Re: [PATCH 03/15] s390x: protvirt: Add diag308 subcodes 8 - 10

[Thomas Huth <thuth@redhat.com>]

On 20/11/2019 12.43, Janosch Frank wrote:
> For diag308 subcodes 8 - 10 we have a new ipib of type 5. The ipib
> holds the address and length of the secure execution header, as well
> as a list of guest components.
> 
> Each component is a block of memory, for example kernel or initrd,
> which needs to be decrypted by the Ultravisor in order to run a
> protected VM. The secure execution header instructs the Ultravisor on
> how to handle the protected VM and its components.
> 
> Subcodes 8 and 9 are similiar to 5 and 6 and subcode 10 will finally
> start the protected guest.
> 
> Subcodes 8-10 are not valid in protected mode, we have to do a subcode
> 3 and then the 8 and 10 combination for a protected reboot.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
[...]
> diff --git a/hw/s390x/ipl.h b/hw/s390x/ipl.h
> index d4813105db..7b8a493509 100644
> --- a/hw/s390x/ipl.h
> +++ b/hw/s390x/ipl.h
> @@ -15,6 +15,24 @@
>  #include "cpu.h"
>  #include "hw/qdev-core.h"
>  
> +struct IPLBlockPVComp {
> +    uint64_t tweak_pref;
> +    uint64_t addr;
> +    uint64_t size;
> +} QEMU_PACKED;
> +typedef struct IPLBlockPVComp IPLBlockPVComp;
> +
> +struct IPLBlockPV {
> +    uint8_t  reserved[84];
> +    uint8_t  reserved67[3];

What does the "67" mean here?

> +    uint8_t  version;
> +    uint32_t num_comp;
> +    uint64_t pv_header_addr;
> +    uint64_t pv_header_len;
> +    struct IPLBlockPVComp components[];
> +} QEMU_PACKED;
> +typedef struct IPLBlockPV IPLBlockPV;

Given the fact that we had quite some headaches with QEMU_PACKED structs
in the past already, and the structs seem to be naturally aligned ...
what about dropping the QEMU_PACKED here and using QEMU_BUILD_BUG() to
assert that the struct has the correct size?

[...]
> @@ -185,4 +211,11 @@ static inline bool iplb_valid_fcp(IplParameterBlock *iplb)
>             iplb->pbt == S390_IPL_TYPE_FCP;
>  }
>  
> +static inline bool iplb_valid_se(IplParameterBlock *iplb)
> +{
> +    return be32_to_cpu(iplb->len) >= S390_IPLB_MIN_PV_LEN &&
> +           iplb->pbt == S390_IPL_TYPE_PV;
> +}
> +
> +

Drop one empty line?

>  #endif
> diff --git a/target/s390x/diag.c b/target/s390x/diag.c
> index 067c667ba7..32049bb4ee 100644
> --- a/target/s390x/diag.c
> +++ b/target/s390x/diag.c
> @@ -52,6 +52,8 @@ int handle_diag_288(CPUS390XState *env, uint64_t r1, uint64_t r3)
>  #define DIAG_308_RC_OK              0x0001
>  #define DIAG_308_RC_NO_CONF         0x0102
>  #define DIAG_308_RC_INVALID         0x0402
> +#define DIAG_308_RC_NO_PV_CONF      0x0a02
> +#define DIAG_308_RC_INV_FOR_PV      0x0b02
>  
>  #define DIAG308_RES_MOD_CLR		0
>  #define DIAG308_RES_LOAD_NORM		1
> @@ -59,6 +61,9 @@ int handle_diag_288(CPUS390XState *env, uint64_t r1, uint64_t r3)
>  #define DIAG308_LOAD_NORMAL_DUMP	4
>  #define DIAG308_SET			5
>  #define DIAG308_STORE			6
> +#define DIAG308_PV_SET			8
> +#define DIAG308_PV_STORE		9
> +#define DIAG308_PV_START		10
>  
>  static int diag308_parm_check(CPUS390XState *env, uint64_t r1, uint64_t addr,
>                                uintptr_t ra, bool write)
> @@ -105,6 +110,7 @@ void handle_diag_308(CPUS390XState *env, uint64_t r1, uint64_t r3, uintptr_t ra)
>          s390_ipl_reset_request(cs, S390_RESET_REIPL);
>          break;
>      case DIAG308_SET:
> +    case DIAG308_PV_SET: /* Set SE parms */
>          if (diag308_parm_check(env, r1, addr, ra, false)) {
>              return;
>          }
> @@ -117,7 +123,8 @@ void handle_diag_308(CPUS390XState *env, uint64_t r1, uint64_t r3, uintptr_t ra)
>  
>          cpu_physical_memory_read(addr, iplb, be32_to_cpu(iplb->len));
>  
> -        if (!iplb_valid_ccw(iplb) && !iplb_valid_fcp(iplb)) {
> +        if (!iplb_valid_ccw(iplb) && !iplb_valid_fcp(iplb) &&
> +            !(iplb_valid_se(iplb) && s390_ipl_pv_check_comp(iplb) >= 0)) {
>              env->regs[r1 + 1] = DIAG_308_RC_INVALID;
>              goto out;
>          }
> @@ -128,10 +135,15 @@ out:
>          g_free(iplb);
>          return;
>      case DIAG308_STORE:
> +    case DIAG308_PV_STORE: /* Get SE parms */
>          if (diag308_parm_check(env, r1, addr, ra, true)) {
>              return;
>          }
> -        iplb = s390_ipl_get_iplb();
> +        if (subcode == DIAG308_PV_STORE) {
> +            iplb = s390_ipl_get_iplb_secure();
> +        } else {
> +            iplb = s390_ipl_get_iplb();
> +        }
>          if (iplb) {
>              cpu_physical_memory_write(addr, iplb, be32_to_cpu(iplb->len));
>              env->regs[r1 + 1] = DIAG_308_RC_OK;
> @@ -139,6 +151,16 @@ out:
>              env->regs[r1 + 1] = DIAG_308_RC_NO_CONF;
>          }
>          return;
> +        break;

<hamletmode>
To return or to break, that's the question...
</hamletmode>

... please choose one of the two.

> +    case DIAG308_PV_START: /* SE start */
> +        iplb = s390_ipl_get_iplb_secure();
> +        if (!iplb_valid_se(iplb)) {
> +            env->regs[r1 + 1] = DIAG_308_RC_NO_PV_CONF;
> +            return;
> +        }
> +
> +        s390_ipl_reset_request(cs, S390_RESET_PV);
> +        break;
>      default:
>          s390_program_interrupt(env, PGM_SPECIFICATION, ra);
>          break;
> 

 Thomas