On Thu, 29 Sep 2016 09:58:55 -0700 Glenn Serre <[email protected]> wrote:
> Add CONFIG_IOMMU_DEFAULT_PT for iommu=pt > > Allow default to iommu=pt without adding to command line. > Add iommu=nopt to turn off default. > > Signed-off-by: Glenn Serre <[email protected]> > --- > Documentation/kernel-parameters.txt | 3 ++- > arch/x86/Kconfig | 7 +++++++ > arch/x86/kernel/pci-dma.c | 6 ++++++ > 3 files changed, 15 insertions(+), 1 deletion(-) > > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -1607,7 +1607,8 @@ > nomerge > forcesac > soft > - pt [x86, IA-64] > + pt [x86] > + nopt [x86] > nobypass [PPC/POWERNV] > Disable IOMMU bypass, using IOMMU for PCI devices. > > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -845,6 +845,15 @@ > def_bool y > depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU > > +config IOMMU_DEFAULT_PT > + int "Default iommu pt value (0-1)" > + range 0 1 > + default "0" > + prompt "Set to 1 to default to iommu=pt" An integer that can be either zero or one... IOW a bool. There's support for bools in Kconfig. > + help > + Setting this option to 1 will set iommu passthrough (iommu=pt) > + by default. Use iommu=nopt to override. > + > config MAXSMP > bool "Enable Maximum number of SMP Processors and NUMA Nodes" > depends on X86_64 && SMP && DEBUG_KERNEL > --- a/arch/x86/kernel/pci-dma.c > +++ b/arch/x86/kernel/pci-dma.c > @@ -43,7 +43,7 @@ > * useful if a user wants to use an IOMMU only for KVM device > assignment to > * guests and not for driver dma translation. > */ > -int iommu_pass_through __read_mostly; > +int iommu_pass_through __read_mostly = CONFIG_IOMMU_DEFAULT_PT; > > extern struct iommu_table_entry __iommu_table[], __iommu_table_end[]; > > @@ -196,6 +196,8 @@ > #endif > if (!strncmp(p, "pt", 2)) > iommu_pass_through = 1; > + if (!strncmp(p, "nopt", 4)) > + iommu_pass_through = 0; > > gart_parse_options(p); > > _______________________________________________ > iommu mailing list > [email protected] > https://lists.linuxfoundation.org/mailman/listinfo/iommu _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
