Commit 189e7d87 authored by Matthew Rosato's avatar Matthew Rosato Committed by Janosch Frank
Browse files

KVM: s390: pci: register pci hooks without interpretation 



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: ca922fec ("KVM: s390: pci: Hook to access KVM lowlevel from VFIO")
Signed-off-by: default avatarMatthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: default avatarPierre 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: default avatarJanosch Frank <frankja@linux.ibm.com>
parent 70ba8fae

arch/s390/kvm/kvm-s390.c

+2 −2
Original line number Diff line number Diff line
@@ -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);

arch/s390/kvm/pci.c

+11 −3
Original line number Diff line number Diff line
@@ -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);

}