We already attempted to set and clear can_do_io before the first
and last insns, but only used the initial value of max_insns and
the call to translator_io_start to find those insns.
Now that we track insn_start in DisasContextBase, and now that
we have emit_before_op, we can wait until we have finished
translation to identify the true first and last insns and emit
the sets of can_do_io at that time.
This fixes the case of a translation block which crossed a page
boundary, and for which the second page turned out to be mmio.
In this case we truncate the block, and the previous logic for
can_do_io could leave a block with a single insn with can_do_io
set to false, which would fail an assertion in cpu_io_recompile.
Reported-by: Jørgen Hansen <Jorgen.Hansen@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Jørgen Hansen <Jorgen.Hansen@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
subj is calling kvm_add_routing_entry() which simply extends
KVMState::irq_routes::entries[]
but doesn't check if number of routes goes beyond limit the kernel
is willing to accept. Which later leads toi the assert
qemu-kvm: ../accel/kvm/kvm-all.c:1833: kvm_irqchip_commit_routes: Assertion `ret == 0' failed
typically it happens during guest boot for large enough guest
Reproduced with:
./qemu --enable-kvm -m 8G -smp 64 -machine pc \
`for b in {1..2}; do echo -n "-device pci-bridge,id=pci$b,chassis_nr=$b ";
for i in {0..31}; do touch /tmp/vblk$b$i;
echo -n "-drive file=/tmp/vblk$b$i,if=none,id=drive$b$i,format=raw
-device virtio-blk-pci,drive=drive$b$i,bus=pci$b ";
done; done`
While crash at boot time is bad, the same might happen at hotplug time
which is unacceptable.
So instead calling kvm_add_routing_entry() unconditionally, check first
that number of routes won't exceed KVM_CAP_IRQ_ROUTING. This way virtio
device insteads killin qemu, will gracefully fail to initialize device
as expected with following warnings on console:
virtio-blk failed to set guest notifier (-28), ensure -accel kvm is set.
virtio_bus_start_ioeventfd: failed. Fallback to userspace (slower).
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-ID: <20240408110956.451558-1-imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Using log_pc produces the pc at the beginning of TB,
not the actual pc installed by cpu_restore_state_from_tb,
which could be any of the guest instructions within TB.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Avoid CPUArchState local variable when cpu_env() is used once.
Mechanical patch using the following Coccinelle spatch script:
@@
type CPUArchState;
identifier env;
expression cs;
@@
{
- CPUArchState *env = cpu_env(cs);
... when != env
- env
+ cpu_env(cs)
... when != env
}
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20240129164514.73104-5-philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
"hw/xen/xen_pt.h" requires "hw/xen/xen_native.h" which is target
specific. It also declares IGD methods, which are not target
specific.
Target-agnostic code can use IGD methods. To allow that, extract
these methos into a new "hw/xen/xen_igd.h" header.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20231114143816.71079-18-philmd@linaro.org>
On i386, after fixing the page walking code to work with pages in
MMIO memory (specifically CXL emulated interleaved memory),
a crash was seen in an interrupt handling path.
