Merge tag 'kvm-s390-next-20150122' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-next

KVM: s390: fixes and features for kvm/next (3.20)

1. Generic
- sparse warning (make function static)
- optimize locking
- bugfixes for interrupt injection
- fix MVPG addressing modes

2. hrtimer/wakeup fun
A recent change can cause KVM hangs if adjtime is used in the host.
The hrtimer might wake up too early or too late. Too early is fatal
as vcpu_block will see that the wakeup condition is not met and
sleep again. This CPU might never wake up again.
This series addresses this problem. adjclock slowing down the host
clock will result in too late wakeups. This will require more work.
In addition to that we also change the hrtimer from REALTIME to
MONOTONIC to avoid similar problems with timedatectl set-time.

3. sigp rework
We will move all "slow" sigps to QEMU (protected with a capability that
can be enabled) to avoid several races between concurrent SIGP orders.

4. Optimize the shadow page table
Provide an interface to announce the maximum guest size. The kernel
will use that to make the pagetable 2,3,4 (or theoretically) 5 levels.

5. Provide an interface to set the guest TOD
We now use two vm attributes instead of two oneregs, as oneregs are
vcpu ioctl and we don't want to call them from other threads.

6. Protected key functions
The real HMC allows to enable/disable protected key CPACF functions.
Lets provide an implementation + an interface for QEMU to activate
this the protected key instructions.

1 files changed, 93 insertions, 67 deletions

diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c
index 6651f9f73973..23b1e86b2122 100644
--- a/arch/s390/kvm/sigp.c
+++ b/arch/s390/kvm/sigp.c
@@ -26,15 +26,17 @@ static int __sigp_sense(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
 	struct kvm_s390_local_interrupt *li;
 	int cpuflags;
 	int rc;
+	int ext_call_pending;
 
 	li = &dst_vcpu->arch.local_int;
 
 	cpuflags = atomic_read(li->cpuflags);
-	if (!(cpuflags & (CPUSTAT_ECALL_PEND | CPUSTAT_STOPPED)))
+	ext_call_pending = kvm_s390_ext_call_pending(dst_vcpu);
+	if (!(cpuflags & CPUSTAT_STOPPED) && !ext_call_pending)
 		rc = SIGP_CC_ORDER_CODE_ACCEPTED;
 	else {
 		*reg &= 0xffffffff00000000UL;
-		if (cpuflags & CPUSTAT_ECALL_PEND)
+		if (ext_call_pending)
 			*reg |= SIGP_STATUS_EXT_CALL_PENDING;
 		if (cpuflags & CPUSTAT_STOPPED)
 			*reg |= SIGP_STATUS_STOPPED;
@@ -96,7 +98,7 @@ static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu,
 }
 
 static int __sigp_external_call(struct kvm_vcpu *vcpu,
-				struct kvm_vcpu *dst_vcpu)
+				struct kvm_vcpu *dst_vcpu, u64 *reg)
 {
 	struct kvm_s390_irq irq = {
 		.type = KVM_S390_INT_EXTERNAL_CALL,
@@ -105,45 +107,31 @@ static int __sigp_external_call(struct kvm_vcpu *vcpu,
 	int rc;
 
 	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
-	if (!rc)
+	if (rc == -EBUSY) {
+		*reg &= 0xffffffff00000000UL;
+		*reg |= SIGP_STATUS_EXT_CALL_PENDING;
+		return SIGP_CC_STATUS_STORED;
+	} else if (rc == 0) {
 		VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x",
 			   dst_vcpu->vcpu_id);
-
-	return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
-}
-
-static int __inject_sigp_stop(struct kvm_vcpu *dst_vcpu, int action)
-{
-	struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
-	int rc = SIGP_CC_ORDER_CODE_ACCEPTED;
-
-	spin_lock(&li->lock);
-	if (li->action_bits & ACTION_STOP_ON_STOP) {
-		/* another SIGP STOP is pending */
-		rc = SIGP_CC_BUSY;
-		goto out;
-	}
-	if ((atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
-		if ((action & ACTION_STORE_ON_STOP) != 0)
-			rc = -ESHUTDOWN;
-		goto out;
 	}
-	set_bit(IRQ_PEND_SIGP_STOP, &li->pending_irqs);
-	li->action_bits |= action;
-	atomic_set_mask(CPUSTAT_STOP_INT, li->cpuflags);
-	kvm_s390_vcpu_wakeup(dst_vcpu);
-out:
-	spin_unlock(&li->lock);
 
