On 03.12.18 10:00, Cornelia Huck wrote:
On Fri, 30 Nov 2018 15:32:08 +0100
Michael Mueller <mimu@xxxxxxxxxxxxx> wrote:
The GIB (Guest Information Block) links the GISA of all guests
that have adapter interrupts pending. These interrupts cannot be
delivered because no vcpu of these guests is currently running in
SIE context. Instead, a GIB alert is issued on the host to schedule
these guests to run.
This mechanism allows to process adapter interrupts for currently
not running guests.
The GIB is created during host initialization and associated with
the Adapter Interruption Facility in case an Adapter Interruption
Virtualization Facility is available.
The GIB initialization and thus the activation of the related code
will be done in an upcoming patch of this series.
Signed-off-by: Michael Mueller <mimu@xxxxxxxxxxxxx>
Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
arch/s390/include/asm/kvm_host.h | 10 ++++++++++
arch/s390/kvm/interrupt.c | 37 +++++++++++++++++++++++++++++++++++++
arch/s390/kvm/kvm-s390.c | 1 +
arch/s390/kvm/kvm-s390.h | 2 ++
4 files changed, 50 insertions(+)
+int kvm_s390_gib_init(u8 nisc)
+{
+ if (!css_general_characteristics.aiv) {
+ KVM_EVENT(3, "%s", "gib not initialized, no AIV facility");
+ return 0;
+ }
+
+ gib = (struct kvm_s390_gib *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
+ if (!gib) {
+ KVM_EVENT(3, "gib 0x%pK memory allocation failed", gib);
+ return -ENOMEM;
+ }
+
+ gib->nisc = nisc;
+ if (chsc_sgib((u32)(u64)gib)) {
+ KVM_EVENT(3, "gib 0x%pK AIV association failed", gib);
I think that's the one place where a message in addition to the dbf
event makes sense (if kvm is built as a module), as mentioned last time.
The message is printed when kvm_s390_gib_init() fails. See last patch of
series.
+ free_page((unsigned long)gib);
+ gib = NULL;
+ return -EIO;
+ }
+
+ KVM_EVENT(3, "gib 0x%pK (nisc=%d) initialized", gib, gib->nisc);
+ return 0;
+}
Otherwise, looks good to me.
