Hi Weiwei Li,

`dyn_csr_base_reg` will be used in `riscv_refresh_dynamic_csr_xml`
We can initialize this variable when the cpu is realized. And used this
variable in `riscv_refresh_dynamic_csr_xml`.

Best regards,
Tommy


On Tue, May 23, 2023 at 10:38 PM Weiwei Li <liweiwei@iscas.ac.cn> wrote:

>
> On 2023/5/23 19:44, Tommy Wu wrote:
> > When we change the cpu extension state after the cpu is
> > realized, we cannot print the value of some CSRs in the remote
> > gdb debugger. The root cause is that the dynamic CSR xml is
> > generated when the cpu is realized.
> >
> > This patch add a function to refresh the dynamic CSR xml after
> > the cpu is realized.
> >
> > Signed-off-by: Tommy Wu <tommy.wu@sifive.com>
> > Reviewed-by: Frank Chang <frank.chang@sifive.com>
> > ---
> >   target/riscv/cpu.h     |  2 ++
> >   target/riscv/gdbstub.c | 12 ++++++++++++
> >   2 files changed, 14 insertions(+)
> >
> > diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> > index de7e43126a..dc8e592275 100644
> > --- a/target/riscv/cpu.h
> > +++ b/target/riscv/cpu.h
> > @@ -494,6 +494,7 @@ struct ArchCPU {
> >       CPUNegativeOffsetState neg;
> >       CPURISCVState env;
> >
> > +    int dyn_csr_base_reg;
>
> dyn_csr_base_reg  seems have no additional effect on the function.
>
> And It remains unmodified in following riscv_refresh_dynamic_csr_xml().
>
> Regards,
>
> Weiwei Li
>
> >       char *dyn_csr_xml;
> >       char *dyn_vreg_xml;
> >
> > @@ -781,6 +782,7 @@ void riscv_get_csr_ops(int csrno,
> riscv_csr_operations *ops);
> >   void riscv_set_csr_ops(int csrno, riscv_csr_operations *ops);
> >
> >   void riscv_cpu_register_gdb_regs_for_features(CPUState *cs);
> > +void riscv_refresh_dynamic_csr_xml(CPUState *cs);
> >
> >   uint8_t satp_mode_max_from_map(uint32_t map);
> >   const char *satp_mode_str(uint8_t satp_mode, bool is_32_bit);
> > diff --git a/target/riscv/gdbstub.c b/target/riscv/gdbstub.c
> > index 524bede865..9e97ee2c35 100644
> > --- a/target/riscv/gdbstub.c
> > +++ b/target/riscv/gdbstub.c
> > @@ -230,6 +230,8 @@ static int riscv_gen_dynamic_csr_xml(CPUState *cs,
> int base_reg)
> >           bitsize = 64;
> >       }
> >
> > +    cpu->dyn_csr_base_reg = base_reg;
> > +
> >       g_string_printf(s, "<?xml version=\"1.0\"?>");
> >       g_string_append_printf(s, "<!DOCTYPE feature SYSTEM
> \"gdb-target.dtd\">");
> >       g_string_append_printf(s, "<feature
> name=\"org.gnu.gdb.riscv.csr\">");
> > @@ -349,3 +351,13 @@ void
> riscv_cpu_register_gdb_regs_for_features(CPUState *cs)
> >                                    "riscv-csr.xml", 0);
> >       }
> >   }
> > +
> > +void riscv_refresh_dynamic_csr_xml(CPUState *cs)
> > +{
> > +    RISCVCPU *cpu = RISCV_CPU(cs);
> > +    if (!cpu->dyn_csr_xml) {
> > +        g_assert_not_reached();
> > +    }
> > +    g_free(cpu->dyn_csr_xml);
> > +    riscv_gen_dynamic_csr_xml(cs, cpu->dyn_csr_base_reg);
> > +}
>
>