ppc/xive: Add support for PQ state bits offload

The trigger message coming from a HW source contains a special bit
informing the XIVE interrupt controller that the PQ bits have been
checked at the source or not. Depending on the value, the IC can
perform the check and the state transition locally using its own PQ
state bits.

The following changes add new accessors to the XiveRouter required to
query and update the PQ state bits. This only applies to the PowerNV
machine. sPAPR accessors are provided but the pSeries machine should
not be concerned by such complex configuration for the moment.

Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

5 files changed, 175 insertions, 14 deletions

diff --git a/hw/intc/pnv_xive.c b/hw/intc/pnv_xive.c
index 621b20a..1ce1d7b 100644
--- a/hw/intc/pnv_xive.c
+++ b/hw/intc/pnv_xive.c
@@ -403,6 +403,34 @@ static int pnv_xive_get_eas(XiveRouter *xrtr, uint8_t blk, uint32_t idx,
     return pnv_xive_vst_read(xive, VST_TSEL_IVT, blk, idx, eas);
 }
 
+static int pnv_xive_get_pq(XiveRouter *xrtr, uint8_t blk, uint32_t idx,
+                           uint8_t *pq)
+{
+    PnvXive *xive = PNV_XIVE(xrtr);
+
+    if (pnv_xive_block_id(xive) != blk) {
+        xive_error(xive, "VST: EAS %x is remote !?", XIVE_EAS(blk, idx));
+        return -1;
+    }
+
+    *pq = xive_source_esb_get(&xive->ipi_source, idx);
+    return 0;
+}
+
+static int pnv_xive_set_pq(XiveRouter *xrtr, uint8_t blk, uint32_t idx,
+                           uint8_t *pq)
+{
+    PnvXive *xive = PNV_XIVE(xrtr);
+
+    if (pnv_xive_block_id(xive) != blk) {
+        xive_error(xive, "VST: EAS %x is remote !?", XIVE_EAS(blk, idx));
+        return -1;
+    }
+
+    *pq = xive_source_esb_set(&xive->ipi_source, idx, *pq);
+    return 0;
+}
+
 /*
  * One bit per thread id. The first register PC_THREAD_EN_REG0 covers
  * the first cores 0-15 (normal) of the chip or 0-7 (fused). The
@@ -499,12 +527,12 @@ static PnvXive *pnv_xive_tm_get_xive(PowerPCCPU *cpu)
  * event notification to the Router. This is required on a multichip
  * system.
  */
-static void pnv_xive_notify(XiveNotifier *xn, uint32_t srcno)
+static void pnv_xive_notify(XiveNotifier *xn, uint32_t srcno, bool pq_checked)
 {
     PnvXive *xive = PNV_XIVE(xn);
     uint8_t blk = pnv_xive_block_id(xive);
 
-    xive_router_notify(xn, XIVE_EAS(blk, srcno));
+    xive_router_notify(xn, XIVE_EAS(blk, srcno), pq_checked);
 }
 
 /*
@@ -1351,7 +1379,8 @@ static void pnv_xive_ic_hw_trigger(PnvXive *xive, hwaddr addr, uint64_t val)
     blk = XIVE_EAS_BLOCK(val);
     idx = XIVE_EAS_INDEX(val);
 
-    xive_router_notify(XIVE_NOTIFIER(xive), XIVE_EAS(blk, idx));
+    xive_router_notify(XIVE_NOTIFIER(xive), XIVE_EAS(blk, idx),
+                       !!(val & XIVE_TRIGGER_PQ));
 }
 
 static void pnv_xive_ic_notify_write(void *opaque, hwaddr addr, uint64_t val,
@@ -1971,6 +2000,8 @@ static void pnv_xive_class_init(ObjectClass *klass, void *data)
     device_class_set_props(dc, pnv_xive_properties);
 
     xrc->get_eas = pnv_xive_get_eas;
+    xrc->get_pq = pnv_xive_get_pq;
+    xrc->set_pq = pnv_xive_set_pq;
     xrc->get_end = pnv_xive_get_end;
     xrc->write_end = pnv_xive_write_end;
     xrc->get_nvt = pnv_xive_get_nvt;
diff --git a/hw/intc/pnv_xive2.c b/hw/intc/pnv_xive2.c
index 35a7f7a..1fa89c7 100644
--- a/hw/intc/pnv_xive2.c
+++ b/hw/intc/pnv_xive2.c
@@ -285,6 +285,34 @@ static int pnv_xive2_vst_write(PnvXive2 *xive, uint32_t type, uint8_t blk,
     return 0;
 }
 
