[Qemu-devel] [PATCH v6 05/37] ppc/xive: introduce the XIVE Event Notification Descriptors

["Cédric Le Goater" <clg@kaod.org>]

To complete the event routing, the IVRE sub-engine uses a second table
containing Event Notification Descriptor (END) structures.

An END specifies on which Event Queue (EQ) the event notification
data, defined in the associated EAS, should be posted when an
exception occurs. It also defines which Notification Virtual Target
(NVT) should be notified.

The Event Queue is a memory page provided by the O/S defining a
circular buffer, one per server and priority couple, containing Event
Queue entries. These are 4 bytes long, the first bit being a
'generation' bit and the 31 following bits the END Data field. They
are pulled by the O/S when the exception occurs.

The END Data field is a way to set an invariant logical event source
number for an IRQ. On sPAPR machines, it is set with the
H_INT_SET_SOURCE_CONFIG hcall when the EISN flag is used.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 include/hw/ppc/xive.h      |  18 ++++
 include/hw/ppc/xive_regs.h |  57 ++++++++++++
 hw/intc/xive.c             | 174 +++++++++++++++++++++++++++++++++++++
 3 files changed, 249 insertions(+)

diff --git a/include/hw/ppc/xive.h b/include/hw/ppc/xive.h
index 57ec9f84f527..d1b4c6c78ec5 100644
--- a/include/hw/ppc/xive.h
+++ b/include/hw/ppc/xive.h
@@ -321,11 +321,29 @@ typedef struct XiveRouterClass {
     /* XIVE table accessors */
     int (*get_eas)(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
                    XiveEAS *eas);
+    int (*get_end)(XiveRouter *xrtr, uint8_t end_blk, uint32_t end_idx,
+                   XiveEND *end);
+    int (*write_end)(XiveRouter *xrtr, uint8_t end_blk, uint32_t end_idx,
+                     XiveEND *end, uint8_t word_number);
 } 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);
+int xive_router_get_end(XiveRouter *xrtr, uint8_t end_blk, uint32_t end_idx,
+                        XiveEND *end);
+int xive_router_write_end(XiveRouter *xrtr, uint8_t end_blk, uint32_t end_idx,
+                          XiveEND *end, uint8_t word_number);
+
+/*
+ * For legacy compatibility, the exceptions define up to 256 different
+ * priorities. P9 implements only 9 levels : 8 active levels [0 - 7]
+ * and the least favored level 0xFF.
+ */
+#define XIVE_PRIORITY_MAX  7
+
+void xive_end_pic_print_info(XiveEND *end, uint32_t end_idx, Monitor *mon);
+void xive_end_queue_pic_print_info(XiveEND *end, uint32_t width, Monitor *mon);
 
 #endif /* PPC_XIVE_H */
diff --git a/include/hw/ppc/xive_regs.h b/include/hw/ppc/xive_regs.h
index 15f2470ed9cc..3c0ebad18b69 100644
--- a/include/hw/ppc/xive_regs.h
+++ b/include/hw/ppc/xive_regs.h
@@ -47,4 +47,61 @@ typedef struct XiveEAS {
 #define GETFIELD_BE64(m, v)      GETFIELD(m, be64_to_cpu(v))
 #define SETFIELD_BE64(m, v, val) cpu_to_be64(SETFIELD(m, be64_to_cpu(v), val))
 
