Re: [PATCH 8/9] physmem,gdbstub: Add helper functions to help *unrealize* vCPU object

["Alex Bennée" <alex.bennee@linaro.org>]

Salil Mehta <salil.mehta@huawei.com> writes:

> vCPU Hot-unplug requires some helper functions to unroll what has happened
> during realization of a CPU object.
>
> Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
> ---
>  gdbstub/gdbstub.c         | 13 +++++++++++++
>  include/exec/cpu-common.h |  8 ++++++++
>  include/exec/gdbstub.h    |  1 +
>  include/hw/core/cpu.h     |  1 +
>  softmmu/physmem.c         | 25 +++++++++++++++++++++++++
>  5 files changed, 48 insertions(+)
>
> diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
> index 349d348c7b..a06ea3adad 100644
> --- a/gdbstub/gdbstub.c
> +++ b/gdbstub/gdbstub.c
> @@ -491,6 +491,19 @@ void gdb_register_coprocessor(CPUState *cpu,
>      }
>  }
>  
> +void gdb_unregister_coprocessor_all(CPUState *cpu)
> +{
> +    GDBRegisterState *s, *p;
> +
> +    p = cpu->gdb_regs;
> +    while (p) {
> +        s = p;
> +        p = p->next;

Maybe add:

      /* s->xml is static const char so isn't freed */

> +        g_free(s);
> +    }
> +    cpu->gdb_regs = NULL;
> +}
> +
>  static void gdb_process_breakpoint_remove_all(GDBProcess *p)
>  {
>      CPUState *cpu = gdb_get_first_cpu_in_process(p);
> diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
> index 41788c0bdd..eb56a228a2 100644
> --- a/include/exec/cpu-common.h
> +++ b/include/exec/cpu-common.h
> @@ -120,6 +120,14 @@ size_t qemu_ram_pagesize_largest(void);
>   */
>  void cpu_address_space_init(CPUState *cpu, int asidx,
>                              const char *prefix, MemoryRegion *mr);
> +/**
> + * cpu_address_space_destroy:
> + * @cpu: CPU for which address space needs to be destroyed
> + * @asidx: integer index of this address space
> + *
> + * Note that with KVM only one address space is supported.
> + */
> +void cpu_address_space_destroy(CPUState *cpu, int asidx);
>  
>  void cpu_physical_memory_rw(hwaddr addr, void *buf,
>                              hwaddr len, bool is_write);
> diff --git a/include/exec/gdbstub.h b/include/exec/gdbstub.h
> index 16a139043f..986d8d2fa5 100644
> --- a/include/exec/gdbstub.h
> +++ b/include/exec/gdbstub.h
> @@ -27,6 +27,7 @@ typedef int (*gdb_set_reg_cb)(CPUArchState *env, uint8_t *buf, int reg);
>  void gdb_register_coprocessor(CPUState *cpu,
>                                gdb_get_reg_cb get_reg, gdb_set_reg_cb set_reg,
>                                int num_regs, const char *xml, int
>  g_pos);

Can we have a kdoc comment here describing the function.

I suspect this should be split into two patches, one for gdbstub and one
for physmem.

> +void gdb_unregister_coprocessor_all(CPUState *cpu);
>  
>  /**
>   * gdbserver_start: start the gdb server
> diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
> index 648b5b3586..65d2ae4581 100644
> --- a/include/hw/core/cpu.h
> +++ b/include/hw/core/cpu.h
> @@ -355,6 +355,7 @@ struct CPUState {
>      QSIMPLEQ_HEAD(, qemu_work_item) work_list;
>  
>      CPUAddressSpace *cpu_ases;
> +    int cpu_ases_count;
>      int num_ases;
>      AddressSpace *as;
>      MemoryRegion *memory;
> diff --git a/softmmu/physmem.c b/softmmu/physmem.c
> index 4f6ca653b3..4dfa0ca66f 100644
> --- a/softmmu/physmem.c
> +++ b/softmmu/physmem.c
> @@ -761,6 +761,7 @@ void cpu_address_space_init(CPUState *cpu, int asidx,
>  
>      if (!cpu->cpu_ases) {
>          cpu->cpu_ases = g_new0(CPUAddressSpace, cpu->num_ases);
> +        cpu->cpu_ases_count = cpu->num_ases;
>      }
>  
>      newas = &cpu->cpu_ases[asidx];
> @@ -774,6 +775,30 @@ void cpu_address_space_init(CPUState *cpu, int asidx,
>      }
>  }
>  
> +void cpu_address_space_destroy(CPUState *cpu, int asidx)
> +{
> +    CPUAddressSpace *cpuas;
> +
> +    assert(asidx < cpu->num_ases);
> +    assert(asidx == 0 || !kvm_enabled());
> +    assert(cpu->cpu_ases);
> +
> +    cpuas = &cpu->cpu_ases[asidx];
> +    if (tcg_enabled()) {
> +        memory_listener_unregister(&cpuas->tcg_as_listener);
> +    }
> +
> +    address_space_destroy(cpuas->as);
> +    g_free_rcu(cpuas->as, rcu);
> +
> +    if (cpu->cpu_ases_count == 1) {
> +        g_free(cpu->cpu_ases);
> +        cpu->cpu_ases = NULL;
> +    }
> +
> +    cpu->cpu_ases_count--;
> +}
> +
>  AddressSpace *cpu_get_address_space(CPUState *cpu, int asidx)
>  {
>      /* Return the AddressSpace corresponding to the specified index */


-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro