1 files changed, 493 insertions, 0 deletions

diff --git a/kernel/arch/s390/kvm/sigp.c b/kernel/arch/s390/kvm/sigp.c
new file mode 100644
index 000000000..72e58bd2b
--- /dev/null
+++ b/kernel/arch/s390/kvm/sigp.c
@@ -0,0 +1,493 @@
+/*
+ * handling interprocessor communication
+ *
+ * Copyright IBM Corp. 2008, 2013
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ *
+ *    Author(s): Carsten Otte <cotte@de.ibm.com>
+ *               Christian Borntraeger <borntraeger@de.ibm.com>
+ *               Christian Ehrhardt <ehrhardt@de.ibm.com>
+ */
+
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <linux/slab.h>
+#include <asm/sigp.h>
+#include "gaccess.h"
+#include "kvm-s390.h"
+#include "trace.h"
+
+static int __sigp_sense(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
+			u64 *reg)
+{
+	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);
+	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 (ext_call_pending)
+			*reg |= SIGP_STATUS_EXT_CALL_PENDING;
+		if (cpuflags & CPUSTAT_STOPPED)
+			*reg |= SIGP_STATUS_STOPPED;
+		rc = SIGP_CC_STATUS_STORED;
+	}
+
+	VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", dst_vcpu->vcpu_id,
+		   rc);
+	return rc;
+}
+
+static int __inject_sigp_emergency(struct kvm_vcpu *vcpu,
+				    struct kvm_vcpu *dst_vcpu)
+{
+	struct kvm_s390_irq irq = {
+		.type = KVM_S390_INT_EMERGENCY,
+		.u.emerg.code = vcpu->vcpu_id,
+	};
+	int rc = 0;
+
+	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
+	if (!rc)
+		VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x",
+			   dst_vcpu->vcpu_id);
+
+	return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
+}
+
+static int __sigp_emergency(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
+{
+	return __inject_sigp_emergency(vcpu, dst_vcpu);
+}
+
+static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu,
+					struct kvm_vcpu *dst_vcpu,
+					u16 asn, u64 *reg)
+{
+	const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT;
+	u16 p_asn, s_asn;
+	psw_t *psw;
+	u32 flags;
+
+	flags = atomic_read(&dst_vcpu->arch.sie_block->cpuflags);
+	psw = &dst_vcpu->arch.sie_block->gpsw;
+	p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff;  /* Primary ASN */
+	s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff;  /* Secondary ASN */
+
+	/* Inject the emergency signal? */
+	if (!(flags & CPUSTAT_STOPPED)
+	    || (psw->mask & psw_int_mask) != psw_int_mask
+	    || ((flags & CPUSTAT_WAIT) && psw->addr != 0)
+	    || (!(flags & CPUSTAT_WAIT) && (asn == p_asn || asn == s_asn))) {
+		return __inject_sigp_emergency(vcpu, dst_vcpu);
+	} else {
+		*reg &= 0xffffffff00000000UL;
+		*reg |= SIGP_STATUS_INCORRECT_STATE;
+		return SIGP_CC_STATUS_STORED;
+	}
+}
+
+static int __sigp_external_call(struct kvm_vcpu *vcpu,
+				struct kvm_vcpu *dst_vcpu, u64 *reg)
+{
+	struct kvm_s390_irq irq = {
+		.type = KVM_S390_INT_EXTERNAL_CALL,
+		.u.extcall.code = vcpu->vcpu_id,
+	};
+	int rc;
+
+	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
+	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 __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
+{
+	struct kvm_s390_irq irq = {
+		.type = KVM_S390_SIGP_STOP,
+	};
+	int rc;
+
+	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;
+}
+
+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 = 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;
+}
+
+static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter)
+{
+	int rc;
+	unsigned int i;
+	struct kvm_vcpu *v;
+
+	switch (parameter & 0xff) {
+	case 0:
+		rc = SIGP_CC_NOT_OPERATIONAL;
+		break;
+	case 1:
+	case 2:
+		kvm_for_each_vcpu(i, v, vcpu->kvm) {
+			v->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
+			kvm_clear_async_pf_completion_queue(v);
+		}
+
+		rc = SIGP_CC_ORDER_CODE_ACCEPTED;
+		break;
+	default:
+		rc = -EOPNOTSUPP;
+	}
+	return rc;
+}
+
+static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
+			     u32 address, u64 *reg)
+{
+	struct kvm_s390_irq irq = {
+		.type = KVM_S390_SIGP_SET_PREFIX,
+		.u.prefix.address = address & 0x7fffe000u,
+	};
+	int rc;
+
+	/*
+	 * 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.
