This function processes the gib alert list. It is required to
run when either a gib alert interruption has been received or
a gisa that might be in the alert list is cleared or dropped.
The GIB alert list contains all GISAs that have pending
adapter interruptions.
Signed-off-by: Michael Mueller <mimu@xxxxxxxxxxxxx>
---
arch/s390/kvm/interrupt.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 251d01f1e9bf..37a5df4e8dac 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -2900,6 +2900,56 @@ static void nullify_gisa(struct kvm_s390_gisa *gisa)
gisa->next_alert = (u32)(u64)gisa;
}
+#define NULL_GISA_ADDR 0x00000000UL
+#define NONE_GISA_ADDR 0x00000001UL
+#define GISA_ADDR_MASK 0xfffff000UL
+
+static void __maybe_unused process_gib_alert_list(void)
+{
+ u32 final, next_alert, origin = 0UL;
+ struct kvm_s390_gisa *gisa;
+ struct kvm_vcpu *vcpu;
+ struct kvm *kvm;
+
+ do {
+ /*
+ * If the NONE_GISA_ADDR is still stored in the alert list
+ * origin, we will leave the outer loop. No further GISA has
+ * been added to the alert list by millicode while processing
+ * the current alert list.
+ */
+ final = (origin & NONE_GISA_ADDR);
+ /*
+ * Cut off the alert list and store the NONE_GISA_ADDR in the
+ * alert list origin to avoid further GAL interruptions.
+ * A new alert list can be build up by millicode in parallel
+ * for guests not in the yet cut-off alert list. When in the
+ * final loop, store the NULL_GISA_ADDR instead. This will re-
+ * enable GAL interruptions on the host again.
+ */
+ for (origin = xchg(&gib->alert_list_origin,
+ (!final) ? NONE_GISA_ADDR : NULL_GISA_ADDR);
+ /* Loop through the just cut-off alert list. */
+ origin & GISA_ADDR_MASK;
+ origin = next_alert) {
+ gisa = (struct kvm_s390_gisa *)(u64)origin;
+ next_alert = gisa->next_alert;
+ /* Unlink the GISA from the alert list. */
+ gisa->next_alert = origin;
+ if (!kvm_s390_gisa_get_ipm(gisa))
+ continue;
+ /*
+ * Wake-up an idle vcpu of the kvm this GISA
+ * belongs to if available.
+ */
+ kvm = container_of(gisa, struct sie_page2, gisa)->kvm;
+ vcpu = __find_vcpu_for_floating_irq(kvm);
+ if (vcpu)
+ kvm_s390_vcpu_wakeup(vcpu);
+ }
+ } while (!final);
+}
+
void kvm_s390_gisa_clear(struct kvm *kvm)
{
if (kvm->arch.gisa) {
--
2.13.4