+/* Event Notification Descriptor (END) */
+typedef struct XiveEND {
+        uint32_t        w0;
+#define END_W0_VALID             PPC_BIT32(0) /* "v" bit */
+#define END_W0_ENQUEUE           PPC_BIT32(1) /* "q" bit */
+#define END_W0_UCOND_NOTIFY      PPC_BIT32(2) /* "n" bit */
+#define END_W0_BACKLOG           PPC_BIT32(3) /* "b" bit */
+#define END_W0_PRECL_ESC_CTL     PPC_BIT32(4) /* "p" bit */
+#define END_W0_ESCALATE_CTL      PPC_BIT32(5) /* "e" bit */
+#define END_W0_UNCOND_ESCALATE   PPC_BIT32(6) /* "u" bit - DD2.0 */
+#define END_W0_SILENT_ESCALATE   PPC_BIT32(7) /* "s" bit - DD2.0 */
+#define END_W0_QSIZE             PPC_BITMASK32(12, 15)
+#define END_W0_SW0               PPC_BIT32(16)
+#define END_W0_FIRMWARE          END_W0_SW0 /* Owned by FW */
+#define END_QSIZE_4K             0
+#define END_QSIZE_64K            4
+#define END_W0_HWDEP             PPC_BITMASK32(24, 31)
+        uint32_t        w1;
+#define END_W1_ESn               PPC_BITMASK32(0, 1)
+#define END_W1_ESn_P             PPC_BIT32(0)
+#define END_W1_ESn_Q             PPC_BIT32(1)
+#define END_W1_ESe               PPC_BITMASK32(2, 3)
+#define END_W1_ESe_P             PPC_BIT32(2)
+#define END_W1_ESe_Q             PPC_BIT32(3)
+#define END_W1_GENERATION        PPC_BIT32(9)
+#define END_W1_PAGE_OFF          PPC_BITMASK32(10, 31)
+        uint32_t        w2;
+#define END_W2_MIGRATION_REG     PPC_BITMASK32(0, 3)
+#define END_W2_OP_DESC_HI        PPC_BITMASK32(4, 31)
+        uint32_t        w3;
+#define END_W3_OP_DESC_LO        PPC_BITMASK32(0, 31)
+        uint32_t        w4;
+#define END_W4_ESC_END_BLOCK     PPC_BITMASK32(4, 7)
+#define END_W4_ESC_END_INDEX     PPC_BITMASK32(8, 31)
+        uint32_t        w5;
+#define END_W5_ESC_END_DATA      PPC_BITMASK32(1, 31)
+        uint32_t        w6;
+#define END_W6_FORMAT_BIT        PPC_BIT32(8)
+#define END_W6_NVT_BLOCK         PPC_BITMASK32(9, 12)
+#define END_W6_NVT_INDEX         PPC_BITMASK32(13, 31)
+        uint32_t        w7;
+#define END_W7_F0_IGNORE         PPC_BIT32(0)
+#define END_W7_F0_BLK_GROUPING   PPC_BIT32(1)
+#define END_W7_F0_PRIORITY       PPC_BITMASK32(8, 15)
+#define END_W7_F1_WAKEZ          PPC_BIT32(0)
+#define END_W7_F1_LOG_SERVER_ID  PPC_BITMASK32(1, 31)
+} XiveEND;
+
+#define xive_end_is_valid(end)    (be32_to_cpu((end)->w0) & END_W0_VALID)
+#define xive_end_is_enqueue(end)  (be32_to_cpu((end)->w0) & END_W0_ENQUEUE)
+#define xive_end_is_notify(end)   (be32_to_cpu((end)->w0) & END_W0_UCOND_NOTIFY)
+#define xive_end_is_backlog(end)  (be32_to_cpu((end)->w0) & END_W0_BACKLOG)
+#define xive_end_is_escalate(end) (be32_to_cpu((end)->w0) & END_W0_ESCALATE_CTL)
+
+#define GETFIELD_BE32(m, v)       GETFIELD(m, be32_to_cpu(v))
+#define SETFIELD_BE32(m, v, val)  cpu_to_be32(SETFIELD(m, be32_to_cpu(v), val))
+
 #endif /* PPC_XIVE_REGS_H */
diff --git a/hw/intc/xive.c b/hw/intc/xive.c
index d21df6674d8c..41d8ba1540d0 100644
--- a/hw/intc/xive.c
+++ b/hw/intc/xive.c
@@ -443,6 +443,95 @@ static const TypeInfo xive_source_info = {
     .class_init    = xive_source_class_init,
 };
 
