ppc/xive: introduce the XiveRouter model

The XiveRouter models the second sub-engine of the XIVE architecture :
the Interrupt Virtualization Routing Engine (IVRE).

The IVRE handles event notifications of the IVSE and performs the
interrupt routing process. For this purpose, it uses a set of tables
stored in system memory, the first of which being the Event Assignment
Structure (EAS) table.

The EAT associates an interrupt source number with an Event Notification
Descriptor (END) which will be used in a second phase of the routing
process to identify a Notification Virtual Target.

The XiveRouter is an abstract class which needs to be inherited from
to define a storage for the EAT, and other upcoming tables.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
[dwg: Folded in parts of a later fix by Cédric fixing field access]
[dwg: Fix style nits]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

hw/intc/xive.c

@@ -444,6 +444,82 @@ static const TypeInfo xive_source_info = {
     .class_init    = xive_source_class_init,
 };
 
+/*
+ * XIVE Router (aka. Virtualization Controller or IVRE)
+ */
+
+int xive_router_get_eas(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
+                        XiveEAS *eas)
+{
+    XiveRouterClass *xrc = XIVE_ROUTER_GET_CLASS(xrtr);
+
+    return xrc->get_eas(xrtr, eas_blk, eas_idx, eas);
+}
+
+static void xive_router_notify(XiveNotifier *xn, uint32_t lisn)
+{
+    XiveRouter *xrtr = XIVE_ROUTER(xn);
+    uint8_t eas_blk = XIVE_SRCNO_BLOCK(lisn);
+    uint32_t eas_idx = XIVE_SRCNO_INDEX(lisn);
+    XiveEAS eas;
+
+    /* EAS cache lookup */
+    if (xive_router_get_eas(xrtr, eas_blk, eas_idx, &eas)) {
+        qemu_log_mask(LOG_GUEST_ERROR, "XIVE: Unknown LISN %x\n", lisn);
+        return;
+    }
+
+    /*
+     * The IVRE checks the State Bit Cache at this point. We skip the
+     * SBC lookup because the state bits of the sources are modeled
+     * internally in QEMU.
+     */
+
+    if (!xive_eas_is_valid(&eas)) {
+        qemu_log_mask(LOG_GUEST_ERROR, "XIVE: invalid LISN %x\n", lisn);
+        return;
+    }
+
+    if (xive_eas_is_masked(&eas)) {
+        /* Notification completed */
+        return;
+    }
+}
+
+static void xive_router_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    XiveNotifierClass *xnc = XIVE_NOTIFIER_CLASS(klass);
+
+    dc->desc    = "XIVE Router Engine";
+    xnc->notify = xive_router_notify;
+}
+
+static const TypeInfo xive_router_info = {
+    .name          = TYPE_XIVE_ROUTER,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .abstract      = true,
+    .class_size    = sizeof(XiveRouterClass),
+    .class_init    = xive_router_class_init,
+    .interfaces    = (InterfaceInfo[]) {
+        { TYPE_XIVE_NOTIFIER },
+        { }
+    }
+};
+
+void xive_eas_pic_print_info(XiveEAS *eas, uint32_t lisn, Monitor *mon)
+{
+    if (!xive_eas_is_valid(eas)) {
+        return;
+    }
+
+    monitor_printf(mon, "  %08x %s end:%02x/%04x data:%08x\n",
+                   lisn, xive_eas_is_masked(eas) ? "M" : " ",
+                   (uint8_t)  xive_get_field64(EAS_END_BLOCK, eas->w),
+                   (uint32_t) xive_get_field64(EAS_END_INDEX, eas->w),
+                   (uint32_t) xive_get_field64(EAS_END_DATA, eas->w));
+}
+
 /*
  * XIVE Fabric
  */
@@ -457,6 +533,7 @@ static void xive_register_types(void)
 {
     type_register_static(&xive_source_info);
     type_register_static(&xive_fabric_info);
+    type_register_static(&xive_router_info);
 }
 
 type_init(xive_register_types)

include/hw/ppc/xive.h

@@ -141,6 +141,8 @@
 #define PPC_XIVE_H
 
 #include "hw/qdev-core.h"
+#include "hw/sysbus.h"
+#include "hw/ppc/xive_regs.h"
 