+static int pnv_xive2_get_pq(Xive2Router *xrtr, uint8_t blk, uint32_t idx,
+                             uint8_t *pq)
+{
+    PnvXive2 *xive = PNV_XIVE2(xrtr);
+
+    if (pnv_xive2_block_id(xive) != blk) {
+        xive2_error(xive, "VST: EAS %x is remote !?", XIVE_EAS(blk, idx));
+        return -1;
+    }
+
+    *pq = xive_source_esb_get(&xive->ipi_source, idx);
+    return 0;
+}
+
+static int pnv_xive2_set_pq(Xive2Router *xrtr, uint8_t blk, uint32_t idx,
+                             uint8_t *pq)
+{
+    PnvXive2 *xive = PNV_XIVE2(xrtr);
+
+    if (pnv_xive2_block_id(xive) != blk) {
+        xive2_error(xive, "VST: EAS %x is remote !?", XIVE_EAS(blk, idx));
+        return -1;
+    }
+
+    *pq = xive_source_esb_set(&xive->ipi_source, idx, *pq);
+    return 0;
+}
+
 static int pnv_xive2_get_end(Xive2Router *xrtr, uint8_t blk, uint32_t idx,
                              Xive2End *end)
 {
@@ -487,12 +515,12 @@ static PnvXive2 *pnv_xive2_tm_get_xive(PowerPCCPU *cpu)
  * source interrupt number before forwarding the source event
  * notification to the Router. This is required on a multichip system.
  */
-static void pnv_xive2_notify(XiveNotifier *xn, uint32_t srcno)
+static void pnv_xive2_notify(XiveNotifier *xn, uint32_t srcno, bool pq_checked)
 {
     PnvXive2 *xive = PNV_XIVE2(xn);
     uint8_t blk = pnv_xive2_block_id(xive);
 
-    xive2_router_notify(xn, XIVE_EAS(blk, srcno));
+    xive2_router_notify(xn, XIVE_EAS(blk, srcno), pq_checked);
 }
 
 /*
@@ -1381,7 +1409,8 @@ static void pnv_xive2_ic_hw_trigger(PnvXive2 *xive, hwaddr addr,
     blk = XIVE_EAS_BLOCK(val);
     idx = XIVE_EAS_INDEX(val);
 
-    xive2_router_notify(XIVE_NOTIFIER(xive), XIVE_EAS(blk, idx));
+    xive2_router_notify(XIVE_NOTIFIER(xive), XIVE_EAS(blk, idx),
+                         !!(val & XIVE_TRIGGER_PQ));
 }
 
 static void pnv_xive2_ic_notify_write(void *opaque, hwaddr offset,
@@ -1880,6 +1909,8 @@ static void pnv_xive2_class_init(ObjectClass *klass, void *data)
     device_class_set_props(dc, pnv_xive2_properties);
 
     xrc->get_eas   = pnv_xive2_get_eas;
+    xrc->get_pq    = pnv_xive2_get_pq;
+    xrc->set_pq    = pnv_xive2_set_pq;
     xrc->get_end   = pnv_xive2_get_end;
     xrc->write_end = pnv_xive2_write_end;
     xrc->get_nvp   = pnv_xive2_get_nvp;
diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c
index eae95c7..dc641cc 100644
--- a/hw/intc/spapr_xive.c
+++ b/hw/intc/spapr_xive.c
@@ -480,6 +480,29 @@ static uint8_t spapr_xive_get_block_id(XiveRouter *xrtr)
     return SPAPR_XIVE_BLOCK_ID;
 }
 
+static int spapr_xive_get_pq(XiveRouter *xrtr, uint8_t blk, uint32_t idx,
+                             uint8_t *pq)
+{
+    SpaprXive *xive = SPAPR_XIVE(xrtr);
+
+    assert(SPAPR_XIVE_BLOCK_ID == blk);
+
+    *pq = xive_source_esb_get(&xive->source, idx);
+    return 0;
+}
+
+static int spapr_xive_set_pq(XiveRouter *xrtr, uint8_t blk, uint32_t idx,
+                             uint8_t *pq)
+{
+    SpaprXive *xive = SPAPR_XIVE(xrtr);
+
+    assert(SPAPR_XIVE_BLOCK_ID == blk);
+
+    *pq = xive_source_esb_set(&xive->source, idx, *pq);
+    return 0;
+}
+
+
 static const VMStateDescription vmstate_spapr_xive_end = {
     .name = TYPE_SPAPR_XIVE "/end",
     .version_id = 1,
@@ -788,6 +811,8 @@ static void spapr_xive_class_init(ObjectClass *klass, void *data)
     dc->vmsd    = &vmstate_spapr_xive;
 
     xrc->get_eas = spapr_xive_get_eas;
+    xrc->get_pq  = spapr_xive_get_pq;
+    xrc->set_pq  = spapr_xive_set_pq;
     xrc->get_end = spapr_xive_get_end;
     xrc->write_end = spapr_xive_write_end;
     xrc->get_nvt = spapr_xive_get_nvt;
diff --git a/hw/intc/xive.c b/hw/intc/xive.c
index 0d98b95..deb0db2 100644
--- a/hw/intc/xive.c
+++ b/hw/intc/xive.c
@@ -938,7 +938,7 @@ static void xive_source_notify(XiveSource *xsrc, int srcno)
     XiveNotifierClass *xnc = XIVE_NOTIFIER_GET_CLASS(xsrc->xive);
 
     if (xnc->notify) {
-        xnc->notify(xsrc->xive, srcno);
+        xnc->notify(xsrc->xive, srcno, true);
     }
 }
 
