[Qemu-devel] [PATCH v2 02/19] spapr: introduce a skeleton for the XIVE interrupt controller

["Cédric Le Goater" <clg@kaod.org>]

With the POWER9 processor comes a new interrupt controller called
XIVE. It is composed of three sub-engines :

  - Interrupt Virtualization Source Engine (IVSE). These are in PHBs,
    in the main controller for the IPIS and in the PSI host
    bridge. They are configured to feed the IVRE with events.

  - Interrupt Virtualization Routing Engine (IVRE). Their job is to
    match an event source with a Notification Virtualization Target
    (NVT), a priority and an Event Queue (EQ) to determine if a
    Virtual Processor can handle the event.

  - Interrupt Virtualization Presentation Engine (IVPE). It maintains
    the interrupt state of each hardware thread and present the
    notification as an external exception.

Each of the engines uses a set of internal tables to redirect
exceptions from event sources to CPU threads. The first table we
introduce is the Interrupt Virtualization Entry (IVE) table, part of
the virtualization engine in charge of routing events. It associates
event sources (IRQ numbers) to event queues which will forward, or
not, the event notification to the presentation controller.

The XIVE model is designed to make use of the full range of the IRQ
number space and does not use an offset like the XICS mode does.
Hence, the IVE table is directly indexed by the IRQ number.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---

 Changes since v1 :

 - used g_new0 instead of g_malloc0
 - removed VMSTATE_STRUCT_VARRAY_UINT32_ALLOC 
 - introduced a device reset handler. the object needs to be parented
   to sysbus when created.
 - renamed spapr_xive_irq_set to spapr_xive_irq_enable
 - renamed spapr_xive_irq_unset to spapr_xive_irq_disable
 - moved the PPC_BIT macros under target/ppc/cpu.h
 - shrinked file copyright header

 default-configs/ppc64-softmmu.mak |   1 +
 hw/intc/Makefile.objs             |   1 +
 hw/intc/spapr_xive.c              | 156 ++++++++++++++++++++++++++++++++++++++
 hw/intc/xive-internal.h           |  41 ++++++++++
 include/hw/ppc/spapr_xive.h       |  35 +++++++++
 5 files changed, 234 insertions(+)
 create mode 100644 hw/intc/spapr_xive.c
 create mode 100644 hw/intc/xive-internal.h
 create mode 100644 include/hw/ppc/spapr_xive.h

