Messages in this thread | | | Date | Wed, 24 Jun 2009 17:05:36 +0200 | From | Pavel Machek <> | Subject | Re: [RFC v5][PATCH 4/4] intel_txt: force IOMMU on for Intel(R) TXT launch |
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On Mon 2009-06-22 17:41:41, Joseph Cihula wrote: > The tboot module will DMA protect all of memory in order to ensure the that > kernel will be able to initialize without compromise (from DMA). Consequently, > the kernel must enable Intel(R) Virtualization Technology for Directed I/O > (VT-d or Intel IOMMU) in order to replace this broad protection with the > appropriate page-granular protection. Otherwise DMA devices will be unable > to read or write from memory and the kernel will eventually panic. > > Because runtime IOMMU support is configurable by command line options, this > patch will force it to be enabled regardless of the options specified, and will > log a message if it was required to force it on. > > > dmar.c | 8 ++++++++ > intel-iommu.c | 28 ++++++++++++++++++++++++++-- > 2 files changed, 34 insertions(+), 2 deletions(-)
This needs documentation. And you probably should panic the kernel if user passes unworkable options, not override his choices.
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