The only portion of FEAT_Debugv8p2 that is relevant to QEMU
is CONTEXTIDR_EL2, which is also conditionally implemented
with FEAT_VHE.  The rest of the debug extension concerns the
External debug interface, which is outside the scope of QEMU.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/cpu.c     | 1 +
 target/arm/cpu64.c   | 1 +
 target/arm/cpu_tcg.c | 2 ++
 3 files changed, 4 insertions(+)

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 6521f350f9..d815d3a397 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -1800,6 +1800,7 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
          * feature registers as well.
          */
         cpu->isar.id_pfr1 = FIELD_DP32(cpu->isar.id_pfr1, ID_PFR1, SECURITY, 0);
+        cpu->isar.id_dfr0 = FIELD_DP32(cpu->isar.id_dfr0, ID_DFR0, COPSDBG, 0);
         cpu->isar.id_aa64pfr0 = FIELD_DP64(cpu->isar.id_aa64pfr0,
                                            ID_AA64PFR0, EL3, 0);
     }
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index ae7114ea79..6b6422070d 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -854,6 +854,7 @@ static void aarch64_max_initfn(Object *obj)
     cpu->isar.id_aa64zfr0 = t;
 
     t = cpu->isar.id_aa64dfr0;
+    t = FIELD_DP64(t, ID_AA64DFR0, DEBUGVER, 8);  /* FEAT_Debugv8p2 */
     t = FIELD_DP64(t, ID_AA64DFR0, PMUVER, 5);    /* FEAT_PMUv3p4 */
     cpu->isar.id_aa64dfr0 = t;
 
diff --git a/target/arm/cpu_tcg.c b/target/arm/cpu_tcg.c
index 9d5cd6ea00..ac91bbea9b 100644
--- a/target/arm/cpu_tcg.c
+++ b/target/arm/cpu_tcg.c
@@ -79,6 +79,8 @@ void arm32_max_features(ARMCPU *cpu)
     cpu->isar.id_pfr2 = t;
 
     t = cpu->isar.id_dfr0;
+    t = FIELD_DP32(t, ID_DFR0, COPDBG, 8);        /* FEAT_Debugv8p2 */
+    t = FIELD_DP32(t, ID_DFR0, COPSDBG, 8);       /* FEAT_Debugv8p2 */
     t = FIELD_DP32(t, ID_DFR0, PERFMON, 5);       /* FEAT_PMUv3p4 */
     cpu->isar.id_dfr0 = t;
 }
-- 
2.25.1

On Sat, 9 Apr 2022 at 01:18, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> The only portion of FEAT_Debugv8p2 that is relevant to QEMU
> is CONTEXTIDR_EL2, which is also conditionally implemented
> with FEAT_VHE.  The rest of the debug extension concerns the
> External debug interface, which is outside the scope of QEMU.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/arm/cpu.c     | 1 +
>  target/arm/cpu64.c   | 1 +
>  target/arm/cpu_tcg.c | 2 ++
>  3 files changed, 4 insertions(+)
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

On Mon, 11 Apr 2022 at 14:09, Peter Maydell <peter.maydell@linaro.org> wrote:
>
> On Sat, 9 Apr 2022 at 01:18, Richard Henderson
> <richard.henderson@linaro.org> wrote:
> >
> > The only portion of FEAT_Debugv8p2 that is relevant to QEMU
> > is CONTEXTIDR_EL2, which is also conditionally implemented
> > with FEAT_VHE.  The rest of the debug extension concerns the
> > External debug interface, which is outside the scope of QEMU.
> >
> > Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> > ---
> >  target/arm/cpu.c     | 1 +
> >  target/arm/cpu64.c   | 1 +
> >  target/arm/cpu_tcg.c | 2 ++
> >  3 files changed, 4 insertions(+)
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

...except that I've just remembered that this patch, and the
others in this and the other series that add support for new
FEAT_* need to update the list in docs/system/arm/emulation.rst
of all the features we implement.

thanks
-- PMM