commit 38afd772f802ff787ea16af73b0c0d24a8c46b6c
author Cédric Le Goater <clg@kaod.org> Mon May 13 10:42:33 2019 +0200
committer David Gibson <david@gibson.dropbear.id.au> Wed May 29 11:39:45 2019 +1000
tree fed30007e103eab9060ee0eec1309e819f312056
parent 75de59416df857b429f1aac028855090c69f2ea9

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>

hw/intc/spapr_xive.c

diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c
index 62e13ac..2763268 100644
--- a/hw/intc/spapr_xive.c
+++ b/hw/intc/spapr_xive.c
@@ -174,7 +174,7 @@
     }
 }
 
-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 @@
     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 @@
     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 @@
     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 @@
 
     /* 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 @@
     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;
 }