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KVM: s390: pci: register pci hooks without interpretation

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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: ca922fecda ("KVM: s390: pci: Hook to access KVM lowlevel from VFIO")
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Link: https://lore.kernel.org/r/20220920193025.135655-1-mjrosato@linux.ibm.com
Message-Id: <20220920193025.135655-1-mjrosato@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
This commit is contained in:
Matthew Rosato 2022-09-20 15:30:25 -04:00 committed by Janosch Frank
parent 70ba8fae27
commit 189e7d876e
2 changed files with 13 additions and 5 deletions
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4
arch/s390/kvm/kvm-s390.c
View file

@ -505,7 +505,7 @@ 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");
@ -527,7 +527,7 @@ 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);

14
arch/s390/kvm/pci.c
View file

@ -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);
}