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Re: [Qemu-arm] [Qemu-devel] [PATCH 4/4] hw/arm/virt: Don't incorrectly c
Re: [Qemu-arm] [Qemu-devel] [PATCH 4/4] hw/arm/virt: Don't incorrectly claim architectural timer to be edge-triggered
Mon, 12 Dec 2016 11:10:10 +0100
On Sun, Dec 11, 2016 at 10:52:25PM +0000, Peter Maydell wrote:
> On 11 December 2016 at 16:35, Christoffer Dall
> <address@hidden> wrote:
> > On Fri, Dec 09, 2016 at 04:30:20PM +0000, Peter Maydell wrote:
> >> + * For backwards-compatibility, virt-2.8 and earlier will continue
> >> + * to say these are edge-triggered, but later machines will report
> >> + * the correct information.
> >> */
> > Is this really necessary?
> It's being conservative -- from the guest's point of view
> (any guest, not necessarily just Linux) "virt-2.8" should behave
> like the "virt" machine in the 2.8 QEMU release, including bugs,
> not providing newer devices, and so on.
> Andrew would be the expert on whether this is being unnecessarily
> conservative in this specific case.
I agree that all DT and ACPI (we need the equivalent change to the GTDT)
changes should require compatibility code. We should document a list of
mach-virt change types that require machine version consideration
somewhere. I can ask our migration experts to help me pull a list