From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Date: Wed, 14 Aug 2019 13:38:31 +0000 Subject: [PATCH 00/10 v2] Cleanup IOMMU passthrough setting (and disable IOMMU Passthrough when SME is active Message-Id: <20190814133841.7095-1-joro@8bytes.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Joerg Roedel Cc: corbet@lwn.net, tony.luck@intel.com, fenghua.yu@intel.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, x86@kernel.org, linux-doc@vger.kernel.org, linux-ia64@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Thomas.Lendacky@amd.com, Suravee.Suthikulpanit@amd.com Hi, This patch-set started out small to overwrite the default passthrough setting (through CONFIG_IOMMU_DEFAULT_PASSTHROUGH=y) when SME is active. But on the way to that Tom reminded me that the current ways to configure passthrough/no-passthrough modes for IOMMU on x86 is a mess. So I added a few more patches to clean that up a bit, getting rid of the iommu_pass_through variable on the way.This information is now kept only in iommu code, with helpers to change that setting from architecture code. And of course this patch-set still disables IOMMU Passthrough mode when SME is active even when CONFIG_IOMMU_DEFAULT_PASSTHROUGH=y is set. The reason for that change is that SME with passthrough mode turned out to be fragile with devices requiring SWIOTLB, mainly because SWIOTLB has a maximum allocation size of 256kb and a limit overall size of the bounce buffer. Therefore having IOMMU in translation mode by default is better when SME is active on a system. Please review. Thanks, Joerg Changes since v1: - Cleaned up the kernel command line parameters to configure passthrough/translated mode, getting rid of the global iommu_pass_through variable Joerg Roedel (10): iommu: Add helpers to set/get default domain type iommu/amd: Request passthrough mode from IOMMU core iommu/vt-d: Request passthrough mode from IOMMU core x86/dma: Get rid of iommu_pass_through ia64: Get rid of iommu_pass_through iommu: Remember when default domain type was set on kernel command line iommu: Print default domain type on boot iommu: Set default domain type at runtime iommu: Disable passthrough mode when SME is active Documentation: Update Documentation for iommu.passthrough .../admin-guide/kernel-parameters.txt | 2 +- arch/ia64/include/asm/iommu.h | 2 - arch/ia64/kernel/pci-dma.c | 2 - arch/x86/include/asm/iommu.h | 1 - arch/x86/kernel/pci-dma.c | 11 +-- drivers/iommu/amd_iommu.c | 6 +- drivers/iommu/intel-iommu.c | 2 +- drivers/iommu/iommu.c | 83 +++++++++++++++++-- include/linux/iommu.h | 16 ++++ 9 files changed, 101 insertions(+), 24 deletions(-) -- 2.17.1