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authorYijing Wang2015-01-28 09:52:17 +0800
committerBjorn Helgaas2015-01-28 09:25:57 -0600
commit6a878e5085fe97bd1e222b7883a1b815fcbbe4ed (patch)
tree2ffcc34c8799f2c387c46c3441aa8c1072000e03 /arch/x86/pci
parent97bf6af1f928216fd6c5a66e8a57bfa95a659672 (diff)
PCI: Fail MSI-X mappings if there's no space assigned to MSI-X BAR
Unlike MSI, which is configured via registers in the MSI capability in Configuration Space, MSI-X is configured via tables in Memory Space. These MSI-X tables are mapped by a device BAR, and if no Memory Space has been assigned to the BAR, MSI-X cannot be used. Fail MSI-X setup if no space has been assigned for the BAR. Previously, we ioremapped the MSI-X table even if the resource hadn't been assigned. In this case, the resource address is undefined (and is often zero), which may lead to warnings or oopses in this path: pci_enable_msix msix_capability_init msix_map_region ioremap_nocache The PCI core sets resource flags to zero when it can't assign space for the resource (see reset_resource()). There are also some cases where it sets the IORESOURCE_UNSET flag, e.g., pci_reassigndev_resource_alignment(), pci_assign_resource(), etc. So we must check for both cases. [bhelgaas: changelog] Reported-by: Zhang Jukuo <zhangjukuo@huawei.com> Tested-by: Zhang Jukuo <zhangjukuo@huawei.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'arch/x86/pci')
-rw-r--r--arch/x86/pci/xen.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index c489ef2c1a39..34fc4189ebf0 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -298,12 +298,16 @@ static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
map_irq.entry_nr = nvec;
} else if (type == PCI_CAP_ID_MSIX) {
int pos;
+ unsigned long flags;
u32 table_offset, bir;
pos = dev->msix_cap;
pci_read_config_dword(dev, pos + PCI_MSIX_TABLE,
&table_offset);
bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
+ flags = pci_resource_flags(dev, bir);
+ if (!flags || (flags & IORESOURCE_UNSET))
+ return -EINVAL;
map_irq.table_base = pci_resource_start(dev, bir);
map_irq.entry_nr = msidesc->msi_attrib.entry_nr;