From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99528C04A6B for ; Wed, 8 May 2019 09:42:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6605321479 for ; Wed, 8 May 2019 09:42:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726916AbfEHJmz (ORCPT ); Wed, 8 May 2019 05:42:55 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:39156 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726603AbfEHJmy (ORCPT ); Wed, 8 May 2019 05:42:54 -0400 Received: from DGGEMS414-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id E2271E1F38C9344801A4; Wed, 8 May 2019 17:42:49 +0800 (CST) Received: from [127.0.0.1] (10.202.227.238) by DGGEMS414-HUB.china.huawei.com (10.3.19.214) with Microsoft SMTP Server id 14.3.439.0; Wed, 8 May 2019 17:42:39 +0800 Subject: Re: [PATCH v6 1/1] iommu: enhance IOMMU dma mode build options To: Zhen Lei , Jean-Philippe Brucker , Robin Murphy , "Will Deacon" , Joerg Roedel , Jonathan Corbet , linux-doc , Sebastian Ott , Gerald Schaefer , "Martin Schwidefsky" , Heiko Carstens , Benjamin Herrenschmidt , Paul Mackerras , "Michael Ellerman" , Tony Luck , Fenghua Yu , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , David Woodhouse , iommu , linux-kernel , linux-s390 , linuxppc-dev , x86 , linux-ia64 References: <20190418135701.24668-1-thunder.leizhen@huawei.com> <20190418135701.24668-2-thunder.leizhen@huawei.com> CC: Hanjun Guo From: John Garry Message-ID: Date: Wed, 8 May 2019 10:42:25 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <20190418135701.24668-2-thunder.leizhen@huawei.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.238] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > --- > 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 > > > > . >