| Message ID | 1637787223-21129-7-git-send-email-olekstysh@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | xen: Add support of extended regions (safe ranges) on Arm | expand |
On Wed, 24 Nov 2021, Oleksandr Tyshchenko wrote: > From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> > > Xen on Arm has gained new support recently to calculate and report > extended regions (unused address space) safe to use for external > mappings. These regions are reported via "reg" property under > "hypervisor" node in the guest device-tree. As region 0 is reserved > for grant table space (always present), the indexes for extended > regions are 1...N. > > No device-tree bindings update is needed (except clarifying the text) > as guest infers the presence of extended regions from the number > of regions in "reg" property. > > Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> > --- > According to the recent update to Xen's guest.txt: > https://xenbits.xen.org/gitweb/?p=xen.git;a=blob_plain;f=docs/misc/arm/device-tree/guest.txt;hb=refs/heads/master > > Changes V2 -> V3: > - new patch > --- > Documentation/devicetree/bindings/arm/xen.txt | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/Documentation/devicetree/bindings/arm/xen.txt b/Documentation/devicetree/bindings/arm/xen.txt > index db5c56d..156fe10b 100644 > --- a/Documentation/devicetree/bindings/arm/xen.txt > +++ b/Documentation/devicetree/bindings/arm/xen.txt > @@ -7,10 +7,14 @@ the following properties: > compatible = "xen,xen-<version>", "xen,xen"; > where <version> is the version of the Xen ABI of the platform. > > -- reg: specifies the base physical address and size of a region in > - memory where the grant table should be mapped to, using an > - HYPERVISOR_memory_op hypercall. The memory region is large enough to map > - the whole grant table (it is larger or equal to gnttab_max_grant_frames()). > +- reg: specifies the base physical address and size of the regions in memory > + where the special resources should be mapped to, using an HYPERVISOR_memory_op > + hypercall. > + Region 0 is reserved for mapping grant table, it must be always present. > + The memory region is large enough to map the whole grant table (it is larger > + or equal to gnttab_max_grant_frames()). > + Regions 1...N are extended regions (unused address space) for mapping foreign > + GFNs and grants, they might be absent if there is nothing to expose. > This property is unnecessary when booting Dom0 using ACPI. I would remove the last sentence about ACPI as the initialization is not done via the xen,xen device tree node in that case anyway. With that change: Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
On 25.11.21 03:09, Stefano Stabellini wrote: Hi Stefano > On Wed, 24 Nov 2021, Oleksandr Tyshchenko wrote: >> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> >> >> Xen on Arm has gained new support recently to calculate and report >> extended regions (unused address space) safe to use for external >> mappings. These regions are reported via "reg" property under >> "hypervisor" node in the guest device-tree. As region 0 is reserved >> for grant table space (always present), the indexes for extended >> regions are 1...N. >> >> No device-tree bindings update is needed (except clarifying the text) >> as guest infers the presence of extended regions from the number >> of regions in "reg" property. >> >> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> >> --- >> According to the recent update to Xen's guest.txt: >> https://xenbits.xen.org/gitweb/?p=xen.git;a=blob_plain;f=docs/misc/arm/device-tree/guest.txt;hb=refs/heads/master >> >> Changes V2 -> V3: >> - new patch >> --- >> Documentation/devicetree/bindings/arm/xen.txt | 12 ++++++++---- >> 1 file changed, 8 insertions(+), 4 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/arm/xen.txt b/Documentation/devicetree/bindings/arm/xen.txt >> index db5c56d..156fe10b 100644 >> --- a/Documentation/devicetree/bindings/arm/xen.txt >> +++ b/Documentation/devicetree/bindings/arm/xen.txt >> @@ -7,10 +7,14 @@ the following properties: >> compatible = "xen,xen-<version>", "xen,xen"; >> where <version> is the version of the Xen ABI of the platform. >> >> -- reg: specifies the base physical address and size of a region in >> - memory where the grant table should be mapped to, using an >> - HYPERVISOR_memory_op hypercall. The memory region is large enough to map >> - the whole grant table (it is larger or equal to gnttab_max_grant_frames()). >> +- reg: specifies the base physical address and size of the regions in memory >> + where the special resources should be mapped to, using an HYPERVISOR_memory_op >> + hypercall. >> + Region 0 is reserved for mapping grant table, it must be always present. >> + The memory region is large enough to map the whole grant table (it is larger >> + or equal to gnttab_max_grant_frames()). >> + Regions 1...N are extended regions (unused address space) for mapping foreign >> + GFNs and grants, they might be absent if there is nothing to expose. >> This property is unnecessary when booting Dom0 using ACPI. > I would remove the last sentence about ACPI as the initialization is not > done via the xen,xen device tree node in that case anyway. Agree, will do. I assume, the similar sentence for the "interrupts" property down the text wants removing as well. > > With that change: > > Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Thanks!
On Wed, 24 Nov 2021 22:53:43 +0200, Oleksandr Tyshchenko wrote: > From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> > > Xen on Arm has gained new support recently to calculate and report > extended regions (unused address space) safe to use for external > mappings. These regions are reported via "reg" property under > "hypervisor" node in the guest device-tree. As region 0 is reserved > for grant table space (always present), the indexes for extended > regions are 1...N. > > No device-tree bindings update is needed (except clarifying the text) > as guest infers the presence of extended regions from the number > of regions in "reg" property. > > Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> > --- > According to the recent update to Xen's guest.txt: > https://xenbits.xen.org/gitweb/?p=xen.git;a=blob_plain;f=docs/misc/arm/device-tree/guest.txt;hb=refs/heads/master > > Changes V2 -> V3: > - new patch > --- > Documentation/devicetree/bindings/arm/xen.txt | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > Acked-by: Rob Herring <robh@kernel.org>
diff --git a/Documentation/devicetree/bindings/arm/xen.txt b/Documentation/devicetree/bindings/arm/xen.txt index db5c56d..156fe10b 100644 --- a/Documentation/devicetree/bindings/arm/xen.txt +++ b/Documentation/devicetree/bindings/arm/xen.txt @@ -7,10 +7,14 @@ the following properties: compatible = "xen,xen-<version>", "xen,xen"; where <version> is the version of the Xen ABI of the platform. -- reg: specifies the base physical address and size of a region in - memory where the grant table should be mapped to, using an - HYPERVISOR_memory_op hypercall. The memory region is large enough to map - the whole grant table (it is larger or equal to gnttab_max_grant_frames()). +- reg: specifies the base physical address and size of the regions in memory + where the special resources should be mapped to, using an HYPERVISOR_memory_op + hypercall. + Region 0 is reserved for mapping grant table, it must be always present. + The memory region is large enough to map the whole grant table (it is larger + or equal to gnttab_max_grant_frames()). + Regions 1...N are extended regions (unused address space) for mapping foreign + GFNs and grants, they might be absent if there is nothing to expose. This property is unnecessary when booting Dom0 using ACPI. - interrupts: the interrupt used by Xen to inject event notifications.