On Tue, 29 Aug 2023 at 17:59, Paolo Bonzini <pbonz...@redhat.com> wrote: > > On Tue, Aug 29, 2023 at 5:46 PM Philippe Mathieu-Daudé > <phi...@linaro.org> wrote: > > > > On 29/8/23 17:25, Paolo Bonzini wrote: > > > Otherwise tcg_handle_interrupt() triggers an assertion failure: > > > > > > #5 0x0000555555c97369 in tcg_handle_interrupt (cpu=0x555557434cb0, > > > mask=2) at ../accel/tcg/tcg-accel-ops.c:83 > > > #6 tcg_handle_interrupt (cpu=0x555557434cb0, mask=2) at > > > ../accel/tcg/tcg-accel-ops.c:81 > > > #7 0x0000555555b4d58b in pic_irq_request (opaque=<optimized out>, > > > irq=<optimized out>, level=1) at ../hw/i386/x86.c:555 > > > #8 0x0000555555b4f218 in gsi_handler (opaque=0x5555579423d0, n=13, > > > level=1) at ../hw/i386/x86.c:611 > > > #9 0x00007fffa42bde14 in code_gen_buffer () > > > #10 0x0000555555c724bb in cpu_tb_exec (cpu=cpu@entry=0x555557434cb0, > > > itb=<optimized out>, tb_exit=tb_exit@entry=0x7fffe9bfd658) at > > > ../accel/tcg/cpu-exec.c:457 > > > > > > Cc: qemu-sta...@nongnu.org > > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1808 > > > Reported-by: NyanCatTW1 <https://gitlab.com/a0939712328> > > > Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> > > > --- > > > target/i386/tcg/sysemu/fpu_helper.c | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/target/i386/tcg/sysemu/fpu_helper.c > > > b/target/i386/tcg/sysemu/fpu_helper.c > > > index 1c3610da3b9..fd8cc72a026 100644 > > > --- a/target/i386/tcg/sysemu/fpu_helper.c > > > +++ b/target/i386/tcg/sysemu/fpu_helper.c > > > @@ -31,7 +31,9 @@ void x86_register_ferr_irq(qemu_irq irq) > > > void fpu_check_raise_ferr_irq(CPUX86State *env) > > > { > > > if (ferr_irq && !(env->hflags2 & HF2_IGNNE_MASK)) { > > > + qemu_mutex_lock_iothread(); > > > qemu_irq_raise(ferr_irq); > > > + qemu_mutex_unlock_iothread(); > > > return; > > > } > > > } > > > > OK, so: > > > > Reviewed-by: Philippe Mathieu-Daudé <phi...@linaro.org> > > Actually Richard has a better (though also slightly incomplete) patch > in the bug, so I'll send v2. > > > void cpu_set_ignne(void) > > { > > CPUX86State *env = &X86_CPU(first_cpu)->env; > > + > > + g_assert(qemu_mutex_iothread_locked()); > > qemu_irq_lower() is fine because it doesn't result in a call to > tcg_handle_interrupt().
It does potentially result in calling code in a device model that assumes that it is protected by the iothread lock, though... -- PMM
