Merge remote-tracking branch 'kvm/linux-next'

[karo-tx-linux.git] / arch / s390 / kvm / kvm-s390.c

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index ed8064cb5c4921424d5981b890e6fd9b07f9ed02..2d67b3bbf1906d4a0f33d72c5e31344c94f2feab 100644 (file)
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -695,9 +695,9 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
        return 0;
 }
 
-static int __vcpu_run(struct kvm_vcpu *vcpu)
+static int vcpu_pre_run(struct kvm_vcpu *vcpu)
 {
-       int rc;
+       int rc, cpuflags;
 
        memcpy(&vcpu->arch.sie_block->gg14, &vcpu->run->s.regs.gprs[14], 16);
 
@@ -715,28 +715,24 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
                return rc;
 
        vcpu->arch.sie_block->icptcode = 0;
-       VCPU_EVENT(vcpu, 6, "entering sie flags %x",
-                  atomic_read(&vcpu->arch.sie_block->cpuflags));
-       trace_kvm_s390_sie_enter(vcpu,
-                                atomic_read(&vcpu->arch.sie_block->cpuflags));
+       cpuflags = atomic_read(&vcpu->arch.sie_block->cpuflags);
+       VCPU_EVENT(vcpu, 6, "entering sie flags %x", cpuflags);
+       trace_kvm_s390_sie_enter(vcpu, cpuflags);
 
-       /*
-        * As PF_VCPU will be used in fault handler, between guest_enter
-        * and guest_exit should be no uaccess.
-        */
-       preempt_disable();
-       kvm_guest_enter();
-       preempt_enable();
-       rc = sie64a(vcpu->arch.sie_block, vcpu->run->s.regs.gprs);
-       kvm_guest_exit();
+       return 0;
+}
+
+static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason)
+{
+       int rc;
 
        VCPU_EVENT(vcpu, 6, "exit sie icptcode %d",
                   vcpu->arch.sie_block->icptcode);
        trace_kvm_s390_sie_exit(vcpu, vcpu->arch.sie_block->icptcode);
 
-       if (rc > 0)
+       if (exit_reason >= 0) {
                rc = 0;
-       if (rc < 0) {
+       } else {
                if (kvm_is_ucontrol(vcpu->kvm)) {
                        rc = SIE_INTERCEPT_UCONTROL;
                } else {
@@ -747,6 +743,49 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
        }
 
        memcpy(&vcpu->run->s.regs.gprs[14], &vcpu->arch.sie_block->gg14, 16);
+
+       if (rc == 0) {
+               if (kvm_is_ucontrol(vcpu->kvm))
+                       rc = -EOPNOTSUPP;
+               else
+                       rc = kvm_handle_sie_intercept(vcpu);
+       }
+
+       return rc;
+}
+
+static int __vcpu_run(struct kvm_vcpu *vcpu)
+{
+       int rc, exit_reason;
+
+       /*
+        * We try to hold kvm->srcu during most of vcpu_run (except when run-
+        * ning the guest), so that memslots (and other stuff) are protected
+        */
+       vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
+
+       do {
+               rc = vcpu_pre_run(vcpu);
+               if (rc)
+                       break;
+
+               srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
+               /*
+                * As PF_VCPU will be used in fault handler, between
+                * guest_enter and guest_exit should be no uaccess.
+                */
+               preempt_disable();
+               kvm_guest_enter();
+               preempt_enable();
+               exit_reason = sie64a(vcpu->arch.sie_block,
+                                    vcpu->run->s.regs.gprs);
+               kvm_guest_exit();
+               vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
+
+               rc = vcpu_post_run(vcpu, exit_reason);
+       } while (!signal_pending(current) && !rc);
+
+       srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
        return rc;
 }
 
@@ -755,7 +794,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
        int rc;
        sigset_t sigsaved;
 
-rerun_vcpu:
        if (vcpu->sigset_active)
                sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
 
@@ -788,19 +826,7 @@ rerun_vcpu:
        }
 
        might_fault();
-
-       do {
-               rc = __vcpu_run(vcpu);
-               if (rc)
-                       break;
-               if (kvm_is_ucontrol(vcpu->kvm))
-                       rc = -EOPNOTSUPP;
-               else
-                       rc = kvm_handle_sie_intercept(vcpu);
-       } while (!signal_pending(current) && !rc);
-
-       if (rc == SIE_INTERCEPT_RERUNVCPU)
-               goto rerun_vcpu;
+       rc = __vcpu_run(vcpu);
 
        if (signal_pending(current) && !rc) {
                kvm_run->exit_reason = KVM_EXIT_INTR;
@@ -958,6 +984,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 {
        struct kvm_vcpu *vcpu = filp->private_data;
        void __user *argp = (void __user *)arg;
+       int idx;
        long r;
 
        switch (ioctl) {
@@ -971,7 +998,9 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
                break;
        }
        case KVM_S390_STORE_STATUS:
+               idx = srcu_read_lock(&vcpu->kvm->srcu);
                r = kvm_s390_vcpu_store_status(vcpu, arg);
+               srcu_read_unlock(&vcpu->kvm->srcu, idx);
                break;
        case KVM_S390_SET_INITIAL_PSW: {
                psw_t psw;