1 files changed, 597 insertions, 93 deletions

diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index 5ee56e5acc23..420ae62977e2 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -1,11 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * in-kernel handling for sie intercepts
  *
- * Copyright IBM Corp. 2008, 2009
- *
- * 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.
+ * Copyright IBM Corp. 2008, 2020
  *
  *    Author(s): Carsten Otte <cotte@de.ibm.com>
  *               Christian Borntraeger <borntraeger@de.ibm.com>
@@ -15,80 +12,80 @@
 #include <linux/errno.h>
 #include <linux/pagemap.h>
 
-#include <asm/kvm_host.h>
+#include <asm/asm-offsets.h>
+#include <asm/irq.h>
+#include <asm/sysinfo.h>
+#include <asm/uv.h>
 
 #include "kvm-s390.h"
 #include "gaccess.h"
 #include "trace.h"
 #include "trace-s390.h"
 
-
-static const intercept_handler_t instruction_handlers[256] = {
-	[0x01] = kvm_s390_handle_01,
-	[0x82] = kvm_s390_handle_lpsw,
-	[0x83] = kvm_s390_handle_diag,
-	[0xae] = kvm_s390_handle_sigp,
-	[0xb2] = kvm_s390_handle_b2,
-	[0xb7] = kvm_s390_handle_lctl,
-	[0xb9] = kvm_s390_handle_b9,
-	[0xe5] = kvm_s390_handle_e5,
-	[0xeb] = kvm_s390_handle_eb,
-};
-
-static int handle_noop(struct kvm_vcpu *vcpu)
+u8 kvm_s390_get_ilen(struct kvm_vcpu *vcpu)
 {
+	struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block;
+	u8 ilen = 0;
+
 	switch (vcpu->arch.sie_block->icptcode) {
-	case 0x0:
-		vcpu->stat.exit_null++;
-		break;
-	case 0x10:
-		vcpu->stat.exit_external_request++;
+	case ICPT_INST:
+	case ICPT_INSTPROGI:
+	case ICPT_OPEREXC:
+	case ICPT_PARTEXEC:
+	case ICPT_IOINST:
+		/* instruction only stored for these icptcodes */
+		ilen = insn_length(vcpu->arch.sie_block->ipa >> 8);
+		/* Use the length of the EXECUTE instruction if necessary */
+		if (sie_block->icptstatus & 1) {
+			ilen = (sie_block->icptstatus >> 4) & 0x6;
+			if (!ilen)
+				ilen = 4;
+		}
 		break;
-	case 0x14:
-		vcpu->stat.exit_external_interrupt++;
+	case ICPT_PROGI:
+		/* bit 1+2 of pgmilc are the ilc, so we directly get ilen */
+		ilen = vcpu->arch.sie_block->pgmilc & 0x6;
 		break;
-	default:
-		break; /* nothing */
 	}
-	return 0;
+	return ilen;
 }
 
 static int handle_stop(struct kvm_vcpu *vcpu)
 {
+	struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
 	int rc = 0;
+	uint8_t flags, stop_pending;
 
 	vcpu->stat.exit_stop_request++;
-	spin_lock_bh(&vcpu->arch.local_int.lock);
 
-	trace_kvm_s390_stop_request(vcpu->arch.local_int.action_bits);
+	/* delay the stop if any non-stop irq is pending */
+	if (kvm_s390_vcpu_has_irq(vcpu, 1))
+		return 0;
 
-	if (vcpu->arch.local_int.action_bits & ACTION_RELOADVCPU_ON_STOP) {
-		vcpu->arch.local_int.action_bits &= ~ACTION_RELOADVCPU_ON_STOP;
-		rc = SIE_INTERCEPT_RERUNVCPU;
-		vcpu->run->exit_reason = KVM_EXIT_INTR;
-	}
+	/* avoid races with the injection/SIGP STOP code */
+	spin_lock(&li->lock);
+	flags = li->irq.stop.flags;
+	stop_pending = kvm_s390_is_stop_irq_pending(vcpu);
+	spin_unlock(&li->lock);
 
-	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;
-	}
+	trace_kvm_s390_stop_request(stop_pending, flags);
+	if (!stop_pending)
+		return 0;
 
