| Message ID | 20220814215154.32112-1-rdunlap@infradead.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vfio-pci/zdev: require KVM to be built-in | expand |
Thank you Randy for this good catch.
However forcing KVM to be include statically in the kernel when using
VFIO_PCI extensions is not a good solution for us I think.
I suggest we better do something like:
----
diff --git a/arch/s390/include/asm/kvm_host.h
b/arch/s390/include/asm/kvm_host.h
index 6287a843e8bc..1733339cc4eb 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -1038,7 +1038,7 @@ static inline void kvm_arch_vcpu_unblocking(struct
kvm_vcpu *vcpu) {}
#define __KVM_HAVE_ARCH_VM_FREE
void kvm_arch_free_vm(struct kvm *kvm);
-#ifdef CONFIG_VFIO_PCI_ZDEV_KVM
+#if defined(CONFIG_VFIO_PCI_ZDEV_KVM) ||
defined(CONFIG_VFIO_PCI_ZDEV_KVM_MODULE)
int kvm_s390_pci_register_kvm(struct zpci_dev *zdev, struct kvm *kvm);
void kvm_s390_pci_unregister_kvm(struct zpci_dev *zdev);
#else
diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
index f9d0c908e738..bbc375b028ef 100644
--- a/drivers/vfio/pci/Kconfig
+++ b/drivers/vfio/pci/Kconfig
@@ -45,9 +45,9 @@ config VFIO_PCI_IGD
endif
config VFIO_PCI_ZDEV_KVM
- bool "VFIO PCI extensions for s390x KVM passthrough"
+ def_tristate y
+ prompt "VFIO PCI extensions for s390x KVM passthrough"
depends on S390 && KVM
- default y
help
Support s390x-specific extensions to enable support for
enhancements
to KVM passthrough capabilities, such as interpretive
execution of
----
What do you think? It seems to me it solves the problem, what do you think?
Regards,
Pierre
On 8/14/22 23:51, Randy Dunlap wrote:
> Fix build errors when CONFIG_KVM=m:
>
> s390-linux-ld: drivers/vfio/pci/vfio_pci_zdev.o: in function `vfio_pci_zdev_open_device':
> vfio_pci_zdev.c:(.text+0x242): undefined reference to `kvm_s390_pci_register_kvm'
> s390-linux-ld: drivers/vfio/pci/vfio_pci_zdev.o: in function `vfio_pci_zdev_close_device':
> vfio_pci_zdev.c:(.text+0x296): undefined reference to `kvm_s390_pci_unregister_kvm'
>
> Having a bool Kconfig symbol depend on a tristate symbol can often
> lead to problems like this.
>
> Fixes: 8061d1c31f1a ("vfio-pci/zdev: add open/close device hooks")
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> Reported-by: kernel test robot <lkp@intel.com>
> Cc: Matthew Rosato <mjrosato@linux.ibm.com>
> Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
> Cc: Pierre Morel <pmorel@linux.ibm.com>
> Cc: Eric Farman <farman@linux.ibm.com>
> Cc: linux-s390@vger.kernel.org
> Cc: kvm@vger.kernel.org
> ---
> drivers/vfio/pci/Kconfig | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/drivers/vfio/pci/Kconfig
> +++ b/drivers/vfio/pci/Kconfig
> @@ -46,7 +46,7 @@ endif
>
> config VFIO_PCI_ZDEV_KVM
> bool "VFIO PCI extensions for s390x KVM passthrough"
> - depends on S390 && KVM
> + depends on S390 && KVM=y
> default y
> help
> Support s390x-specific extensions to enable support for enhancements
>
