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    SubjectRe: [PATCH v9 21/22] KVM: s390: CPU model support for AP virtualization
    On Mon, 13 Aug 2018 17:48:18 -0400
    Tony Krowiak <akrowiak@linux.vnet.ibm.com> wrote:

    > From: Tony Krowiak <akrowiak@linux.ibm.com>
    >
    > Introduces a new CPU model feature and two CPU model
    > facilities to support AP virtualization for KVM guests.
    >
    > CPU model feature:
    >
    > The KVM_S390_VM_CPU_FEAT_AP feature indicates that
    > AP instructions are available on the guest. This
    > feature will be enabled by the kernel only if the AP
    > instructions are installed on the linux host. This feature
    > must be specifically turned on for the KVM guest from
    > userspace to use the VFIO AP device driver for guest
    > access to AP devices.
    >
    > CPU model facilities:
    >
    > 1. AP Query Configuration Information (QCI) facility is installed.
    >
    > This is indicated by setting facilities bit 12 for
    > the guest. The kernel will not enable this facility
    > for the guest if it is not set on the host.
    >
    > If this facility is not set for the KVM guest, then only
    > APQNs with an APQI less than 16 will be used by a Linux
    > guest regardless of the matrix configuration for the virtual
    > machine. This is a limitation of the Linux AP bus.
    >
    > 2. AP Facilities Test facility (APFT) is installed.
    >
    > This is indicated by setting facilities bit 15 for
    > the guest. The kernel will not enable this facility for
    > the guest if it is not set on the host.
    >
    > If this facility is not set for the KVM guest, then no
    > AP devices will be available to the guest regardless of
    > the guest's matrix configuration for the virtual
    > machine. This is a limitation of the Linux AP bus.
    >
    > Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
    > Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
    > Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
    > Tested-by: Michael Mueller <mimu@linux.ibm.com>
    > Tested-by: Farhan Ali <alifm@linux.ibm.com>
    > Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
    > ---
    > arch/s390/kvm/kvm-s390.c | 5 +++++
    > arch/s390/tools/gen_facilities.c | 2 ++
    > 2 files changed, 7 insertions(+), 0 deletions(-)

    Looks sane to me.

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