-	if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {
-		vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;
-		/* store status must be called unlocked. Since local_int.lock
-		 * only protects local_int.* and not guest memory we can give
-		 * up the lock here */
-		spin_unlock_bh(&vcpu->arch.local_int.lock);
+	if (flags & KVM_S390_STOP_FLAG_STORE_STATUS) {
 		rc = kvm_s390_vcpu_store_status(vcpu,
 						KVM_S390_STORE_STATUS_NOADDR);
-		if (rc >= 0)
-			rc = -EOPNOTSUPP;
-	} else
-		spin_unlock_bh(&vcpu->arch.local_int.lock);
-	return rc;
+		if (rc)
+			return rc;
+	}
+
+	/*
+	 * no need to check the return value of vcpu_stop as it can only have
+	 * an error for protvirt, but protvirt means user cpu state
+	 */
+	if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
+		kvm_s390_vcpu_stop(vcpu);
+	return -EOPNOTSUPP;
 }
 
 static int handle_validity(struct kvm_vcpu *vcpu)
@@ -97,68 +94,575 @@ static int handle_validity(struct kvm_vcpu *vcpu)
 
 	vcpu->stat.exit_validity++;
 	trace_kvm_s390_intercept_validity(vcpu, viwhy);
-	WARN_ONCE(true, "kvm: unhandled validity intercept 0x%x\n", viwhy);
-	return -EOPNOTSUPP;
+	KVM_EVENT(3, "validity intercept 0x%x for pid %u (kvm 0x%p)", viwhy,
+		  current->pid, vcpu->kvm);
+
+	/* do not warn on invalid runtime instrumentation mode */
+	WARN_ONCE(viwhy != 0x44, "kvm: unhandled validity intercept 0x%x\n",
+		  viwhy);
+	return -EINVAL;
 }
 
