> From: Alex Bennée <alex.ben...@linaro.org>
> Sent: Friday, September 29, 2023 3:35 PM
> To: Salil Mehta <salil.me...@huawei.com>
> Cc: qemu-devel@nongnu.org; qemu-...@nongnu.org; m...@kernel.org; jean-
> phili...@linaro.org; Jonathan Cameron <jonathan.came...@huawei.com>;
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> zhukeqian <zhukeqi...@huawei.com>; wangxiongfeng (C)
> <wangxiongfe...@huawei.com>; wangyanan (Y) <wangyana...@huawei.com>;
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> <linux...@huawei.com>
> Subject: Re: [PATCH 8/9] physmem,gdbstub: Add helper functions to help
> *unrealize* vCPU object
>
>
> Salil Mehta <salil.me...@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.me...@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 */
Sure.
> > + 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.
Ok.
>
> I suspect this should be split into two patches, one for gdbstub and one
> for physmem.
No issues. Can do that.
> > +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
