[v7] Error recovery for vfio-pci devices on s390x

[PATCH v7 9/9] vfio: Remove the pcie check for VFIO_PCI_ERR_IRQ_INDEX

Posted by Farhan Ali 1 month ago

We are configuring the error signaling on the vast majority of devices and
it's extremely rare that it fires anyway. This allows userspace to be
notified on errors for legacy PCI devices. The Internal Shared Memory (ISM)
device on s390x is one such device. For PCI devices on IBM s390x error
recovery involves platform firmware and notification to operating system
is done by architecture specific way. So the ISM device can still be
recovered when notified of an error.

Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
---
 drivers/vfio/pci/vfio_pci_core.c  | 6 ++----
 drivers/vfio/pci/vfio_pci_intrs.c | 3 +--
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index c92c6c512b24..0fdce5234914 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -778,8 +778,7 @@ static int vfio_pci_get_irq_count(struct vfio_pci_core_device *vdev, int irq_typ
 			return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
 		}
 	} else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX) {
-		if (pci_is_pcie(vdev->pdev))
-			return 1;
+		return 1;
 	} else if (irq_type == VFIO_PCI_REQ_IRQ_INDEX) {
 		return 1;
 	}
@@ -1157,8 +1156,7 @@ static int vfio_pci_ioctl_get_irq_info(struct vfio_pci_core_device *vdev,
 	case VFIO_PCI_REQ_IRQ_INDEX:
 		break;
 	case VFIO_PCI_ERR_IRQ_INDEX:
-		if (pci_is_pcie(vdev->pdev))
-			break;
+		break;
 		fallthrough;
 	default:
 		return -EINVAL;
diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
index c76e753b3cec..b6cedaf0bcca 100644
--- a/drivers/vfio/pci/vfio_pci_intrs.c
+++ b/drivers/vfio/pci/vfio_pci_intrs.c
@@ -859,8 +859,7 @@ int vfio_pci_set_irqs_ioctl(struct vfio_pci_core_device *vdev, uint32_t flags,
 	case VFIO_PCI_ERR_IRQ_INDEX:
 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
 		case VFIO_IRQ_SET_ACTION_TRIGGER:
-			if (pci_is_pcie(vdev->pdev))
-				func = vfio_pci_set_err_trigger;
+			func = vfio_pci_set_err_trigger;
 			break;
 		}
 		break;
-- 
2.43.0

Re: [PATCH v7 9/9] vfio: Remove the pcie check for VFIO_PCI_ERR_IRQ_INDEX

Posted by Julian Ruess 2 weeks, 5 days ago

On Wed Jan 7, 2026 at 7:32 PM CET, Farhan Ali wrote:
> We are configuring the error signaling on the vast majority of devices and
> it's extremely rare that it fires anyway. This allows userspace to be
> notified on errors for legacy PCI devices. The Internal Shared Memory (ISM)
> device on s390x is one such device. For PCI devices on IBM s390x error
> recovery involves platform firmware and notification to operating system
> is done by architecture specific way. So the ISM device can still be
> recovered when notified of an error.
>
> Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
> ---
>  drivers/vfio/pci/vfio_pci_core.c  | 6 ++----
>  drivers/vfio/pci/vfio_pci_intrs.c | 3 +--
>  2 files changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
> index c92c6c512b24..0fdce5234914 100644
> --- a/drivers/vfio/pci/vfio_pci_core.c
> +++ b/drivers/vfio/pci/vfio_pci_core.c
> @@ -778,8 +778,7 @@ static int vfio_pci_get_irq_count(struct vfio_pci_core_device *vdev, int irq_typ
>  			return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
>  		}
>  	} else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX) {
> -		if (pci_is_pcie(vdev->pdev))
> -			return 1;
> +		return 1;
>  	} else if (irq_type == VFIO_PCI_REQ_IRQ_INDEX) {
>  		return 1;
>  	}
> @@ -1157,8 +1156,7 @@ static int vfio_pci_ioctl_get_irq_info(struct vfio_pci_core_device *vdev,
>  	case VFIO_PCI_REQ_IRQ_INDEX:
>  		break;
>  	case VFIO_PCI_ERR_IRQ_INDEX:
> -		if (pci_is_pcie(vdev->pdev))
> -			break;
> +		break;
>  		fallthrough;

Isn't the fallthrough unreachable now?

-- snip --

Re: [PATCH v7 9/9] vfio: Remove the pcie check for VFIO_PCI_ERR_IRQ_INDEX

Posted by Farhan Ali 2 weeks, 4 days ago

On 1/19/2026 8:56 AM, Julian Ruess wrote:
> On Wed Jan 7, 2026 at 7:32 PM CET, Farhan Ali wrote:
>> We are configuring the error signaling on the vast majority of devices and
>> it's extremely rare that it fires anyway. This allows userspace to be
>> notified on errors for legacy PCI devices. The Internal Shared Memory (ISM)
>> device on s390x is one such device. For PCI devices on IBM s390x error
>> recovery involves platform firmware and notification to operating system
>> is done by architecture specific way. So the ISM device can still be
>> recovered when notified of an error.
>>
>> Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
>> ---
>>   drivers/vfio/pci/vfio_pci_core.c  | 6 ++----
>>   drivers/vfio/pci/vfio_pci_intrs.c | 3 +--
>>   2 files changed, 3 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
>> index c92c6c512b24..0fdce5234914 100644
>> --- a/drivers/vfio/pci/vfio_pci_core.c
>> +++ b/drivers/vfio/pci/vfio_pci_core.c
>> @@ -778,8 +778,7 @@ static int vfio_pci_get_irq_count(struct vfio_pci_core_device *vdev, int irq_typ
>>   			return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
>>   		}
>>   	} else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX) {
>> -		if (pci_is_pcie(vdev->pdev))
>> -			return 1;
>> +		return 1;
>>   	} else if (irq_type == VFIO_PCI_REQ_IRQ_INDEX) {
>>   		return 1;
>>   	}
>> @@ -1157,8 +1156,7 @@ static int vfio_pci_ioctl_get_irq_info(struct vfio_pci_core_device *vdev,
>>   	case VFIO_PCI_REQ_IRQ_INDEX:
>>   		break;
>>   	case VFIO_PCI_ERR_IRQ_INDEX:
>> -		if (pci_is_pcie(vdev->pdev))
>> -			break;
>> +		break;
>>   		fallthrough;
> Isn't the fallthrough unreachable now?
>
> -- snip --

Yes indeed, I forget why I still had the fallthrough statement. But I 
don't think that's needed anymore, since we will have explicit break 
statements for all the valid cases.

Thanks

Farhan