+	 */
+	if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) {
+		*reg &= 0xffffffff00000000UL;
+		*reg |= SIGP_STATUS_INVALID_PARAMETER;
+		return SIGP_CC_STATUS_STORED;
+	}
+
+	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
+	if (rc == -EBUSY) {
+		*reg &= 0xffffffff00000000UL;
+		*reg |= SIGP_STATUS_INCORRECT_STATE;
+		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);
+	}
+
+	return rc;
+}
+
+static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu,
+				       struct kvm_vcpu *dst_vcpu,
+				       u32 addr, u64 *reg)
+{
+	int flags;
+	int rc;
+
+	flags = atomic_read(dst_vcpu->arch.local_int.cpuflags);
+	if (!(flags & CPUSTAT_STOPPED)) {
+		*reg &= 0xffffffff00000000UL;
+		*reg |= SIGP_STATUS_INCORRECT_STATE;
+		return SIGP_CC_STATUS_STORED;
+	}
+
+	addr &= 0x7ffffe00;
+	rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
+	if (rc == -EFAULT) {
+		*reg &= 0xffffffff00000000UL;
+		*reg |= SIGP_STATUS_INVALID_PARAMETER;
+		rc = SIGP_CC_STATUS_STORED;
+	}
+	return rc;
+}
+
+static int __sigp_sense_running(struct kvm_vcpu *vcpu,
+				struct kvm_vcpu *dst_vcpu, u64 *reg)
+{
+	struct kvm_s390_local_interrupt *li;
+	int rc;
+
+	li = &dst_vcpu->arch.local_int;
+	if (atomic_read(li->cpuflags) & CPUSTAT_RUNNING) {
+		/* running */
+		rc = SIGP_CC_ORDER_CODE_ACCEPTED;
+	} else {
+		/* not running */
+		*reg &= 0xffffffff00000000UL;
+		*reg |= SIGP_STATUS_NOT_RUNNING;
+		rc = SIGP_CC_STATUS_STORED;
+	}
+
+	VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x",
+		   dst_vcpu->vcpu_id, rc);
+
+	return rc;
+}
+
+static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu,
+				   struct kvm_vcpu *dst_vcpu, u8 order_code)
+{
+	struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
+	/* handle (RE)START in user space */
+	int rc = -EOPNOTSUPP;
+
+	/* make sure we don't race with STOP irq injection */
+	spin_lock(&li->lock);
+	if (kvm_s390_is_stop_irq_pending(dst_vcpu))
+		rc = SIGP_CC_BUSY;
+	spin_unlock(&li->lock);
+
+	return rc;
+}
+
+static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu,
+				    struct kvm_vcpu *dst_vcpu, u8 order_code)
+{
+	/* handle (INITIAL) CPU RESET in user space */
+	return -EOPNOTSUPP;
+}
+
+static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu,
+				  struct kvm_vcpu *dst_vcpu)
+{
+	/* handle unknown orders in user space */
+	return -EOPNOTSUPP;
+}
+
+static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
+			   u16 cpu_addr, u32 parameter, u64 *status_reg)
+{
+	int rc;
+	struct kvm_vcpu *dst_vcpu;
+
+	if (cpu_addr >= KVM_MAX_VCPUS)
+		return SIGP_CC_NOT_OPERATIONAL;
+
+	dst_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
+	if (!dst_vcpu)
+		return SIGP_CC_NOT_OPERATIONAL;
+
+	switch (order_code) {
+	case SIGP_SENSE:
+		vcpu->stat.instruction_sigp_sense++;
+		rc = __sigp_sense(vcpu, dst_vcpu, status_reg);
+		break;
+	case SIGP_EXTERNAL_CALL:
+		vcpu->stat.instruction_sigp_external_call++;
+		rc = __sigp_external_call(vcpu, dst_vcpu, status_reg);
+		break;
+	case SIGP_EMERGENCY_SIGNAL:
+		vcpu->stat.instruction_sigp_emergency++;
+		rc = __sigp_emergency(vcpu, dst_vcpu);
+		break;
+	case SIGP_STOP:
+		vcpu->stat.instruction_sigp_stop++;
+		rc = __sigp_stop(vcpu, dst_vcpu);
+		break;
+	case SIGP_STOP_AND_STORE_STATUS:
+		vcpu->stat.instruction_sigp_stop_store_status++;
+		rc = __sigp_stop_and_store_status(vcpu, dst_vcpu, status_reg);
+		break;
+	case SIGP_STORE_STATUS_AT_ADDRESS:
+		vcpu->stat.instruction_sigp_store_status++;
+		rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter,