 /*
  * XIVE Fabric (Interface between Source and Router)
@@ -297,4 +299,33 @@ static inline void xive_source_irq_set(XiveSource *xsrc, uint32_t srcno,
     }
 }
 
+/*
+ * XIVE Router
+ */
+
+typedef struct XiveRouter {
+    SysBusDevice    parent;
+} XiveRouter;
+
+#define TYPE_XIVE_ROUTER "xive-router"
+#define XIVE_ROUTER(obj)                                \
+    OBJECT_CHECK(XiveRouter, (obj), TYPE_XIVE_ROUTER)
+#define XIVE_ROUTER_CLASS(klass)                                        \
+    OBJECT_CLASS_CHECK(XiveRouterClass, (klass), TYPE_XIVE_ROUTER)
+#define XIVE_ROUTER_GET_CLASS(obj)                              \
+    OBJECT_GET_CLASS(XiveRouterClass, (obj), TYPE_XIVE_ROUTER)
+
+typedef struct XiveRouterClass {
+    SysBusDeviceClass parent;
+
+    /* XIVE table accessors */
+    int (*get_eas)(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
+                   XiveEAS *eas);
+} XiveRouterClass;
+
+void xive_eas_pic_print_info(XiveEAS *eas, uint32_t lisn, Monitor *mon);
+
+int xive_router_get_eas(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
+                        XiveEAS *eas);
+
 #endif /* PPC_XIVE_H */

include/hw/ppc/xive_regs.h

@@ -0,0 +1,62 @@
+/*
+ * QEMU PowerPC XIVE internal structure definitions
+ *
+ *
+ * The XIVE structures are accessed by the HW and their format is
+ * architected to be big-endian. Some macros are provided to ease
+ * access to the different fields.
+ *
+ *
+ * Copyright (c) 2016-2018, IBM Corporation.
+ *
+ * This code is licensed under the GPL version 2 or later. See the
+ * COPYING file in the top-level directory.
+ */
+
+#ifndef PPC_XIVE_REGS_H
+#define PPC_XIVE_REGS_H
+
+/*
+ * Interrupt source number encoding on PowerBUS
+ */
+#define XIVE_SRCNO_BLOCK(srcno) (((srcno) >> 28) & 0xf)
+#define XIVE_SRCNO_INDEX(srcno) ((srcno) & 0x0fffffff)
+#define XIVE_SRCNO(blk, idx)    ((uint32_t)(blk) << 28 | (idx))
+
+/*
+ * EAS (Event Assignment Structure)
+ *
+ * One per interrupt source. Targets an interrupt to a given Event
+ * Notification Descriptor (END) and provides the corresponding
+ * logical interrupt number (END data)
+ */
+typedef struct XiveEAS {
+        /*
+         * Use a single 64-bit definition to make it easier to perform
+         * atomic updates
+         */
+        uint64_t        w;
+#define EAS_VALID       PPC_BIT(0)
+#define EAS_END_BLOCK   PPC_BITMASK(4, 7)        /* Destination END block# */
+#define EAS_END_INDEX   PPC_BITMASK(8, 31)       /* Destination END index */
+#define EAS_MASKED      PPC_BIT(32)              /* Masked */
+#define EAS_END_DATA    PPC_BITMASK(33, 63)      /* Data written to the END */
+} XiveEAS;
+
+#define xive_eas_is_valid(eas)   (be64_to_cpu((eas)->w) & EAS_VALID)
+#define xive_eas_is_masked(eas)  (be64_to_cpu((eas)->w) & EAS_MASKED)
+
+static inline uint64_t xive_get_field64(uint64_t mask, uint64_t word)
+{
+    return (be64_to_cpu(word) & mask) >> ctz64(mask);
+}
+
+static inline uint64_t xive_set_field64(uint64_t mask, uint64_t word,
+                                        uint64_t value)
+{
+    uint64_t tmp =
+        (be64_to_cpu(word) & ~mask) | ((value << ctz64(mask)) & mask);
+    return cpu_to_be64(tmp);
+}
+
+#endif /* PPC_XIVE_REGS_H */