushes, where all mmu_idx
are flushed at the same time.

Now count "partial" tlb flushes where sets of mmu_idx are flushed,
but the set is not maximal.  Account one per mmu_idx flushed, as
that is the unit of work performed.

We don't actually count elided flushes yet, but go ahead and change
the interface presented to the monitor all at once.

Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31 12:16:30 +00:00
Richard Henderson
f8144c6c1e cputlb: Merge tlb_flush_page into tlb_flush_page_by_mmuidx
The difference between the two sets of APIs is now miniscule.

Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31 12:16:26 +00:00
Richard Henderson
64f2674bbc cputlb: Merge tlb_flush_nocheck into tlb_flush_by_mmuidx_async_work
The difference between the two sets of APIs is now miniscule.

This allows tlb_flush, tlb_flush_all_cpus, and tlb_flush_all_cpus_synced
to be merged with their corresponding by_mmuidx functions as well.  For
accounting, consider mmu_idx_bitmask = ALL_MMUIDX_BITS to be a full flush.

Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31 12:16:16 +00:00
Richard Henderson
d5363e5849 cputlb: Move env->vtlb_index to env->tlb_d.vindex
The rest of the tlb victim cache is per-tlb,
the next use index should be as well.

Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31 12:16:12 +00:00
Richard Henderson
1308e02671 cputlb: Split large page tracking per mmu_idx
The set of large pages in the kernel is probably not the same
as the set of large pages in the application.  Forcing one
range to cover both will flush more often than necessary.

This allows tlb_flush_page_async_work to flush just the one
mmu_idx implicated, which in turn allows us to remove
tlb_check_page_and_flush_by_mmuidx_async_work.

Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31 12:16:08 +00:00
Richard Henderson
60a2ad7d86 cputlb: Move cpu->pending_tlb_flush to env->tlb_c.pending_flush
Protect it with the tlb_lock instead of using atomics.
The move puts it in or near the same cacheline as the lock;
using the lock means we don't need a second atomic operation
in order to perform the update.  Which makes it cheap to also
update pending_flush in tlb_flush_by_mmuidx_async_work.

Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31 12:16:02 +00:00
Richard Henderson
8ab102667e cputlb: Remove tcg_enabled hack from tlb_flush_nocheck
The bugs this was working around were fixed with commits
022d6378c7  target/unicore32: remove tlb_flush from uc32_init_fn
6e11beecfd  target/alpha: remove tlb_flush from alpha_cpu_initfn

Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31 12:15:57 +00:00
Richard Henderson
53d284554c cputlb: Move tlb_lock to CPUTLBCommon
This is the first of several moves to reduce the size of the
CPU_COMMON_TLB macro and improve some locality of refernce.

Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-31 12:15:28 +00:00
Emilio G. Cota
403f290c06 cputlb: read CPUTLBEntry.addr_write atomically
Updates can come from other threads, so readers that do not
take tlb_lock must use atomic_read to avoid undefined
behaviour (UB).

This completes the conversion to tlb_lock. This conversion results
on average in no performance loss, as the following experiments
(run on an Intel i7-6700K CPU @ 4.00GHz) show.

1. aarch64 bootup+shutdown test:

- Before:
 Performance counter stats for 'taskset -c 0 ../img/aarch64/die.sh' (10 runs):

       7487.087786      task-clock (msec)         #    0.998 CPUs utilized            ( +-  0.12% )
    31,574,905,303      cycles                    #    4.217 GHz                      ( +-  0.12% )
    57,097,908,812      instructions              #    1.81  insns per cycle          ( +-  0.08% )
    10,255,415,367      branches                  # 1369.747 M/sec                    ( +-  0.08% )
       173,278,962      branch-misses             #    1.69% of all branches          ( +-  0.18% )

       7.504481349 seconds time elapsed                                          ( +-  0.14% )

- After:
 Performance counter stats for 'taskset -c 0 ../img/aarch64/die.sh' (10 runs):

       7462.441328      task-clock (msec)         #    0.998 CPUs utilized            ( +-  0.07% )
    31,478,476,520      cycles                    #    4.218 GHz                      ( +-  0.07% )
    57,017,330,084      instructions              #    1.81  insns per cycle          ( +-  0.05% )
    10,251,929,667      branches                  # 1373.804 M/sec                    ( +-  0.05% )
       173,023,787      branch-misses             #    1.69% of all branches          ( +-  0.11% )

       7.474970463 seconds time elapsed                                          ( +-  0.07% )

