On 11/22/19 2:39 PM, Cornelia Huck wrote:
> On Wed, 20 Nov 2019 06:43:25 -0500
> Janosch Frank <frankja@linux.ibm.com> wrote:
> 
>> When a guest has saved a ipib of type 5 and call diagnose308 with
>> subcode 10, we have to setup the protected processing environment via
>> Ultravisor calls. The calls are done by KVM and are exposed via an API.
>>
>> The following steps are necessary:
>> 1. Create a VM (register it with the Ultravisor)
>> 2. Create secure CPUs for all of our current cpus
>> 3. Forward the secure header to the Ultravisor (has all information on
>> how to decrypt the image and VM information)
>> 4. Protect image pages from the host and decrypt them
>> 5. Verify the image integrity
>>
>> Only after step 5 a protected VM is allowed to run.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> ---
>>  hw/s390x/Makefile.objs              |   1 +
>>  hw/s390x/ipl.c                      |  33 ++++++++
>>  hw/s390x/ipl.h                      |   2 +
>>  hw/s390x/pv.c                       | 118 ++++++++++++++++++++++++++++
>>  hw/s390x/pv.h                       |  26 ++++++
>>  hw/s390x/s390-virtio-ccw.c          |  45 ++++++++---
>>  target/s390x/cpu_features_def.inc.h |   1 +
>>  7 files changed, 216 insertions(+), 10 deletions(-)
>>  create mode 100644 hw/s390x/pv.c
>>  create mode 100644 hw/s390x/pv.h
>>
> 
>> +static int s390_pv_cmd(uint32_t cmd, void *data)
>> +{
>> +    int rc;
>> +    struct kvm_pv_cmd pv_cmd = {
>> +        .cmd = cmd,
>> +        .data = (uint64_t)data,
>> +    };
>> +
>> +    rc = kvm_vm_ioctl(kvm_state, KVM_S390_PV_COMMAND, &pv_cmd);
>> +    if (rc) {
>> +        error_report("KVM PV command failed cmd: %d rc: %d", cmd, rc);
>> +        exit(1);
>> +    }
>> +    return rc;
>> +}
>> +
>> +static int s390_pv_cmd_vcpu(CPUState *cs, uint32_t cmd, void *data)
>> +{
>> +    int rc;
>> +    struct kvm_pv_cmd pv_cmd = {
>> +        .cmd = cmd,
>> +        .data = (uint64_t)data,
>> +    };
>> +
>> +    rc = kvm_vcpu_ioctl(cs, KVM_S390_PV_COMMAND_VCPU, &pv_cmd);
>> +    if (rc) {
>> +        error_report("KVM PV VCPU command failed cmd: %d rc: %d", cmd, rc);
>> +        exit(1);
>> +    }
>> +    return rc;
>> +}
> 
> If you do a hard exit for any rc != 0 anyway, returning rc does not
> sound very useful :)
> 

Yeah, that's also what Pierre said.
I'll need to rethink if there's actually a call where we could recover
from an error and if not make everything void.