Re: [Xen-devel] [PATCH v2 6/6] docs/pvh: document initial MTRR state

[Jan Beulich]

>>> On 15.05.18 at 16:36,  wrote:
> Provided to both Dom0 and DomUs.
> 
> Signed-off-by: Roger Pau Monné 
> ---
> Cc: Andrew Cooper 
> Cc: George Dunlap 
> Cc: Ian Jackson 
> Cc: Jan Beulich 
> Cc: Julien Grall 
> Cc: Konrad Rzeszutek Wilk 
> Cc: Stefano Stabellini 
> Cc: Tim Deegan 
> Cc: Wei Liu 
> ---
> Changes since v1:
>  - Add an extra paragraph to clarify the initial MTRR state.
> ---
>  docs/misc/pvh.markdown | 18 ++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/docs/misc/pvh.markdown b/docs/misc/pvh.markdown
> index e85fb15374..fc31132618 100644
> --- a/docs/misc/pvh.markdown
> +++ b/docs/misc/pvh.markdown
> @@ -92,3 +92,21 @@ 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.
> +
> +Xen guarantees that RAM regions will always have the WB cache type set in the
> +initial MTRR state, either set by the default MTRR type or by other means.

While adding the second paragraph has helped, I still think the first one is 
lacking
"currently" or some such in the first sentence.

Jan


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

[Xen-devel] [PATCH v2 6/6] docs/pvh: document initial MTRR state

[Roger Pau Monne]

Provided to both Dom0 and DomUs.

Signed-off-by: Roger Pau Monné 
---
Cc: Andrew Cooper 
Cc: George Dunlap 
Cc: Ian Jackson 
Cc: Jan Beulich 
Cc: Julien Grall 
Cc: Konrad Rzeszutek Wilk 
Cc: Stefano Stabellini 
Cc: Tim Deegan 
Cc: Wei Liu 
---
Changes since v1:
 - Add an extra paragraph to clarify the initial MTRR state.
---
 docs/misc/pvh.markdown | 18 ++
 1 file changed, 18 insertions(+)

diff --git a/docs/misc/pvh.markdown b/docs/misc/pvh.markdown
index e85fb15374..fc31132618 100644
--- a/docs/misc/pvh.markdown
+++ b/docs/misc/pvh.markdown
@@ -92,3 +92,21 @@ 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.
+
+Xen guarantees that RAM regions will always have the WB cache type set in the
+initial MTRR state, either set by the default MTRR type or by other means.
+
+### 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@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel