[Xen-devel] [PATCH v2 5/6] ARM: Dummy Virtual Machine platform support

On Tue, 18 Dec 2012, Will Deacon wrote:

Hi Stefano,

On Tue, Dec 18, 2012 at 12:04:38PM +0000, Stefano Stabellini wrote:

quoted

On Mon, 17 Dec 2012, Will Deacon wrote:

quoted

From: Marc Zyngier <redacted>

Add support for the smallest, dumbest possible platform, to be
used as a guest for KVM or other hypervisors.

It only mandates a GIC and architected timers. Fits nicely with
a multiplatform zImage. Uses very little silicon area.

Signed-off-by: Marc Zyngier <redacted>
Signed-off-by: Will Deacon <redacted>
---
 arch/arm/Kconfig            |  2 ++
 arch/arm/Makefile           |  1 +
 arch/arm/mach-virt/Kconfig  |  9 +++++++
 arch/arm/mach-virt/Makefile |  5 ++++
 arch/arm/mach-virt/virt.c   | 65 +++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 82 insertions(+)
 create mode 100644 arch/arm/mach-virt/Kconfig
 create mode 100644 arch/arm/mach-virt/Makefile
 create mode 100644 arch/arm/mach-virt/virt.c

Should it come along with a DTS?

The only things the platform needs are GIC, timers, memory and a CPU.
Furthermore, the location, size, frequency etc properties of these aren't
fixed, so a dts would be fairly useless because it will probably not match
the particular mach-virt instance you're targetting.

For kvmtool, I've been generating the device-tree at runtime based on how
kvmtool is invoked and it's been working pretty well so far.

I agree on the fact that it should be generated, but I personally think
that it would still be useful as an example.