 static int handle_instruction(struct kvm_vcpu *vcpu)
 {
-	intercept_handler_t handler;
-
 	vcpu->stat.exit_instruction++;
 	trace_kvm_s390_intercept_instruction(vcpu,
 					     vcpu->arch.sie_block->ipa,
 					     vcpu->arch.sie_block->ipb);
-	handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
-	if (handler)
-		return handler(vcpu);
-	return -EOPNOTSUPP;
+
+	switch (vcpu->arch.sie_block->ipa >> 8) {
+	case 0x01:
+		return kvm_s390_handle_01(vcpu);
+	case 0x82:
+		return kvm_s390_handle_lpsw(vcpu);
+	case 0x83:
+		return kvm_s390_handle_diag(vcpu);
+	case 0xaa:
+		return kvm_s390_handle_aa(vcpu);
+	case 0xae:
+		return kvm_s390_handle_sigp(vcpu);
+	case 0xb2:
+		return kvm_s390_handle_b2(vcpu);
+	case 0xb6:
+		return kvm_s390_handle_stctl(vcpu);
+	case 0xb7:
+		return kvm_s390_handle_lctl(vcpu);
+	case 0xb9:
+		return kvm_s390_handle_b9(vcpu);
+	case 0xe3:
+		return kvm_s390_handle_e3(vcpu);
+	case 0xe5:
+		return kvm_s390_handle_e5(vcpu);
+	case 0xeb:
+		return kvm_s390_handle_eb(vcpu);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int inject_prog_on_prog_intercept(struct kvm_vcpu *vcpu)
+{
+	struct kvm_s390_pgm_info pgm_info = {
+		.code = vcpu->arch.sie_block->iprcc,
+		/* the PSW has already been rewound */
+		.flags = KVM_S390_PGM_FLAGS_NO_REWIND,
+	};
+
+	switch (vcpu->arch.sie_block->iprcc & ~PGM_PER) {
+	case PGM_AFX_TRANSLATION:
+	case PGM_ASX_TRANSLATION:
+	case PGM_EX_TRANSLATION:
+	case PGM_LFX_TRANSLATION:
+	case PGM_LSTE_SEQUENCE:
+	case PGM_LSX_TRANSLATION:
+	case PGM_LX_TRANSLATION:
+	case PGM_PRIMARY_AUTHORITY:
+	case PGM_SECONDARY_AUTHORITY:
+	case PGM_SPACE_SWITCH:
+		pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
+		break;
+	case PGM_ALEN_TRANSLATION:
+	case PGM_ALE_SEQUENCE:
+	case PGM_ASTE_INSTANCE:
+	case PGM_ASTE_SEQUENCE:
+	case PGM_ASTE_VALIDITY:
+	case PGM_EXTENDED_AUTHORITY:
+		pgm_info.exc_access_id = vcpu->arch.sie_block->eai;
+		break;
+	case PGM_ASCE_TYPE:
+	case PGM_PAGE_TRANSLATION:
+	case PGM_REGION_FIRST_TRANS:
+	case PGM_REGION_SECOND_TRANS:
+	case PGM_REGION_THIRD_TRANS:
+	case PGM_SEGMENT_TRANSLATION:
+		pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
+		pgm_info.exc_access_id  = vcpu->arch.sie_block->eai;
+		pgm_info.op_access_id  = vcpu->arch.sie_block->oai;
+		break;
+	case PGM_MONITOR:
+		pgm_info.mon_class_nr = vcpu->arch.sie_block->mcn;
+		pgm_info.mon_code = vcpu->arch.sie_block->tecmc;
+		break;
+	case PGM_VECTOR_PROCESSING:
+	case PGM_DATA:
+		pgm_info.data_exc_code = vcpu->arch.sie_block->dxc;
+		break;
+	case PGM_PROTECTION:
+		pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
+		pgm_info.exc_access_id  = vcpu->arch.sie_block->eai;
+		break;
+	default:
+		break;
+	}
+
+	if (vcpu->arch.sie_block->iprcc & PGM_PER) {
+		pgm_info.per_code = vcpu->arch.sie_block->perc;
+		pgm_info.per_atmid = vcpu->arch.sie_block->peratmid;
+		pgm_info.per_address = vcpu->arch.sie_block->peraddr;
+		pgm_info.per_access_id = vcpu->arch.sie_block->peraid;
+	}
+	return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
+}
+
+/*
+ * restore ITDB to program-interruption TDB in guest lowcore
+ * and set TX abort indication if required
+*/
+static int handle_itdb(struct kvm_vcpu *vcpu)
+{
+	struct kvm_s390_itdb *itdb;
+	int rc;
+
+	if (!IS_TE_ENABLED(vcpu) || !IS_ITDB_VALID(vcpu))
+		return 0;
+	if (current->thread.per_flags & PER_FLAG_NO_TE)
+		return 0;
+	itdb = phys_to_virt(vcpu->arch.sie_block->itdba);
+	rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
+	if (rc)
+		return rc;
+	memset(itdb, 0, sizeof(*itdb));
+
+	return 0;
+}
+
+#define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
+
+static bool should_handle_per_event(const struct kvm_vcpu *vcpu)
+{
+	if (!guestdbg_enabled(vcpu) || !per_event(vcpu))
+		return false;
+	if (guestdbg_sstep_enabled(vcpu) &&
+	    vcpu->arch.sie_block->iprcc != PGM_PER) {
+		/*
+		 * __vcpu_run() will exit after delivering the concurrently
+		 * indicated condition.
+		 */
+		return false;
+	}
+	return true;
 }
 
