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

[Janosch Frank <frankja@linux.ibm.com>]

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On 11/21/19 3:36 PM, Thomas Huth wrote:
> 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?

Was compacted to reserved[87]

> 
>> +    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?

As the struct in which IPLBlockPV is embeded are also packed, removing
the PACKED annotation results in this:

/mnt/dev/qemu/hw/s390x/ipl.c:544:27: error: taking address of packed
member of ‘struct <anonymous>’ may result in an unaligned pointer value
[-Werror=address-of-packed-member]


> 
> [...]
>> @@ -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?
ack.

> 
>>  #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
> 
> 



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