On 1/14/22 21:31, Matthew Rosato wrote:
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.
Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
---
arch/s390/include/asm/kvm_host.h | 4 ++++
arch/s390/kvm/kvm-s390.c | 40 ++++++++++++++++++++++++++++++++
arch/s390/kvm/kvm-s390.h | 10 ++++++++
3 files changed, 54 insertions(+)
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 3f147b8d050b..38982c1de413 100644
--- 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;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index ab8b56deed11..b6c32fc3b272 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1029,6 +1029,44 @@ static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr)
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;
As far as I understood, the interpretation is only possible if a gisa
designation is associated with the PCI function via CLP enable.
Why do we setup the SIE ECB only when the guest requests for
interpretation and not systematically in vcpu_setup?
If ECB2_ZPCI_LSI, ECB3_AISII or ECB3_AISI have an effect when the gisa
designation is not specified shouldn't we have a way to clear these bits?
+}
+
+void kvm_s390_vcpu_pci_enable_interp(struct kvm *kvm)
+{
+ struct kvm_vcpu *vcpu;
+ int i;
+
+ /*
+ * If host is configured for PCI and the necessary facilities are
+ * available, turn on interpretation for the life of this guest
+ */
+ if (!IS_ENABLED(CONFIG_PCI) || !sclp.has_zpci_lsi || !sclp.has_aisii ||
+ !sclp.has_aeni || !sclp.has_aisi)
+ return;
+
+ mutex_lock(&kvm->lock);
+
+ 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);
+ mutex_unlock(&kvm->lock);
+}
+
static void kvm_s390_sync_request_broadcast(struct kvm *kvm, int req)
{
int cx;
@@ -3282,6 +3320,8 @@ static int kvm_s390_vcpu_setup(struct kvm_vcpu *vcpu)
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);
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index c07a050d757d..a2eccb8b977e 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -481,6 +481,16 @@ void kvm_s390_reinject_machine_check(struct kvm_vcpu *vcpu,
*/
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
*
--
Pierre Morel
IBM Lab Boeblingen