-	return rc;
+	return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
 }
 
 static int __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
 {
+	struct kvm_s390_irq irq = {
+		.type = KVM_S390_SIGP_STOP,
+	};
 	int rc;
 
-	rc = __inject_sigp_stop(dst_vcpu, ACTION_STOP_ON_STOP);
-	VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x", dst_vcpu->vcpu_id);
+	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
+	if (rc == -EBUSY)
+		rc = SIGP_CC_BUSY;
+	else if (rc == 0)
+		VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x",
+			   dst_vcpu->vcpu_id);
 
 	return rc;
 }
@@ -151,20 +139,18 @@ static int __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
 static int __sigp_stop_and_store_status(struct kvm_vcpu *vcpu,
 					struct kvm_vcpu *dst_vcpu, u64 *reg)
 {
+	struct kvm_s390_irq irq = {
+		.type = KVM_S390_SIGP_STOP,
+		.u.stop.flags = KVM_S390_STOP_FLAG_STORE_STATUS,
+	};
 	int rc;
 
-	rc = __inject_sigp_stop(dst_vcpu, ACTION_STOP_ON_STOP |
-					      ACTION_STORE_ON_STOP);
-	VCPU_EVENT(vcpu, 4, "sent sigp stop and store status to cpu %x",
-		   dst_vcpu->vcpu_id);
-
-	if (rc == -ESHUTDOWN) {
-		/* If the CPU has already been stopped, we still have
-		 * to save the status when doing stop-and-store. This
-		 * has to be done after unlocking all spinlocks. */
-		rc = kvm_s390_store_status_unloaded(dst_vcpu,
-						KVM_S390_STORE_STATUS_NOADDR);
-	}
+	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
+	if (rc == -EBUSY)
+		rc = SIGP_CC_BUSY;
+	else if (rc == 0)
+		VCPU_EVENT(vcpu, 4, "sent sigp stop and store status to cpu %x",
+			   dst_vcpu->vcpu_id);
 
 	return rc;
 }
@@ -197,41 +183,33 @@ static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter)
 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
 			     u32 address, u64 *reg)
 {
-	struct kvm_s390_local_interrupt *li;
+	struct kvm_s390_irq irq = {
+		.type = KVM_S390_SIGP_SET_PREFIX,
+		.u.prefix.address = address & 0x7fffe000u,
+	};
 	int rc;
 
-	li = &dst_vcpu->arch.local_int;
-
 	/*
 	 * Make sure the new value is valid memory. We only need to check the
 	 * first page, since address is 8k aligned and memory pieces are always
 	 * at least 1MB aligned and have at least a size of 1MB.
 	 */
-	address &= 0x7fffe000u;
-	if (kvm_is_error_gpa(vcpu->kvm, address)) {
+	if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) {
 		*reg &= 0xffffffff00000000UL;
 		*reg |= SIGP_STATUS_INVALID_PARAMETER;
 		return SIGP_CC_STATUS_STORED;
 	}
 
-	spin_lock(&li->lock);
-	/* cpu must be in stopped state */
-	if (!(atomic_read(li->cpuflags) & CPUSTAT_STOPPED)) {
+	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
+	if (rc == -EBUSY) {
 		*reg &= 0xffffffff00000000UL;
 		*reg |= SIGP_STATUS_INCORRECT_STATE;
-		rc = SIGP_CC_STATUS_STORED;
-		goto out_li;
+		return SIGP_CC_STATUS_STORED;
+	} else if (rc == 0) {
+		VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x",
+			   dst_vcpu->vcpu_id, irq.u.prefix.address);
 	}
 
