Re: [PATCH v2 11/13] s390x: protvirt: Move diag 308 data over SIDAD

[David Hildenbrand <david@redhat.com>]

On 29.11.19 10:48, Janosch Frank wrote:
> For protected guests the IPIB is written/read to/from the satellite
> block, so we need to make those accesses virtual to make them go
> through KVM mem ops.

same comment regarding virt mem access. IMHO, the KVM mem ops should
return a hard error in case we're in pv mode.

> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  target/s390x/diag.c | 26 +++++++++++++++++++++++---
>  1 file changed, 23 insertions(+), 3 deletions(-)
> 
> diff --git a/target/s390x/diag.c b/target/s390x/diag.c
> index 5489fc721a..6d78759151 100644
> --- a/target/s390x/diag.c
> +++ b/target/s390x/diag.c
> @@ -88,6 +88,7 @@ static int diag308_parm_check(CPUS390XState *env, uint64_t r1, uint64_t addr,
>  void handle_diag_308(CPUS390XState *env, uint64_t r1, uint64_t r3, uintptr_t ra)
>  {
>      CPUState *cs = env_cpu(env);
> +    S390CPU *cpu = S390_CPU(cs);
>      uint64_t addr =  env->regs[r1];
>      uint64_t subcode = env->regs[r3];
>      IplParameterBlock *iplb;
> @@ -118,14 +119,27 @@ void handle_diag_308(CPUS390XState *env, uint64_t r1, uint64_t r3, uintptr_t ra)
>          if (diag308_parm_check(env, r1, addr, ra, false)) {
>              return;
>          }
> +
>          iplb = g_new0(IplParameterBlock, 1);
> -        cpu_physical_memory_read(addr, iplb, sizeof(iplb->len));
> +        if (!env->pv) {
> +            cpu_physical_memory_read(addr, iplb, sizeof(iplb->len));
> +        } else {
> +            s390_cpu_virt_mem_read(cpu, 0, 0, iplb, sizeof(iplb->len));
> +            s390_cpu_virt_mem_handle_exc(cpu, ra);
> +        }
> +
>          if (!iplb_valid_len(iplb)) {
>              env->regs[r1 + 1] = DIAG_308_RC_INVALID;
>              goto out;
>          }
>  
> -        cpu_physical_memory_read(addr, iplb, be32_to_cpu(iplb->len));
> +        if (!env->pv) {
> +            cpu_physical_memory_read(addr, iplb, be32_to_cpu(iplb->len));
> +        } else {
> +            s390_cpu_virt_mem_read(cpu, 0, 0, iplb, be32_to_cpu(iplb->len));
> +            s390_cpu_virt_mem_handle_exc(cpu, ra);
> +        }
> +
>  
>          if (!iplb_valid_ccw(iplb) && !iplb_valid_fcp(iplb) &&
>              !(iplb_valid_se(iplb) && s390_ipl_pv_check_comp(iplb) >= 0)) {
> @@ -149,7 +163,13 @@ out:
>              iplb = s390_ipl_get_iplb();
>          }
>          if (iplb) {
> -            cpu_physical_memory_write(addr, iplb, be32_to_cpu(iplb->len));
> +            if (!env->pv) {
> +                cpu_physical_memory_write(addr, iplb, be32_to_cpu(iplb->len));
> +            } else {
> +                s390_cpu_virt_mem_write(cpu, 0, 0, iplb,
> +                                        be32_to_cpu(iplb->len));
> +                s390_cpu_virt_mem_handle_exc(cpu, ra);

... exactly due to this handling where we actually can't have
exceptions, I don't like reusing this infrastructure/interface.

-- 
Thanks,

David / dhildenb