Re: [PATCH v6 02/18] s390x: protvirt: Add diag308 subcodes 8 - 10

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

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On 3/4/20 7:59 PM, Christian Borntraeger wrote:
> 
> 
> On 04.03.20 12:42, 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>
>> ---
>>  hw/s390x/ipl.c      | 47 ++++++++++++++++++++++++++++++++++++++++++---
>>  hw/s390x/ipl.h      | 32 ++++++++++++++++++++++++++++++
>>  target/s390x/diag.c | 26 ++++++++++++++++++++++---
>>  3 files changed, 99 insertions(+), 6 deletions(-)
>>
>> diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
>> index 9c1ecd423c..80c6ab233a 100644
>> --- a/hw/s390x/ipl.c
>> +++ b/hw/s390x/ipl.c
> 
> Can you update the copyright dates for files that you touch?
> 
>> @@ -538,15 +538,55 @@ static bool is_virtio_scsi_device(IplParameterBlock *iplb)
>>      return is_virtio_ccw_device_of_type(iplb, VIRTIO_ID_SCSI);
>>  }
>>  
>> +int s390_ipl_pv_check_components(IplParameterBlock *iplb)
>> +{
>> +    int i;
>> +    IPLBlockPV *ipib_pv = &iplb->pv;
>> +
>> +    if (ipib_pv->num_comp == 0) {
>> +        return -EINVAL;
>> +    }
>> +
>> +    for (i = 0; i < ipib_pv->num_comp; i++) {
>> +        /* Addr must be 4k aligned */
>> +        if (ipib_pv->components[i].addr & ~TARGET_PAGE_MASK) {
>> +            return -EINVAL;
>> +        }
>> +
>> +        /* Tweak prefix is monotonously increasing with each component */
>> +        if (i < ipib_pv->num_comp - 1 &&
> 
> Why do we need this check? Isnt that already ensured by the for loop?

This is "i < ipib_pv->num_comp - 1" because we use i + 1 below, not "i <
ipib_pv->num_comp"

> 
>> +            ipib_pv->components[i].tweak_pref >
>> +            ipib_pv->components[i + 1].tweak_pref) {
> 
> I think i+1 must be greater than i. So ">=" instead?

Ack

> 
>> +            return -EINVAL;
>> +        }
>> +    }
>> +    return 0;
>> +}
>> +
>>  void s390_ipl_update_diag308(IplParameterBlock *iplb)
> 
> maybe add a comment that explains that a guest can have 2 IPLBs. one for
> the secure guest and one thsat we go back to when rebooting.

Sure

>>  {
>>      S390IPLState *ipl = get_ipl_device();
>>  
>> -    ipl->iplb = *iplb;
>> -    ipl->iplb_valid = true;
>> +    if (iplb->pbt == S390_IPL_TYPE_PV) {
>> +        ipl->iplb_pv = *iplb;
>> +        ipl->iplb_valid_pv = true;
>> +    } else {
>> +        ipl->iplb = *iplb;
>> +        ipl->iplb_valid = true;
>> +    }
>>      ipl->netboot = is_virtio_net_device(iplb);
>>  }
>>  
>> +IplParameterBlock *s390_ipl_get_iplb_secure(void)
>> +{
>> +    S390IPLState *ipl = get_ipl_device();
>> +
>> +    if (!ipl->iplb_valid_pv) {
>> +        return NULL;
>> +    }
>> +    return &ipl->iplb_pv;
>> +}
>> +
>>  IplParameterBlock *s390_ipl_get_iplb(void)
>>  {
>>      S390IPLState *ipl = get_ipl_device();
>> @@ -561,7 +601,8 @@ void s390_ipl_reset_request(CPUState *cs, enum s390_reset reset_type)
>>  {
>>      S390IPLState *ipl = get_ipl_device();
>>  
>> -    if (reset_type == S390_RESET_EXTERNAL || reset_type == S390_RESET_REIPL) {
>> +    if (reset_type == S390_RESET_EXTERNAL || reset_type == S390_RESET_REIPL ||
>> +        reset_type == S390_RESET_PV) {
>>          /* use CPU 0 for full resets */
>>          ipl->reset_cpu_index = 0;
>>      } else {
>> diff --git a/hw/s390x/ipl.h b/hw/s390x/ipl.h
>> index d4813105db..04be63cee1 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[87];
>> +    uint8_t  version;
>> +    uint32_t reserved70;
> 
> Here you have 70 (the offset in hex I guess), I tßhink this is an odd name. In addition the reserved field 2 lines above has no address part in its
> name. 

I wanted to prepare for my ipl cleanup patch set which adds offsets to
all the reserved fields. Do you want me to remove it or make the first
one "reserved18" ?



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