KVM: s390: Provide access to program parameter

commit d208c79d63e06457eef077af770d23dc4cde4d43 (KVM: s390: Enable
the LPP facility for guests) enabled the LPP instruction for guests.
We should expose the program parameter as a pseudo register for
migration/reset etc. Lets also reset this value on initial CPU
reset.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>

3 files changed, 13 insertions, 1 deletions

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 2c69ba285e81..062b78cde307 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -107,7 +107,9 @@ struct kvm_s390_sie_block {
         __u64   gbea;                   /* 0x0180 */
         __u8    reserved188[24];        /* 0x0188 */
         __u32   fac;                    /* 0x01a0 */
-        __u8    reserved1a4[68];        /* 0x01a4 */
+        __u8    reserved1a4[58];        /* 0x01a4 */
+        __u64   pp;                     /* 0x01de */
+        __u8    reserved1e6[2];         /* 0x01e6 */
         __u64   itdba;                  /* 0x01e8 */
         __u8    reserved1f0[16];        /* 0x01f0 */
 } __attribute__((packed));
diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
index cb4c1eb8a0a5..766324476f12 100644
--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -76,4 +76,5 @@ struct kvm_sync_regs {
 #define KVM_REG_S390_PFTOKEN    (KVM_REG_S390 | KVM_REG_SIZE_U64 | 0x5)
 #define KVM_REG_S390_PFCOMPARE  (KVM_REG_S390 | KVM_REG_SIZE_U64 | 0x6)
 #define KVM_REG_S390_PFSELECT   (KVM_REG_S390 | KVM_REG_SIZE_U64 | 0x7)
+#define KVM_REG_S390_PP         (KVM_REG_S390 | KVM_REG_SIZE_U64 | 0x8)
 #endif
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 18959bb75c51..0262936e18be 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -386,6 +386,7 @@ static void kvm_s390_vcpu_initial_reset(struct kvm_vcpu *vcpu)
         vcpu->arch.guest_fpregs.fpc = 0;
         asm volatile("lfpc %0" : : "Q" (vcpu->arch.guest_fpregs.fpc));
         vcpu->arch.sie_block->gbea = 1;
+        vcpu->arch.sie_block->pp = 0;
         vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
         kvm_clear_async_pf_completion_queue(vcpu);
         atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
@@ -571,6 +572,10 @@ static int kvm_arch_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu,
                 r = put_user(vcpu->arch.pfault_select,
                              (u64 __user *)reg->addr);
                 break;
+        case KVM_REG_S390_PP:
+                r = put_user(vcpu->arch.sie_block->pp,
+                             (u64 __user *)reg->addr);
+                break;
         default:
                 break;
         }
@@ -612,6 +617,10 @@ static int kvm_arch_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu,
                 r = get_user(vcpu->arch.pfault_select,
                              (u64 __user *)reg->addr);
                 break;
+        case KVM_REG_S390_PP:
+                r = get_user(vcpu->arch.sie_block->pp,
+                             (u64 __user *)reg->addr);
+                break;
         default:
                 break;
         }