We have a cross dependency between KVM and VFIO when using
s390 vfio_pci_zdev extensions for PCI passthrough
To be able to keep both subsystem modular we add a registering
hook inside the S390 core code.
This fixes a build problem when VFIO is built-in and KVM is built
as a module.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Fixes:
09340b2fca007 ("KVM: s390: pci: add routines to start/stop interpretive execution")
Cc: <stable@vger.kernel.org>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Link: https://lore.kernel.org/r/20220819122945.9309-1-pmorel@linux.ibm.com
Message-Id: <
20220819122945.9309-1-pmorel@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
#define __KVM_HAVE_ARCH_VM_FREE
void kvm_arch_free_vm(struct kvm *kvm);
-#ifdef CONFIG_VFIO_PCI_ZDEV_KVM
-int kvm_s390_pci_register_kvm(struct zpci_dev *zdev, struct kvm *kvm);
-void kvm_s390_pci_unregister_kvm(struct zpci_dev *zdev);
-#else
-static inline int kvm_s390_pci_register_kvm(struct zpci_dev *dev,
- struct kvm *kvm)
-{
- return -EPERM;
-}
-static inline void kvm_s390_pci_unregister_kvm(struct zpci_dev *dev) {}
-#endif
+struct zpci_kvm_hook {
+ int (*kvm_register)(void *opaque, struct kvm *kvm);
+ void (*kvm_unregister)(void *opaque);
+};
+
+extern struct zpci_kvm_hook zpci_kvm_hook;
#endif
* available, enable them and let userspace indicate whether or not they will
* be used (specify SHM bit to disable).
*/
-int kvm_s390_pci_register_kvm(struct zpci_dev *zdev, struct kvm *kvm)
+static int kvm_s390_pci_register_kvm(void *opaque, struct kvm *kvm)
{
+ struct zpci_dev *zdev = opaque;
int rc;
if (!zdev)
kvm_put_kvm(kvm);
return rc;
}
-EXPORT_SYMBOL_GPL(kvm_s390_pci_register_kvm);
-void kvm_s390_pci_unregister_kvm(struct zpci_dev *zdev)
+static void kvm_s390_pci_unregister_kvm(void *opaque)
{
+ struct zpci_dev *zdev = opaque;
struct kvm *kvm;
if (!zdev)
kvm_put_kvm(kvm);
}
-EXPORT_SYMBOL_GPL(kvm_s390_pci_unregister_kvm);
void kvm_s390_pci_init_list(struct kvm *kvm)
{
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;
kfree(aift);
}
obj-$(CONFIG_PCI) += pci.o pci_irq.o pci_dma.o pci_clp.o pci_sysfs.o \
pci_event.o pci_debug.o pci_insn.o pci_mmio.o \
- pci_bus.o
+ pci_bus.o pci_kvm_hook.o
obj-$(CONFIG_PCI_IOV) += pci_iov.o
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VFIO ZPCI devices support
+ *
+ * Copyright (C) IBM Corp. 2022. All rights reserved.
+ * Author(s): Pierre Morel <pmorel@linux.ibm.com>
+ */
+#include <linux/kvm_host.h>
+
+struct zpci_kvm_hook zpci_kvm_hook;
+EXPORT_SYMBOL_GPL(zpci_kvm_hook);
if (!vdev->vdev.kvm)
return 0;
- return kvm_s390_pci_register_kvm(zdev, vdev->vdev.kvm);
+ if (zpci_kvm_hook.kvm_register)
+ return zpci_kvm_hook.kvm_register(zdev, vdev->vdev.kvm);
+
+ return -ENOENT;
}
void vfio_pci_zdev_close_device(struct vfio_pci_core_device *vdev)
if (!zdev || !vdev->vdev.kvm)
return;
- kvm_s390_pci_unregister_kvm(zdev);
+ if (zpci_kvm_hook.kvm_unregister)
+ zpci_kvm_hook.kvm_unregister(zdev);
}