6 files changed, 63 insertions, 10 deletions

diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
index 87cedd61be0..8943e82cd4d 100644
--- a/arch/s390/kvm/diag.c
+++ b/arch/s390/kvm/diag.c
@@ -70,7 +70,7 @@ static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
                 return -EOPNOTSUPP;
         }
 
-        atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
+        atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
         vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
         vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
         vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index c7c51898984..02434543eab 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -132,7 +132,6 @@ static int handle_stop(struct kvm_vcpu *vcpu)
         int rc = 0;
 
         vcpu->stat.exit_stop_request++;
-        atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
         spin_lock_bh(&vcpu->arch.local_int.lock);
         if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {
                 vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;
@@ -149,6 +148,8 @@ static int handle_stop(struct kvm_vcpu *vcpu)
         }
 
         if (vcpu->arch.local_int.action_bits & ACTION_STOP_ON_STOP) {
+                atomic_set_mask(CPUSTAT_STOPPED,
+                                &vcpu->arch.sie_block->cpuflags);
                 vcpu->arch.local_int.action_bits &= ~ACTION_STOP_ON_STOP;
                 VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");
                 rc = -EOPNOTSUPP;
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 87c16705b38..278ee009ce6 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -252,6 +252,7 @@ static void __do_deliver_interrupt(struct kvm_vcpu *vcpu,
                         offsetof(struct _lowcore, restart_psw), sizeof(psw_t));
                 if (rc == -EFAULT)
                         exception = 1;
+                atomic_clear_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
                 break;
 
         case KVM_S390_PROGRAM_INT:
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 0bd3bea1e4c..d1c44573245 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) },
@@ -127,6 +128,7 @@ int kvm_dev_ioctl_check_extension(long ext)
         switch (ext) {
         case KVM_CAP_S390_PSW:
         case KVM_CAP_S390_GMAP:
+        case KVM_CAP_SYNC_MMU:
                 r = 1;
                 break;
         default:
@@ -270,10 +272,12 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
         restore_fp_regs(&vcpu->arch.guest_fpregs);
         restore_access_regs(vcpu->arch.guest_acrs);
         gmap_enable(vcpu->arch.gmap);
+        atomic_set_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
 }
 
 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 {
+        atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
         gmap_disable(vcpu->arch.gmap);
         save_fp_regs(&vcpu->arch.guest_fpregs);
         save_access_regs(vcpu->arch.guest_acrs);
@@ -301,7 +305,9 @@ static void kvm_s390_vcpu_initial_reset(struct kvm_vcpu *vcpu)
 
 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
 {
-        atomic_set(&vcpu->arch.sie_block->cpuflags, CPUSTAT_ZARCH | CPUSTAT_SM);
+        atomic_set(&vcpu->arch.sie_block->cpuflags, CPUSTAT_ZARCH |
+                                                    CPUSTAT_SM |
+                                                    CPUSTAT_STOPPED);
         vcpu->arch.sie_block->ecb   = 6;
         vcpu->arch.sie_block->eca   = 0xC1002001U;
         vcpu->arch.sie_block->fac   = (int) (long) facilities;
@@ -428,7 +434,7 @@ static int kvm_arch_vcpu_ioctl_set_initial_psw(struct kvm_vcpu *vcpu, psw_t psw)
 {
         int rc = 0;
 
-        if (atomic_read(&vcpu->arch.sie_block->cpuflags) & CPUSTAT_RUNNING)
+        if (!(atomic_read(&vcpu->arch.sie_block->cpuflags) & CPUSTAT_STOPPED))
                 rc = -EBUSY;
         else {
                 vcpu->run->psw_mask = psw.mask;
@@ -501,7 +507,7 @@ rerun_vcpu:
         if (vcpu->sigset_active)
                 sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
 
-        atomic_set_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
+        atomic_clear_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
 
         BUG_ON(vcpu->kvm->arch.float_int.local_int[vcpu->vcpu_id] == NULL);
 
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 39162636108..d0263895992 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -336,6 +336,7 @@ static int handle_tprot(struct kvm_vcpu *vcpu)
         u64 address1 = disp1 + base1 ? vcpu->arch.guest_gprs[base1] : 0;
         u64 address2 = disp2 + base2 ? vcpu->arch.guest_gprs[base2] : 0;
         struct vm_area_struct *vma;
+        unsigned long user_address;
 
         vcpu->stat.instruction_tprot++;
 
@@ -349,9 +350,14 @@ static int handle_tprot(struct kvm_vcpu *vcpu)
                 return -EOPNOTSUPP;
 
 
+        /* we must resolve the address without holding the mmap semaphore.
+         * This is ok since the userspace hypervisor is not supposed to change
+         * the mapping while the guest queries the memory. Otherwise the guest
+         * might crash or get wrong info anyway. */
+        user_address = (unsigned long) __guestaddr_to_user(vcpu, address1);
+
         down_read(&current->mm->mmap_sem);
-        vma = find_vma(current->mm,
-                        (unsigned long) __guestaddr_to_user(vcpu, address1));
+        vma = find_vma(current->mm, user_address);
         if (!vma) {
                 up_read(&current->mm->mmap_sem);
                 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c
index f815118835f..0a7941d74bc 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
@@ -57,8 +59,8 @@ static int __sigp_sense(struct kvm_vcpu *vcpu, u16 cpu_addr,
         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) {
+        else if (!(atomic_read(fi->local_int[cpu_addr]->cpuflags)
+                  & CPUSTAT_STOPPED)) {
                 *reg &= 0xffffffff00000000UL;
                 rc = 1; /* status stored */
         } else {
@@ -251,7 +253,7 @@ static int __sigp_set_prefix(struct kvm_vcpu *vcpu, u16 cpu_addr, u32 address,
 
         spin_lock_bh(&li->lock);
         /* cpu must be in stopped state */
-        if (atomic_read(li->cpuflags) & CPUSTAT_RUNNING) {
+        if (!(atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
                 rc = 1; /* incorrect state */
                 *reg &= SIGP_STAT_INCORRECT_STATE;
                 kfree(inti);
@@ -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 */