Re: [Xen-devel] [PATCH 03/10] pvh: Set online VCPU map to avail_vcpus

[Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>]

On 11/07/2016 10:36 AM, Konrad Rzeszutek Wilk wrote:
> On Sun, Nov 06, 2016 at 04:42:36PM -0500, Boris Ostrovsky wrote:
>> ACPI builder marks VCPUS set in vcpu_online map as enabled in MADT.
>> With ACPI-based CPU hotplug we only want VCPUs that are started by
>> the guest to be marked as such. Remaining VCPUs will be set to
> Oh, so this is a bug then? We always marked them as enabled?
> Is this mentioned somewhere in the ACPI docs?
>
> But what about guests that don't want to start their CPUs using
> ACPI but are using SMP MPtables?

This code is only applicable to PVH guests and it wasn't a bug because
until now I assumed PV-like CPU hotplug (where the guest would watch
xenstore). That required having all VCPUs marked as enabled in MADT and
the guest (well, Linux guest) would immediately offline them.

Now that we are going full-ACPI this is no longer the case.

>
>> "enable" by ACPI code during hotplug.
> . which ACPI code? The libacpi one? You may want to be specific.
> Or the QEMU code?

AML code in DSDT. I'll update the comment.

(No qemu --- this is PVH)

-boris

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