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authorYijing Wang <wangyijing@huawei.com>2014-10-27 05:44:36 +0300
committerBjorn Helgaas <bhelgaas@google.com>2014-11-07 02:34:39 +0300
commit38737d82f9f0168955f9944c3f8bd3bb262c7e88 (patch)
treed43a3bc4a84dad0e3a178f74478ea6996c0773c8 /include/linux/msi.h
parentf114040e3ea6e07372334ade75d1ee0775c355e1 (diff)
downloadlinux-38737d82f9f0168955f9944c3f8bd3bb262c7e88.tar.xz
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 <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> CC: xen-devel@lists.xenproject.org
Diffstat (limited to 'include/linux/msi.h')
-rw-r--r--include/linux/msi.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 44f4746d033b..86dc501a1534 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -10,6 +10,7 @@ struct msi_msg {
u32 data; /* 16 bits of msi message data */
};
+extern int pci_msi_ignore_mask;
/* Helper functions */
struct irq_data;
struct msi_desc;