From: Matthew Rosato <mjrosato@linux.ibm.com>
Date: Mon, 6 Jun 2022 16:33:18 -0400
Subject: KVM: s390: mechanism to enable guest zPCI Interpretation
Git-commit: 3f4bbb4342ec637b14d0e367e487fd38b31d8b48
Patch-mainline: v6.0-rc1
References: bsc#1205701

The guest must have access to certain facilities in order to allow
interpretive execution of zPCI instructions and adapter event
notifications.  However, there are some cases where a guest might
disable interpretation -- provide a mechanism via which we can defer
enabling the associated zPCI interpretation facilities until the guest
indicates it wishes to use them.

Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220606203325.110625-15-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
 arch/s390/include/asm/kvm_host.h |    4 ++++
 arch/s390/kvm/kvm-s390.c         |   38 ++++++++++++++++++++++++++++++++++++++
 arch/s390/kvm/kvm-s390.h         |   10 ++++++++++
 3 files changed, 52 insertions(+)

--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -252,7 +252,10 @@ struct kvm_s390_sie_block {
 #define ECB2_IEP	0x20
 #define ECB2_PFMFI	0x08
 #define ECB2_ESCA	0x04
+#define ECB2_ZPCI_LSI	0x02
 	__u8    ecb2;                   /* 0x0062 */
+#define ECB3_AISI	0x20
+#define ECB3_AISII	0x10
 #define ECB3_DEA 0x08
 #define ECB3_AES 0x04
 #define ECB3_RI  0x01
@@ -938,6 +941,7 @@ struct kvm_arch{
 	int use_cmma;
 	int use_pfmfi;
 	int use_skf;
+	int use_zpci_interp;
 	int user_cpu_state_ctrl;
 	int user_sigp;
 	int user_stsi;
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1034,6 +1034,42 @@ static int kvm_s390_vm_set_crypto(struct
 	return 0;
 }
 
+static void kvm_s390_vcpu_pci_setup(struct kvm_vcpu *vcpu)
+{
+	/* Only set the ECB bits after guest requests zPCI interpretation */
+	if (!vcpu->kvm->arch.use_zpci_interp)
+		return;
+
+	vcpu->arch.sie_block->ecb2 |= ECB2_ZPCI_LSI;
+	vcpu->arch.sie_block->ecb3 |= ECB3_AISII + ECB3_AISI;
+}
+
+void kvm_s390_vcpu_pci_enable_interp(struct kvm *kvm)
+{
+	struct kvm_vcpu *vcpu;
+	unsigned long i;
+
+	lockdep_assert_held(&kvm->lock);
+
+	if (!kvm_s390_pci_interp_allowed())
+		return;
+
+	/*
+	 * If host is configured for PCI and the necessary facilities are
+	 * available, turn on interpretation for the life of this guest
+	 */
+	kvm->arch.use_zpci_interp = 1;
+
+	kvm_s390_vcpu_block_all(kvm);
+
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		kvm_s390_vcpu_pci_setup(vcpu);
+		kvm_s390_sync_request(KVM_REQ_VSIE_RESTART, vcpu);
+	}
+
+	kvm_s390_vcpu_unblock_all(kvm);
+}
+
 static void kvm_s390_sync_request_broadcast(struct kvm *kvm, int req)
 {
 	int cx;
@@ -3366,6 +3402,8 @@ static int kvm_s390_vcpu_setup(struct kv
 
 	kvm_s390_vcpu_crypto_setup(vcpu);
 
+	kvm_s390_vcpu_pci_setup(vcpu);
+
 	mutex_lock(&vcpu->kvm->lock);
 	if (kvm_s390_pv_is_protected(vcpu->kvm)) {
 		rc = kvm_s390_pv_create_cpu(vcpu, &uvrc, &uvrrc);
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -483,6 +483,16 @@ void kvm_s390_reinject_machine_check(str
 void kvm_s390_vcpu_crypto_reset_all(struct kvm *kvm);
 
 /**
+ * kvm_s390_vcpu_pci_enable_interp
+ *
+ * Set the associated PCI attributes for each vcpu to allow for zPCI Load/Store
+ * interpretation as well as adapter interruption forwarding.
+ *
+ * @kvm: the KVM guest
+ */
+void kvm_s390_vcpu_pci_enable_interp(struct kvm *kvm);
+
+/**
  * diag9c_forwarding_hz
  *
  * Set the maximum number of diag9c forwarding per second