 static int handle_prog(struct kvm_vcpu *vcpu)
 {
+	psw_t psw;
+	int rc;
+
 	vcpu->stat.exit_program_interruption++;
+
+	/*
+	 * Intercept 8 indicates a loop of specification exceptions
+	 * for protected guests.
+	 */
+	if (kvm_s390_pv_cpu_is_protected(vcpu))
+		return -EOPNOTSUPP;
+
+	if (should_handle_per_event(vcpu)) {
+		rc = kvm_s390_handle_per_event(vcpu);
+		if (rc)
+			return rc;
+		/* the interrupt might have been filtered out completely */
+		if (vcpu->arch.sie_block->iprcc == 0)
+			return 0;
+	}
+
 	trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
-	return kvm_s390_inject_program_int(vcpu, vcpu->arch.sie_block->iprcc);
+	if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
+		rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
+		if (rc)
+			return rc;
+		/* Avoid endless loops of specification exceptions */
+		if (!is_valid_psw(&psw))
+			return -EOPNOTSUPP;
+	}
+	rc = handle_itdb(vcpu);
+	if (rc)
+		return rc;
+
+	return inject_prog_on_prog_intercept(vcpu);
+}
+
+/**
+ * handle_external_interrupt - used for external interruption interceptions
+ * @vcpu: virtual cpu
+ *
+ * This interception occurs if:
+ * - the CPUSTAT_EXT_INT bit was already set when the external interrupt
+ *   occurred. In this case, the interrupt needs to be injected manually to
+ *   preserve interrupt priority.
+ * - the external new PSW has external interrupts enabled, which will cause an
+ *   interruption loop. We drop to userspace in this case.
+ *
+ * The latter case can be detected by inspecting the external mask bit in the
+ * external new psw.
+ *
+ * Under PV, only the latter case can occur, since interrupt priorities are
+ * handled in the ultravisor.
+ */
+static int handle_external_interrupt(struct kvm_vcpu *vcpu)
+{
+	u16 eic = vcpu->arch.sie_block->eic;
+	struct kvm_s390_irq irq;
+	psw_t newpsw;
+	int rc;
+
+	vcpu->stat.exit_external_interrupt++;
+
+	if (kvm_s390_pv_cpu_is_protected(vcpu)) {
+		newpsw = vcpu->arch.sie_block->gpsw;
+	} else {
+		rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
+		if (rc)
+			return rc;
+	}
+
+	/*
+	 * Clock comparator or timer interrupt with external interrupt enabled
+	 * will cause interrupt loop. Drop to userspace.
+	 */
+	if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
+	    (newpsw.mask & PSW_MASK_EXT))
+		return -EOPNOTSUPP;
+
+	switch (eic) {
+	case EXT_IRQ_CLK_COMP:
+		irq.type = KVM_S390_INT_CLOCK_COMP;
+		break;
+	case EXT_IRQ_CPU_TIMER:
+		irq.type = KVM_S390_INT_CPU_TIMER;
+		break;
+	case EXT_IRQ_EXTERNAL_CALL:
+		irq.type = KVM_S390_INT_EXTERNAL_CALL;
+		irq.u.extcall.code = vcpu->arch.sie_block->extcpuaddr;
+		rc = kvm_s390_inject_vcpu(vcpu, &irq);
+		/* ignore if another external call is already pending */
+		if (rc == -EBUSY)
+			return 0;
+		return rc;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return kvm_s390_inject_vcpu(vcpu, &irq);
+}
+
+/**
+ * handle_mvpg_pei - Handle MOVE PAGE partial execution interception.
+ * @vcpu: virtual cpu
+ *
+ * This interception can only happen for guests with DAT disabled and