Hi-- On 8/15/22 02:43, Pierre Morel wrote: > Thank you Randy for this good catch. > However forcing KVM to be include statically in the kernel when using VFIO_PCI extensions is not a good solution for us I think. > > I suggest we better do something like: > > ---- > > diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h > index 6287a843e8bc..1733339cc4eb 100644 > --- a/arch/s390/include/asm/kvm_host.h > +++ b/arch/s390/include/asm/kvm_host.h > @@ -1038,7 +1038,7 @@ static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} > #define __KVM_HAVE_ARCH_VM_FREE > void kvm_arch_free_vm(struct kvm *kvm); > > -#ifdef CONFIG_VFIO_PCI_ZDEV_KVM > +#if defined(CONFIG_VFIO_PCI_ZDEV_KVM) || defined(CONFIG_VFIO_PCI_ZDEV_KVM_MODULE) This all looks good except for the line above. It should be: #if IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM) Thanks. > int kvm_s390_pci_register_kvm(struct zpci_dev *zdev, struct kvm *kvm); > void kvm_s390_pci_unregister_kvm(struct zpci_dev *zdev); > #else > diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig > index f9d0c908e738..bbc375b028ef 100644 > --- a/drivers/vfio/pci/Kconfig > +++ b/drivers/vfio/pci/Kconfig > @@ -45,9 +45,9 @@ config VFIO_PCI_IGD > endif > > config VFIO_PCI_ZDEV_KVM > - bool "VFIO PCI extensions for s390x KVM passthrough" > + def_tristate y > + prompt "VFIO PCI extensions for s390x KVM passthrough" > depends on S390 && KVM > - default y > help > Support s390x-specific extensions to enable support for enhancements > to KVM passthrough capabilities, such as interpretive execution of > > ---- > > What do you think? It seems to me it solves the problem, what do you think? > > Regards, > Pierre
On 8/16/22 08:04, Randy Dunlap wrote: > Hi-- > > On 8/15/22 02:43, Pierre Morel wrote: >> Thank you Randy for this good catch. >> However forcing KVM to be include statically in the kernel when using VFIO_PCI extensions is not a good solution for us I think. >> >> I suggest we better do something like: >> >> ---- >> >> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h >> index 6287a843e8bc..1733339cc4eb 100644 >> --- a/arch/s390/include/asm/kvm_host.h >> +++ b/arch/s390/include/asm/kvm_host.h >> @@ -1038,7 +1038,7 @@ static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} >> #define __KVM_HAVE_ARCH_VM_FREE >> void kvm_arch_free_vm(struct kvm *kvm); >> >> -#ifdef CONFIG_VFIO_PCI_ZDEV_KVM >> +#if defined(CONFIG_VFIO_PCI_ZDEV_KVM) || defined(CONFIG_VFIO_PCI_ZDEV_KVM_MODULE) > > This all looks good except for the line above. > It should be: > > #if IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM) > > Thanks. Yes, better, thanks. How do we do? Should I repost it with reported-by you or do you want to post it? Pierre > > >> int kvm_s390_pci_register_kvm(struct zpci_dev *zdev, struct kvm *kvm); >> void kvm_s390_pci_unregister_kvm(struct zpci_dev *zdev); >> #else >> diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig >> index f9d0c908e738..bbc375b028ef 100644 >> --- a/drivers/vfio/pci/Kconfig >> +++ b/drivers/vfio/pci/Kconfig >> @@ -45,9 +45,9 @@ config VFIO_PCI_IGD >> endif >> >> config VFIO_PCI_ZDEV_KVM >> - bool "VFIO PCI extensions for s390x KVM passthrough" >> + def_tristate y >> + prompt "VFIO PCI extensions for s390x KVM passthrough" >> depends on S390 && KVM >> - default y >> help >> Support s390x-specific extensions to enable support for enhancements >> to KVM passthrough capabilities, such as interpretive execution of >> >> ---- >> >> What do you think? It seems to me it solves the problem, what do you think? >> >> Regards, >> Pierre > >