2. SPEC06int:
                                              SPEC06int (test set)
                                           [Y axis: Speedup over master]
  1.15 +-+----+------+------+------+------+------+-------+------+------+------+------+------+------+----+-+
       |                                                                                                  |
   1.1 +-+.................................+++.............................+  tlb-lock-v2 (m+++x)       +-+
       |                                +++ |                   +++        tlb-lock-v3 (spinl|ck)         |
       |                    +++          |  |     +++    +++     |                           |            |
  1.05 +-+....+++...........####.........|####.+++.|......|.....###....+++...........+++....###.........+-+
       |      ###         ++#| #         |# |# ***### +++### +++#+#     |     +++     |     #|#    ###    |
     1 +-+++***+#++++####+++#++#++++++++++#++#+*+*++#++++#+#+****+#++++###++++###++++###++++#+#++++#+#+++-+
       |    *+* #    #++# ***  #   #### ***  # * *++# ****+# *| * # ****|#   |# #    #|#    #+#    # #    |
  0.95 +-+..*.*.#....#..#.*|*..#...#..#.*|*..#.*.*..#.*|.*.#.*++*.#.*++*+#.****.#....#+#....#.#..++#.#..+-+
       |    * * #    #  # *|*  #   #  # *|*  # * *  # *++* # *  * # *  * # * |* #  ++# #    # #  *** #    |
       |    * * #  ++#  # *+*  #   #  # *|*  # * *  # *  * # *  * # *  * # *++* # **** #  ++# #  * * #    |
   0.9 +-+..*.*.#...|#..#.*.*..#.++#..#.*|*..#.*.*..#.*..*.#.*..*.#.*..*.#.*..*.#.*.|*.#...|#.#..*.*.#..+-+
       |    * * #  ***  # * *  #  |#  # *+*  # * *  # *  * # *  * # *  * # *  * # *++* #   |# #  * * #    |
  0.85 +-+..*.*.#..*|*..#.*.*..#.***..#.*.*..#.*.*..#.*..*.#.*..*.#.*..*.#.*..*.#.*..*.#.****.#..*.*.#..+-+
       |    * * #  *+*  # * *  # *|*  # * *  # * *  # *  * # *  * # *  * # *  * # *  * # * |* #  * * #    |
       |    * * #  * *  # * *  # *+*  # * *  # * *  # *  * # *  * # *  * # *  * # *  * # * |* #  * * #    |
   0.8 +-+..*.*.#..*.*..#.*.*..#.*.*..#.*.*..#.*.*..#.*..*.#.*..*.#.*..*.#.*..*.#.*..*.#.*++*.#..*.*.#..+-+
       |    * * #  * *  # * *  # * *  # * *  # * *  # *  * # *  * # *  * # *  * # *  * # *  * #  * * #    |
  0.75 +-+--***##--***###-***###-***###-***###-***###-****##-****##-****##-****##-****##-****##--***##--+-+
 400.perlben401.bzip2403.gcc429.m445.gob456.hmme45462.libqua464.h26471.omnet473483.xalancbmkgeomean

  png: https://imgur.com/a/BHzpPTW

Notes:
- tlb-lock-v2 corresponds to an implementation with a mutex.
- tlb-lock-v3 corresponds to the current implementation, i.e.
  a spinlock and a single lock acquisition in tlb_set_page_with_attrs.

Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20181016153840.25877-1-cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18 19:46:53 -07:00
Richard Henderson
e6cd4bb59b tcg: Split CONFIG_ATOMIC128
GCC7+ will no longer advertise support for 16-byte __atomic operations
if only cmpxchg is supported, as for x86_64.  Fortunately, x86_64 still
has support for __sync_compare_and_swap_16 and we can make use of that.
AArch64 does not have, nor ever has had such support, so open-code it.

Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18 19:46:36 -07:00
Richard Henderson
383beda9cf tcg: Add tlb_index and tlb_entry helpers
Isolate the computation of an index from an address into a
helper before we change that function.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
[ cota: convert tlb_vaddr_to_host; use atomic_read on addr_write ]
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20181009175129.17888-2-cota@braap.org>
2018-10-18 18:58:10 -07:00
Emilio G. Cota
71aec3541d cputlb: serialize tlb updates with env->tlb_lock
Currently we rely on atomic operations for cross-CPU invalidations.
There are two cases that these atomics miss: cross-CPU invalidations
can race with either (1) vCPU threads flushing their TLB, which
happens via memset, or (2) vCPUs calling tlb_reset_dirty on their TLB,
which updates .addr_write with a regular store. This results in
undefined behaviour, since we're mixing regular and atomic ops
on concurrent accesses.

