[dpdk-dev] [PATCH v2 2/2] igb_uio: fix interrupt enablement after FLR in VM

Wu, Jingjing jingjing.wu at intel.com
Thu Oct 12 07:43:29 CEST 2017


Hi, Shjith

Could you help to review and verify if this fix can meet your requirement?

Thanks
Jingjing

> -----Original Message-----
> From: Wu, Jingjing
> Sent: Tuesday, October 10, 2017 6:09 AM
> To: Yigit, Ferruh <ferruh.yigit at intel.com>; Tan, Jianfeng
> <jianfeng.tan at intel.com>; shijith.thotton at caviumnetworks.com;
> gregory at weka.io; Xing, Beilei <beilei.xing at intel.com>
> Cc: dev at dpdk.org; Wu, Jingjing <jingjing.wu at intel.com>; stable at dpdk.org
> Subject: [PATCH v2 2/2] igb_uio: fix interrupt enablement after FLR in VM
> 
> If pass-through a VF by vfio-pci to a Qemu VM, after FLR in VM, the interrupt
> setting is not recoverd correctly to host as below:
>  in VM guest:
>         Capabilities: [70] MSI-X: Enable+ Count=5 Masked-  in Host:
>         Capabilities: [70] MSI-X: Enable+ Count=5 Masked-
> 
> That was because in pci_reset_function, it first reads the PCI configure and set
> FLR reset, and then writes PCI configure as restoration. But not all the writing
> are successful to Host.
> Because vfio-pci driver doesn't allow directly write PCI MSI-X Cap.
> 
> To fix this issue, we need to move the interrupt enablement from igb_uio probe
> to open device file. While it is also the similar as the behaviour in vfio_pci
> kernel module code.
> 
> Fixes: b58eedfc7dd5 ("igb_uio: issue FLR during open and release of device file")
> 
> Cc: stable at dpdk.org
> 
> Signed-off-by: Jingjing Wu <jingjing.wu at intel.com>
> Signed-off-by: Jianfeng Tan <jianfeng.tan at intel.com>
> ---
> v2 change:
>  - fix typo
>  - remove duplicated debug info
> 
>  lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 221 ++++++++++++++++--------------
>  1 file changed, 119 insertions(+), 102 deletions(-)
> 
> diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> index c8dd5f4..d943795 100644
> --- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> +++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> @@ -49,7 +49,6 @@ struct rte_uio_pci_dev {
> 
>  static char *intr_mode;
>  static enum rte_intr_mode igbuio_intr_mode_preferred =
> RTE_INTR_MODE_MSIX;
> -
>  /* sriov sysfs */
>  static ssize_t
>  show_max_vfs(struct device *dev, struct device_attribute *attr, @@ -144,8
> +143,10 @@ igbuio_pci_irqcontrol(struct uio_info *info, s32 irq_state)
>   * If yes, disable it here and will be enable later.
