kvm-vfio: do not use module_init

/me got confused between the kernel and QEMU.  In the kernel, you can
only have one module_init function, and it will prevent unloading the
module unless you also have the corresponding module_exit function.

So, commit 80ce163972 (KVM: VFIO: register kvm_device_ops dynamically,
2014-09-02) broke unloading of the kvm module, by adding a module_init
function and no module_exit.

Repair it by making kvm_vfio_ops_init weak, and checking it in
kvm_init.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Alex Williamson <Alex.Williamson@redhat.com>
Fixes: 80ce163972
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2014-09-24 13:02:46 +02:00
parent 29f1b65b59
commit 3c3c29fd0d
3 changed files with 19 additions and 2 deletions

View file

@ -57,6 +57,7 @@
#include "coalesced_mmio.h"
#include "async_pf.h"
#include "vfio.h"
#define CREATE_TRACE_POINTS
#include <trace/events/kvm.h>
@ -3226,6 +3227,9 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
goto out_undebugfs;
}
r = kvm_vfio_ops_init();
WARN_ON(r);
return 0;
out_undebugfs:

View file

@ -18,6 +18,7 @@
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/vfio.h>
#include "vfio.h"
struct kvm_vfio_group {
struct list_head node;
@ -278,8 +279,7 @@ static int kvm_vfio_create(struct kvm_device *dev, u32 type)
return 0;
}
static int __init kvm_vfio_ops_init(void)
int kvm_vfio_ops_init(void)
{
return kvm_register_device_ops(&kvm_vfio_ops, KVM_DEV_TYPE_VFIO);
}
module_init(kvm_vfio_ops_init);

13
virt/kvm/vfio.h Normal file
View file

@ -0,0 +1,13 @@
#ifndef __KVM_VFIO_H
#define __KVM_VFIO_H
#ifdef CONFIG_KVM_VFIO
int kvm_vfio_ops_init(void);
#else
static inline int kvm_vfio_ops_init(void)
{
return 0;
}
#endif
#endif