The kvm registration hooks must be registered even if the facilities necessary for zPCI interpretation are unavailable, as vfio-pci-zdev will expect to use the hooks regardless. This fixes an issue where vfio-pci-zdev will fail its open function because of a missing kvm_register when running on hardware that does not support zPCI interpretation. Fixes: ca922fecda6c ("KVM: s390: pci: Hook to access KVM lowlevel from VFIO") Signed-off-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx> --- arch/s390/kvm/kvm-s390.c | 4 ++-- arch/s390/kvm/pci.c | 14 +++++++++++--- 2 files changed, 13 insertions(+), 5 deletions(-) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index e20e126944aa..5c7f5f97ea09 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -510,7 +510,7 @@ int kvm_arch_init(void *opaque) goto out; } - if (kvm_s390_pci_interp_allowed()) { + if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM)) { rc = kvm_s390_pci_init(); if (rc) { pr_err("Unable to allocate AIFT for PCI\n"); @@ -532,7 +532,7 @@ int kvm_arch_init(void *opaque) void kvm_arch_exit(void) { kvm_s390_gib_destroy(); - if (kvm_s390_pci_interp_allowed()) + if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM)) kvm_s390_pci_exit(); debug_unregister(kvm_s390_dbf); debug_unregister(kvm_s390_dbf_uv); diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c index 90aaba80696a..c50c1645c0ae 100644 --- a/arch/s390/kvm/pci.c +++ b/arch/s390/kvm/pci.c @@ -672,23 +672,31 @@ int kvm_s390_pci_zpci_op(struct kvm *kvm, struct kvm_s390_zpci_op *args) int kvm_s390_pci_init(void) { + zpci_kvm_hook.kvm_register = kvm_s390_pci_register_kvm; + zpci_kvm_hook.kvm_unregister = kvm_s390_pci_unregister_kvm; + + if (!kvm_s390_pci_interp_allowed()) + return 0; + aift = kzalloc(sizeof(struct zpci_aift), GFP_KERNEL); if (!aift) return -ENOMEM; spin_lock_init(&aift->gait_lock); mutex_init(&aift->aift_lock); - zpci_kvm_hook.kvm_register = kvm_s390_pci_register_kvm; - zpci_kvm_hook.kvm_unregister = kvm_s390_pci_unregister_kvm; return 0; } void kvm_s390_pci_exit(void) { - mutex_destroy(&aift->aift_lock); zpci_kvm_hook.kvm_register = NULL; zpci_kvm_hook.kvm_unregister = NULL; + if (!kvm_s390_pci_interp_allowed()) + return; + + mutex_destroy(&aift->aift_lock); + kfree(aift); } -- 2.37.3