spapr/xive: add KVM support

This introduces a set of helpers when KVM is in use, which create the
KVM XIVE device, initialize the interrupt sources at a KVM level and
connect the interrupt presenters to the vCPU.

They also handle the initialization of the TIMA and the source ESB
memory regions of the controller. These have a different type under
KVM. They are 'ram device' memory mappings, similarly to VFIO, exposed
to the guest and the associated VMAs on the host are populated
dynamically with the appropriate pages using a fault handler.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190513084245.25755-3-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 42 insertions, 6 deletions

diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c
index 62e13ac353..27632683e6 100644
--- a/hw/intc/spapr_xive.c
+++ b/hw/intc/spapr_xive.c
@@ -174,7 +174,7 @@ void spapr_xive_pic_print_info(SpaprXive *xive, Monitor *mon)
     }
 }
 
-static void spapr_xive_map_mmio(SpaprXive *xive)
+void spapr_xive_map_mmio(SpaprXive *xive)
 {
     sysbus_mmio_map(SYS_BUS_DEVICE(xive), 0, xive->vc_base);
     sysbus_mmio_map(SYS_BUS_DEVICE(xive), 1, xive->end_base);
@@ -251,6 +251,9 @@ static void spapr_xive_instance_init(Object *obj)
     object_initialize_child(obj, "end_source", &xive->end_source,
                             sizeof(xive->end_source), TYPE_XIVE_END_SOURCE,
                             &error_abort, NULL);
+
+    /* Not connected to the KVM XIVE device */
+    xive->fd = -1;
 }
 
 static void spapr_xive_realize(DeviceState *dev, Error **errp)
@@ -259,6 +262,7 @@ static void spapr_xive_realize(DeviceState *dev, Error **errp)
     XiveSource *xsrc = &xive->source;
     XiveENDSource *end_xsrc = &xive->end_source;
     Error *local_err = NULL;
+    MachineState *machine = MACHINE(qdev_get_machine());
 
     if (!xive->nr_irqs) {
         error_setg(errp, "Number of interrupt needs to be greater 0");
@@ -305,6 +309,32 @@ static void spapr_xive_realize(DeviceState *dev, Error **errp)
     xive->eat = g_new0(XiveEAS, xive->nr_irqs);
     xive->endt = g_new0(XiveEND, xive->nr_ends);
 
+    xive->nodename = g_strdup_printf("interrupt-controller@%" PRIx64,
+                           xive->tm_base + XIVE_TM_USER_PAGE * (1 << TM_SHIFT));
+
+    qemu_register_reset(spapr_xive_reset, dev);
+
+    if (kvm_enabled() && machine_kernel_irqchip_allowed(machine)) {
+        kvmppc_xive_connect(xive, &local_err);
+        if (local_err && machine_kernel_irqchip_required(machine)) {
+            error_prepend(&local_err,
+                          "kernel_irqchip requested but unavailable: ");
+            error_propagate(errp, local_err);
+            return;
+        }
+
+        if (!local_err) {
+            return;
+        }
+
+        /*
+         * We failed to initialize the XIVE KVM device, fallback to
+         * emulated mode
+         */
+        error_prepend(&local_err, "kernel_irqchip allowed but unavailable: ");
+        warn_report_err(local_err);
+    }
+
     /* TIMA initialization */
     memory_region_init_io(&xive->tm_mmio, OBJECT(xive), &xive_tm_ops, xive,
                           "xive.tima", 4ull << TM_SHIFT);
@@ -316,11 +346,6 @@ static void spapr_xive_realize(DeviceState *dev, Error **errp)
 
     /* Map all regions */
     spapr_xive_map_mmio(xive);
-
-    xive->nodename = g_strdup_printf("interrupt-controller@%" PRIx64,
-                           xive->tm_base + XIVE_TM_USER_PAGE * (1 << TM_SHIFT));
-
-    qemu_register_reset(spapr_xive_reset, dev);
 }
 
 static int spapr_xive_get_eas(XiveRouter *xrtr, uint8_t eas_blk,
@@ -495,6 +520,17 @@ bool spapr_xive_irq_claim(SpaprXive *xive, uint32_t lisn, bool lsi)
     if (lsi) {
         xive_source_irq_set_lsi(xsrc, lisn);
     }
+
+    if (kvm_irqchip_in_kernel()) {
+        Error *local_err = NULL;
+
+        kvmppc_xive_source_reset_one(xsrc, lisn, &local_err);
+        if (local_err) {
+            error_report_err(local_err);
+            return false;
+        }
+    }
+
     return true;
 }