+ * addresses that are currently not mapped in the host. Thus we try to
+ * set up the mappings for the corresponding user pages here (or throw
+ * addressing exceptions in case of illegal guest addresses).
+ */
+static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
+{
+	unsigned long srcaddr, dstaddr;
+	int reg1, reg2, rc;
+
+	kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
+
+	/* Ensure that the source is paged-in, no actual access -> no key checking */
+	rc = guest_translate_address_with_key(vcpu, vcpu->run->s.regs.gprs[reg2],
+					      reg2, &srcaddr, GACC_FETCH, 0);
+	if (rc)
+		return kvm_s390_inject_prog_cond(vcpu, rc);
+	rc = kvm_s390_handle_dat_fault(vcpu, srcaddr, 0);
+	if (rc != 0)
+		return rc;
+
+	/* Ensure that the source is paged-in, no actual access -> no key checking */
+	rc = guest_translate_address_with_key(vcpu, vcpu->run->s.regs.gprs[reg1],
+					      reg1, &dstaddr, GACC_STORE, 0);
+	if (rc)
+		return kvm_s390_inject_prog_cond(vcpu, rc);
+	rc = kvm_s390_handle_dat_fault(vcpu, dstaddr, FOLL_WRITE);
+	if (rc != 0)
+		return rc;
+
+	kvm_s390_retry_instr(vcpu);
+
+	return 0;
+}
+
+static int handle_partial_execution(struct kvm_vcpu *vcpu)
+{
+	vcpu->stat.exit_pei++;
+
+	if (vcpu->arch.sie_block->ipa == 0xb254)	/* MVPG */
+		return handle_mvpg_pei(vcpu);
+	if (vcpu->arch.sie_block->ipa >> 8 == 0xae)	/* SIGP */
+		return kvm_s390_handle_sigp_pei(vcpu);
+
+	return -EOPNOTSUPP;
+}
+
+/*
+ * Handle the sthyi instruction that provides the guest with system
+ * information, like current CPU resources available at each level of
+ * the machine.
+ */
+int handle_sthyi(struct kvm_vcpu *vcpu)
+{
+	int reg1, reg2, cc = 0, r = 0;
+	u64 code, addr, rc = 0;
+	struct sthyi_sctns *sctns = NULL;
+
+	if (!test_kvm_facility(vcpu->kvm, 74))
+		return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
+
+	kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
+	code = vcpu->run->s.regs.gprs[reg1];
+	addr = vcpu->run->s.regs.gprs[reg2];
+
+	vcpu->stat.instruction_sthyi++;
+	VCPU_EVENT(vcpu, 3, "STHYI: fc: %llu addr: 0x%016llx", code, addr);
+	trace_kvm_s390_handle_sthyi(vcpu, code, addr);
+
+	if (reg1 == reg2 || reg1 & 1 || reg2 & 1)
+		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+
+	if (code & 0xffff) {
+		cc = 3;
+		rc = 4;
+		goto out;
+	}
+
+	if (!kvm_s390_pv_cpu_is_protected(vcpu) && (addr & ~PAGE_MASK))
+		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+
+	sctns = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
+	if (!sctns)
+		return -ENOMEM;
+
+	cc = sthyi_fill(sctns, &rc);
+	if (cc < 0) {
+		free_page((unsigned long)sctns);
+		return cc;
+	}
+out:
+	if (!cc) {
+		if (kvm_s390_pv_cpu_is_protected(vcpu)) {
+			memcpy(sida_addr(vcpu->arch.sie_block), sctns, PAGE_SIZE);
+		} else {
+			r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);
+			if (r) {
+				free_page((unsigned long)sctns);
+				return kvm_s390_inject_prog_cond(vcpu, r);
+			}
+		}
+	}
+
+	free_page((unsigned long)sctns);
+	vcpu->run->s.regs.gprs[reg2 + 1] = rc;
+	kvm_s390_set_psw_cc(vcpu, cc);
+	return r;
 }
 