>   */
>  static irqreturn_t
> -igbuio_pci_irqhandler(int irq, struct uio_info *info)
> +igbuio_pci_irqhandler(int irq, void *dev_id)
>  {
> +	struct uio_device *idev = (struct uio_device *)dev_id;
> +	struct uio_info *info = idev->info;
>  	struct rte_uio_pci_dev *udev = info->priv;
> 
>  	/* Legacy mode need to mask in hardware */ @@ -153,10 +154,115
> @@ igbuio_pci_irqhandler(int irq, struct uio_info *info)
>  	    !pci_check_and_mask_intx(udev->pdev))
>  		return IRQ_NONE;
> 
> +	uio_event_notify(info);
> +
>  	/* Message signal mode, no share IRQ and automasked */
>  	return IRQ_HANDLED;
>  }
> 
> +static int
> +igbuio_pci_enable_interrupts(struct rte_uio_pci_dev *udev) {
> +	int err = 0;
> +#ifndef HAVE_ALLOC_IRQ_VECTORS
> +	struct msix_entry msix_entry;
> +#endif
> +
> +	switch (igbuio_intr_mode_preferred) {
> +	case RTE_INTR_MODE_MSIX:
> +		/* Only 1 msi-x vector needed */
> +#ifndef HAVE_ALLOC_IRQ_VECTORS
> +		msix_entry.entry = 0;
> +		if (pci_enable_msix(udev->pdev, &msix_entry, 1) == 0) {
> +			dev_dbg(&udev->pdev->dev, "using MSI-X");
> +			udev->info.irq_flags = IRQF_NO_THREAD;
> +			udev->info.irq = msix_entry.vector;
> +			udev->mode = RTE_INTR_MODE_MSIX;
> +			break;
> +		}
> +#else
> +		if (pci_alloc_irq_vectors(udev->pdev, 1, 1, PCI_IRQ_MSIX) == 1)
> {
> +			dev_dbg(&udev->pdev->dev, "using MSI-X");
> +			udev->info.irq_flags = IRQF_NO_THREAD;
> +			udev->info.irq = pci_irq_vector(udev->pdev, 0);
> +			udev->mode = RTE_INTR_MODE_MSIX;
> +			break;
> +		}
> +#endif
> +
> +	/* fall back to MSI */
> +	case RTE_INTR_MODE_MSI:
> +#ifndef HAVE_ALLOC_IRQ_VECTORS
> +		if (pci_enable_msi(udev->pdev) == 0) {
> +			dev_dbg(&udev->pdev->dev, "using MSI");
> +			udev->info.irq_flags = IRQF_NO_THREAD;
> +			udev->info.irq = udev->pdev->irq;
> +			udev->mode = RTE_INTR_MODE_MSI;
> +			break;
> +		}
> +#else
> +		if (pci_alloc_irq_vectors(udev->pdev, 1, 1, PCI_IRQ_MSI) == 1)
> {
> +			dev_dbg(&udev->pdev->dev, "using MSI");
> +			udev->info.irq_flags = IRQF_NO_THREAD;
> +			udev->info.irq = pci_irq_vector(udev->pdev, 0);
> +			udev->mode = RTE_INTR_MODE_MSI;
> +			break;
> +		}
> +#endif
> +	/* fall back to INTX */
> +	case RTE_INTR_MODE_LEGACY:
> +		if (pci_intx_mask_supported(udev->pdev)) {
> +			dev_dbg(&udev->pdev->dev, "using INTX");
> +			udev->info.irq_flags = IRQF_SHARED |
> IRQF_NO_THREAD;
> +			udev->info.irq = udev->pdev->irq;
> +			udev->mode = RTE_INTR_MODE_LEGACY;
> +			break;
> +		}
> +		dev_notice(&udev->pdev->dev, "PCI INTX mask not
> supported\n");
> +	/* fall back to no IRQ */
> +	case RTE_INTR_MODE_NONE:
> +		udev->mode = RTE_INTR_MODE_NONE;
> +		udev->info.irq = UIO_IRQ_NONE;
> +		break;
> +
> +	default:
> +		dev_err(&udev->pdev->dev, "invalid IRQ mode %u",
> +			igbuio_intr_mode_preferred);
> +		udev->info.irq = UIO_IRQ_NONE;
> +		err = -EINVAL;
> +	}
> +
> +	if (udev->info.irq != UIO_IRQ_NONE)
> +		err = request_irq(udev->info.irq, igbuio_pci_irqhandler,
> +				  udev->info.irq_flags, udev->info.name,
> +				  udev->info.uio_dev);
> +	dev_info(&udev->pdev->dev, "uio device registered with irq %lx\n",
> +		 udev->info.irq);
> +
> +	return err;
> +}
> +
> +static void
> +igbuio_pci_disable_interrupts(struct rte_uio_pci_dev *udev) {
> +	if (udev->info.irq) {
> +		free_irq(udev->info.irq, udev->info.uio_dev);
> +		udev->info.irq = 0;
> +	}
> +
> +#ifndef HAVE_ALLOC_IRQ_VECTORS
> +	if (udev->mode == RTE_INTR_MODE_MSIX)
> +		pci_disable_msix(udev->pdev);
> +	if (udev->mode == RTE_INTR_MODE_MSI)
> +		pci_disable_msi(udev->pdev);
> +#else
> +	if (udev->mode == RTE_INTR_MODE_MSIX ||
> +	    udev->mode == RTE_INTR_MODE_MSI)
> +		pci_free_irq_vectors(udev->pdev);
> +#endif
> +}
> +
> +
>  /**
>   * This gets called while opening uio device file.
