| Message ID | 20241025141453.1210600-3-david@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | virtio-mem: s390 support | expand |
On Fri, Oct 25, 2024 at 04:14:47PM +0200, David Hildenbrand wrote: > Let's document our new diag500 subfunction that can be implemented by > userspace. > > Signed-off-by: David Hildenbrand <david@redhat.com> > --- > Documentation/virt/kvm/s390/s390-diag.rst | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
On Fri, 2024-10-25 at 16:14 +0200, David Hildenbrand wrote: > Let's document our new diag500 subfunction that can be implemented by > userspace. > > Signed-off-by: David Hildenbrand <david@redhat.com> > --- > Documentation/virt/kvm/s390/s390-diag.rst | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) Reviewed-by: Eric Farman <farman@linux.ibm.com>
diff --git a/Documentation/virt/kvm/s390/s390-diag.rst b/Documentation/virt/kvm/s390/s390-diag.rst index 48a326d41cc0..3e4f9e3bef81 100644 --- a/Documentation/virt/kvm/s390/s390-diag.rst +++ b/Documentation/virt/kvm/s390/s390-diag.rst @@ -80,6 +80,23 @@ Subcode 3 - virtio-ccw notification See also the virtio standard for a discussion of this hypercall. +Subcode 4 - storage-limit + Handled by userspace. + + After completion of the DIAGNOSE call, general register 2 will + contain the storage limit: the maximum physical address that might be + used for storage throughout the lifetime of the VM. + + The storage limit does not indicate currently usable storage, it may + include holes, standby storage and areas reserved for other means, such + as memory hotplug or virtio-mem devices. Other interfaces for detecting + actually usable storage, such as SCLP, must be used in conjunction with + this subfunction. + + Note that the storage limit can be larger, but never smaller than the + maximum storage address indicated by SCLP via the "maximum storage + increment" and the "increment size". + DIAGNOSE function code 'X'501 - KVM breakpoint ----------------------------------------------
Let's document our new diag500 subfunction that can be implemented by userspace. Signed-off-by: David Hildenbrand <david@redhat.com> --- Documentation/virt/kvm/s390/s390-diag.rst | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)