On 23.06.20 10:42, Thomas Huth wrote:
> On 22/06/2020 17.46, Collin Walling wrote:
>> DIAGNOSE 0x318 (diag318) sets information regarding the environment
>> the VM is running in (Linux, z/VM, etc) and is observed via
>> firmware/service events.
>>
>> This is a privileged s390x instruction that must be intercepted by
>> SIE. Userspace handles the instruction as well as migration. Data
>> is communicated via VCPU register synchronization.
>>
>> The Control Program Name Code (CPNC) is stored in the SIE block. The
>> CPNC along with the Control Program Version Code (CPVC) are stored
>> in the kvm_vcpu_arch struct.
>>
>> This data is reset on load normal and clear resets.
>>
>> Signed-off-by: Collin Walling <walling@xxxxxxxxxxxxx>
>> Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
>> ---
>> arch/s390/include/asm/kvm_host.h | 4 +++-
>> arch/s390/include/uapi/asm/kvm.h | 5 ++++-
>> arch/s390/kvm/kvm-s390.c | 11 ++++++++++-
>> arch/s390/kvm/vsie.c | 1 +
>> include/uapi/linux/kvm.h | 1 +
>> 5 files changed, 19 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
>> index 3d554887794e..8bdf6f1607ca 100644
>> --- a/arch/s390/include/asm/kvm_host.h
>> +++ b/arch/s390/include/asm/kvm_host.h
>> @@ -260,7 +260,8 @@ struct kvm_s390_sie_block {
>> __u32 scaol; /* 0x0064 */
>> __u8 sdf; /* 0x0068 */
>> __u8 epdx; /* 0x0069 */
>> - __u8 reserved6a[2]; /* 0x006a */
>> + __u8 cpnc; /* 0x006a */
>> + __u8 reserved6b; /* 0x006b */
>> __u32 todpr; /* 0x006c */
>> #define GISA_FORMAT1 0x00000001
>> __u32 gd; /* 0x0070 */
>> @@ -745,6 +746,7 @@ struct kvm_vcpu_arch {
>> bool gs_enabled;
>> bool skey_enabled;
>> struct kvm_s390_pv_vcpu pv;
>> + union diag318_info diag318_info;
>> };
>>
>> struct kvm_vm_stat {
>> diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
>> index 436ec7636927..2ae1b660086c 100644
>> --- a/arch/s390/include/uapi/asm/kvm.h
>> +++ b/arch/s390/include/uapi/asm/kvm.h
>> @@ -231,11 +231,13 @@ struct kvm_guest_debug_arch {
>> #define KVM_SYNC_GSCB (1UL << 9)
>> #define KVM_SYNC_BPBC (1UL << 10)
>> #define KVM_SYNC_ETOKEN (1UL << 11)
>> +#define KVM_SYNC_DIAG318 (1UL << 12)
>>
>> #define KVM_SYNC_S390_VALID_FIELDS \
>> (KVM_SYNC_PREFIX | KVM_SYNC_GPRS | KVM_SYNC_ACRS | KVM_SYNC_CRS | \
>> KVM_SYNC_ARCH0 | KVM_SYNC_PFAULT | KVM_SYNC_VRS | KVM_SYNC_RICCB | \
>> - KVM_SYNC_FPRS | KVM_SYNC_GSCB | KVM_SYNC_BPBC | KVM_SYNC_ETOKEN)
>> + KVM_SYNC_FPRS | KVM_SYNC_GSCB | KVM_SYNC_BPBC | KVM_SYNC_ETOKEN | \
>> + KVM_SYNC_DIAG318)
>>
>> /* length and alignment of the sdnx as a power of two */
>> #define SDNXC 8
>> @@ -254,6 +256,7 @@ struct kvm_sync_regs {
>> __u64 pft; /* pfault token [PFAULT] */
>> __u64 pfs; /* pfault select [PFAULT] */
>> __u64 pfc; /* pfault compare [PFAULT] */
>> + __u64 diag318; /* diagnose 0x318 info */
>> union {
>> __u64 vrs[32][2]; /* vector registers (KVM_SYNC_VRS) */
>> __u64 fprs[16]; /* fp registers (KVM_SYNC_FPRS) */
>
> It's been a while since I touched kvm_sync_regs the last time ... but
> can your really extend this structure right in the middle without
> breaking older user spaces (ie. QEMUs) ? This is a uapi header ... so I
> think you rather have to add this add the end or e.g. put it into the
> padding2 region or something like that...? Or do I miss something?
Argh. You are right. It should go to the end and not in the middle. Will fixup.
