Re: [PATCH v4 15/15] spapr: nested: Set the PCR when logical PVR is set

[Harsh Prateek Bora <harshpb@linux.ibm.com>]

On 2/27/24 15:53, Nicholas Piggin wrote:
> On Tue Feb 20, 2024 at 6:36 PM AEST, Harsh Prateek Bora wrote:
>> From: Amit Machhiwal <amachhiw@linux.vnet.ibm.com>
>>
>> In APIv1, KVM L0 sets the PCR, while in the nested papr APIv2, this
>> doesn't work as the PCR can't be set via the guest state buffer; the
>> logical PVR is set via the GSB though.
>>
>> This change sets the PCR whenever the logical PVR is set via the GSB.
>> Also, unlike the other registers, the value 1 in a defined bit in the
>> PCR makes the affected resources unavailable and the value 0 makes
>> them available. Hence, the PCR is set accordingly.
> 
> Should this be squashed in as a fix?

Yeh, it can be squashed with 10/15 GSB initialization patch, will update 
as suggested in v5.

regards,
Harsh
> 
> Thanks,
> Nick
> 
>>
>> Signed-off-by: Amit Machhiwal <amachhiw@linux.vnet.ibm.com>
>> Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
>> ---
>>   include/hw/ppc/spapr_nested.h |  9 +++++++++
>>   hw/ppc/spapr_nested.c         | 24 ++++++++++++++++++++++++
>>   2 files changed, 33 insertions(+)
>>
>> diff --git a/include/hw/ppc/spapr_nested.h b/include/hw/ppc/spapr_nested.h
>> index da918d2dd0..f67c721f53 100644
>> --- a/include/hw/ppc/spapr_nested.h
>> +++ b/include/hw/ppc/spapr_nested.h
>> @@ -229,6 +229,15 @@ typedef struct SpaprMachineStateNestedGuest {
>>   #define GUEST_STATE_REQUEST_GUEST_WIDE       0x1
>>   #define GUEST_STATE_REQUEST_SET              0x2
>>   
>> +/* As per ISA v3.1B, following bits are reserved:
>> + *      0:2
>> + *      4:57  (ISA mentions bit 58 as well but it should be used for P10)
>> + *      61:63 (hence, haven't included PCR bits for v2.06 and v2.05
>> + *             in LOW BITS)
>> + */
>> +#define PCR_LOW_BITS   (PCR_COMPAT_3_10 | PCR_COMPAT_3_00)
>> +#define HVMASK_PCR     ~PCR_LOW_BITS
>> +
>>   #define GUEST_STATE_ELEMENT(i, sz, s, f, ptr, c) { \
>>       .id = (i),                                     \
>>       .size = (sz),                                  \
>> diff --git a/hw/ppc/spapr_nested.c b/hw/ppc/spapr_nested.c
>> index 6e6a90616e..af8a482337 100644
>> --- a/hw/ppc/spapr_nested.c
>> +++ b/hw/ppc/spapr_nested.c
>> @@ -740,9 +740,11 @@ static void out_buf_min_size(void *a, void *b, bool set)
>>   
>>   static void copy_logical_pvr(void *a, void *b, bool set)
>>   {
>> +    SpaprMachineStateNestedGuest *guest;
>>       uint32_t *buf; /* 1 word */
>>       uint32_t *pvr_logical_ptr;
>>       uint32_t pvr_logical;
>> +    target_ulong pcr = 0;
>>   
>>       pvr_logical_ptr = a;
>>       buf = b;
>> @@ -755,6 +757,28 @@ static void copy_logical_pvr(void *a, void *b, bool set)
>>       pvr_logical = be32_to_cpu(buf[0]);
>>   
>>       *pvr_logical_ptr = pvr_logical;
>> +
>> +    if (*pvr_logical_ptr) {
>> +        switch (*pvr_logical_ptr) {
>> +            case CPU_POWERPC_LOGICAL_3_10:
>> +                pcr = PCR_COMPAT_3_10 | PCR_COMPAT_3_00;
>> +                break;
>> +            case CPU_POWERPC_LOGICAL_3_00:
>> +                pcr = PCR_COMPAT_3_00;
>> +                break;
>> +            default:
>> +                qemu_log_mask(LOG_GUEST_ERROR,
>> +                    "Could not set PCR for LPVR=0x%08x\n", *pvr_logical_ptr);
>> +                return;
>> +        }
>> +    }
>> +
>> +    guest = container_of(pvr_logical_ptr,
>> +                         struct SpaprMachineStateNestedGuest,
>> +                         pvr_logical);
>> +    for (int i = 0; i < guest->vcpus; i++) {
>> +        guest->vcpu[i].state.pcr = ~pcr | HVMASK_PCR;
>> +    }
>>   }
>>   
>>   static void copy_tb_offset(void *a, void *b, bool set)
>