@@ -1370,6 +1370,24 @@ 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);
 }
 
+static
+int xive_router_get_pq(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
+                       uint8_t *pq)
+{
+    XiveRouterClass *xrc = XIVE_ROUTER_GET_CLASS(xrtr);
+
+    return xrc->get_pq(xrtr, eas_blk, eas_idx, pq);
+}
+
+static
+int xive_router_set_pq(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
+                       uint8_t *pq)
+{
+    XiveRouterClass *xrc = XIVE_ROUTER_GET_CLASS(xrtr);
+
+    return xrc->set_pq(xrtr, eas_blk, eas_idx, pq);
+}
+
 int xive_router_get_end(XiveRouter *xrtr, uint8_t end_blk, uint32_t end_idx,
                         XiveEND *end)
 {
@@ -1721,7 +1739,7 @@ do_escalation:
                            xive_get_field32(END_W5_ESC_END_DATA,  end.w5));
 }
 
-void xive_router_notify(XiveNotifier *xn, uint32_t lisn)
+void xive_router_notify(XiveNotifier *xn, uint32_t lisn, bool pq_checked)
 {
     XiveRouter *xrtr = XIVE_ROUTER(xn);
     uint8_t eas_blk = XIVE_EAS_BLOCK(lisn);
@@ -1734,11 +1752,27 @@ void xive_router_notify(XiveNotifier *xn, uint32_t 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 (!pq_checked) {
+        bool notify;
+        uint8_t pq;
+
+        /* PQ cache lookup */
+        if (xive_router_get_pq(xrtr, eas_blk, eas_idx, &pq)) {
+            /* Set FIR */
+            g_assert_not_reached();
+        }
+
+        notify = xive_esb_trigger(&pq);
+
+        if (xive_router_set_pq(xrtr, eas_blk, eas_idx, &pq)) {
+            /* Set FIR */
+            g_assert_not_reached();
+        }
+
+        if (!notify) {
+            return;
+        }
+    }
 
     if (!xive_eas_is_valid(&eas)) {
         qemu_log_mask(LOG_GUEST_ERROR, "XIVE: invalid LISN %x\n", lisn);
diff --git a/hw/intc/xive2.c b/hw/intc/xive2.c
index 2836bbd..3720e70 100644
--- a/hw/intc/xive2.c
+++ b/hw/intc/xive2.c
@@ -171,6 +171,24 @@ int xive2_router_get_eas(Xive2Router *xrtr, uint8_t eas_blk, uint32_t eas_idx,
     return xrc->get_eas(xrtr, eas_blk, eas_idx, eas);
 }
 
+static
+int xive2_router_get_pq(Xive2Router *xrtr, uint8_t eas_blk, uint32_t eas_idx,
+                       uint8_t *pq)
+{
+    Xive2RouterClass *xrc = XIVE2_ROUTER_GET_CLASS(xrtr);
+
+    return xrc->get_pq(xrtr, eas_blk, eas_idx, pq);
+}
+
+static
+int xive2_router_set_pq(Xive2Router *xrtr, uint8_t eas_blk, uint32_t eas_idx,
+                       uint8_t *pq)
+{
+    Xive2RouterClass *xrc = XIVE2_ROUTER_GET_CLASS(xrtr);
+
+    return xrc->set_pq(xrtr, eas_blk, eas_idx, pq);
+}
+
 int xive2_router_get_end(Xive2Router *xrtr, uint8_t end_blk, uint32_t end_idx,
                          Xive2End *end)
 {
@@ -480,7 +498,7 @@ do_escalation:
                            xive_get_field32(END2_W5_ESC_END_DATA,  end.w5));
 }
 
-void xive2_router_notify(XiveNotifier *xn, uint32_t lisn)
+void xive2_router_notify(XiveNotifier *xn, uint32_t lisn, bool pq_checked)
 {
     Xive2Router *xrtr = XIVE2_ROUTER(xn);
     uint8_t eas_blk = XIVE_EAS_BLOCK(lisn);
@@ -493,6 +511,28 @@ void xive2_router_notify(XiveNotifier *xn, uint32_t lisn)
         return;
     }
 
+    if (!pq_checked) {
+        bool notify;
+        uint8_t pq;
+
+        /* PQ cache lookup */
+        if (xive2_router_get_pq(xrtr, eas_blk, eas_idx, &pq)) {
+            /* Set FIR */
+            g_assert_not_reached();
+        }
+
+        notify = xive_esb_trigger(&pq);
+
+        if (xive2_router_set_pq(xrtr, eas_blk, eas_idx, &pq)) {
+            /* Set FIR */
+            g_assert_not_reached();
+        }
+
+        if (!notify) {
+            return;
+        }
+    }
+
     if (!xive2_eas_is_valid(&eas)) {
         qemu_log_mask(LOG_GUEST_ERROR, "XIVE: Invalid LISN %x\n", lisn);
         return;