linux/virt/kvm/vfio.h

#ifndef __KVM_VFIO_H
#define __KVM_VFIO_H

#ifdef CONFIG_KVM_VFIO
int kvm_vfio_ops_init(void);
void kvm_vfio_ops_exit(void);
#else
static inline int kvm_vfio_ops_init(void)
{
	return 0;
}
static inline void kvm_vfio_ops_exit(void)
{
}
#endif

#endif
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 80ce1639727e (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: 80ce1639727e9d38729c34f162378508c307ca25 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 2014-09-24 11:02:46 +00:00			`#ifndef __KVM_VFIO_H`
			`#define __KVM_VFIO_H`

			`#ifdef CONFIG_KVM_VFIO`
			`int kvm_vfio_ops_init(void);`
kvm: vfio: fix unregister kvm_device_ops of vfio After commit 80ce163 (KVM: VFIO: register kvm_device_ops dynamically), kvm_device_ops of vfio can be registered dynamically. Commit 3c3c29fd (kvm-vfio: do not use module_init) move the dynamic register invoked by kvm_init in order to fix broke unloading of the kvm module. However, kvm_device_ops of vfio is unregistered after rmmod kvm-intel module which lead to device type collision detection warning after kvm-intel module reinsmod. WARNING: CPU: 1 PID: 10358 at /root/cathy/kvm/arch/x86/kvm/../../../virt/kvm/kvm_main.c:3289 kvm_init+0x234/0x282 [kvm]() Modules linked in: kvm_intel(O+) kvm(O) nfsv3 nfs_acl auth_rpcgss oid_registry nfsv4 dns_resolver nfs fscache lockd sunrpc pci_stub bridge stp llc autofs4 8021q cpufreq_ondemand ipv6 joydev microcode pcspkr igb i2c_algo_bit ehci_pci ehci_hcd e1000e i2c_i801 ixgbe ptp pps_core hwmon mdio tpm_tis tpm ipmi_si ipmi_msghandler acpi_cpufreq isci libsas scsi_transport_sas button dm_mirror dm_region_hash dm_log dm_mod [last unloaded: kvm_intel] CPU: 1 PID: 10358 Comm: insmod Tainted: G W O 3.17.0-rc1 #2 Hardware name: Intel Corporation S2600CP/S2600CP, BIOS RMLSDP.86I.00.29.D696.1311111329 11/11/2013 0000000000000cd9 ffff880ff08cfd18 ffffffff814a61d9 0000000000000cd9 0000000000000000 ffff880ff08cfd58 ffffffff810417b7 ffff880ff08cfd48 ffffffffa045bcac ffffffffa049c420 0000000000000040 00000000000000ff Call Trace: [<ffffffff814a61d9>] dump_stack+0x49/0x60 [<ffffffff810417b7>] warn_slowpath_common+0x7c/0x96 [<ffffffffa045bcac>] ? kvm_init+0x234/0x282 [kvm] [<ffffffff810417e6>] warn_slowpath_null+0x15/0x17 [<ffffffffa045bcac>] kvm_init+0x234/0x282 [kvm] [<ffffffffa016e995>] vmx_init+0x1bf/0x42a [kvm_intel] [<ffffffffa016e7d6>] ? vmx_check_processor_compat+0x64/0x64 [kvm_intel] [<ffffffff810002ab>] do_one_initcall+0xe3/0x170 [<ffffffff811168a9>] ? __vunmap+0xad/0xb8 [<ffffffff8109c58f>] do_init_module+0x2b/0x174 [<ffffffff8109d414>] load_module+0x43e/0x569 [<ffffffff8109c6d8>] ? do_init_module+0x174/0x174 [<ffffffff8109c75a>] ? copy_module_from_user+0x39/0x82 [<ffffffff8109b7dd>] ? module_sect_show+0x20/0x20 [<ffffffff8109d65f>] SyS_init_module+0x54/0x81 [<ffffffff814a9a12>] system_call_fastpath+0x16/0x1b ---[ end trace 0626f4a3ddea56f3 ]--- The bug can be reproduced by: rmmod kvm_intel.ko insmod kvm_intel.ko without rmmod/insmod kvm.ko This patch fixes the bug by unregistering kvm_device_ops of vfio when the kvm-intel module is removed. Reported-by: Liu Rongrong <rongrongx.liu@intel.com> Fixes: 3c3c29fd0d7cddc32862c350d0700ce69953e3bd Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 2014-10-09 10:30:08 +00:00			`void kvm_vfio_ops_exit(void);`