-	li->irq.prefix.address = address;
-	set_bit(IRQ_PEND_SET_PREFIX, &li->pending_irqs);
-	kvm_s390_vcpu_wakeup(dst_vcpu);
-	rc = SIGP_CC_ORDER_CODE_ACCEPTED;
-
-	VCPU_EVENT(vcpu, 4, "set prefix of cpu %02x to %x", dst_vcpu->vcpu_id,
-		   address);
-out_li:
-	spin_unlock(&li->lock);
 	return rc;
 }
 
@@ -242,9 +220,7 @@ static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu,
 	int flags;
 	int rc;
 
-	spin_lock(&dst_vcpu->arch.local_int.lock);
 	flags = atomic_read(dst_vcpu->arch.local_int.cpuflags);
-	spin_unlock(&dst_vcpu->arch.local_int.lock);
 	if (!(flags & CPUSTAT_STOPPED)) {
 		*reg &= 0xffffffff00000000UL;
 		*reg |= SIGP_STATUS_INCORRECT_STATE;
@@ -291,8 +267,9 @@ static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu,
 	/* handle (RE)START in user space */
 	int rc = -EOPNOTSUPP;
 
+	/* make sure we don't race with STOP irq injection */
 	spin_lock(&li->lock);
-	if (li->action_bits & ACTION_STOP_ON_STOP)
+	if (kvm_s390_is_stop_irq_pending(dst_vcpu))
 		rc = SIGP_CC_BUSY;
 	spin_unlock(&li->lock);
 
@@ -333,7 +310,7 @@ static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
 		break;
 	case SIGP_EXTERNAL_CALL:
 		vcpu->stat.instruction_sigp_external_call++;
-		rc = __sigp_external_call(vcpu, dst_vcpu);
+		rc = __sigp_external_call(vcpu, dst_vcpu, status_reg);
 		break;
 	case SIGP_EMERGENCY_SIGNAL:
 		vcpu->stat.instruction_sigp_emergency++;
@@ -394,6 +371,53 @@ static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
 	return rc;
 }
 
+static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code)
+{
+	if (!vcpu->kvm->arch.user_sigp)
+		return 0;
+
+	switch (order_code) {
+	case SIGP_SENSE:
+	case SIGP_EXTERNAL_CALL:
+	case SIGP_EMERGENCY_SIGNAL:
+	case SIGP_COND_EMERGENCY_SIGNAL:
+	case SIGP_SENSE_RUNNING:
+		return 0;
+	/* update counters as we're directly dropping to user space */
+	case SIGP_STOP:
+		vcpu->stat.instruction_sigp_stop++;
+		break;
+	case SIGP_STOP_AND_STORE_STATUS:
+		vcpu->stat.instruction_sigp_stop_store_status++;
+		break;
+	case SIGP_STORE_STATUS_AT_ADDRESS:
+		vcpu->stat.instruction_sigp_store_status++;
+		break;
+	case SIGP_SET_PREFIX:
+		vcpu->stat.instruction_sigp_prefix++;
+		break;
+	case SIGP_START:
+		vcpu->stat.instruction_sigp_start++;
+		break;
+	case SIGP_RESTART:
+		vcpu->stat.instruction_sigp_restart++;
+		break;
+	case SIGP_INITIAL_CPU_RESET:
+		vcpu->stat.instruction_sigp_init_cpu_reset++;
+		break;
+	case SIGP_CPU_RESET:
+		vcpu->stat.instruction_sigp_cpu_reset++;
+		break;
+	default:
+		vcpu->stat.instruction_sigp_unknown++;
+	}
+
+	VCPU_EVENT(vcpu, 4, "sigp order %u: completely handled in user space",
+		   order_code);
+
+	return 1;
+}
+
 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
 {
 	int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
@@ -408,6 +432,8 @@ int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
 		return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
 
 	order_code = kvm_s390_get_base_disp_rs(vcpu);
+	if (handle_sigp_order_in_user_space(vcpu, order_code))
+		return -EOPNOTSUPP;
 
 	if (r1 % 2)
 		parameter = vcpu->run->s.regs.gprs[r1];