Re: [PATCH v6 0/1] iommu: enhance IOMMU dma mode build options

From: "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>
To: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>,
	John Garry <john.garry@huawei.com>,
	Robin Murphy <robin.murphy@arm.com>,
	Will Deacon <will.deacon@arm.com>, Joerg Roedel <joro@8bytes.org>,
	Jonathan Corbet <corbet@lwn.net>,
	linux-doc <linux-doc@vger.kernel.org>,
	Sebastian Ott <sebott@linux.ibm.com>,
	Gerald Schaefer <gerald.schaefer@de.ibm.com>,
	"Martin Schwidefsky" <schwidefsky@de.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	"Michael Ellerman" <mpe@ellerman.id.au>,
	Tony Luck <tony.luck@intel.com>,
	Fenghua Yu <fenghua.yu@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H . Peter Anvin" <hpa@zytor.com>,
	David Woodhouse <dwmw2@infradead.org>,
	iommu <iommu@lists.linux-foundation.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	linux-s390 <linux-s390@vger.kernel.org>,
	linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	x86 <x86@kernel.org>, linux-ia64 <linux-ia64@vger.kernel.org>
Cc: Hanjun Guo <guohanjun@huawei.com>
Subject: Re: [PATCH v6 0/1] iommu: enhance IOMMU dma mode build options
Date: Sat, 4 May 2019 16:44:23 +0800	[thread overview]
Message-ID: <5CCD50E7.3070505@huawei.com> (raw)
In-Reply-To: <20190418135701.24668-1-thunder.leizhen@huawei.com>

Hi all,
  Can anybody review or comment?

On 2019/4/18 21:57, Zhen Lei wrote:
> v5 --> v6:
> 1. give up adding boot option iommu.dma_mode
> 
> v4 --> v5:
> As Hanjun and Thomas Gleixner's suggestion:
> 1. Keep the old ARCH specific boot options no change.
> 2. Keep build option CONFIG_IOMMU_DEFAULT_PASSTHROUGH no change.
> 
> v4:
> As Robin Murphy's suggestion:
> "It's also not necessarily obvious to the user how this interacts with
> IOMMU_DEFAULT_PASSTHROUGH, so if we really do go down this route, maybe it
> would be better to refactor the whole lot into a single selection of something
> like IOMMU_DEFAULT_MODE anyway."
> 
> In this version, I tried to normalize the IOMMU dma mode boot options for all
> ARCHs. When IOMMU is enabled, there are 3 dma modes: paasthrough(bypass),
> lazy(mapping but defer the IOTLB invalidation), strict. But currently each
> ARCHs defined their private boot options, different with each other. For
> example, to enable/disable "passthrough", ARM64 use iommu.passthrough=1/0,
> X86 use iommu=pt/nopt, PPC/POWERNV use iommu=nobypass.
> 
> Zhen Lei (1):
>   iommu: enhance IOMMU dma mode build options
> 
>  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(-)
> 

-- 
Thanks!
BestRegards