Re: [RFC PATCH v3 10/13] target/arm/cpu: Add cpu cache description for arm

[Ying Fang]

On 11/30/2020 9:00 PM, Peter Maydell wrote:
> On Mon, 9 Nov 2020 at 03:05, Ying Fang <fangying1@huawei.com> wrote:
> > Add the CPUCacheInfo structure to hold cpu cache information for ARM cpus.
> > A classic three level cache topology is used here. The default cache
> > capacity is given and userspace can overwrite these values.
> >
> > Signed-off-by: Ying Fang <fangying1@huawei.com>
> > ---
> >   target/arm/cpu.c | 42 ++++++++++++++++++++++++++++++++++++++++++
> >   target/arm/cpu.h | 27 +++++++++++++++++++++++++++
> >   2 files changed, 69 insertions(+)
> >
> > diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> > index 056319859f..f1bac7452c 100644
> > --- a/target/arm/cpu.c
> > +++ b/target/arm/cpu.c
> > @@ -27,6 +27,7 @@
> >   #include "qapi/visitor.h"
> >   #include "cpu.h"
> >   #include "internals.h"
> > +#include "qemu/units.h"
> >   #include "exec/exec-all.h"
> >   #include "hw/qdev-properties.h"
> >   #if !defined(CONFIG_USER_ONLY)
> > @@ -997,6 +998,45 @@ uint64_t arm_cpu_mp_affinity(int idx, uint8_t clustersz)
> >       return (Aff1 << ARM_AFF1_SHIFT) | Aff0;
> >   }
> >
> > +static CPUCaches default_cache_info = {
> > +    .l1d_cache = &(CPUCacheInfo) {
> > +    .type = DATA_CACHE,
> > +        .level = 1,
> > +        .size = 64 * KiB,
> > +        .line_size = 64,
> > +        .associativity = 4,
> > +        .sets = 256,
> > +        .attributes = 0x02,
> > +    },
>
> Would it be possible to populate this structure from the
> CLIDR/CCSIDR ID register values, rather than having to
> specify the same thing in two places?

Sorry I missed this reply.

I had tried to fetch CLIDR/CCSID ID register values of host cpu
from KVM, however I did not get the value expected. May I made
some mistakes in KVM side.

Thanks for your guide, I'll try to populate them again.

> thanks
> -- PMM
> .

Thanks.
Ying.