Fix it by using tlb_lock, a per-vCPU lock. All updaters of tlb_table
and the corresponding victim cache now hold the lock.
The readers that do not hold tlb_lock must use atomic reads when
reading .addr_write, since this field can be updated by other threads;
the conversion to atomic reads is done in the next patch.

Note that an alternative fix would be to expand the use of atomic ops.
However, in the case of TLB flushes this would have a huge performance
impact, since (1) TLB flushes can happen very frequently and (2) we
currently use a full memory barrier to flush each TLB entry, and a TLB
has many entries. Instead, acquiring the lock is barely slower than a
full memory barrier since it is uncontended, and with a single lock
acquisition we can flush the entire TLB.

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20181009174557.16125-6-cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18 18:58:10 -07:00
Emilio G. Cota
ea9025cb49 cputlb: fix assert_cpu_is_self macro
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20181009174557.16125-5-cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18 18:58:10 -07:00
Emilio G. Cota
5005e2537d exec: introduce tlb_init
Paves the way for the addition of a per-TLB lock.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20181009174557.16125-4-cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-10-18 18:58:10 -07:00
Peter Maydell
55a7cb144d accel/tcg: Check whether TLB entry is RAM consistently with how we set it up
We set up TLB entries in tlb_set_page_with_attrs(), where we have
some logic for determining whether the TLB entry is considered
to be RAM-backed, and thus has a valid addend field. When we
look at the TLB entry in get_page_addr_code(), we use different
logic for determining whether to treat the page as RAM-backed
and use the addend field. This is confusing, and in fact buggy,
because the code in tlb_set_page_with_attrs() correctly decides
that rom_device memory regions not in romd mode are not RAM-backed,
but the code in get_page_addr_code() thinks they are RAM-backed.
This typically results in "Bad ram pointer" assertion if the
guest tries to execute from such a memory region.

Fix this by making get_page_addr_code() just look at the
TLB_MMIO bit in the code_address field of the TLB, which
tlb_set_page_with_attrs() sets if and only if the addend
field is not valid for code execution.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20180713150945.12348-1-peter.maydell@linaro.org
2018-08-14 17:17:19 +01:00
Peter Maydell
20cb6ae472 accel/tcg: Return -1 for execution from MMIO regions in get_page_addr_code()
Now that all the callers can handle get_page_addr_code() returning -1,
remove all the code which tries to handle execution from MMIO regions
or small-MMU-region RAM areas. This will mean that we can correctly
execute from these areas, rather than ending up either aborting QEMU
or delivering an incorrect guest exception.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20180710160013.26559-6-peter.maydell@linaro.org
2018-08-14 17:17:19 +01:00
Peter Maydell
dbea78a4d6 accel/tcg: Pass read access type through to io_readx()
The io_readx() function needs to know whether the load it is
doing is an MMU_DATA_LOAD or an MMU_INST_FETCH, so that it
can pass the right value to the cpu_transaction_failed()
function. Plumb this information through from the softmmu
code.

This is currently not often going to give the wrong answer,
because usually instruction fetches go via get_page_addr_code().
However once we switch over to handling execution from non-RAM by
creating single-insn TBs, the path for an insn fetch to generate
a bus error will be through cpu_ld*_code() and io_readx(),
so without this change we will generate a d-side fault when we
should generate an i-side fault.

We also have to pass the access type via a CPU struct global
down to unassigned_mem_read(), for the benefit of the targets
which still use the cpu_unassigned_access() hook (m68k, mips,
sparc, xtensa).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20180710160013.26559-2-peter.maydell@linaro.org
2018-08-14 17:17:19 +01:00
Peter Maydell
3474c98a2a accel/tcg: Assert that tlb fill gave us a valid TLB entry
In commit 4b1a3e1e34 we added a check for whether the TLB entry
we had following a tlb_fill had the INVALID bit set.  This could
happen in some circumstances because a stale or wrong TLB entry was
pulled out of the victim cache.  However, after commit
68fea03855 (which prevents stale entries being in the victim
cache) and the previous commit (which ensures we don't incorrectly
hit in the victim cache)) this should never be possible.