-static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
+static int handle_operexc(struct kvm_vcpu *vcpu)
 {
-	int rc, rc2;
+	psw_t oldpsw, newpsw;
+	int rc;
+
+	vcpu->stat.exit_operation_exception++;
+	trace_kvm_s390_handle_operexc(vcpu, vcpu->arch.sie_block->ipa,
+				      vcpu->arch.sie_block->ipb);
 
-	vcpu->stat.exit_instr_and_program++;
-	rc = handle_instruction(vcpu);
-	rc2 = handle_prog(vcpu);
+	if (vcpu->arch.sie_block->ipa == 0xb256)
+		return handle_sthyi(vcpu);
 
-	if (rc == -EOPNOTSUPP)
-		vcpu->arch.sie_block->icptcode = 0x04;
+	if (vcpu->kvm->arch.user_operexec)
+		return -EOPNOTSUPP;
+
+	if (vcpu->arch.sie_block->ipa == 0 && vcpu->kvm->arch.user_instr0)
+		return -EOPNOTSUPP;
+	rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &newpsw, sizeof(psw_t));
 	if (rc)
 		return rc;
-	return rc2;
-}
-
-static const intercept_handler_t intercept_funcs[] = {
-	[0x00 >> 2] = handle_noop,
-	[0x04 >> 2] = handle_instruction,
-	[0x08 >> 2] = handle_prog,
-	[0x0C >> 2] = handle_instruction_and_prog,
-	[0x10 >> 2] = handle_noop,
-	[0x14 >> 2] = handle_noop,
-	[0x18 >> 2] = handle_noop,
-	[0x1C >> 2] = kvm_s390_handle_wait,
-	[0x20 >> 2] = handle_validity,
-	[0x28 >> 2] = handle_stop,
-};
+	/*
+	 * Avoid endless loops of operation exceptions, if the pgm new
+	 * PSW will cause a new operation exception.
+	 * The heuristic checks if the pgm new psw is within 6 bytes before
+	 * the faulting psw address (with same DAT, AS settings) and the
+	 * new psw is not a wait psw and the fault was not triggered by
+	 * problem state.
+	 */
+	oldpsw = vcpu->arch.sie_block->gpsw;
+	if (oldpsw.addr - newpsw.addr <= 6 &&
+	    !(newpsw.mask & PSW_MASK_WAIT) &&
+	    !(oldpsw.mask & PSW_MASK_PSTATE) &&
+	    (newpsw.mask & PSW_MASK_ASC) == (oldpsw.mask & PSW_MASK_ASC) &&
+	    (newpsw.mask & PSW_MASK_DAT) == (oldpsw.mask & PSW_MASK_DAT))
+		return -EOPNOTSUPP;
+
+	return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
+}
+
+static int handle_pv_spx(struct kvm_vcpu *vcpu)
+{
+	u32 pref = *(u32 *)sida_addr(vcpu->arch.sie_block);
+
+	kvm_s390_set_prefix(vcpu, pref);
+	trace_kvm_s390_handle_prefix(vcpu, 1, pref);
+	return 0;
+}
+
+static int handle_pv_sclp(struct kvm_vcpu *vcpu)
+{
+	struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
+
+	spin_lock(&fi->lock);
+	/*
+	 * 2 cases:
+	 * a: an sccb answering interrupt was already pending or in flight.
+	 *    As the sccb value is not known we can simply set some value to
+	 *    trigger delivery of a saved SCCB. UV will then use its saved
+	 *    copy of the SCCB value.
+	 * b: an error SCCB interrupt needs to be injected so we also inject
+	 *    a fake SCCB address. Firmware will use the proper one.
+	 * This makes sure, that both errors and real sccb returns will only
+	 * be delivered after a notification intercept (instruction has
+	 * finished) but not after others.
+	 */
+	fi->srv_signal.ext_params |= 0x43000;
+	set_bit(IRQ_PEND_EXT_SERVICE, &fi->pending_irqs);
+	clear_bit(IRQ_PEND_EXT_SERVICE, &fi->masked_irqs);
+	spin_unlock(&fi->lock);
+	return 0;
+}
+
+static int handle_pv_uvc(struct kvm_vcpu *vcpu)
+{
+	struct uv_cb_share *guest_uvcb = sida_addr(vcpu->arch.sie_block);
+	struct uv_cb_cts uvcb = {
+		.header.cmd	= UVC_CMD_UNPIN_PAGE_SHARED,
+		.header.len	= sizeof(uvcb),
+		.guest_handle	= kvm_s390_pv_get_handle(vcpu->kvm),
+		.gaddr		= guest_uvcb->paddr,
+	};
+	int rc;
+
+	if (guest_uvcb->header.cmd != UVC_CMD_REMOVE_SHARED_ACCESS) {
+		WARN_ONCE(1, "Unexpected notification intercept for UVC 0x%x\n",
+			  guest_uvcb->header.cmd);
+		return 0;
+	}
+	rc = kvm_s390_pv_make_secure(vcpu->kvm, uvcb.gaddr, &uvcb);
+	/*
+	 * If the unpin did not succeed, the guest will exit again for the UVC
+	 * and we will retry the unpin.
+	 */
+	if (rc == -EINVAL || rc == -ENXIO)
+		return 0;
+	/*
+	 * If we got -EAGAIN here, we simply return it. It will eventually
+	 * get propagated all the way to userspace, which should then try
+	 * again.
+	 */
+	return rc;
+}
+
+static int handle_pv_notification(struct kvm_vcpu *vcpu)
+{
+	int ret;
+
+	if (vcpu->arch.sie_block->ipa == 0xb210)
+		return handle_pv_spx(vcpu);
+	if (vcpu->arch.sie_block->ipa == 0xb220)
+		return handle_pv_sclp(vcpu);
+	if (vcpu->arch.sie_block->ipa == 0xb9a4)
+		return handle_pv_uvc(vcpu);
+	if (vcpu->arch.sie_block->ipa >> 8 == 0xae) {
+		/*
+		 * Besides external call, other SIGP orders also cause a
+		 * 108 (pv notify) intercept. In contrast to external call,
+		 * these orders need to be emulated and hence the appropriate
+		 * place to handle them is in handle_instruction().
+		 * So first try kvm_s390_handle_sigp_pei() and if that isn't
+		 * successful, go on with handle_instruction().
+		 */
+		ret = kvm_s390_handle_sigp_pei(vcpu);
+		if (!ret)
+			return ret;
+	}
+
+	return handle_instruction(vcpu);
+}
+
+static bool should_handle_per_ifetch(const struct kvm_vcpu *vcpu, int rc)
+{
+	/* Process PER, also if the instruction is processed in user space. */
+	if (!(vcpu->arch.sie_block->icptstatus & 0x02))
+		return false;
+	if (rc != 0 && rc != -EOPNOTSUPP)
+		return false;
+	if (guestdbg_sstep_enabled(vcpu) && vcpu->arch.local_int.pending_irqs)
+		/* __vcpu_run() will exit after delivering the interrupt. */
+		return false;
+	return true;
+}
 
