| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20190409125308.18304-3-thunder.leizhen@huawei.com>
Date: Tue, 9 Apr 2019 20:53:04 +0800
From: Zhen Lei <thunder.leizhen@...wei.com>
To: Jean-Philippe Brucker <jean-philippe.brucker@....com>,
John Garry <john.garry@...wei.com>,
Robin Murphy <robin.murphy@....com>,
Will Deacon <will.deacon@....com>,
Joerg Roedel <joro@...tes.org>,
Jonathan Corbet <corbet@....net>,
linux-doc <linux-doc@...r.kernel.org>,
Sebastian Ott <sebott@...ux.ibm.com>,
Gerald Schaefer <gerald.schaefer@...ibm.com>,
"Martin Schwidefsky" <schwidefsky@...ibm.com>,
Heiko Carstens <heiko.carstens@...ibm.com>,
Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Paul Mackerras <paulus@...ba.org>,
"Michael Ellerman" <mpe@...erman.id.au>,
Tony Luck <tony.luck@...el.com>,
Fenghua Yu <fenghua.yu@...el.com>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
"H . Peter Anvin" <hpa@...or.com>,
David Woodhouse <dwmw2@...radead.org>,
iommu <iommu@...ts.linux-foundation.org>,
linux-kernel <linux-kernel@...r.kernel.org>,
linux-s390 <linux-s390@...r.kernel.org>,
linuxppc-dev <linuxppc-dev@...ts.ozlabs.org>,
x86 <x86@...nel.org>, linux-ia64 <linux-ia64@...r.kernel.org>
CC: Zhen Lei <thunder.leizhen@...wei.com>,
Hanjun Guo <guohanjun@...wei.com>
Subject: [PATCH v5 2/6] iommu: add build options corresponding to iommu.dma_mode
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 same to the boot options iommu.dma_mode.
Signed-off-by: Zhen Lei <thunder.leizhen@...wei.com>
---
Documentation/admin-guide/kernel-parameters.txt | 6 ++--
drivers/iommu/Kconfig | 43 +++++++++++++++++++++----
drivers/iommu/iommu.c | 4 ++-
3 files changed, 42 insertions(+), 11 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index f7766f8ac8b9084..92d1b3151d003c2 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1811,9 +1811,9 @@
1 - Bypass the IOMMU for DMA.
unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
- iommu.dma_mode= Configure default dma mode. if unset, use the value
- of CONFIG_IOMMU_DEFAULT_PASSTHROUGH to determine
- passthrough or not.
+ iommu.dma_mode= Configure default dma mode. if unset, use the build
+ options(such as CONFIG_IOMMU_DEFAULT_PASSTHROUGH) to
+ choose which mode to be used.
Note: For historical reasons, ARM64/S390/PPC/X86 have
their specific options. Currently, only ARM64 support
this boot option, and hope other ARCHs to use this as
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 6f07f3b21816c64..1986f9767da488b 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -74,17 +74,46 @@ 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"
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_STRICT
+ help
+ This option allows IOMMU dma mode to be chose at build time, to
+ override the default dma mode of each ARCHs, removing the need to
+ pass in kernel parameters through command line. You can still use the
+ generic boot option iommu.dma_mode or ARCHs specific boot options to
+ override this option again.
+
+config IOMMU_DEFAULT_PASSTHROUGH
+ 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
+ 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
+ performace scenarios.
+
+endchoice
+
config OF_IOMMU
def_bool y
depends on OF && IOMMU_API
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index df1ce8e22385b48..f4171bf4b46eaeb 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -39,8 +39,10 @@
static struct kset *iommu_group_kset;
static DEFINE_IDA(iommu_group_ida);
-#ifdef CONFIG_IOMMU_DEFAULT_PASSTHROUGH
+#if defined(CONFIG_IOMMU_DEFAULT_PASSTHROUGH)
#define IOMMU_DEFAULT_DMA_MODE IOMMU_DMA_MODE_PASSTHROUGH
+#elif defined(CONFIG_IOMMU_DEFAULT_LAZY)
+#define IOMMU_DEFAULT_DMA_MODE IOMMU_DMA_MODE_LAZY
#else
#define IOMMU_DEFAULT_DMA_MODE IOMMU_DMA_MODE_STRICT
#endif
--
1.8.3
Powered by blists - more mailing lists