Useful part of backtrace
7 0x0000555555ab1929 in bql_lock_impl (file=0x555556049122 "../../accel/tcg/cputlb.c", line=2033) at ../../system/cpus.c:524
8 bql_lock_impl (file=file@entry=0x555556049122 "../../accel/tcg/cputlb.c", line=line@entry=2033) at ../../system/cpus.c:520
9 0x0000555555c9f7d6 in do_ld_mmio_beN (cpu=0x5555578e0cb0, full=0x7ffe88012950, ret_be=ret_be@entry=0, addr=19595792376, size=size@entry=8, mmu_idx=4, type=MMU_DATA_LOAD, ra=0) at ../../accel/tcg/cputlb.c:2033
10 0x0000555555ca0fbd in do_ld_8 (cpu=cpu@entry=0x5555578e0cb0, p=p@entry=0x7ffff4efd1d0, mmu_idx=<optimized out>, type=type@entry=MMU_DATA_LOAD, memop=<optimized out>, ra=ra@entry=0) at ../../accel/tcg/cputlb.c:2356
11 0x0000555555ca341f in do_ld8_mmu (cpu=cpu@entry=0x5555578e0cb0, addr=addr@entry=19595792376, oi=oi@entry=52, ra=0, ra@entry=52, access_type=access_type@entry=MMU_DATA_LOAD) at ../../accel/tcg/cputlb.c:2439
12 0x0000555555ca5f59 in cpu_ldq_mmu (ra=52, oi=52, addr=19595792376, env=0x5555578e3470) at ../../accel/tcg/ldst_common.c.inc:169
13 cpu_ldq_le_mmuidx_ra (env=0x5555578e3470, addr=19595792376, mmu_idx=<optimized out>, ra=ra@entry=0) at ../../accel/tcg/ldst_common.c.inc:301
14 0x0000555555b4b5fc in ptw_ldq (ra=0, in=0x7ffff4efd320) at ../../target/i386/tcg/sysemu/excp_helper.c:98
15 ptw_ldq (ra=0, in=0x7ffff4efd320) at ../../target/i386/tcg/sysemu/excp_helper.c:93
16 mmu_translate (env=env@entry=0x5555578e3470, in=0x7ffff4efd3e0, out=0x7ffff4efd3b0, err=err@entry=0x7ffff4efd3c0, ra=ra@entry=0) at ../../target/i386/tcg/sysemu/excp_helper.c:174
17 0x0000555555b4c4b3 in get_physical_address (ra=0, err=0x7ffff4efd3c0, out=0x7ffff4efd3b0, mmu_idx=0, access_type=MMU_DATA_LOAD, addr=18446741874686299840, env=0x5555578e3470) at ../../target/i386/tcg/sysemu/excp_helper.c:580
18 x86_cpu_tlb_fill (cs=0x5555578e0cb0, addr=18446741874686299840, size=<optimized out>, access_type=MMU_DATA_LOAD, mmu_idx=0, probe=<optimized out>, retaddr=0) at ../../target/i386/tcg/sysemu/excp_helper.c:606
19 0x0000555555ca0ee9 in tlb_fill (retaddr=0, mmu_idx=0, access_type=MMU_DATA_LOAD, size=<optimized out>, addr=18446741874686299840, cpu=0x7ffff4efd540) at ../../accel/tcg/cputlb.c:1315
20 mmu_lookup1 (cpu=cpu@entry=0x5555578e0cb0, data=data@entry=0x7ffff4efd540, mmu_idx=0, access_type=access_type@entry=MMU_DATA_LOAD, ra=ra@entry=0) at ../../accel/tcg/cputlb.c:1713
21 0x0000555555ca2c61 in mmu_lookup (cpu=cpu@entry=0x5555578e0cb0, addr=addr@entry=18446741874686299840, oi=oi@entry=32, ra=ra@entry=0, type=type@entry=MMU_DATA_LOAD, l=l@entry=0x7ffff4efd540) at ../../accel/tcg/cputlb.c:1803
22 0x0000555555ca3165 in do_ld4_mmu (cpu=cpu@entry=0x5555578e0cb0, addr=addr@entry=18446741874686299840, oi=oi@entry=32, ra=ra@entry=0, access_type=access_type@entry=MMU_DATA_LOAD) at ../../accel/tcg/cputlb.c:2416
23 0x0000555555ca5ef9 in cpu_ldl_mmu (ra=0, oi=32, addr=18446741874686299840, env=0x5555578e3470) at ../../accel/tcg/ldst_common.c.inc:158
24 cpu_ldl_le_mmuidx_ra (env=env@entry=0x5555578e3470, addr=addr@entry=18446741874686299840, mmu_idx=<optimized out>, ra=ra@entry=0) at ../../accel/tcg/ldst_common.c.inc:294
25 0x0000555555bb6cdd in do_interrupt64 (is_hw=1, next_eip=18446744072399775809, error_code=0, is_int=0, intno=236, env=0x5555578e3470) at ../../target/i386/tcg/seg_helper.c:889
26 do_interrupt_all (cpu=cpu@entry=0x5555578e0cb0, intno=236, is_int=is_int@entry=0, error_code=error_code@entry=0, next_eip=next_eip@entry=0, is_hw=is_hw@entry=1) at ../../target/i386/tcg/seg_helper.c:1130
27 0x0000555555bb87da in do_interrupt_x86_hardirq (env=env@entry=0x5555578e3470, intno=<optimized out>, is_hw=is_hw@entry=1) at ../../target/i386/tcg/seg_helper.c:1162
28 0x0000555555b5039c in x86_cpu_exec_interrupt (cs=0x5555578e0cb0, interrupt_request=<optimized out>) at ../../target/i386/tcg/sysemu/seg_helper.c:197
29 0x0000555555c94480 in cpu_handle_interrupt (last_tb=<synthetic pointer>, cpu=0x5555578e0cb0) at ../../accel/tcg/cpu-exec.c:844
Peter identified this as being due to the BQL already being
held when the page table walker encounters MMIO memory and attempts
to take the lock again. There are other examples of similar paths
TCG, so this follows the approach taken in those of simply checking
if the lock is already held and if it is, don't take it again.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20240219173153.12114-4-Jonathan.Cameron@huawei.com>
[rth: Use BQL_LOCK_GUARD]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
A memory page poisoned from the hypervisor level is no longer readable.
