Re: [PATCH v6 08/18] s390x: Add SIDA memory ops

[David Hildenbrand]

On 04.03.20 12:42, Janosch Frank wrote:
> Protected guests save the instruction control blocks in the SIDA
> instead of QEMU/KVM directly accessing the guest's memory.
> 
> Let's introduce new functions to access the SIDA.

"The new memops are available with KVM_CAP_S390_PROTECTED, so let's
check for that."

> 
> Signed-off-by: Janosch Frank <address@hidden>
> ---
>  linux-headers/linux/kvm.h |  2 ++
>  target/s390x/cpu.h        |  7 ++++++-
>  target/s390x/kvm.c        | 25 +++++++++++++++++++++++++
>  target/s390x/kvm_s390x.h  |  2 ++
>  target/s390x/mmu_helper.c | 14 ++++++++++++++
>  5 files changed, 49 insertions(+), 1 deletion(-)
> 
> diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
> index e36f761194..c30344ab00 100644
> --- a/linux-headers/linux/kvm.h
> +++ b/linux-headers/linux/kvm.h
> @@ -483,6 +483,8 @@ struct kvm_s390_mem_op {
>  /* types for kvm_s390_mem_op->op */
>  #define KVM_S390_MEMOP_LOGICAL_READ  0
>  #define KVM_S390_MEMOP_LOGICAL_WRITE 1
> +#define KVM_S390_MEMOP_SIDA_READ     2
> +#define KVM_S390_MEMOP_SIDA_WRITE    3
>  /* flags for kvm_s390_mem_op->flags */
>  #define KVM_S390_MEMOP_F_CHECK_ONLY          (1ULL << 0)
>  #define KVM_S390_MEMOP_F_INJECT_EXCEPTION    (1ULL << 1)

This should go into the header sync.

[...]

> index 7e4d9d267c..2578c838f8 100644
> --- a/target/s390x/cpu.h
> +++ b/target/s390x/cpu.h
> @@ -824,7 +824,12 @@ int s390_cpu_virt_mem_rw(S390CPU *cpu, vaddr laddr, 
> uint8_t ar, void *hostbuf,
>  #define s390_cpu_virt_mem_check_write(cpu, laddr, ar, len)   \
>          s390_cpu_virt_mem_rw(cpu, laddr, ar, NULL, len, true)
>  void s390_cpu_virt_mem_handle_exc(S390CPU *cpu, uintptr_t ra);
> -
> +int s390_cpu_pv_mem_rw(S390CPU *cpu, unsigned int offset,  void *hostbuf,

double space after "offset,"

[...]

>  
> +int s390_cpu_pv_mem_rw(S390CPU *cpu, unsigned int offset, void *hostbuf,
> +                       int len, bool is_write)
> +{
> +    int ret;
> +
> +    if (kvm_enabled()) {
> +        ret = kvm_s390_mem_op_pv(cpu, offset, hostbuf, len, is_write);
> +    } else {
> +        /* Protected Virtualization is a KVM/Hardware only feature */
> +        g_assert_not_reached();
> +    }
> +    return ret;
> +}


I suspect nobody will ever check the return value, correct?

With the things changed

Reviewed-by: David Hildenbrand <address@hidden>

-- 
Thanks,

David / dhildenb