Re: [Qemu-devel] [PATCH v2 3/4] qom/cpu: remove host_tid field

[Claudio Imbrenda]

On Thu, 1 Jun 2017 17:32:13 +0200
Greg Kurz <address@hidden> wrote:

> On Thu,  1 Jun 2017 15:49:14 +0100
> Alex Bennée <address@hidden> wrote:
> 
> > This was only used by the gdbstub and even then was only being set
> > for subsequent threads. Rather the continue duplicating the number
> > just make the gdbstub get the information from TaskState structure.
> > 
> > Now the tid is correctly reported for all threads the bug I was
> > seeing with "vCont;C04:0;c" packets is fixed as the correct tid is
> > reported to gdb.
> > 
> > I moved cpu_gdb_index into the gdbstub to facilitate easy access to
> > the TaskState which is used elsewhere in gdbstub.
> >   
> 
> FWIW, this change would make more sense in patch 2 since all users
> are in gdbstub.c and it would avoid to change things twice. No big
> deal compared to the benefit of dropping the broken @host_tid :)

I agree with this

> > Signed-off-by: Alex Bennée <address@hidden>
> > ---  
> 
> In any case.
> 
> Reviewed-by: Greg Kurz <address@hidden>

and me too

Reviewed-by: Claudio Imbrenda <address@hidden>
 
> >  gdbstub.c              | 15 +++++++++++++++
> >  include/exec/gdbstub.h | 14 --------------
> >  include/qom/cpu.h      |  2 --
> >  linux-user/syscall.c   |  1 -
> >  4 files changed, 15 insertions(+), 17 deletions(-)
> > 
> > diff --git a/gdbstub.c b/gdbstub.c
> > index 026d1fe6bb..45a3a0b16b 100644
> > --- a/gdbstub.c
> > +++ b/gdbstub.c
> > @@ -55,6 +55,21 @@ static inline int
> > target_memory_rw_debug(CPUState *cpu, target_ulong addr, return
> > cpu_memory_rw_debug(cpu, addr, buf, len, is_write); }
> >  
> > +/* Return the GDB index for a given vCPU state.
> > + *
> > + * For user mode this is simply the thread id. In system mode GDB
> > + * numbers CPUs from 1 as 0 is reserved as an "any cpu" index.
> > + */
> > +static inline int cpu_gdb_index(CPUState *cpu)
> > +{
> > +#if defined(CONFIG_USER_ONLY)
> > +    TaskState *ts = (TaskState *) cpu->opaque;
> > +    return ts->ts_tid;
> > +#else
> > +    return cpu->cpu_index + 1;
> > +#endif
> > +}
> > +
> >  enum {
> >      GDB_SIGNAL_0 = 0,
> >      GDB_SIGNAL_INT = 2,
> > diff --git a/include/exec/gdbstub.h b/include/exec/gdbstub.h
> > index c4fe567600..9aa7756d92 100644
> > --- a/include/exec/gdbstub.h
> > +++ b/include/exec/gdbstub.h
> > @@ -58,20 +58,6 @@ void gdb_register_coprocessor(CPUState *cpu,
> >                                gdb_reg_cb get_reg, gdb_reg_cb
> > set_reg, int num_regs, const char *xml, int g_pos);
> >  
> > -/* Return the GDB index for a given vCPU state.
> > - *
> > - * For user mode this is simply the thread id. In system mode GDB
> > - * numbers CPUs from 1 as 0 is reserved as an "any cpu" index.
> > - */
> > -static inline int cpu_gdb_index(CPUState *cpu)
> > -{
> > -#if defined(CONFIG_USER_ONLY)
> > -    return cpu->host_tid;
> > -#else
> > -    return cpu->cpu_index + 1;
> > -#endif
> > -}
> > -
> >  /* The GDB remote protocol transfers values in target byte order.
> > This means
> >   * we can use the raw memory access routines to access the value
> > buffer.
> >   * Conveniently, these also handle the case where the buffer is
> > mis-aligned. diff --git a/include/qom/cpu.h b/include/qom/cpu.h
> > index 55214ce131..909e7ae994 100644
> > --- a/include/qom/cpu.h
> > +++ b/include/qom/cpu.h
> > @@ -266,7 +266,6 @@ struct qemu_work_item;
> >   * @nr_cores: Number of cores within this CPU package.
> >   * @nr_threads: Number of threads within this CPU.
> >   * @numa_node: NUMA node this CPU is belonging to.
> > - * @host_tid: Host thread ID.
> >   * @running: #true if CPU is currently running (lockless).
> >   * @has_waiter: #true if a CPU is currently waiting for the
> > cpu_exec_end;
> >   * valid under cpu_list_lock.
> > @@ -321,7 +320,6 @@ struct CPUState {
> >      HANDLE hThread;
> >  #endif
> >      int thread_id;
> > -    uint32_t host_tid;
> >      bool running, has_waiter;
> >      struct QemuCond *halt_cond;
> >      bool thread_kicked;
> > diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> > index cec8428589..cada188e58 100644
> > --- a/linux-user/syscall.c
> > +++ b/linux-user/syscall.c
> > @@ -6216,7 +6216,6 @@ static void *clone_func(void *arg)
> >      thread_cpu = cpu;
> >      ts = (TaskState *)cpu->opaque;
> >      info->tid = gettid();
> > -    cpu->host_tid = info->tid;
> >      task_settid(ts);
> >      if (info->child_tidptr)
> >          put_user_u32(info->tid, info->child_tidptr);  
>