Drop the check on TLB_INVALID_MASK from the "is this a TLB_RECHECK?"
condition, and instead assert that the tlb fill procedure has given
us a valid TLB entry (or longjumped out with a guest exception).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180713141636.18665-3-peter.maydell@linaro.org
2018-07-16 17:26:01 +01:00
Peter Maydell
b493ccf1fc accel/tcg: Use correct test when looking in victim TLB for code
In get_page_addr_code(), we were incorrectly looking in the victim
TLB for an entry which matched the target address for reads, not
for code accesses. This meant that we could hit on a victim TLB
entry that indicated that the address was readable but not
executable, and incorrectly bypass the call to tlb_fill() which
should generate the guest MMU exception. Fix this bug.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180713141636.18665-2-peter.maydell@linaro.org
2018-07-16 17:26:01 +01:00
Richard Henderson
68fea03855 accel/tcg: Avoid caching overwritten tlb entries
When installing a TLB entry, remove any cached version of the
same page in the VTLB.  If the existing TLB entry matches, do
not copy into the VTLB, but overwrite it.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-07-02 08:05:16 -07:00
Peter Maydell
4b1a3e1e34 accel/tcg: Don't treat invalid TLB entries as needing recheck
In get_page_addr_code() when we check whether the TLB entry
is marked as TLB_RECHECK, we should not go down that code
path if the TLB entry is not valid at all (ie the TLB_INVALID
bit is set).

Tested-by: Laurent Vivier <laurent@vivier.eu>
Reported-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20180629161731.16239-1-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-07-02 08:02:20 -07:00
Peter Maydell
e4c967a720 accel/tcg: Correct "is this a TLB miss" check in get_page_addr_code()
In commit 71b9a45330 we changed the condition we use
to determine whether we need to refill the TLB in
get_page_addr_code() to
    if (unlikely(env->tlb_table[mmu_idx][index].addr_code !=
                 (addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK)))) {

This isn't the right check (it will falsely fail if the
input addr happens to have the low bit corresponding to
TLB_INVALID_MASK set, for instance). Replace it with a
use of the new tlb_hit() function, which is the correct test.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20180629162122.19376-3-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-07-02 08:02:20 -07:00
Peter Maydell
334692bce7 tcg: Define and use new tlb_hit() and tlb_hit_page() functions
The condition to check whether an address has hit against a particular
TLB entry is not completely trivial. We do this in various places, and
in fact in one place (get_page_addr_code()) we have got the condition
wrong. Abstract it out into new tlb_hit() and tlb_hit_page() inline
functions (one for a known-page-aligned address and one for an
arbitrary address), and use them in all the places where we had the
condition correct.

This is a no-behaviour-change patch; we leave fixing the buggy
code in get_page_addr_code() to a subsequent patch.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20180629162122.19376-2-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-07-02 08:02:20 -07:00
Peter Maydell
55df6fcf54 tcg: Support MMU protection regions smaller than TARGET_PAGE_SIZE
Add support for MMU protection regions that are smaller than
TARGET_PAGE_SIZE. We do this by marking the TLB entry for those
pages with a flag TLB_RECHECK. This flag causes us to always
take the slow-path for accesses. In the slow path we can then
special case them to always call tlb_fill() again, so we have
the correct information for the exact address being accessed.

This change allows us to handle reading and writing from small
regions; we cannot deal with execution from the small region.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180620130619.11362-2-peter.maydell@linaro.org
2018-06-26 17:50:41 +01:00
Emilio G. Cota
b7542f7fe8 cputlb: remove tb_lock from tlb_flush functions
The acquisition of tb_lock was added when the async tlb_flush
was introduced in e3b9ca810 ("cputlb: introduce tlb_flush_* async work.")

tb_lock was there to allow us to do memset() on the tb_jmp_cache's.
However, since f3ced3c592 ("tcg: consistently access cpu->tb_jmp_cache
atomically") all accesses to tb_jmp_cache are atomic, so tb_lock
is not needed here. Get rid of it.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2018-06-15 08:18:48 -10:00
Peter Maydell
1f871c5e6b exec.c: Handle IOMMUs in address_space_translate_for_iotlb()
Currently we don't support board configurations that put an IOMMU
in the path of the CPU's memory transactions, and instead just
assert() if the memory region fonud in address_space_translate_for_iotlb()
is an IOMMUMemoryRegion.