Randy, I need to provide the correction patch rapidly. Without answer I will propose the patch. Regards, Pierre On 8/16/22 09:55, Pierre Morel wrote: > > > On 8/16/22 08:04, Randy Dunlap wrote: >> Hi-- >> >> On 8/15/22 02:43, Pierre Morel wrote: >>> Thank you Randy for this good catch. >>> However forcing KVM to be include statically in the kernel when using >>> VFIO_PCI extensions is not a good solution for us I think. >>> >>> I suggest we better do something like: >>> >>> ---- >>> >>> diff --git a/arch/s390/include/asm/kvm_host.h >>> b/arch/s390/include/asm/kvm_host.h >>> index 6287a843e8bc..1733339cc4eb 100644 >>> --- a/arch/s390/include/asm/kvm_host.h >>> +++ b/arch/s390/include/asm/kvm_host.h >>> @@ -1038,7 +1038,7 @@ static inline void >>> kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} >>> #define __KVM_HAVE_ARCH_VM_FREE >>> void kvm_arch_free_vm(struct kvm *kvm); >>> >>> -#ifdef CONFIG_VFIO_PCI_ZDEV_KVM >>> +#if defined(CONFIG_VFIO_PCI_ZDEV_KVM) || >>> defined(CONFIG_VFIO_PCI_ZDEV_KVM_MODULE) >> >> This all looks good except for the line above. >> It should be: >> >> #if IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM) >> >> Thanks. > > Yes, better, thanks. > How do we do? Should I repost it with reported-by you or do you want to > post it? > > Pierre > > >> >> >>> int kvm_s390_pci_register_kvm(struct zpci_dev *zdev, struct kvm *kvm); >>> void kvm_s390_pci_unregister_kvm(struct zpci_dev *zdev); >>> #else >>> diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig >>> index f9d0c908e738..bbc375b028ef 100644 >>> --- a/drivers/vfio/pci/Kconfig >>> +++ b/drivers/vfio/pci/Kconfig >>> @@ -45,9 +45,9 @@ config VFIO_PCI_IGD >>> endif >>> >>> config VFIO_PCI_ZDEV_KVM >>> - bool "VFIO PCI extensions for s390x KVM passthrough" >>> + def_tristate y >>> + prompt "VFIO PCI extensions for s390x KVM passthrough" >>> depends on S390 && KVM >>> - default y >>> help >>> Support s390x-specific extensions to enable support for >>> enhancements >>> to KVM passthrough capabilities, such as interpretive >>> execution of >>> >>> ---- >>> >>> What do you think? It seems to me it solves the problem, what do you >>> think? >>> >>> Regards, >>> Pierre >> >> >
On 8/16/22 06:47, Pierre Morel wrote: > Randy, > > I need to provide the correction patch rapidly. > Without answer I will propose the patch. > > Regards, > Pierre Please go ahead with it. Thanks. > > On 8/16/22 09:55, Pierre Morel wrote: >> >> >> On 8/16/22 08:04, Randy Dunlap wrote: >>> Hi-- >>> >>> On 8/15/22 02:43, Pierre Morel wrote: >>>> Thank you Randy for this good catch. >>>> However forcing KVM to be include statically in the kernel when using VFIO_PCI extensions is not a good solution for us I think. >>>> >>>> I suggest we better do something like: >>>> >>>> ---- >>>> >>>> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h >>>> index 6287a843e8bc..1733339cc4eb 100644 >>>> --- a/arch/s390/include/asm/kvm_host.h >>>> +++ b/arch/s390/include/asm/kvm_host.h >>>> @@ -1038,7 +1038,7 @@ static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} >>>> #define __KVM_HAVE_ARCH_VM_FREE >>>> void kvm_arch_free_vm(struct kvm *kvm); >>>> >>>> -#ifdef CONFIG_VFIO_PCI_ZDEV_KVM >>>> +#if defined(CONFIG_VFIO_PCI_ZDEV_KVM) || defined(CONFIG_VFIO_PCI_ZDEV_KVM_MODULE) >>> >>> This