Re: [Xen-devel] [PATCH 5/5] docs/pvh: document initial MTRR state

[Wei Liu <wei.liu2@xxxxxxxxxx>]

On Thu, May 10, 2018 at 06:15:05PM +0100, Roger Pau Monne wrote:
> Provided to both Dom0 and DomUs.
> 
> Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> ---
> Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> Cc: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
> Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
> Cc: Jan Beulich <jbeulich@xxxxxxxx>
> Cc: Julien Grall <julien.grall@xxxxxxx>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
> Cc: Tim Deegan <tim@xxxxxxx>
> Cc: Wei Liu <wei.liu2@xxxxxxxxxx>
> ---
>  docs/misc/pvh.markdown | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/docs/misc/pvh.markdown b/docs/misc/pvh.markdown
> index e85fb15374..639401a887 100644
> --- a/docs/misc/pvh.markdown
> +++ b/docs/misc/pvh.markdown
> @@ -92,3 +92,18 @@ event channels. Delivery of those interrupts can be 
> configured in the same way
>  as HVM guests, check xen/include/public/hvm/params.h and
>  xen/include/public/hvm/hvm\_op.h for more information about available 
> delivery
>  methods.
> +
> +## MTRR ##
> +
> +### Unprivileged guests ###
> +
> +PVH guests are booted with the default MTRR type set to write-back and MTRR
> +enabled. This allows DomUs to start with a sane MTRR state. Note that this 
> will
> +have to be revisited when pci-passthrough is added to PVH in order to set 
> MMIO
> +regions as UC.

My reading is "revisited" implies the default type will change. In fact
it shouldn't. We should clarify: for ram it will remain WB, for MMIO
holes it will be UC.

Please correct me if I'm wrong.

Wei.

> +
> +### Hardware domain ###
> +
> +A PVH hardware domain is booted with the same MTRR state as the one found on
> +the host. This is done because the hardware domain memory map is already a
> +modified copy of the host memory map, so the same MTRR setup should work.
> -- 
> 2.17.0
> 

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel