On 13/05/2022 21.15, 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.
Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
Reviewed-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx>
---
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(+)
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index c1518a505060..8e381603b6a7 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -254,7 +254,10 @@ 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
@@ -940,6 +943,7 @@ 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 5a0fbfd19c4a..0797661732cc 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1031,6 +1031,42 @@ 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;
+}
+
+void kvm_s390_vcpu_pci_enable_interp(struct kvm *kvm)
+{
+ struct kvm_vcpu *vcpu;
+ unsigned long i;
+
+ lockdep_assert_held(&kvm->lock);
+
+ /*
+ * If host is configured for PCI and the necessary facilities are
+ * available, turn on interpretation for the life of this guest
+ */
I'd suggest to move the comment after the if-statement - it seems to fit
better there.
+ if (!kvm_s390_pci_interp_allowed())
+ return;
+
+ 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);
+}
Thomas
