Re: KVM: PPC: Book3S HV: Fix pending_pri value in kvmppc_xive_get_icp()

From: Michael Ellerman
Date: Fri Dec 22 2017 - 06:24:19 EST


On Tue, 2017-12-12 at 17:23:56 UTC, Laurent Vivier wrote:
> When we migrate a VM from a POWER8 host (XICS) to a POWER9 host
> (XICS-on-XIVE), we have an error:
>
> qemu-kvm: Unable to restore KVM interrupt controller state \
> (0xff000000) for CPU 0: Invalid argument
>
> This is because kvmppc_xics_set_icp() checks the new state
> is internaly consistent, and especially:
>
> ...
> 1129 if (xisr == 0) {
> 1130 if (pending_pri != 0xff)
> 1131 return -EINVAL;
> ...
>
> On the other side, kvmppc_xive_get_icp() doesn't set
> neither the pending_pri value, nor the xisr value (set to 0)
> (and kvmppc_xive_set_icp() ignores the pending_pri value)
>
> As xisr is 0, pending_pri must be set to 0xff.
>
> Signed-off-by: Laurent Vivier <lvivier@xxxxxxxxxx>
> Acked-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/7333b5aca412d6ad02667b5a513485

cheers