xen: handled remapped IRQs when enabling a pcifront PCI device. (3f2a230c) · Commits · 戴 / test

This happens to not be an issue currently because we take pains to try to ensure that the GSI-IRQ mapping is 1-1 in a PV guest and that regular event channels do not clash. However a subsequent patch is going to break this 1-1 mapping. Signed-off-by:

Ian Campbell <ian.campbell@citrix.com> Signed-off-by:

Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org>

arch/x86/pci/xen.c

+14 −8

Original line number	Diff line number	Diff line
		@@ -226,21 +226,27 @@ static int xen_pcifront_enable_irq(struct pci_dev *dev)
		{
		int rc;
		int share = 1;
		u8 gsi;

		dev_info(&dev->dev, "Xen PCI enabling IRQ: %d\n", dev->irq);

		if (dev->irq < 0)
		return -EINVAL;
		rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
		if (rc < 0) {
		dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
		rc);
		return rc;
		}

		if (dev->irq < NR_IRQS_LEGACY)
		if (gsi < NR_IRQS_LEGACY)
		share = 0;

		rc = xen_allocate_pirq(dev->irq, share, "pcifront");
		rc = xen_allocate_pirq(gsi, share, "pcifront");
		if (rc < 0) {
		dev_warn(&dev->dev, "Xen PCI IRQ: %d, failed to register:%d\n",
		dev->irq, rc);
		dev_warn(&dev->dev, "Xen PCI: failed to register GSI%d: %d\n",
		gsi, rc);
		return rc;
		}

		dev->irq = rc;
		dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);
		return 0;
		}

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