all looks good except for the line above. >>> It should be: >>> >>> #if IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM) >>> >>> Thanks. >> >> Yes, better, thanks. >> How do we do? Should I repost it with reported-by you or do you want to post it? >> >> Pierre >> >> >>> >>> >>>> int kvm_s390_pci_register_kvm(struct zpci_dev *zdev, struct kvm *kvm); >>>> void kvm_s390_pci_unregister_kvm(struct zpci_dev *zdev); >>>> #else >>>> diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig >>>> index f9d0c908e738..bbc375b028ef 100644 >>>> --- a/drivers/vfio/pci/Kconfig >>>> +++ b/drivers/vfio/pci/Kconfig >>>> @@ -45,9 +45,9 @@ config VFIO_PCI_IGD >>>> endif >>>> >>>> config VFIO_PCI_ZDEV_KVM >>>> - bool "VFIO PCI extensions for s390x KVM passthrough" >>>> + def_tristate y >>>> + prompt "VFIO PCI extensions for s390x KVM passthrough" >>>> depends on S390 && KVM >>>> - default y >>>> help >>>> Support s390x-specific extensions to enable support for enhancements >>>> to KVM passthrough capabilities, such as interpretive execution of >>>> >>>> ---- >>>> >>>> What do you think? It seems to me it solves the problem, what do you think? >>>> >>>> Regards, >>>> Pierre >>> >>> >> >
On 8/16/22 3:55 AM, Pierre Morel wrote: > > > On 8/16/22 08:04, Randy Dunlap wrote: >> Hi-- >> >> On 8/15/22 02:43, Pierre Morel wrote: >>> Thank you Randy for this good catch. >>> However forcing KVM to be include statically in the kernel when using VFIO_PCI extensions is not a good solution for us I think. >>> >>> I suggest we better do something like: >>> >>> ---- >>> >>> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h >>> index 6287a843e8bc..1733339cc4eb 100644 >>> --- a/arch/s390/include/asm/kvm_host.h >>> +++ b/arch/s390/include/asm/kvm_host.h >>> @@ -1038,7 +1038,7 @@ static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} >>> #define __KVM_HAVE_ARCH_VM_FREE >>> void kvm_arch_free_vm(struct kvm *kvm); >>> >>> -#ifdef CONFIG_VFIO_PCI_ZDEV_KVM >>> +#if defined(CONFIG_VFIO_PCI_ZDEV_KVM) || defined(CONFIG_VFIO_PCI_ZDEV_KVM_MODULE) >> >> This all looks good except for the line above. >> It should be: >> >> #if IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM) >> >> Thanks. > > Yes, better, thanks. > How do we do? Should I repost it with reported-by you or do you want to post it? > > Pierre Thanks for looking into this while I was away. I think the issue is not just CONFIG_KVM=m && CONFIG_VFIO_PCI_ZDEV_KVM=y -- it also requires CONFIG_VFIO_PCI=y && CONFIG_VFIO_PCI_CORE=y. This combination results in building in vfio_pci (which tries to link the calls to kvm_s390_pci_register_kvm and kvm_s390_pci_unregister_kvm which is not built in). However... this tristate + IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM) check in kvm_host.h will not solve the issue. Rather, due to the #ifdef CONFIG_VFIO_PCI_ZDEV_KVM in include/linux/vfio_pci_core.h, this change will just cause us to never call kvm_s390_pci_register_kvm or kvm_s390_pci_unregister_kvm when CONFIG_VFIO_PCI_ZDEV_KVM=m, effectively treating CONFIG_VFIO_PCI_ZDEV_KVM=m as a 'n' and we don't get the zdev kvm extensions, which I don't think was the intent. I'm still thinking & am open to other ideas, but one solution to avoiding building in KVM would