Re: [PATCH v3 06/10] arm/kvm: Allow reading all the writable ID registers

[Cornelia Huck <cohuck@redhat.com>]

On Tue, May 13 2025, Eric Auger <eric.auger@redhat.com> wrote:

> On 4/14/25 6:38 PM, Cornelia Huck wrote:
>> From: Eric Auger <eric.auger@redhat.com>
>>
>> At the moment kvm_arm_get_host_cpu_features() reads a subset of the
>> ID regs. As we want to introduce properties for all writable ID reg
>> fields, we want more genericity and read more default host register
>> values.
>>
>> Introduce a new get_host_cpu_idregs() helper and add a new exhaustive
>> boolean parameter to kvm_arm_get_host_cpu_features() and
>> kvm_arm_set_cpu_features_from_host() to select the right behavior.
>> The host cpu model will keep the legacy behavior unless the writable
>> id register interface is available.
>>
>> A writable_map IdRegMap is introduced in the CPU object. A subsequent
>> patch will populate it.
>>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
>> ---
>>  target/arm/cpu-sysregs.h |  2 ++
>>  target/arm/cpu.h         |  3 ++
>>  target/arm/cpu64.c       |  2 +-
>>  target/arm/kvm.c         | 78 ++++++++++++++++++++++++++++++++++++++--
>>  target/arm/kvm_arm.h     |  9 +++--
>>  target/arm/trace-events  |  1 +
>>  6 files changed, 89 insertions(+), 6 deletions(-)
>>

(...)

>> diff --git a/target/arm/cpu.h b/target/arm/cpu.h
>> index 775a8aebc5d3..8717c5e7695b 100644
>> --- a/target/arm/cpu.h
>> +++ b/target/arm/cpu.h
>> @@ -1088,6 +1088,9 @@ struct ArchCPU {
>>       */
>>      ARMIdRegsState writable_id_regs;
>>  
>> +    /* ID reg writable bitmask (KVM only) */
>> +    IdRegMap *writable_map;
> as it is KVM only we may put it in ifdef CONFIG_KVM block above

Forgot to reply here; the CONFIG_KVM block is gone with a725f3710231
("target/arm/cpu: always define kvm related registers")