On 11/01/2025 00:42, Samuel Holland wrote:
> Hi Clément,
>
> On 2025-01-06 9:48 AM, Clément Léger wrote:
>> The FWFT SBI extension will need to dynamically allocate memory and do
>> init time specific initialization. Add an init/deinit callbacks that
>> allows to do so.
>>
>> Signed-off-by: Clément Léger <cleger@xxxxxxxxxxxx>
>> ---
>> arch/riscv/include/asm/kvm_vcpu_sbi.h | 9 ++++++++
>> arch/riscv/kvm/vcpu.c | 2 ++
>> arch/riscv/kvm/vcpu_sbi.c | 31 ++++++++++++++++++++++++++-
>> 3 files changed, 41 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h
>> index b96705258cf9..8c465ce90e73 100644
>> --- a/arch/riscv/include/asm/kvm_vcpu_sbi.h
>> +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h
>> @@ -49,6 +49,14 @@ struct kvm_vcpu_sbi_extension {
>>
>> /* Extension specific probe function */
>> unsigned long (*probe)(struct kvm_vcpu *vcpu);
>> +
>> + /*
>> + * Init/deinit function called once during VCPU init/destroy. These
>> + * might be use if the SBI extensions need to allocate or do specific
>> + * init time only configuration.
>> + */
>> + int (*init)(struct kvm_vcpu *vcpu);
>> + void (*deinit)(struct kvm_vcpu *vcpu);
>> };
>>
>> void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run);
>> @@ -69,6 +77,7 @@ const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(
>> bool riscv_vcpu_supports_sbi_ext(struct kvm_vcpu *vcpu, int idx);
>> int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run);
>> void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu);
>> +void kvm_riscv_vcpu_sbi_deinit(struct kvm_vcpu *vcpu);
>>
>> int kvm_riscv_vcpu_get_reg_sbi_sta(struct kvm_vcpu *vcpu, unsigned long reg_num,
>> unsigned long *reg_val);
>> diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
>> index e048dcc6e65e..3420a4a62c94 100644
>> --- a/arch/riscv/kvm/vcpu.c
>> +++ b/arch/riscv/kvm/vcpu.c
>> @@ -180,6 +180,8 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
>>
>> void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
>> {
>> + kvm_riscv_vcpu_sbi_deinit(vcpu);
>> +
>> /* Cleanup VCPU AIA context */
>> kvm_riscv_vcpu_aia_deinit(vcpu);
>>
>> diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
>> index 6e704ed86a83..d2dbb0762072 100644
>> --- a/arch/riscv/kvm/vcpu_sbi.c
>> +++ b/arch/riscv/kvm/vcpu_sbi.c
>> @@ -486,7 +486,7 @@ void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu)
>> struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context;
>> const struct kvm_riscv_sbi_extension_entry *entry;
>> const struct kvm_vcpu_sbi_extension *ext;
>> - int idx, i;
>> + int idx, i, ret;
>>
>> for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
>> entry = &sbi_ext[i];
>> @@ -501,8 +501,37 @@ void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu)
>> continue;
>> }
>>
>> + if (ext->init) {
>> + ret = ext->init(vcpu);
>> + if (ret)
>> + scontext->ext_status[idx] =
>> + KVM_RISCV_SBI_EXT_STATUS_UNAVAILABLE;
>> + }
>> +
>> scontext->ext_status[idx] = ext->default_disabled ?
>> KVM_RISCV_SBI_EXT_STATUS_DISABLED :
>> KVM_RISCV_SBI_EXT_STATUS_ENABLED;
>
> This will overwrite the KVM_RISCV_SBI_EXT_STATUS_UNAVAILABLE set above.
Oh yes indeed, I should add a "continue" under the if above.
>
>> }
>> }
>> +
>> +void kvm_riscv_vcpu_sbi_deinit(struct kvm_vcpu *vcpu)
>> +{
>> + struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context;
>> + const struct kvm_riscv_sbi_extension_entry *entry;
>> + const struct kvm_vcpu_sbi_extension *ext;
>> + int idx, i;
>> +
>> + for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
>> + entry = &sbi_ext[i];
>> + ext = entry->ext_ptr;
>> + idx = entry->ext_idx;
>> +
>> + if (idx < 0 || idx >= ARRAY_SIZE(scontext->ext_status))
>> + continue;
>> +
>> + if (scontext->ext_status[idx] != KVM_RISCV_SBI_EXT_STATUS_ENABLED || !ext->deinit)
>
> Given that an extension can be enabled/disabled after initialization, this
> should only skip deinit if the status is UNAVAILABLE.
yeah, make sense as well,
Thanks for the review,
Clément
>
> Regards,
> Samuel
>
>> + continue;
>> +
>> + ext->deinit(vcpu);
>> + }
>> +}
>