>   */
> @@ -165,12 +271,19 @@ igbuio_pci_open(struct uio_info *info, struct inode
> *inode)  {
>  	struct rte_uio_pci_dev *udev = info->priv;
>  	struct pci_dev *dev = udev->pdev;
> +	int err;
> 
>  	pci_reset_function(dev);
> 
>  	/* set bus master, which was cleared by the reset function */
>  	pci_set_master(dev);
> 
> +	/* enable interrupts */
> +	err = igbuio_pci_enable_interrupts(udev);
> +	if (err) {
> +		dev_err(&dev->dev, "Enable interrupt fails\n");
> +		return err;
> +	}
>  	return 0;
>  }
> 
> @@ -180,6 +293,9 @@ igbuio_pci_release(struct uio_info *info, struct inode
> *inode)
>  	struct rte_uio_pci_dev *udev = info->priv;
>  	struct pci_dev *dev = udev->pdev;
> 
> +	/* disable interrupts */
> +	igbuio_pci_disable_interrupts(udev);
> +
>  	/* stop the device from further DMA */
>  	pci_clear_master(dev);
> 
> @@ -250,94 +366,6 @@ igbuio_pci_release_iomem(struct uio_info *info)  }
> 
>  static int
> -igbuio_pci_enable_interrupts(struct rte_uio_pci_dev *udev) -{
> -	int err = 0;
> -#ifndef HAVE_ALLOC_IRQ_VECTORS
> -	struct msix_entry msix_entry;
> -#endif
> -
> -	switch (igbuio_intr_mode_preferred) {
> -	case RTE_INTR_MODE_MSIX:
> -		/* Only 1 msi-x vector needed */
> -#ifndef HAVE_ALLOC_IRQ_VECTORS
> -		msix_entry.entry = 0;
> -		if (pci_enable_msix(udev->pdev, &msix_entry, 1) == 0) {
> -			dev_dbg(&udev->pdev->dev, "using MSI-X");
> -			udev->info.irq_flags = IRQF_NO_THREAD;
> -			udev->info.irq = msix_entry.vector;
> -			udev->mode = RTE_INTR_MODE_MSIX;
> -			break;
> -		}
> -#else
> -		if (pci_alloc_irq_vectors(udev->pdev, 1, 1, PCI_IRQ_MSIX) == 1)
> {
> -			dev_dbg(&udev->pdev->dev, "using MSI-X");
> -			udev->info.irq_flags = IRQF_NO_THREAD;
> -			udev->info.irq = pci_irq_vector(udev->pdev, 0);
> -			udev->mode = RTE_INTR_MODE_MSIX;
> -			break;
> -		}
> -#endif
> -	/* fall back to MSI */
> -	case RTE_INTR_MODE_MSI:
> -#ifndef HAVE_ALLOC_IRQ_VECTORS
> -		if (pci_enable_msi(udev->pdev) == 0) {
> -			dev_dbg(&udev->pdev->dev, "using MSI");
> -			udev->info.irq_flags = IRQF_NO_THREAD;
> -			udev->info.irq = udev->pdev->irq;
> -			udev->mode = RTE_INTR_MODE_MSI;
> -			break;
> -		}
> -#else
> -		if (pci_alloc_irq_vectors(udev->pdev, 1, 1, PCI_IRQ_MSI) == 1)
> {
> -			dev_dbg(&udev->pdev->dev, "using MSI");
> -			udev->info.irq_flags = IRQF_NO_THREAD;
> -			udev->info.irq = pci_irq_vector(udev->pdev, 0);
> -			udev->mode = RTE_INTR_MODE_MSI;
> -			break;
> -		}
> -#endif
> -	/* fall back to INTX */
> -	case RTE_INTR_MODE_LEGACY:
> -		if (pci_intx_mask_supported(udev->pdev)) {
> -			dev_dbg(&udev->pdev->dev, "using INTX");
> -			udev->info.irq_flags = IRQF_SHARED |
> IRQF_NO_THREAD;
> -			udev->info.irq = udev->pdev->irq;
> -			udev->mode = RTE_INTR_MODE_LEGACY;
