1 files changed, 81 insertions, 22 deletions

diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index 8bd42a20d924..b16352083ff9 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -217,7 +217,7 @@ static int handle_itdb(struct kvm_vcpu *vcpu)
 		return 0;
 	if (current->thread.per_flags & PER_FLAG_NO_TE)
 		return 0;
-	itdb = (struct kvm_s390_itdb *)vcpu->arch.sie_block->itdba;
+	itdb = phys_to_virt(vcpu->arch.sie_block->itdba);
 	rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
 	if (rc)
 		return rc;
@@ -228,6 +228,21 @@ static int handle_itdb(struct kvm_vcpu *vcpu)
 
 #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;
@@ -242,7 +257,7 @@ static int handle_prog(struct kvm_vcpu *vcpu)
 	if (kvm_s390_pv_cpu_is_protected(vcpu))
 		return -EOPNOTSUPP;
 
-	if (guestdbg_enabled(vcpu) && per_event(vcpu)) {
+	if (should_handle_per_event(vcpu)) {
 		rc = kvm_s390_handle_per_event(vcpu);
 		if (rc)
 			return rc;
@@ -271,10 +286,18 @@ static int handle_prog(struct kvm_vcpu *vcpu)
  * handle_external_interrupt - used for external interruption interceptions
  * @vcpu: virtual cpu
  *
- * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
- * the new PSW does not have external interrupts disabled. In the first case,
- * we've got to deliver the interrupt manually, and in the second case, we
- * drop to userspace to handle the situation there.
+ * 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)
 {
@@ -285,10 +308,18 @@ static int handle_external_interrupt(struct kvm_vcpu *vcpu)
 
 	vcpu->stat.exit_external_interrupt++;
 
-	rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
-	if (rc)
-		return rc;
-	/* We can not handle clock comparator or timer interrupt with bad PSW */
+	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;
@@ -373,8 +404,8 @@ static int handle_partial_execution(struct kvm_vcpu *vcpu)
  */
 int handle_sthyi(struct kvm_vcpu *vcpu)
 {
-	int reg1, reg2, r = 0;
-	u64 code, addr, cc = 0, rc = 0;
+	int reg1, reg2, cc = 0, r = 0;
+	u64 code, addr, rc = 0;
 	struct sthyi_sctns *sctns = NULL;
 
 	if (!test_kvm_facility(vcpu->kvm, 74))
@@ -405,12 +436,14 @@ int handle_sthyi(struct kvm_vcpu *vcpu)
 		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((void *)(sida_origin(vcpu->arch.sie_block)),
-			       sctns, PAGE_SIZE);
+			memcpy(sida_addr(vcpu->arch.sie_block), sctns, PAGE_SIZE);
 		} else {
 			r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);
 			if (r) {
@@ -464,7 +497,7 @@ static int handle_operexc(struct kvm_vcpu *vcpu)
 
 static int handle_pv_spx(struct kvm_vcpu *vcpu)
 {
-	u32 pref = *(u32 *)vcpu->arch.sie_block->sidad;
+	u32 pref = *(u32 *)sida_addr(vcpu->arch.sie_block);
 
 	kvm_s390_set_prefix(vcpu, pref);
 	trace_kvm_s390_handle_prefix(vcpu, 1, pref);
@@ -497,7 +530,7 @@ static int handle_pv_sclp(struct kvm_vcpu *vcpu)
 
 static int handle_pv_uvc(struct kvm_vcpu *vcpu)
 {
-	struct uv_cb_share *guest_uvcb = (void *)vcpu->arch.sie_block->sidad;
+	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),
@@ -528,16 +561,44 @@ static int handle_pv_uvc(struct kvm_vcpu *vcpu)
 
 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)
 {
 	int rc, per_rc = 0;
@@ -572,8 +633,8 @@ int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 		rc = handle_partial_execution(vcpu);
 		break;
 	case ICPT_KSS:
-		rc = kvm_s390_skey_check_enable(vcpu);
-		break;
+		/* Instruction will be redriven, skip the PER check. */
+		return kvm_s390_skey_check_enable(vcpu);
 	case ICPT_MCHKREQ:
 	case ICPT_INT_ENABLE:
 		/*
@@ -600,9 +661,7 @@ int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 		return -EOPNOTSUPP;
 	}
 
-	/* process PER, also if the instrution is processed in user space */
-	if (vcpu->arch.sie_block->icptstatus & 0x02 &&
-	    (!rc || rc == -EOPNOTSUPP))
+	if (should_handle_per_ifetch(vcpu, rc))
 		per_rc = kvm_s390_handle_per_ifetch_icpt(vcpu);
 	return per_rc ? per_rc : rc;
 }