From: Yijing Wang Date: Mon, 27 Oct 2014 02:44:36 +0000 (+0800) Subject: PCI/MSI: Add pci_msi_ignore_mask to prevent writes to MSI/MSI-X Mask Bits X-Git-Tag: omap-for-v3.19/fixes-rc1~77^2~61 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=38737d82f9f0168955f9944c3f8bd3bb262c7e88;p=pandora-kernel.git PCI/MSI: Add pci_msi_ignore_mask to prevent writes to MSI/MSI-X Mask Bits MSI-X vector Mask Bits are in MSI-X Tables in PCI memory space. Xen PV guests can't write to those tables. MSI vector Mask Bits are in PCI configuration space. Xen PV guests can write to config space, but those writes are ignored. Commit 0e4ccb1505a9 ("PCI: Add x86_msi.msi_mask_irq() and msix_mask_irq()") added a way to override default_mask_msi_irqs() and default_mask_msix_irqs() so they can be no-ops in Xen guests, but this is more complicated than necessary. Add "pci_msi_ignore_mask" in the core PCI MSI code. If set, default_mask_msi_irqs() and default_mask_msix_irqs() return without doing anything. This is less flexible, but much simpler. [bhelgaas: changelog] Signed-off-by: Yijing Wang Signed-off-by: Bjorn Helgaas Reviewed-by: David Vrabel CC: Konrad Rzeszutek Wilk CC: xen-devel@lists.xenproject.org --- Reading git-diff-tree failed