diff --git a/default-configs/ppc64-softmmu.mak b/default-configs/ppc64-softmmu.mak
index d1b3a6dd50f8..4a7f6a0696de 100644
--- a/default-configs/ppc64-softmmu.mak
+++ b/default-configs/ppc64-softmmu.mak
@@ -56,6 +56,7 @@ CONFIG_SM501=y
 CONFIG_XICS=$(CONFIG_PSERIES)
 CONFIG_XICS_SPAPR=$(CONFIG_PSERIES)
 CONFIG_XICS_KVM=$(call land,$(CONFIG_PSERIES),$(CONFIG_KVM))
+CONFIG_XIVE_SPAPR=$(CONFIG_PSERIES)
 # For PReP
 CONFIG_SERIAL_ISA=y
 CONFIG_MC146818RTC=y
diff --git a/hw/intc/Makefile.objs b/hw/intc/Makefile.objs
index ae358569a155..49e13e7aeeee 100644
--- a/hw/intc/Makefile.objs
+++ b/hw/intc/Makefile.objs
@@ -35,6 +35,7 @@ obj-$(CONFIG_SH4) += sh_intc.o
 obj-$(CONFIG_XICS) += xics.o
 obj-$(CONFIG_XICS_SPAPR) += xics_spapr.o
 obj-$(CONFIG_XICS_KVM) += xics_kvm.o
+obj-$(CONFIG_XIVE_SPAPR) += spapr_xive.o
 obj-$(CONFIG_POWERNV) += xics_pnv.o
 obj-$(CONFIG_ALLWINNER_A10_PIC) += allwinner-a10-pic.o
 obj-$(CONFIG_S390_FLIC) += s390_flic.o
diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c
new file mode 100644
index 000000000000..e6e8841add17
--- /dev/null
+++ b/hw/intc/spapr_xive.c
@@ -0,0 +1,156 @@
+/*
+ * QEMU PowerPC sPAPR XIVE interrupt controller model
+ *
+ * Copyright (c) 2017, IBM Corporation.
+ *
+ * This code is licensed under the GPL version 2 or later. See the
+ * COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qapi/error.h"
+#include "target/ppc/cpu.h"
+#include "sysemu/cpus.h"
+#include "sysemu/dma.h"
+#include "monitor/monitor.h"
+#include "hw/ppc/spapr_xive.h"
+
+#include "xive-internal.h"
+
+/*
+ * Main XIVE object
+ */
+
+void spapr_xive_pic_print_info(sPAPRXive *xive, Monitor *mon)
+{
+    int i;
+
+    for (i = 0; i < xive->nr_irqs; i++) {
+        XiveIVE *ive = &xive->ivt[i];
+
+        if (!(ive->w & IVE_VALID)) {
+            continue;
+        }
+
+        monitor_printf(mon, "  %4x %s %08x %08x\n", i,
+                       ive->w & IVE_MASKED ? "M" : " ",
+                       (int) GETFIELD(IVE_EQ_INDEX, ive->w),
+                       (int) GETFIELD(IVE_EQ_DATA, ive->w));
+    }
+}
+
+static void spapr_xive_reset(DeviceState *dev)
+{
+    sPAPRXive *xive = SPAPR_XIVE(dev);
+    int i;
+
+    /* Mask all valid IVEs in the IRQ number space. */
+    for (i = 0; i < xive->nr_irqs; i++) {
+        XiveIVE *ive = &xive->ivt[i];
+        if (ive->w & IVE_VALID) {
+            ive->w |= IVE_MASKED;
+        }
+    }
+}
+
+static void spapr_xive_realize(DeviceState *dev, Error **errp)
+{
+    sPAPRXive *xive = SPAPR_XIVE(dev);
+
+    if (!xive->nr_irqs) {
+        error_setg(errp, "Number of interrupt needs to be greater 0");
+        return;
+    }
+
+    /* Allocate the IVT (Interrupt Virtualization Table) */
+    xive->ivt = g_new0(XiveIVE, xive->nr_irqs);
+}
+
+static const VMStateDescription vmstate_spapr_xive_ive = {
+    .name = TYPE_SPAPR_XIVE "/ive",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField []) {
+        VMSTATE_UINT64(w, XiveIVE),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static bool vmstate_spapr_xive_needed(void *opaque)
+{
+    /* TODO check machine XIVE support */
+    return true;
+}
+
+static const VMStateDescription vmstate_spapr_xive = {
+    .name = TYPE_SPAPR_XIVE,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = vmstate_spapr_xive_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32_EQUAL(nr_irqs, sPAPRXive, NULL),
+        VMSTATE_STRUCT_VARRAY_UINT32(ivt, sPAPRXive, nr_irqs, 1,
+                                     vmstate_spapr_xive_ive, XiveIVE),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static Property spapr_xive_properties[] = {
+    DEFINE_PROP_UINT32("nr-irqs", sPAPRXive, nr_irqs, 0),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void spapr_xive_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = spapr_xive_realize;
