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106 lines
3.2 KiB
106 lines
3.2 KiB
From 59a403750d3796b45376041a4843fcde436ae37e Mon Sep 17 00:00:00 2001
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From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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Date: Wed, 1 Apr 2015 10:49:47 -0400
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Subject: [PATCH v2 XSA157 4/5] xen/pciback: For XEN_PCI_OP_disable_msi[|x]
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only disable if device has MSI(X) enabled.
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Otherwise just continue on, returning the same values as
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previously (return of 0, and op->result has the PIRQ value).
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This does not change the behavior of XEN_PCI_OP_disable_msi[|x].
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The pci_disable_msi or pci_disable_msix have the checks for
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msi_enabled or msix_enabled so they will error out immediately.
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However the guest can still call these operations and cause
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us to disable the 'ack_intr'. That means the backend IRQ handler
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for the legacy interrupt will not respond to interrupts anymore.
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This will lead to (if the device is causing an interrupt storm)
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for the Linux generic code to disable the interrupt line.
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Naturally this will only happen if the device in question
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is plugged in on the motherboard on shared level interrupt GSI.
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This is part of XSA-157
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CC: stable@vger.kernel.org
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Reviewed-by: David Vrabel <david.vrabel@citrix.com>
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Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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---
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drivers/xen/xen-pciback/pciback_ops.c | 33 ++++++++++++++++++++-------------
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1 file changed, 20 insertions(+), 13 deletions(-)
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diff --git a/drivers/xen/xen-pciback/pciback_ops.c b/drivers/xen/xen-pciback/pciback_ops.c
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index 5bb76c0..648c09c 100644
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--- a/drivers/xen/xen-pciback/pciback_ops.c
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+++ b/drivers/xen/xen-pciback/pciback_ops.c
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@@ -185,20 +185,23 @@ static
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int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev,
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struct pci_dev *dev, struct xen_pci_op *op)
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{
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- struct xen_pcibk_dev_data *dev_data;
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-
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: disable MSI\n",
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pci_name(dev));
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- pci_disable_msi(dev);
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+ if (dev->msi_enabled) {
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+ struct xen_pcibk_dev_data *dev_data;
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+
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+ pci_disable_msi(dev);
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+
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+ dev_data = pci_get_drvdata(dev);
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+ if (dev_data)
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+ dev_data->ack_intr = 1;
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+ }
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op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
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op->value);
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- dev_data = pci_get_drvdata(dev);
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- if (dev_data)
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- dev_data->ack_intr = 1;
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return 0;
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}
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@@ -264,23 +267,27 @@ static
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int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
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struct pci_dev *dev, struct xen_pci_op *op)
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{
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- struct xen_pcibk_dev_data *dev_data;
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if (unlikely(verbose_request))
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printk(KERN_DEBUG DRV_NAME ": %s: disable MSI-X\n",
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pci_name(dev));
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- pci_disable_msix(dev);
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+ if (dev->msix_enabled) {
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+ struct xen_pcibk_dev_data *dev_data;
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+
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+ pci_disable_msix(dev);
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+
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+ dev_data = pci_get_drvdata(dev);
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+ if (dev_data)
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+ dev_data->ack_intr = 1;
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+ }
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/*
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* SR-IOV devices (which don't have any legacy IRQ) have
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* an undefined IRQ value of zero.
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*/
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op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
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if (unlikely(verbose_request))
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- printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n", pci_name(dev),
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- op->value);
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- dev_data = pci_get_drvdata(dev);
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- if (dev_data)
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- dev_data->ack_intr = 1;
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+ printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n",
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+ pci_name(dev), op->value);
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return 0;
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}
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#endif
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--
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2.1.0
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