> -			break;
> -		}
> -		dev_notice(&udev->pdev->dev, "PCI INTX mask not
> supported\n");
> -	/* fall back to no IRQ */
> -	case RTE_INTR_MODE_NONE:
> -		udev->mode = RTE_INTR_MODE_NONE;
> -		udev->info.irq = UIO_IRQ_NONE;
> -		break;
> -
> -	default:
> -		dev_err(&udev->pdev->dev, "invalid IRQ mode %u",
> -			igbuio_intr_mode_preferred);
> -		err = -EINVAL;
> -	}
> -
> -	return err;
> -}
> -
> -static void
> -igbuio_pci_disable_interrupts(struct rte_uio_pci_dev *udev) -{ -#ifndef
> HAVE_ALLOC_IRQ_VECTORS
> -	if (udev->mode == RTE_INTR_MODE_MSIX)
> -		pci_disable_msix(udev->pdev);
> -	if (udev->mode == RTE_INTR_MODE_MSI)
> -		pci_disable_msi(udev->pdev);
> -#else
> -	if (udev->mode == RTE_INTR_MODE_MSIX ||
> -	    udev->mode == RTE_INTR_MODE_MSI)
> -		pci_free_irq_vectors(udev->pdev);
> -#endif
> -}
> -
> -static int
>  igbuio_setup_bars(struct pci_dev *dev, struct uio_info *info)  {
>  	int i, iom, iop, ret;
> @@ -427,20 +455,15 @@ igbuio_pci_probe(struct pci_dev *dev, const struct
> pci_device_id *id)
>  	/* fill uio infos */
>  	udev->info.name = "igb_uio";
>  	udev->info.version = "0.1";
> -	udev->info.handler = igbuio_pci_irqhandler;
>  	udev->info.irqcontrol = igbuio_pci_irqcontrol;
>  	udev->info.open = igbuio_pci_open;
>  	udev->info.release = igbuio_pci_release;
>  	udev->info.priv = udev;
>  	udev->pdev = dev;
> 
> -	err = igbuio_pci_enable_interrupts(udev);
> -	if (err != 0)
> -		goto fail_release_iomem;
> -
>  	err = sysfs_create_group(&dev->dev.kobj, &dev_attr_grp);
>  	if (err != 0)
> -		goto fail_disable_interrupts;
> +		goto fail_release_iomem;
> 
>  	/* register uio driver */
>  	err = uio_register_device(&dev->dev, &udev->info); @@ -449,9 +472,6
> @@ igbuio_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
> 
>  	pci_set_drvdata(dev, udev);
> 
> -	dev_info(&dev->dev, "uio device registered with irq %lx\n",
> -		 udev->info.irq);
> -
>  	/*
>  	 * Doing a harmless dma mapping for attaching the device to
>  	 * the iommu identity mapping if kernel boots with iommu=pt.
> @@ -477,8 +497,6 @@ igbuio_pci_probe(struct pci_dev *dev, const struct
> pci_device_id *id)
> 
>  fail_remove_group:
>  	sysfs_remove_group(&dev->dev.kobj, &dev_attr_grp);
> -fail_disable_interrupts:
> -	igbuio_pci_disable_interrupts(udev);
>  fail_release_iomem:
>  	igbuio_pci_release_iomem(&udev->info);
>  	pci_disable_device(dev);
> @@ -495,7 +513,6 @@ igbuio_pci_remove(struct pci_dev *dev)
> 
>  	sysfs_remove_group(&dev->dev.kobj, &dev_attr_grp);
>  	uio_unregister_device(&udev->info);
> -	igbuio_pci_disable_interrupts(udev);
>  	igbuio_pci_release_iomem(&udev->info);
>  	pci_disable_device(dev);
>  	pci_set_drvdata(dev, NULL);
> --
> 2.7.4



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