Documentations/x86/x86_64/boot-options.txt is the more appropriate
place for the descriptions of the VT-d IOMMU kernel parameters.
Signed-off-by: FUJITA Tomonori <[email protected]>
---
Documentation/kernel-parameters.txt | 22 ----------------------
Documentation/x86/x86_64/boot-options.txt | 21 +++++++++++++++++++++
2 files changed, 21 insertions(+), 22 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index cd98762..a96f6f7 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -874,28 +874,6 @@ and is between 256 and 4096 characters. It is defined in the file
forcesac
soft
-
- intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
- off
- Disable intel iommu driver.
- igfx_off [Default Off]
- By default, gfx is mapped as normal device. If a gfx
- device has a dedicated DMAR unit, the DMAR unit is
- bypassed by not enabling DMAR with this option. In
- this case, gfx device will use physical address for
- DMA.
- forcedac [x86_64]
- With this option iommu will not optimize to look
- for io virtual address below 32 bit forcing dual
- address cycle on pci bus for cards supporting greater
- than 32 bit addressing. The default is to look
- for translation below 32 bit and if not available
- then look in the higher range.
- strict [Default Off]
- With this option on every unmap_single operation will
- result in a hardware IOTLB flush operation as opposed
- to batching them for performance.
-
io_delay= [X86-32,X86-64] I/O delay method
0x80
Standard port 0x80 based delay
diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt
index b0c7b6c..46cef05 100644
--- a/Documentation/x86/x86_64/boot-options.txt
+++ b/Documentation/x86/x86_64/boot-options.txt
@@ -216,6 +216,10 @@ IOMMU (input/output memory management unit)
mapping with memory protection, etc.
Kernel boot message: "PCI-DMA: Using Calgary IOMMU"
+ 5. <drivers/pci/intel-iommu.c> : Intel VT-d hardware IOMMU.
+ Kernel boot message: "PCI-DMA: Intel(R) Virtualization Technology for
+ Directed I/O\n"
+
iommu=[<size>][,noagp][,off][,force][,noforce][,leak[=<nr_of_leak_pages>]
[,memaper[=<order>]][,merge][,forcesac][,fullflush][,nomerge]
[,noaperture][,calgary]
@@ -287,6 +291,23 @@ IOMMU (input/output memory management unit)
space might stop working. Use this option if you have devices that
are accessed from userspace directly on some PCI host bridge.
+ iommu options only relevant to the Intel VT-d hardware IOMMU:
+ off Disable intel iommu driver.
+ igfx_off By default, gfx is mapped as normal device. If a gfx
+ device has a dedicated DMAR unit, the DMAR unit is
+ bypassed by not enabling DMAR with this option. In
+ this case, gfx device will use physical address for
+ DMA (Default Off).
+ forcedac With this option iommu will not optimize to look
+ for io virtual address below 32 bit forcing dual
+ address cycle on pci bus for cards supporting greater
+ than 32 bit addressing. The default is to look
+ for translation below 32 bit and if not available
+ then look in the higher range.
+ strict With this option on every unmap_single operation will
+ result in a hardware IOTLB flush operation as opposed
+ to batching them for performance (Default Off).
+
Debugging
oops=panic Always panic on oopses. Default is to just kill the process,
--
1.5.5.GIT
On Mon, 7 Jul 2008 17:17:11 +0900
FUJITA Tomonori <[email protected]> wrote:
> Documentations/x86/x86_64/boot-options.txt is the more appropriate
> place for the descriptions of the VT-d IOMMU kernel parameters.
>
> Signed-off-by: FUJITA Tomonori <[email protected]>
> ---
> Documentation/kernel-parameters.txt | 22
> ---------------------- Documentation/x86/x86_64/boot-options.txt |
I disagree.
Documentation/kernel-parameters.txt needs to contain ALL of them.
It already can deal with some of them being only for some
architectures, but it really should be the one-stop-shop for kernel
parameters.
--
If you want to reach me at my work email, use [email protected]
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
On Mon, 7 Jul 2008 06:58:16 -0700
Arjan van de Ven <[email protected]> wrote:
> On Mon, 7 Jul 2008 17:17:11 +0900
> FUJITA Tomonori <[email protected]> wrote:
>
> > Documentations/x86/x86_64/boot-options.txt is the more appropriate
> > place for the descriptions of the VT-d IOMMU kernel parameters.
> >
> > Signed-off-by: FUJITA Tomonori <[email protected]>
> > ---
> > Documentation/kernel-parameters.txt | 22
> > ---------------------- Documentation/x86/x86_64/boot-options.txt |
>
>
> I disagree.
> Documentation/kernel-parameters.txt needs to contain ALL of them.
That's fine with me.
Now the descriptions of other x86_64 IOMMUs parameters are in
x86_64/boot-options.txt. That's confusing. I just want to clean up it.
> It already can deal with some of them being only for some
> architectures, but it really should be the one-stop-shop for kernel
> parameters.
Yeah, seems that only x86 and m64k have the own kernel parameters
file. I think that it would be better to merge them into
Documentation/kernel-parameters.txt. Or splitting
Documentation/kernel-parameters.txt cleanly (such as making a
kernel-parameters directory) would be nice too since the file is
huge.
On Mon, 7 Jul 2008 23:23:39 +0900
FUJITA Tomonori <[email protected]> wrote:
> On Mon, 7 Jul 2008 06:58:16 -0700
> Arjan van de Ven <[email protected]> wrote:
>
> > On Mon, 7 Jul 2008 17:17:11 +0900
> > FUJITA Tomonori <[email protected]> wrote:
> >
> > > Documentations/x86/x86_64/boot-options.txt is the more appropriate
> > > place for the descriptions of the VT-d IOMMU kernel parameters.
> > >
> > > Signed-off-by: FUJITA Tomonori <[email protected]>
> > > ---
> > > Documentation/kernel-parameters.txt | 22
> > > ---------------------- Documentation/x86/x86_64/boot-options.txt |
> >
> >
> > I disagree.
> > Documentation/kernel-parameters.txt needs to contain ALL of them.
>
> That's fine with me.
>
> Now the descriptions of other x86_64 IOMMUs parameters are in
> x86_64/boot-options.txt. That's confusing. I just want to clean up it.
>
>
> > It already can deal with some of them being only for some
> > architectures, but it really should be the one-stop-shop for kernel
> > parameters.
>
> Yeah, seems that only x86 and m64k have the own kernel parameters
> file. I think that it would be better to merge them into
> Documentation/kernel-parameters.txt.
I like this alternative; one stop shop is for this information is very
valuable
--
If you want to reach me at my work email, use [email protected]
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
* Arjan van de Ven <[email protected]> wrote:
> > Yeah, seems that only x86 and m64k have the own kernel parameters
> > file. I think that it would be better to merge them into
> > Documentation/kernel-parameters.txt.
>
> I like this alternative; one stop shop is for this information is very
> valuable
yes. In fact someone might want to think about providing all these
options during bootup, in a mini session, letting people to choose and
shape them. (these are the moments where i wish the boot loader was
integrated into the kernel proper)
Ingo