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Diffstat (limited to 'arch/x86/kernel/pci-dma.c')
| -rw-r--r-- | arch/x86/kernel/pci-dma.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index acfd04121da3..7ba73fe0d917 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -40,8 +40,14 @@ int iommu_detected __read_mostly = 0; * devices and allow every device to access to whole physical memory. This is * useful if a user wants to use an IOMMU only for KVM device assignment to * guests and not for driver dma translation. + * It is also possible to disable by default in kernel config, and enable with + * iommu=nopt at boot time. */ +#ifdef CONFIG_IOMMU_DEFAULT_PASSTHROUGH +int iommu_pass_through __read_mostly = 1; +#else int iommu_pass_through __read_mostly; +#endif extern struct iommu_table_entry __iommu_table[], __iommu_table_end[]; @@ -135,6 +141,8 @@ static __init int iommu_setup(char *p) #endif if (!strncmp(p, "pt", 2)) iommu_pass_through = 1; + if (!strncmp(p, "nopt", 4)) + iommu_pass_through = 0; gart_parse_options(p); |