be to go back to using symbol_get for these 2 interfaces (kvm_s390_pci_register_kvm and kvm_s390_pci_unregister_kvm) as was done in a prior version of this series like virt/kvm/vfio.c does and otherwise leave CONFIG_VFIO_PCI_ZDEV_KVM as-is. diff --git a/drivers/vfio/pci/vfio_pci_zdev.c b/drivers/vfio/pci/vfio_pci_zdev.c index e163aa9f6144..09c2758134c7 100644 --- a/drivers/vfio/pci/vfio_pci_zdev.c +++ b/drivers/vfio/pci/vfio_pci_zdev.c @@ -144,6 +144,8 @@ int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev, int vfio_pci_zdev_open_device(struct vfio_pci_core_device *vdev) { struct zpci_dev *zdev = to_zpci(vdev->pdev); + int (*fn)(struct zpci_dev *zdev, struct kvm *kvm); + int rc; if (!zdev) return -ENODEV; @@ -151,15 +153,30 @@ int vfio_pci_zdev_open_device(struct vfio_pci_core_device *vdev) if (!vdev->vdev.kvm) return 0; - return kvm_s390_pci_register_kvm(zdev, vdev->vdev.kvm); + fn = symbol_get(kvm_s390_pci_register_kvm); + if (!fn) + return -EPERM; + + rc = fn(zdev, vdev->vdev.kvm); + + symbol_put(kvm_s390_pci_register_kvm); + + return rc; } void vfio_pci_zdev_close_device(struct vfio_pci_core_device *vdev) { struct zpci_dev *zdev = to_zpci(vdev->pdev); + void (*fn)(struct zpci_dev *zdev); if (!zdev || !vdev->vdev.kvm) return; - kvm_s390_pci_unregister_kvm(zdev); + fn = symbol_get(kvm_s390_pci_unregister_kvm); + if (!fn) + return; + + fn(zdev); + + symbol_put(kvm_s390_pci_unregister_kvm); }
On 8/16/22 21:46, Matthew Rosato wrote: > On 8/16/22 3:55 AM, Pierre Morel wrote: >> >> >> On 8/16/22 08:04, Randy Dunlap wrote: >>> Hi-- >>> >>> On 8/15/22 02:43, Pierre Morel wrote: >>>> Thank you Randy for this good catch. >>>> However forcing KVM to be include statically in the kernel when using VFIO_PCI extensions is not a good solution for us I think. >>>> >>>> I suggest we better do something like: >>>> >>>> ---- >>>> >>>> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h >>>> index 6287a843e8bc..1733339cc4eb 100644 >>>> --- a/arch/s390/include/asm/kvm_host.h >>>> +++ b/arch/s390/include/asm/kvm_host.h >>>> @@ -1038,7 +1038,7 @@ static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {} >>>> #define __KVM_HAVE_ARCH_VM_FREE >>>> void kvm_arch_free_vm(struct kvm *kvm); >>>> >>>> -#ifdef CONFIG_VFIO_PCI_ZDEV_KVM >>>> +#if defined(CONFIG_VFIO_PCI_ZDEV_KVM) || defined(CONFIG_VFIO_PCI_ZDEV_KVM_MODULE) >>> >>> This all looks good except for the line above. >>> It should be: >>> >>> #if IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM) >>> >>> Thanks. >> >> Yes, better, thanks. >> How do we do? Should I repost it with reported-by you or do you want to post it? >> >> Pierre > > Thanks for looking into this while I was away. > > I think the issue is not just CONFIG_KVM=m && CONFIG_VFIO_PCI_ZDEV_KVM=y -- it also requires CONFIG_VFIO_PCI=y && CONFIG_VFIO_PCI_CORE=y. This combination results in building in vfio_pci (which tries to link the calls to kvm_s390_pci_register_kvm and kvm_s390_pci_unregister_kvm which is not built in). > > However... this tristate + IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM) check in kvm_host.h will not solve the issue. Rather, due to the #ifdef CONFIG_VFIO_PCI_ZDEV_KVM in include/linux/vfio_pci_core.h, this change will just cause us to never call