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 80ce1639727e (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: 80ce1639727e9d38729c34f162378508c307ca25 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 2014-09-24 11:02:46 +00:00			`#else`
			`static inline int kvm_vfio_ops_init(void)`
			`{`
			`return 0;`
			`}`
kvm: vfio: fix unregister kvm_device_ops of vfio After commit 80ce163 (KVM: VFIO: register kvm_device_ops dynamically), kvm_device_ops of vfio can be registered dynamically. Commit 3c3c29fd (kvm-vfio: do not use module_init) move the dynamic register invoked by kvm_init in order to fix broke unloading of the kvm module. However, kvm_device_ops of vfio is unregistered after rmmod kvm-intel module which lead to device type collision detection warning after kvm-intel module reinsmod. WARNING: CPU: 1 PID: 10358 at /root/cathy/kvm/arch/x86/kvm/../../../virt/kvm/kvm_main.c:3289 kvm_init+0x234/0x282 [kvm]() Modules linked in: kvm_intel(O+) kvm(O) nfsv3 nfs_acl auth_rpcgss oid_registry nfsv4 dns_resolver nfs fscache lockd sunrpc pci_stub bridge stp llc autofs4 8021q cpufreq_ondemand ipv6 joydev microcode pcspkr igb i2c_algo_bit ehci_pci ehci_hcd e1000e i2c_i801 ixgbe ptp pps_core hwmon mdio tpm_tis tpm ipmi_si ipmi_msghandler acpi_cpufreq isci libsas scsi_transport_sas button dm_mirror dm_region_hash dm_log dm_mod [last unloaded: kvm_intel] CPU: 1 PID: 10358 Comm: insmod Tainted: G W O 3.17.0-rc1 #2 Hardware name: Intel Corporation S2600CP/S2600CP, BIOS RMLSDP.86I.00.29.D696.1311111329 11/11/2013 0000000000000cd9 ffff880ff08cfd18 ffffffff814a61d9 0000000000000cd9 0000000000000000 ffff880ff08cfd58 ffffffff810417b7 ffff880ff08cfd48 ffffffffa045bcac ffffffffa049c420 0000000000000040 00000000000000ff Call Trace: [<ffffffff814a61d9>] dump_stack+0x49/0x60 [<ffffffff810417b7>] warn_slowpath_common+0x7c/0x96 [<ffffffffa045bcac>] ? kvm_init+0x234/0x282 [kvm] [<ffffffff810417e6>] warn_slowpath_null+0x15/0x17 [<ffffffffa045bcac>] kvm_init+0x234/0x282 [kvm] [<ffffffffa016e995>] vmx_init+0x1bf/0x42a [kvm_intel] [<ffffffffa016e7d6>] ? vmx_check_processor_compat+0x64/0x64 [kvm_intel] [<ffffffff810002ab>] do_one_initcall+0xe3/0x170 [<ffffffff811168a9>] ? __vunmap+0xad/0xb8 [<ffffffff8109c58f>] do_init_module+0x2b/0x174 [<ffffffff8109d414>] load_module+0x43e/0x569 [<ffffffff8109c6d8>] ? do_init_module+0x174/0x174 [<ffffffff8109c75a>] ? copy_module_from_user+0x39/0x82 [<ffffffff8109b7dd>] ? module_sect_show+0x20/0x20 [<ffffffff8109d65f>] SyS_init_module+0x54/0x81 [<ffffffff814a9a12>] system_call_fastpath+0x16/0x1b ---[ end trace 0626f4a3ddea56f3 ]--- The bug can be reproduced by: rmmod kvm_intel.ko insmod kvm_intel.ko without rmmod/insmod kvm.ko This patch fixes the bug by unregistering kvm_device_ops of vfio when the kvm-intel module is removed. Reported-by: Liu Rongrong <rongrongx.liu@intel.com> Fixes: 3c3c29fd0d7cddc32862c350d0700ce69953e3bd Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 2014-10-09 10:30:08 +00:00			`static inline void kvm_vfio_ops_exit(void)`
			`{`
			`}`
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 80ce1639727e (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: 80ce1639727e9d38729c34f162378508c307ca25 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> 2014-09-24 11:02:46 +00:00			`#endif`

			`#endif`