+						 status_reg);
+		break;
+	case SIGP_SET_PREFIX:
+		vcpu->stat.instruction_sigp_prefix++;
+		rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg);
+		break;
+	case SIGP_COND_EMERGENCY_SIGNAL:
+		vcpu->stat.instruction_sigp_cond_emergency++;
+		rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter,
+						  status_reg);
+		break;
+	case SIGP_SENSE_RUNNING:
+		vcpu->stat.instruction_sigp_sense_running++;
+		rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg);
+		break;
+	case SIGP_START:
+		vcpu->stat.instruction_sigp_start++;
+		rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
+		break;
+	case SIGP_RESTART:
+		vcpu->stat.instruction_sigp_restart++;
+		rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
+		break;
+	case SIGP_INITIAL_CPU_RESET:
+		vcpu->stat.instruction_sigp_init_cpu_reset++;
+		rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
+		break;
+	case SIGP_CPU_RESET:
+		vcpu->stat.instruction_sigp_cpu_reset++;
+		rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
+		break;
+	default:
+		vcpu->stat.instruction_sigp_unknown++;
+		rc = __prepare_sigp_unknown(vcpu, dst_vcpu);
+	}
+
+	if (rc == -EOPNOTSUPP)
+		VCPU_EVENT(vcpu, 4,
+			   "sigp order %u -> cpu %x: handled in user space",
+			   order_code, dst_vcpu->vcpu_id);
+
+	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_STORE_ADDITIONAL_STATUS:
+		vcpu->stat.instruction_sigp_store_adtl_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;
+	int r3 = vcpu->arch.sie_block->ipa & 0x000f;
+	u32 parameter;
+	u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
+	u8 order_code;
+	int rc;
+
+	/* sigp in userspace can exit */
+	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
+		return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
+
+	order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
+	if (handle_sigp_order_in_user_space(vcpu, order_code))
+		return -EOPNOTSUPP;
+
+	if (r1 % 2)
+		parameter = vcpu->run->s.regs.gprs[r1];
+	else
+		parameter = vcpu->run->s.regs.gprs[r1 + 1];
+
+	trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
+	switch (order_code) {
+	case SIGP_SET_ARCHITECTURE:
+		vcpu->stat.instruction_sigp_arch++;
+		rc = __sigp_set_arch(vcpu, parameter);
+		break;
+	default:
+		rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
+				     parameter,
+				     &vcpu->run->s.regs.gprs[r1]);
+	}
+
+	if (rc < 0)
+		return rc;
+
+	kvm_s390_set_psw_cc(vcpu, rc);
+	return 0;
+}
+
+/*
+ * Handle SIGP partial execution interception.
+ *
+ * This interception will occur at the source cpu when a source cpu sends an
+ * external call to a target cpu and the target cpu has the WAIT bit set in
+ * its cpuflags. Interception will occurr after the interrupt indicator bits at
+ * the target cpu have been set. All error cases will lead to instruction
+ * interception, therefore nothing is to be checked or prepared.
+ */
+int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
+{
+	int r3 = vcpu->arch.sie_block->ipa & 0x000f;
+	u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
+	struct kvm_vcpu *dest_vcpu;
+	u8 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
+
+	trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
+
+	if (order_code == SIGP_EXTERNAL_CALL) {
+		dest_vcpu = kvm_get_vcpu(vcpu->kvm, cpu_addr);
+		BUG_ON(dest_vcpu == NULL);
+
+		kvm_s390_vcpu_wakeup(dest_vcpu);
+		kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
+		return 0;
+	}
+
+	return -EOPNOTSUPP;
+}