+/*
+ * XiveEND helpers
+ */
+
+void xive_end_queue_pic_print_info(XiveEND *end, uint32_t width, Monitor *mon)
+{
+    uint64_t qaddr_base = (uint64_t) be32_to_cpu(end->w2 & 0x0fffffff) << 32
+        | be32_to_cpu(end->w3);
+    uint32_t qsize = GETFIELD_BE32(END_W0_QSIZE, end->w0);
+    uint32_t qindex = GETFIELD_BE32(END_W1_PAGE_OFF, end->w1);
+    uint32_t qentries = 1 << (qsize + 10);
+    int i;
+
+    /*
+     * print out the [ (qindex - (width - 1)) .. (qindex + 1)] window
+     */
+    monitor_printf(mon, " [ ");
+    qindex = (qindex - (width - 1)) & (qentries - 1);
+    for (i = 0; i < width; i++) {
+        uint64_t qaddr = qaddr_base + (qindex << 2);
+        uint32_t qdata = -1;
+
+        if (dma_memory_read(&address_space_memory, qaddr, &qdata,
+                            sizeof(qdata))) {
+            qemu_log_mask(LOG_GUEST_ERROR, "XIVE: failed to read EQ @0x%"
+                          HWADDR_PRIx "\n", qaddr);
+            return;
+        }
+        monitor_printf(mon, "%s%08x ", i == width - 1 ? "^" : "",
+                       be32_to_cpu(qdata));
+        qindex = (qindex + 1) & (qentries - 1);
+    }
+}
+
+void xive_end_pic_print_info(XiveEND *end, uint32_t end_idx, Monitor *mon)
+{
+    uint64_t qaddr_base = (uint64_t) be32_to_cpu(end->w2 & 0x0fffffff) << 32
+        | be32_to_cpu(end->w3);
+    uint32_t qindex = GETFIELD_BE32(END_W1_PAGE_OFF, end->w1);
+    uint32_t qgen = GETFIELD_BE32(END_W1_GENERATION, end->w1);
+    uint32_t qsize = GETFIELD_BE32(END_W0_QSIZE, end->w0);
+    uint32_t qentries = 1 << (qsize + 10);
+
+    uint32_t nvt = GETFIELD_BE32(END_W6_NVT_INDEX, end->w6);
+    uint8_t priority = GETFIELD_BE32(END_W7_F0_PRIORITY, end->w7);
+
+    if (!xive_end_is_valid(end)) {
+        return;
+    }
+
+    monitor_printf(mon, "  %08x %c%c%c%c%c prio:%d nvt:%04x eq:@%08"PRIx64
+                   "% 6d/%5d ^%d", end_idx,
+                   xive_end_is_valid(end)    ? 'v' : '-',
+                   xive_end_is_enqueue(end)  ? 'q' : '-',
+                   xive_end_is_notify(end)   ? 'n' : '-',
+                   xive_end_is_backlog(end)  ? 'b' : '-',
+                   xive_end_is_escalate(end) ? 'e' : '-',
+                   priority, nvt, qaddr_base, qindex, qentries, qgen);
+
+    xive_end_queue_pic_print_info(end, 6, mon);
+    monitor_printf(mon, "]\n");
+}
+
+static void xive_end_enqueue(XiveEND *end, uint32_t data)
+{
+    uint64_t qaddr_base = (uint64_t) be32_to_cpu(end->w2 & 0x0fffffff) << 32
+        | be32_to_cpu(end->w3);
+    uint32_t qsize = GETFIELD_BE32(END_W0_QSIZE, end->w0);
+    uint32_t qindex = GETFIELD_BE32(END_W1_PAGE_OFF, end->w1);
+    uint32_t qgen = GETFIELD_BE32(END_W1_GENERATION, end->w1);
+
+    uint64_t qaddr = qaddr_base + (qindex << 2);
+    uint32_t qdata = cpu_to_be32((qgen << 31) | (data & 0x7fffffff));
+    uint32_t qentries = 1 << (qsize + 10);
+
+    if (dma_memory_write(&address_space_memory, qaddr, &qdata, sizeof(qdata))) {
+        qemu_log_mask(LOG_GUEST_ERROR, "XIVE: failed to write END data @0x%"
+                      HWADDR_PRIx "\n", qaddr);
+        return;
+    }
+
+    qindex = (qindex + 1) & (qentries - 1);
+    if (qindex == 0) {
+        qgen ^= 1;
+        end->w1 = SETFIELD_BE32(END_W1_GENERATION, end->w1, qgen);
+    }
+    end->w1 = SETFIELD_BE32(END_W1_PAGE_OFF, end->w1, qindex);
+}
+
 /*
  * XIVE Router (aka. Virtualization Controller or IVRE)
  */
@@ -455,6 +544,83 @@ int xive_router_get_eas(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
     return xrc->get_eas(xrtr, eas_blk, eas_idx, eas);
 }
 