 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 {
-	intercept_handler_t func;
-	u8 code = vcpu->arch.sie_block->icptcode;
+	int rc, per_rc = 0;
 
-	if (code & 3 || (code >> 2) >= ARRAY_SIZE(intercept_funcs))
+	if (kvm_is_ucontrol(vcpu->kvm))
 		return -EOPNOTSUPP;
-	func = intercept_funcs[code >> 2];
-	if (func)
-		return func(vcpu);
-	return -EOPNOTSUPP;
+
+	switch (vcpu->arch.sie_block->icptcode) {
+	case ICPT_EXTREQ:
+		vcpu->stat.exit_external_request++;
+		return 0;
+	case ICPT_IOREQ:
+		vcpu->stat.exit_io_request++;
+		return 0;
+	case ICPT_INST:
+		rc = handle_instruction(vcpu);
+		break;
+	case ICPT_PROGI:
+		return handle_prog(vcpu);
+	case ICPT_EXTINT:
+		return handle_external_interrupt(vcpu);
+	case ICPT_WAIT:
+		return kvm_s390_handle_wait(vcpu);
+	case ICPT_VALIDITY:
+		return handle_validity(vcpu);
+	case ICPT_STOP:
+		return handle_stop(vcpu);
+	case ICPT_OPEREXC:
+		rc = handle_operexc(vcpu);
+		break;
+	case ICPT_PARTEXEC:
+		rc = handle_partial_execution(vcpu);
+		break;
+	case ICPT_KSS:
+		/* Instruction will be redriven, skip the PER check. */
+		return kvm_s390_skey_check_enable(vcpu);
+	case ICPT_MCHKREQ:
+	case ICPT_INT_ENABLE:
+		/*
+		 * PSW bit 13 or a CR (0, 6, 14) changed and we might
+		 * now be able to deliver interrupts. The pre-run code
+		 * will take care of this.
+		 */
+		rc = 0;
+		break;
+	case ICPT_PV_INSTR:
+		rc = handle_instruction(vcpu);
+		break;
+	case ICPT_PV_NOTIFY:
+		rc = handle_pv_notification(vcpu);
+		break;
+	case ICPT_PV_PREF:
+		rc = 0;
+		kvm_s390_pv_convert_to_secure(vcpu->kvm, kvm_s390_get_prefix(vcpu));
+		kvm_s390_pv_convert_to_secure(vcpu->kvm, kvm_s390_get_prefix(vcpu) + PAGE_SIZE);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	if (should_handle_per_ifetch(vcpu, rc))
+		per_rc = kvm_s390_handle_per_ifetch_icpt(vcpu);
+	return per_rc ? per_rc : rc;
 }