kvm_s390_pci_register_kvm or kvm_s390_pci_unregister_kvm when CONFIG_VFIO_PCI_ZDEV_KVM=m, effectively treating CONFIG_VFIO_PCI_ZDEV_KVM=m as a 'n' and we don't get the zdev kvm extensions, which I don't think was the intent. > > I'm still thinking & am open to other ideas, but one solution to avoiding building in KVM would be to go back to using symbol_get for these 2 interfaces (kvm_s390_pci_register_kvm and kvm_s390_pci_unregister_kvm) as was done in a prior version of this series like virt/kvm/vfio.c does and otherwise leave CONFIG_VFIO_PCI_ZDEV_KVM as-is. > > diff --git a/drivers/vfio/pci/vfio_pci_zdev.c b/drivers/vfio/pci/vfio_pci_zdev.c > index e163aa9f6144..09c2758134c7 100644 > --- a/drivers/vfio/pci/vfio_pci_zdev.c > +++ b/drivers/vfio/pci/vfio_pci_zdev.c > @@ -144,6 +144,8 @@ int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev, > int vfio_pci_zdev_open_device(struct vfio_pci_core_device *vdev) > { > struct zpci_dev *zdev = to_zpci(vdev->pdev); > + int (*fn)(struct zpci_dev *zdev, struct kvm *kvm); > + int rc; > > if (!zdev) > return -ENODEV; > @@ -151,15 +153,30 @@ int vfio_pci_zdev_open_device(struct vfio_pci_core_device *vdev) > if (!vdev->vdev.kvm) > return 0; > > - return kvm_s390_pci_register_kvm(zdev, vdev->vdev.kvm); > + fn = symbol_get(kvm_s390_pci_register_kvm); > + if (!fn) > + return -EPERM; > + > + rc = fn(zdev, vdev->vdev.kvm); > + > + symbol_put(kvm_s390_pci_register_kvm); > + > + return rc; > } > > void vfio_pci_zdev_close_device(struct vfio_pci_core_device *vdev) > { > struct zpci_dev *zdev = to_zpci(vdev->pdev); > + void (*fn)(struct zpci_dev *zdev); > > if (!zdev || !vdev->vdev.kvm) > return; > > - kvm_s390_pci_unregister_kvm(zdev); > + fn = symbol_get(kvm_s390_pci_unregister_kvm); > + if (!fn) > + return; > + > + fn(zdev); > + > + symbol_put(kvm_s390_pci_unregister_kvm); > } > > Hello Matt, In between I came to another solution that seems to satisfy the dependencies. Still need to check that the functionality is still intact :) I send you the proposition as a reply. Regards, Pierre
--- a/drivers/vfio/pci/Kconfig +++ b/drivers/vfio/pci/Kconfig @@ -46,7 +46,7 @@ endif config VFIO_PCI_ZDEV_KVM bool "VFIO PCI extensions for s390x KVM passthrough" - depends on S390 && KVM + depends on S390 && KVM=y default y help Support s390x-specific extensions to enable support for enhancements
Fix build errors when CONFIG_KVM=m: s390-linux-ld: drivers/vfio/pci/vfio_pci_zdev.o: in function `vfio_pci_zdev_open_device': vfio_pci_zdev.c:(.text+0x242): undefined reference to `kvm_s390_pci_register_kvm' s390-linux-ld: drivers/vfio/pci/vfio_pci_zdev.o: in function `vfio_pci_zdev_close_device': vfio_pci_zdev.c:(.text+0x296): undefined reference to `kvm_s390_pci_unregister_kvm' Having a bool Kconfig symbol depend on a tristate symbol can often lead to problems like this. Fixes: 8061d1c31f1a ("vfio-pci/zdev: add open/close device hooks") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: kernel test robot <lkp@intel.com> Cc: Matthew Rosato <mjrosato@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Pierre Morel <pmorel@linux.ibm.com> Cc: Eric Farman <farman@linux.ibm.com> Cc: linux-s390@vger.kernel.org Cc: kvm@vger.kernel.org --- drivers/vfio/pci/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)