@@ -185,20 +185,23 @@ static
int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev,
struct pci_dev *dev, struct xen_pci_op *op)
{
- struct xen_pcibk_dev_data *dev_data;
-
if (unlikely(verbose_request))
printk(KERN_DEBUG DRV_NAME ": %s: disable MSI\n",
pci_name(dev));
- pci_disable_msi(dev);
+ if (dev->msi_enabled) {
+ struct xen_pcibk_dev_data *dev_data;
+
+ pci_disable_msi(dev);
+
+ dev_data = pci_get_drvdata(dev);
+ if (dev_data)
+ dev_data->ack_intr = 1;
+ }
op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
if (unlikely(verbose_request))
printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
op->value);
- dev_data = pci_get_drvdata(dev);
- if (dev_data)
- dev_data->ack_intr = 1;
return 0;
}
@@ -264,23 +267,27 @@ static
int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
struct pci_dev *dev, struct xen_pci_op *op)
{
- struct xen_pcibk_dev_data *dev_data;
if (unlikely(verbose_request))
printk(KERN_DEBUG DRV_NAME ": %s: disable MSI-X\n",
pci_name(dev));
- pci_disable_msix(dev);
+ if (dev->msix_enabled) {
+ struct xen_pcibk_dev_data *dev_data;
+
+ pci_disable_msix(dev);
+
+ dev_data = pci_get_drvdata(dev);
+ if (dev_data)
+ dev_data->ack_intr = 1;
+ }
/*
* SR-IOV devices (which don't have any legacy IRQ) have
* an undefined IRQ value of zero.
*/
op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
if (unlikely(verbose_request))
- printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n", pci_name(dev),
- op->value);
- dev_data = pci_get_drvdata(dev);
- if (dev_data)
- dev_data->ack_intr = 1;
+ printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n",
+ pci_name(dev), op->value);
return 0;
}
#endif
This is a note to let you know that I have just added a patch titled xen/pciback: For XEN_PCI_OP_disable_msi[|x] only disable if device has MSI(X) enabled. to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue This patch is scheduled to be released in version 4.2.8-ckt2. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 4.2.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ---8<------------------------------------------------------------ From 7e6b7e8f7c168a2cfb3c971c6fe1c5c0811ba376 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Date: Wed, 1 Apr 2015 10:49:47 -0400 Subject: xen/pciback: For XEN_PCI_OP_disable_msi[|x] only disable if device has MSI(X) enabled. commit 7cfb905b9638982862f0331b36ccaaca5d383b49 upstream. Otherwise just continue on, returning the same values as previously (return of 0, and op->result has the PIRQ value). This does not change the behavior of XEN_PCI_OP_disable_msi[|x]. The pci_disable_msi or pci_disable_msix have the checks for msi_enabled or msix_enabled so they will error out immediately. However the guest can still call these operations and cause us to disable the 'ack_intr'. That means the backend IRQ handler for the legacy interrupt will not respond to interrupts anymore. This will lead to (if the device is causing an interrupt storm) for the Linux generic code to disable the interrupt line. Naturally this will only happen if the device in question is plugged in on the motherboard on shared level interrupt GSI. This is part of XSA-157 Reviewed-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/xen/xen-pciback/pciback_ops.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) -- 1.9.1