+int xive_router_get_end(XiveRouter *xrtr, uint8_t end_blk, uint32_t end_idx,
+                        XiveEND *end)
+{
+   XiveRouterClass *xrc = XIVE_ROUTER_GET_CLASS(xrtr);
+
+   return xrc->get_end(xrtr, end_blk, end_idx, end);
+}
+
+int xive_router_write_end(XiveRouter *xrtr, uint8_t end_blk, uint32_t end_idx,
+                          XiveEND *end, uint8_t word_number)
+{
+   XiveRouterClass *xrc = XIVE_ROUTER_GET_CLASS(xrtr);
+
+   return xrc->write_end(xrtr, end_blk, end_idx, end, word_number);
+}
+
+/*
+ * An END trigger can come from an event trigger (IPI or HW) or from
+ * another chip. We don't model the PowerBus but the END trigger
+ * message has the same parameters than in the function below.
+ */
+static void xive_router_end_notify(XiveRouter *xrtr, uint8_t end_blk,
+                                   uint32_t end_idx, uint32_t end_data)
+{
+    XiveEND end;
+    uint8_t priority;
+    uint8_t format;
+
+    /* END cache lookup */
+    if (xive_router_get_end(xrtr, end_blk, end_idx, &end)) {
+        qemu_log_mask(LOG_GUEST_ERROR, "XIVE: No END %x/%x\n", end_blk,
+                      end_idx);
+        return;
+    }
+
+    if (!xive_end_is_valid(&end)) {
+        qemu_log_mask(LOG_GUEST_ERROR, "XIVE: END %x/%x is invalid\n",
+                      end_blk, end_idx);
+        return;
+    }
+
+    if (xive_end_is_enqueue(&end)) {
+        xive_end_enqueue(&end, end_data);
+        /* Enqueuing event data modifies the EQ toggle and index */
+        xive_router_write_end(xrtr, end_blk, end_idx, &end, 1);
+    }
+
+    /*
+     * The W7 format depends on the F bit in W6. It defines the type
+     * of the notification :
+     *
+     *   F=0 : single or multiple NVT notification
+     *   F=1 : User level Event-Based Branch (EBB) notification, no
+     *         priority
+     */
+    format = GETFIELD_BE32(END_W6_FORMAT_BIT, end.w6);
+    priority = GETFIELD_BE32(END_W7_F0_PRIORITY, end.w7);
+
+    /* The END is masked */
+    if (format == 0 && priority == 0xff) {
+        return;
+    }
+
+    /*
+     * Check the END ESn (Event State Buffer for notification) for
+     * even futher coalescing in the Router
+     */
+    if (!xive_end_is_notify(&end)) {
+        qemu_log_mask(LOG_UNIMP, "XIVE: !UCOND_NOTIFY not implemented\n");
+        return;
+    }
+
+    /*
+     * Follows IVPE notification
+     */
+}
+
 static void xive_router_notify(XiveNotifier *xn, uint32_t lisn)
 {
     XiveRouter *xrtr = XIVE_ROUTER(xn);
@@ -482,6 +648,14 @@ static void xive_router_notify(XiveNotifier *xn, uint32_t lisn)
         /* Notification completed */
         return;
     }
+
+    /*
+     * The event trigger becomes an END trigger
+     */
+    xive_router_end_notify(xrtr,
+                           GETFIELD_BE64(EAS_END_BLOCK, eas.w),
+                           GETFIELD_BE64(EAS_END_INDEX, eas.w),
+                           GETFIELD_BE64(EAS_END_DATA,  eas.w));
 }
 
 static void xive_router_class_init(ObjectClass *klass, void *data)
-- 
2.17.2