This new interface will allow targets to probe for a page
and then handle watchpoints themselves. This will be most
useful for vector predicated memory operations, where one
page lookup can be used for many operations, and one test
can avoid many watchpoint checks.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200508154359.7494-6-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We have validated that addr+size does not cross a page boundary.
Therefore we need to validate exactly one page. We can achieve
that passing any value 1 <= x <= size to page_check_range.
Passing 1 will simplify the next patch.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200508154359.7494-5-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We currently search both the root and the tcg/ directories for tcg
files:
$ git grep '#include "tcg/' | wc -l
28
$ git grep '#include "tcg[^/]' | wc -l
94
To simplify the preprocessor search path, unify by expliciting the
tcg/ directory.
Patch created mechanically by running:
$ for x in \
tcg.h tcg-mo.h tcg-op.h tcg-opc.h \
tcg-op-gvec.h tcg-gvec-desc.h; do \
sed -i "s,#include \"$x\",#include \"tcg/$x\"," \
$(git grep -l "#include \"$x\""); \
done
Acked-by: David Gibson <david@gibson.dropbear.id.au> (ppc parts)
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200101112303.20724-2-philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
With the tracing hooks, the inline functions are no longer
so simple. Reduce the amount of preprocessor obfuscation
by expanding the text of each of the functions generated.
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
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>
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>
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>
... 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>
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>
Factor it out into common code. Similar to the !CONFIG_USER_ONLY variant,
let's not allow to cross page boundaries.
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190826075112.25637-4-david@redhat.com>
[rth: Move cpu & cc variables inside if block.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Turn helper_retaddr into a multi-state flag that may now also
indicate when we're performing a read on behalf of the translator.
In this case, release the mmap_lock before the longjmp back to
the main cpu loop, and thereby avoid a failing assert therein.
Fixes: https://bugs.launchpad.net/qemu/+bug/1832353
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
At present we have a potential error in that helper_retaddr contains
data for handle_cpu_signal, but we have not ensured that those stores
will be scheduled properly before the operation that may fault.
It might be that these races are not in practice observable, due to
our use of -fno-strict-aliasing, but better safe than sorry.
Adjust all of the setters of helper_retaddr.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
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>
This hook is now completely replaced by tlb_fill.
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>
This hook will replace the (user-only mode specific) handle_mmu_fault
hook, and the (system mode specific) tlb_fill function.
The handle_mmu_fault hook was written as if there was a valid
way to recover from an mmu fault, and had 3 possible return states.
In reality, the only valid action is to raise an exception,
return to the main loop, and deliver the SIGSEGV to the guest.
Note that all of the current implementations of handle_mmu_fault
for guests which support linux-user do in fact only ever return 1,
which is the signal to return to the main loop.
Using the hook for system mode requires that all targets be converted,
so for now the hook is (optionally) used only from user-only mode.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
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>
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>
In cpu_signal_handler() for aarch64 hosts, currently we parse
the faulting instruction to see if it is a load or a store.
Since the 3.16 kernel (~2014), the kernel has provided us with
the syndrome register for a fault, which includes the WnR bit.
Use this instead if it is present, only falling back to
instruction parsing if not.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190108180014.32386-1-peter.maydell@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Michael Clark <mjc@sifive.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <c445175310fa836b61fd862a55628907f0093194.1545246859.git.alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
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>
In icount mode, instructions that access io memory spaces in the middle
of the translation block invoke TB recompilation. After recompilation,
such instructions become last in the TB and are allowed to access io
memory spaces.
When the code includes instruction like i386 'xchg eax, 0xffffd080'
which accesses APIC, QEMU goes into an infinite loop of the recompilation.
This instruction includes two memory accesses - one read and one write.
After the first access, APIC calls cpu_report_tpr_access, which restores
the CPU state to get the current eip. But cpu_restore_state_from_tb
resets the cpu->can_do_io flag which makes the second memory access invalid.
Therefore the second memory access causes a recompilation of the block.
Then these operations repeat again and again.
This patch moves resetting cpu->can_do_io flag from
cpu_restore_state_from_tb to cpu_loop_exit* functions.
It also adds a parameter for cpu_restore_state which controls restoring
icount. There is no need to restore icount when we only query CPU state
without breaking the TB. Restoring it in such cases leads to the
incorrect flow of the virtual time.
In most cases new parameter is true (icount should be recalculated).
But there are two cases in i386 and openrisc when the CPU state is only
queried without the need to break the TB. This patch fixes both of
these cases.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Message-Id: <20180409091320.12504.35329.stgit@pasha-VirtualBox>
[rth: Make can_do_io setting unconditional; move from cpu_exec;
make cpu_loop_exit_{noexc,restore} call cpu_loop_exit.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We dropped support for ia64 host CPUs in the 2.11 release (removing
the TCG backend for it, and advertising the support as being
completely removed in the changelog). However there are a few bits
and pieces of code still floating about. Remove those, too.
We can drop the check in configure for "ia64 or hppa host?"
entirely, because we don't support hppa hosts either any more.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <1516897189-11035-1-git-send-email-peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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>
If multiple guest threads in user-mode emulation write to a
page which QEMU has marked read-only because of cached TCG
translations, the threads can race in page_unprotect:
* threads A & B both try to do a write to a page with code in it at
the same time (ie which we've made non-writeable, so SEGV)
* they race into the signal handler with this faulting address
* thread A happens to get to page_unprotect() first and takes the
mmap lock, so thread B sits waiting for it to be done
* A then finds the page, marks it PAGE_WRITE and mprotect()s it writable
* A can then continue OK (returns from signal handler to retry the
memory access)
* ...but when B gets the mmap lock it finds that the page is already
PAGE_WRITE, and so it exits page_unprotect() via the "not due to
protected translation" code path, and wrongly delivers the signal
to the guest rather than just retrying the access
In particular, this meant that trying to run 'javac' in user-mode
emulation would fail with a spurious guest SIGSEGV.
Handle this by making page_unprotect() assume that a call for a page
which is already PAGE_WRITE is due to a race of this sort and return
a "fault handled" indication.
Since this would cause an infinite loop if we ever called
page_unprotect() for some other kind of fault than "write failed due
to bad access permissions", tighten the condition in
handle_cpu_signal() to check the signal number and si_code, and add a
comment so that if somebody does ever find themselves debugging an
infinite loop of faults they have some clue about why.
(The trick for identifying the correct setting for
current_tb_invalidated for thread B (needed to handle the precise-SMC
case) is due to Richard Henderson. Paolo Bonzini suggested just
relying on si_code rather than trying anything more complicated.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <1511879725-9576-3-git-send-email-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Currently all the architecture/OS specific cpu_signal_handler()
functions call handle_cpu_signal() without passing it the
siginfo_t. We're going to want that so we can look at the si_code
to determine whether this is a SEGV_ACCERR access violation or
some other kind of fault, so change the functions to pass through
the pointer to the siginfo_t rather than just the si_addr value.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1511879725-9576-2-git-send-email-peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
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
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>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20170912211934.20919-1-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20170911213328.9701-3-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Richard Henderson