+    dc->reset = spapr_xive_reset;
+    dc->props = spapr_xive_properties;
+    dc->desc = "sPAPR XIVE interrupt controller";
+    dc->vmsd = &vmstate_spapr_xive;
+}
+
+static const TypeInfo spapr_xive_info = {
+    .name = TYPE_SPAPR_XIVE,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(sPAPRXive),
+    .class_init = spapr_xive_class_init,
+};
+
+static void spapr_xive_register_types(void)
+{
+    type_register_static(&spapr_xive_info);
+}
+
+type_init(spapr_xive_register_types)
+
+XiveIVE *spapr_xive_get_ive(sPAPRXive *xive, uint32_t lisn)
+{
+    return lisn < xive->nr_irqs ? &xive->ivt[lisn] : NULL;
+}
+
+bool spapr_xive_irq_enable(sPAPRXive *xive, uint32_t lisn)
+{
+    XiveIVE *ive = spapr_xive_get_ive(xive, lisn);
+
+    if (!ive) {
+        return false;
+    }
+
+    ive->w |= IVE_VALID;
+    return true;
+}
+
+bool spapr_xive_irq_disable(sPAPRXive *xive, uint32_t lisn)
+{
+    XiveIVE *ive = spapr_xive_get_ive(xive, lisn);
+
+    if (!ive) {
+        return false;
+    }
+
+    ive->w &= ~IVE_VALID;
+    return true;
+}
diff --git a/hw/intc/xive-internal.h b/hw/intc/xive-internal.h
new file mode 100644
index 000000000000..132b71a6daf0
--- /dev/null
+++ b/hw/intc/xive-internal.h
@@ -0,0 +1,41 @@
+/*
+ * QEMU PowerPC XIVE interrupt controller model
+ *
+ * Copyright (c) 2016-2017, IBM Corporation.
+ *
+ * This code is licensed under the GPL version 2 or later. See the
+ * COPYING file in the top-level directory.
+ */
+
+#ifndef _INTC_XIVE_INTERNAL_H
+#define _INTC_XIVE_INTERNAL_H
+
+/* Utilities to manipulate these (originaly from OPAL) */
+#define MASK_TO_LSH(m)          (__builtin_ffsl(m) - 1)
+#define GETFIELD(m, v)          (((v) & (m)) >> MASK_TO_LSH(m))
+#define SETFIELD(m, v, val)                             \
+        (((v) & ~(m)) | ((((typeof(v))(val)) << MASK_TO_LSH(m)) & (m)))
+
+/* IVE/EAS
+ *
+ * One per interrupt source. Targets that interrupt to a given EQ
+ * and provides the corresponding logical interrupt number (EQ data)
+ *
+ * We also map this structure to the escalation descriptor inside
+ * an EQ, though in that case the valid and masked bits are not used.
+ */
+typedef struct XiveIVE {
+        /* Use a single 64-bit definition to make it easier to
+         * perform atomic updates
+         */
+        uint64_t        w;
+#define IVE_VALID       PPC_BIT(0)
+#define IVE_EQ_BLOCK    PPC_BITMASK(4, 7)        /* Destination EQ block# */
+#define IVE_EQ_INDEX    PPC_BITMASK(8, 31)       /* Destination EQ index */
+#define IVE_MASKED      PPC_BIT(32)              /* Masked */
+#define IVE_EQ_DATA     PPC_BITMASK(33, 63)      /* Data written to the EQ */
+} XiveIVE;
+
+XiveIVE *spapr_xive_get_ive(sPAPRXive *xive, uint32_t lisn);
+
+#endif /* _INTC_XIVE_INTERNAL_H */
diff --git a/include/hw/ppc/spapr_xive.h b/include/hw/ppc/spapr_xive.h
new file mode 100644
index 000000000000..5b1f78e06a1e
--- /dev/null
+++ b/include/hw/ppc/spapr_xive.h
@@ -0,0 +1,35 @@
+/*
+ * QEMU PowerPC sPAPR XIVE interrupt controller model
+ *
+ * Copyright (c) 2017, IBM Corporation.
+ *
+ * This code is licensed under the GPL version 2 or later. See the
+ * COPYING file in the top-level directory.
+ */
+
+#ifndef PPC_SPAPR_XIVE_H
+#define PPC_SPAPR_XIVE_H
+
+#include <hw/sysbus.h>
+
+typedef struct sPAPRXive sPAPRXive;
+typedef struct XiveIVE XiveIVE;
+
+#define TYPE_SPAPR_XIVE "spapr-xive"
+#define SPAPR_XIVE(obj) OBJECT_CHECK(sPAPRXive, (obj), TYPE_SPAPR_XIVE)
+
+struct sPAPRXive {
+    SysBusDevice parent;
+
+    /* Properties */
+    uint32_t     nr_irqs;
+
+    /* XIVE internal tables */
+    XiveIVE      *ivt;
+};
+
+bool spapr_xive_irq_enable(sPAPRXive *xive, uint32_t lisn);
+bool spapr_xive_irq_disable(sPAPRXive *xive, uint32_t lisn);
+void spapr_xive_pic_print_info(sPAPRXive *xive, Monitor *mon);
+
+#endif /* PPC_SPAPR_XIVE_H */
-- 
2.13.6