diff options
| author | Olof Johansson <olof@lixom.net> | 2018-07-20 11:02:23 -0700 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2018-07-27 09:36:50 +0200 |
| commit | 58d1131777a4b7c228267b809bd88f7be66edcfb (patch) | |
| tree | 915247adf72282f7594fb17bfcfef6307754a5cb | |
| parent | c52c72d3dee81af893cee0414444818ed91e2e11 (diff) | |
iommu: Add config option to set passthrough as default
This allows the default behavior to be controlled by a kernel config
option instead of changing the commandline for the kernel to include
"iommu.passthrough=on" or "iommu=pt" on machines where this is desired.
Likewise, for machines where this config option is enabled, it can be
disabled at boot time with "iommu.passthrough=off" or "iommu=nopt".
Also corrected iommu=pt documentation for IA-64, since it has no code that
parses iommu= at all.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/pci-dma.c | 8 | ||||
| -rw-r--r-- | drivers/iommu/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/iommu/iommu.c | 4 |
4 files changed, 25 insertions, 1 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index efc7aa7a0670..d79c14d0b1f0 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1716,7 +1716,8 @@ merge nomerge soft - pt [x86, IA-64] + pt [x86] + nopt [x86] nobypass [PPC/POWERNV] Disable IOMMU bypass, using IOMMU for PCI devices. diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index ab5d9dd668d2..0acb135de7fb 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); diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 8d0a2886658f..08c957759e74 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -70,6 +70,17 @@ config IOMMU_DEBUGFS debug/iommu directory, and then populate a subdirectory with entries as required. +config IOMMU_DEFAULT_PASSTHROUGH + bool "IOMMU passthrough by default" + depends on IOMMU_API + help + Enable passthrough by default, removing the need to pass in + iommu.passthrough=on or iommu=pt through command line. If this + is enabled, you can still disable with iommu.passthrough=off + or iommu=nopt depending on the architecture. + + If unsure, say N here. + config IOMMU_IOVA tristate diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 7f50013b0bcf..f3698006cb53 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -36,7 +36,11 @@ static struct kset *iommu_group_kset; static DEFINE_IDA(iommu_group_ida); +#ifdef CONFIG_IOMMU_DEFAULT_PASSTHROUGH +static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_IDENTITY; +#else static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_DMA; +#endif struct iommu_callback_data { const struct iommu_ops *ops; |