Remove this limitation by having the function handle IOMMUs.
This is mostly straightforward, but we must make sure we have
a notifier registered for every IOMMU that a transaction has
passed through, so that we can flush the TLB appropriately
when any of the IOMMUs change their mappings.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20180604152941.20374-5-peter.maydell@linaro.org
2018-06-15 15:23:34 +01:00
Peter Maydell
2d54f19401 cputlb: Pass cpu_transaction_failed() the correct physaddr
The API for cpu_transaction_failed() says that it takes the physical
address for the failed transaction. However we were actually passing
it the offset within the target MemoryRegion. We don't currently
have any target CPU implementations of this hook that require the
physical address; fix this bug so we don't get confused if we ever
do add one.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180611125633.32755-3-peter.maydell@linaro.org
2018-06-15 15:23:34 +01:00
Peter Maydell
ace4109011 cpu-defs.h: Document CPUIOTLBEntry 'addr' field
The 'addr' field in the CPUIOTLBEntry struct has a rather non-obvious
use; add a comment documenting it (reverse-engineered from what
the code that sets it is doing).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180611125633.32755-2-peter.maydell@linaro.org
2018-06-15 15:23:34 +01:00
Laurent Vivier
98670d47cd accel/tcg: add size paremeter in tlb_fill()
The MC68040 MMU provides the size of the access that
triggers the page fault.

This size is set in the Special Status Word which
is written in the stack frame of the access fault
exception.

So we need the size in m68k_cpu_unassigned_access() and
m68k_cpu_handle_mmu_fault().

To be able to do that, this patch modifies the prototype of
handle_mmu_fault handler, tlb_fill() and probe_write().
do_unassigned_access() already includes a size parameter.

This patch also updates handle_mmu_fault handlers and
tlb_fill() of all targets (only parameter, no code change).

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180118193846.24953-2-laurent@vivier.eu>
2018-01-25 16:02:24 +01:00
Peter Maydell
34d49937e4 accel/tcg: Handle atomic accesses to notdirty memory correctly
To do a write to memory that is marked as notdirty, we need
to invalidate any TBs we have cached for that memory, and
update the cpu physical memory dirty flags for VGA and migration.
The slowpath code in notdirty_mem_write() does all this correctly,
but the new atomic handling code in atomic_mmu_lookup() doesn't
do anything at all, it just clears the dirty bit in the TLB.

The effect of this bug is that if the first write to a notdirty
page for which we have cached TBs is by a guest atomic access,
we fail to invalidate the TBs and subsequently will execute
incorrect code. This can be seen by trying to run 'javac' on AArch64.

Use the new notdirty_call_before() and notdirty_call_after()
functions to correctly handle the update to notdirty memory
in the atomic codepath.

Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1511201308-23580-3-git-send-email-peter.maydell@linaro.org
2017-11-21 12:09:25 +00:00
Richard Henderson
ec603b5584 tcg: Record code_gen_buffer address for user-only memory helpers
When we handle a signal from a fault within a user-only memory helper,
we cannot cpu_restore_state with the PC found within the signal frame.
Use a TLS variable, helper_retaddr, to record the unwind start point
to find the faulting guest insn.

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-11-15 10:33:27 +01:00
David Hildenbrand
f52bfb1214 accel/tcg: allow to invalidate a write TLB entry immediately
Background: s390x implements Low-Address Protection (LAP). If LAP is
enabled, writing to effective addresses (before any translation)
0-511 and 4096-4607 triggers a protection exception.

So we have subpage protection on the first two pages of every address
space (where the lowcore - the CPU private data resides).

By immediately invalidating the write entry but allowing the caller to
continue, we force every write access onto these first two pages into
the slow path. we will get a tlb fault with the specific accessed
addresses and can then evaluate if protection applies or not.

We have to make sure to ignore the invalid bit if tlb_fill() succeeds.

Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20171016202358.3633-2-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2017-10-20 13:32:10 +02:00
Emilio G. Cota
83974cf4f8 cputlb: bring back tlb_flush_count under !TLB_DEBUG
Commit f0aff0f124 ("cputlb: add assert_cpu_is_self checks") buried
the increment of tlb_flush_count under TLB_DEBUG. This results in
"info jit" always (mis)reporting 0 TLB flushes when !TLB_DEBUG.

Besides, under MTTCG tlb_flush_count is updated by several threads,
so in order not to lose counts we'd either have to use atomic ops
or distribute the counter, which is more scalable.

This patch does the latter by embedding tlb_flush_count in CPUArchState.
The global count is then easily obtained by iterating over the CPU list.

