Messages in this thread | | | Subject | Re: [PATCH v6 1/1] iommu: enhance IOMMU dma mode build options | From | John Garry <> | Date | Wed, 8 May 2019 10:42:25 +0100 |
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On 18/04/2019 14:57, Zhen Lei wrote: > First, add build option IOMMU_DEFAULT_{LAZY|STRICT}, so that we have the > opportunity to set {lazy|strict} mode as default at build time. Then put > the three config options in an choice, make people can only choose one of > the three at a time. > > The default IOMMU dma modes on each ARCHs have no change. > > Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> > --- > arch/ia64/kernel/pci-dma.c | 2 +- > arch/powerpc/platforms/powernv/pci-ioda.c | 3 ++- > arch/s390/pci/pci_dma.c | 2 +- > arch/x86/kernel/pci-dma.c | 7 ++--- > drivers/iommu/Kconfig | 44 ++++++++++++++++++++++++++----- > drivers/iommu/amd_iommu_init.c | 3 ++- > drivers/iommu/intel-iommu.c | 2 +- > drivers/iommu/iommu.c | 3 ++- > 8 files changed, 48 insertions(+), 18 deletions(-) > > diff --git a/arch/ia64/kernel/pci-dma.c b/arch/ia64/kernel/pci-dma.c > index fe988c49f01ce6a..655511dbf3c3b34 100644 > --- a/arch/ia64/kernel/pci-dma.c > +++ b/arch/ia64/kernel/pci-dma.c > @@ -22,7 +22,7 @@ > int force_iommu __read_mostly; > #endif > > -int iommu_pass_through; > +int iommu_pass_through = IS_ENABLED(CONFIG_IOMMU_DEFAULT_PASSTHROUGH); > > static int __init pci_iommu_init(void) > { > diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c > index 3ead4c237ed0ec9..383e082a9bb985c 100644 > --- a/arch/powerpc/platforms/powernv/pci-ioda.c > +++ b/arch/powerpc/platforms/powernv/pci-ioda.c > @@ -85,7 +85,8 @@ void pe_level_printk(const struct pnv_ioda_pe *pe, const char *level, > va_end(args); > } > > -static bool pnv_iommu_bypass_disabled __read_mostly; > +static bool pnv_iommu_bypass_disabled __read_mostly = > + !IS_ENABLED(CONFIG_IOMMU_DEFAULT_PASSTHROUGH); > static bool pci_reset_phbs __read_mostly; > > static int __init iommu_setup(char *str) > diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c > index 9e52d1527f71495..784ad1e0acecfb1 100644 > --- a/arch/s390/pci/pci_dma.c > +++ b/arch/s390/pci/pci_dma.c > @@ -17,7 +17,7 @@ > > static struct kmem_cache *dma_region_table_cache; > static struct kmem_cache *dma_page_table_cache; > -static int s390_iommu_strict; > +static int s390_iommu_strict = IS_ENABLED(CONFIG_IOMMU_DEFAULT_STRICT); > > static int zpci_refresh_global(struct zpci_dev *zdev) > { > diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c > index d460998ae828514..fb2bab42a0a3173 100644 > --- a/arch/x86/kernel/pci-dma.c > +++ b/arch/x86/kernel/pci-dma.c > @@ -43,11 +43,8 @@ > * 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 > +int iommu_pass_through __read_mostly = > + IS_ENABLED(CONFIG_IOMMU_DEFAULT_PASSTHROUGH); > > extern struct iommu_table_entry __iommu_table[], __iommu_table_end[]; > > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig > index 6f07f3b21816c64..8a1f1793cde76b4 100644 > --- a/drivers/iommu/Kconfig > +++ b/drivers/iommu/Kconfig > @@ -74,17 +74,47 @@ config IOMMU_DEBUGFS > debug/iommu directory, and then populate a subdirectory with > entries as required. > > -config IOMMU_DEFAULT_PASSTHROUGH > - bool "IOMMU passthrough by default" > +choice > + prompt "IOMMU dma mode"
/s/dma/DMA/
And how about add "default", as in "Default IOMMU DMA mode" or "IOMMU default DMA mode"?
> 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. > + default IOMMU_DEFAULT_PASSTHROUGH if (PPC_POWERNV && PCI) > + default IOMMU_DEFAULT_LAZY if (AMD_IOMMU || INTEL_IOMMU || S390_IOMMU) > + default IOMMU_DEFAULT_STRICT > + help > + This option allows IOMMU dma mode to be chose at build time, to
again, capitalize acronyms, i.e. /s/dma/DMA/ (more of these above and below)
> + override the default dma mode of each ARCHs, removing the need to > + pass in kernel parameters through command line. You can still use > + ARCHs specific boot options to override this option again. > + > +config IOMMU_DEFAULT_PASSTHROUGH
I think that it may need to be indented, along with the other choices
> + bool "passthrough" > + help > + In this mode, the dma access through IOMMU without any addresses > + transformation. That means, the wrong or illegal dma access can not
transformation, or translation?
> + be caught, no error information will be reported. > > If unsure, say N here. > > +config IOMMU_DEFAULT_LAZY > + bool "lazy" > + help > + Support lazy mode, where for every IOMMU DMA unmap operation, the > + flush operation of IOTLB and the free operation of IOVA are deferred. > + They are only guaranteed to be done before the related IOVA will be > + reused. > + > +config IOMMU_DEFAULT_STRICT > + bool "strict" > + help > + For every IOMMU DMA unmap operation, the flush operation of IOTLB and > + the free operation of IOVA are guaranteed to be done in the unmap > + function. > + > + This mode is safer than the two above, but it maybe slow in some high
slow, or slower? And passthough is not safe, so anything is implicitly safer.
> + performace scenarios. > + > +endchoice > + > config OF_IOMMU > def_bool y > depends on OF && IOMMU_API > diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c > index ff40ba758cf365e..16c02b08adb4cb2 100644 > --- a/drivers/iommu/amd_iommu_init.c > +++ b/drivers/iommu/amd_iommu_init.c > @@ -166,7 +166,8 @@ struct ivmd_header { > to handle */ > LIST_HEAD(amd_iommu_unity_map); /* a list of required unity mappings > we find in ACPI */ > -bool amd_iommu_unmap_flush; /* if true, flush on every unmap */ > +bool amd_iommu_unmap_flush = IS_ENABLED(CONFIG_IOMMU_DEFAULT_STRICT); > + /* if true, flush on every unmap */ > > LIST_HEAD(amd_iommu_list); /* list of all AMD IOMMUs in the > system */ > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > index 28cb713d728ceef..0c3cc716210f35a 100644 > --- a/drivers/iommu/intel-iommu.c > +++ b/drivers/iommu/intel-iommu.c > @@ -362,7 +362,7 @@ static int domain_detach_iommu(struct dmar_domain *domain, > > static int dmar_map_gfx = 1; > static int dmar_forcedac; > -static int intel_iommu_strict; > +static int intel_iommu_strict = IS_ENABLED(CONFIG_IOMMU_DEFAULT_STRICT); > static int intel_iommu_superpage = 1; > static int intel_iommu_sm; > static int iommu_identity_mapping; > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index 109de67d5d727c2..0ec5952ac60e2a3 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -43,7 +43,8 @@ > #else > static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_DMA; > #endif > -static bool iommu_dma_strict __read_mostly = true; > +static bool iommu_dma_strict __read_mostly = > + IS_ENABLED(CONFIG_IOMMU_DEFAULT_STRICT); > > struct iommu_callback_data { > const struct iommu_ops *ops; > -- > 1.8.3 > > > > . >
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