Re: [PATCH v2 04/13] s390x/tcg: check for addressing exceptions for RRBE, SSKE and ISKE

[Cornelia Huck]

On Wed, Aug 11 2021, David Hildenbrand <david@redhat.com> wrote:

> Let's replace the ram_size check by a proper physical address space
> check (for example, to prepare for memory hotplug), trigger addressing
> exceptions and trace the return value of the storage key getter/setter.
>
> Provide an helper mmu_absolute_addr_valid() to be used in other context
> soon. Always test for "read" instead of "write" as we are not actually
> modifying the page itself.
>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  target/s390x/helper.h         |  6 +++---
>  target/s390x/mmu_helper.c     |  8 ++++++++
>  target/s390x/s390x-internal.h |  1 +
>  target/s390x/tcg/mem_helper.c | 36 ++++++++++++++++++++++-------------
>  4 files changed, 35 insertions(+), 16 deletions(-)
>

> diff --git a/target/s390x/tcg/mem_helper.c b/target/s390x/tcg/mem_helper.c
> index dd506d8d17..90ac82fdcc 100644
> --- a/target/s390x/tcg/mem_helper.c
> +++ b/target/s390x/tcg/mem_helper.c
> @@ -28,6 +28,7 @@
>  #include "qemu/int128.h"
>  #include "qemu/atomic128.h"
>  #include "tcg/tcg.h"
> +#include "trace.h"
>  
>  #if !defined(CONFIG_USER_ONLY)
>  #include "hw/s390x/storage-keys.h"
> @@ -2171,15 +2172,15 @@ uint32_t HELPER(tprot)(CPUS390XState *env, uint64_t 
> a1, uint64_t a2)
>  /* insert storage key extended */
>  uint64_t HELPER(iske)(CPUS390XState *env, uint64_t r2)
>  {
> -    MachineState *ms = MACHINE(qdev_get_machine());
>      static S390SKeysState *ss;
>      static S390SKeysClass *skeyclass;
>      uint64_t addr = wrap_address(env, r2);
>      uint8_t key;
> +    int rc;
>  
>      addr = mmu_real2abs(env, addr);
> -    if (addr > ms->ram_size) {
> -        return 0;
> +    if (!mmu_absolute_addr_valid(addr, false)) {
> +        trigger_pgm_exception(env, PGM_ADDRESSING);

Don't you need s390_program_interrupt() instead?

>      }
>  
>      if (unlikely(!ss)) {