Note that this change also requires updating the accessors to
tlb_flush_count to use atomic_read/set whenever there may be conflicting
accesses (as defined in C11) to it.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-10-10 07:37:10 -07:00
Alex Bennée
8b81253332 accel/tcg/cputlb: avoid recursive BQL (fixes #1706296)
The mmio path (see exec.c:prepare_mmio_access) already protects itself
against recursive locking and it makes sense to do the same for
io_readx/writex. Otherwise any helper running in the BQL context will
assert when it attempts to write to device memory as in the case of
the bug report.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
CC: Richard Jones <rjones@redhat.com>
CC: Paolo Bonzini <bonzini@gnu.org>
CC: qemu-stable@nongnu.org
Message-Id: <20170921110625.9500-1-alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2017-09-25 11:23:30 -07:00
Peter Maydell
04e3aabde3 cputlb: Support generating CPU exceptions on memory transaction failures
Call the new cpu_transaction_failed() hook at the places where
CPU generated code interacts with the memory system:
 io_readx()
 io_writex()
 get_page_addr_code()

Any access from C code (eg via cpu_physical_memory_rw(),
address_space_rw(), ld/st_*_phys()) will *not* trigger CPU exceptions
via cpu_transaction_failed().  Handling for transactions failures for
this kind of call should be done by using a function which returns a
MemTxResult and treating the failure case appropriately in the
calling code.

In an ideal world we would not generate CPU exceptions for
instruction fetch failures in get_page_addr_code() but instead wait
until the code translation process tried a load and it failed;
however that change would require too great a restructuring and
redesign to attempt at this point.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2017-09-04 15:21:55 +01:00
Emilio G. Cota
f3ced3c592 tcg: consistently access cpu->tb_jmp_cache atomically
Some code paths can lead to atomic accesses racing with memset()
on cpu->tb_jmp_cache, which can result in torn reads/writes
and is undefined behaviour in C11.

These torn accesses are unlikely to show up as bugs, but from code
inspection they seem possible. For example, tb_phys_invalidate does:
    /* remove the TB from the hash list */
    h = tb_jmp_cache_hash_func(tb->pc);
    CPU_FOREACH(cpu) {
        if (atomic_read(&cpu->tb_jmp_cache[h]) == tb) {
            atomic_set(&cpu->tb_jmp_cache[h], NULL);
        }
    }
Here atomic_set might race with a concurrent memset (such as the
ones scheduled via "unsafe" async work, e.g. tlb_flush_page) and
therefore we might end up with a torn pointer (or who knows what,
because we are under undefined behaviour).

This patch converts parallel accesses to cpu->tb_jmp_cache to use
atomic primitives, thereby bringing these accesses back to defined
behaviour. The price to pay is to potentially execute more instructions
when clearing cpu->tb_jmp_cache, but given how infrequently they happen
and the small size of the cache, the performance impact I have measured
is within noise range when booting debian-arm.

Note that under "safe async" work (e.g. do_tb_flush) we could use memset
because no other vcpus are running. However I'm keeping these accesses
atomic as well to keep things simple and to avoid confusing analysis
tools such as ThreadSanitizer.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1497486973-25845-1-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2017-06-30 11:40:59 -07:00
KONRAD Frederic
c935674635 exec: allow to get a pointer for some mmio memory region
This introduces a special callback which allows to run code from some MMIO
devices.

SysBusDevice with a MemoryRegion which implements the request_ptr callback will
be notified when the guest try to execute code from their offset. Then it will
be able to eg: pre-load some code from an SPI device or ask a pointer from an
external simulator, etc..

When the pointer or the data in it are no longer valid the device has to
invalidate it.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2017-06-27 15:09:15 +02:00
KONRAD Frederic
71b9a45330 cputlb: fix the way get_page_addr_code fills the tlb
get_page_addr_code(..) does a cpu_ldub_code to fill the tlb:
This can lead to some side effects if a device is mapped at this address.

So this patch replaces the cpu_memory_ld by a tlb_fill.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2017-06-27 15:09:15 +02:00
KONRAD Frederic
f2553f0489 cputlb: move get_page_addr_code
This just moves the code before VICTIM_TLB_HIT macro definition
so we can use it.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2017-06-27 15:09:14 +02:00
KONRAD Frederic
3416343255 cputlb: cleanup get_page_addr_code to use VICTIM_TLB_HIT
This replaces env1 and page_index variables by env and index
so we can use VICTIM_TLB_HIT macro later.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
2017-06-27 15:09:04 +02:00
Yang Zhong
d9bb58e510 tcg: move tcg related files into accel/tcg/ subdirectory
move cputlb.c, cpu-exec-common.c and cpu-exec.c related tcg exec
file into accel/tcg/ subdirectory.

Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <1496383606-18060-3-git-send-email-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-15 11:04:06 +02:00