kvm-vfio: do not use module_init (3c3c29fd) · Commits · 戴 / test

/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 (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: Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

virt/kvm/kvm_main.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -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:

virt/kvm/vfio.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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);

virt/kvm/vfio.h

0 → 100644

+13 −0

Original line number	Diff line number	Diff line
		#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

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