The migration of a VM will crash Qemu when it tries to read the
memory address space and stumbles on the poisoned page with a similar
stack trace:
Program terminated with signal SIGBUS, Bus error.
#0 _mm256_loadu_si256
#1 buffer_zero_avx2
#2 select_accel_fn
#3 buffer_is_zero
#4 save_zero_page
#5 ram_save_target_page_legacy
#6 ram_save_host_page
#7 ram_find_and_save_block
#8 ram_save_iterate
#9 qemu_savevm_state_iterate
#10 migration_iteration_run
#11 migration_thread
#12 qemu_thread_start
To avoid this VM crash during the migration, prevent the migration
when a known hardware poison exists on the VM.
Signed-off-by: William Roche <william.roche@oracle.com>
Link: https://lore.kernel.org/r/20240130190640.139364-2-william.roche@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>
The function is now trivial, and with inlining we can
re-use the calling function's tcg_ops variable.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Unless I'm missing something egregious, the jmp cache is only every
populated with a valid entry by the same thread that reads the cache.
Therefore, the contents of any valid entry are always consistent and
there is no need for any acquire/release magic.
Indeed ->tb has to be accessed with atomics, because concurrent
invalidations would otherwise cause data races. But ->pc is only ever
accessed by one thread, and accesses to ->tb and ->pc within tb_lookup
can never race with another tb_lookup. While the TranslationBlock
(especially the flags) could be modified by a concurrent invalidation,
store-release and load-acquire operations on the cache entry would
not add any additional ordering beyond what you get from performing
the accesses within a single thread.
Because of this, there is really nothing to win in splitting the CF_PCREL
and !CF_PCREL paths. It is easier to just always use the ->pc field in
the jump cache.
I noticed this while working on splitting commit 8ed558ec0c
("accel/tcg: Introduce TARGET_TB_PCREL", 2022-10-04) into multiple
pieces, for the sake of finding a more fine-grained bisection
result for https://gitlab.com/qemu-project/qemu/-/issues/2092.
It does not (and does not intend to) fix that issue; therefore
it may make sense to not commit it until the root cause
of issue #2092 is found.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240122153409.351959-1-pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Since previous commit, tb_invalidate_phys_page() is not used
anymore in system emulation. Make it static for user emulation
and remove its public declaration in "exec/translate-all.h".
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20231130205600.35727-1-philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
'can_do_io' is specific to TCG. It was added to other
accelerators in 626cf8f4c6 ("icount: set can_do_io outside
TB execution"), then likely copy/pasted in commit c97d6d2cdf
("i386: hvf: add code base from Google's QEMU repository").
Having it set in non-TCG code is confusing, so remove it from
QTest / HVF / KVM.
Fixes: 626cf8f4c6 ("icount: set can_do_io outside TB execution")
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20231129205037.16849-1-philmd@linaro.org>
This allows passing the KVM device node to use as a file
descriptor via /dev/fdset/XX. Passing the device node to
use as a file descriptor allows running qemu unprivileged
even when the user running qemu is not in the kvm group
on distributions where access to /dev/kvm is gated behind
membership of the kvm group (as long as the process invoking
qemu is able to open /dev/kvm and passes the file descriptor
to qemu).
Signed-off-by: Daan De Meyer <daan.j.demeyer@gmail.com>
Message-ID: <20231021134015.1119597-1-daan.j.demeyer@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
