KVM: s390: handle SIGP sense running intercepts

SIGP sense running may cause an intercept on higher level
virtualization, so handle it by checking the CPUSTAT_RUNNING flag.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

3 files changed, 41 insertions, 0 deletions

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 20f9068cd6b5..b0c235cb6ad5 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -139,6 +139,7 @@ struct kvm_vcpu_stat {
         u32 instruction_stfl;
         u32 instruction_tprot;
         u32 instruction_sigp_sense;
+        u32 instruction_sigp_sense_running;
         u32 instruction_sigp_external_call;
         u32 instruction_sigp_emergency;
         u32 instruction_sigp_stop;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 630ab65b488b..0891926ea953 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -65,6 +65,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
         { "instruction_stfl", VCPU_STAT(instruction_stfl) },
         { "instruction_tprot", VCPU_STAT(instruction_tprot) },
         { "instruction_sigp_sense", VCPU_STAT(instruction_sigp_sense) },
+        { "instruction_sigp_sense_running", VCPU_STAT(instruction_sigp_sense_running) },
         { "instruction_sigp_external_call", VCPU_STAT(instruction_sigp_external_call) },
         { "instruction_sigp_emergency", VCPU_STAT(instruction_sigp_emergency) },
         { "instruction_sigp_stop", VCPU_STAT(instruction_sigp_stop) },
diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c
index 4a488a98d7f8..0a7941d74bc6 100644
--- a/arch/s390/kvm/sigp.c
+++ b/arch/s390/kvm/sigp.c
@@ -31,9 +31,11 @@
 #define SIGP_SET_PREFIX        0x0d
 #define SIGP_STORE_STATUS_ADDR 0x0e
 #define SIGP_SET_ARCH          0x12
+#define SIGP_SENSE_RUNNING     0x15
 
 /* cpu status bits */
 #define SIGP_STAT_EQUIPMENT_CHECK   0x80000000UL
+#define SIGP_STAT_NOT_RUNNING       0x00000400UL
 #define SIGP_STAT_INCORRECT_STATE   0x00000200UL
 #define SIGP_STAT_INVALID_PARAMETER 0x00000100UL
 #define SIGP_STAT_EXT_CALL_PENDING  0x00000080UL
@@ -275,6 +277,38 @@ out_fi:
         return rc;
 }
 
+static int __sigp_sense_running(struct kvm_vcpu *vcpu, u16 cpu_addr,
+                                unsigned long *reg)
+{
+        int rc;
+        struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
+
+        if (cpu_addr >= KVM_MAX_VCPUS)
+                return 3; /* not operational */
+
+        spin_lock(&fi->lock);
+        if (fi->local_int[cpu_addr] == NULL)
+                rc = 3; /* not operational */
+        else {
+                if (atomic_read(fi->local_int[cpu_addr]->cpuflags)
+                    & CPUSTAT_RUNNING) {
+                        /* running */
+                        rc = 1;
+                } else {
+                        /* not running */
+                        *reg &= 0xffffffff00000000UL;
+                        *reg |= SIGP_STAT_NOT_RUNNING;
+                        rc = 0;
+                }
+        }
+        spin_unlock(&fi->lock);
+
+        VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x", cpu_addr,
+                   rc);
+
+        return rc;
+}
+
 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
 {
         int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
@@ -331,6 +365,11 @@ int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
                 rc = __sigp_set_prefix(vcpu, cpu_addr, parameter,
                                        &vcpu->arch.guest_gprs[r1]);
                 break;
+        case SIGP_SENSE_RUNNING:
+                vcpu->stat.instruction_sigp_sense_running++;
+                rc = __sigp_sense_running(vcpu, cpu_addr,
+                                          &vcpu->arch.guest_gprs[r1]);
+                break;
         case SIGP_RESTART:
                 vcpu->stat.instruction_sigp_restart++;
                 /* user space must know about restart */