[PATCH v2 2/2] ppc/xive: Add support for PQ state bits offload

[Cédric Le Goater]

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 is only applies to the
PowerNV machine, sPAPR is not concerned by such complex configuration.

Signed-off-by: Cédric Le Goater <address@hidden>
---
 include/hw/ppc/xive.h  |  8 +++++--
 hw/intc/pnv_xive.c     | 37 +++++++++++++++++++++++++++++---
 hw/intc/xive.c         | 48 ++++++++++++++++++++++++++++++++++++------
 hw/pci-host/pnv_phb4.c |  9 ++++++--
 hw/ppc/pnv_psi.c       |  8 +++++--
 5 files changed, 94 insertions(+), 16 deletions(-)

diff --git a/include/hw/ppc/xive.h b/include/hw/ppc/xive.h
index 112fb6fb6dbe..050e49c14fd9 100644
--- a/include/hw/ppc/xive.h
+++ b/include/hw/ppc/xive.h
@@ -160,7 +160,7 @@ typedef struct XiveNotifier XiveNotifier;
 
 typedef struct XiveNotifierClass {
     InterfaceClass parent;
-    void (*notify)(XiveNotifier *xn, uint32_t lisn);
+    void (*notify)(XiveNotifier *xn, uint32_t lisn, bool pq_checked);
 } XiveNotifierClass;
 
 /*
@@ -354,6 +354,10 @@ typedef struct XiveRouterClass {
     /* XIVE table accessors */
     int (*get_eas)(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
                    XiveEAS *eas);
+    int (*get_pq)(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
+                  uint8_t *pq);
+    int (*set_pq)(XiveRouter *xrtr, uint8_t eas_blk, uint32_t eas_idx,
+                  uint8_t *pq);
     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,
@@ -375,7 +379,7 @@ int xive_router_get_nvt(XiveRouter *xrtr, uint8_t nvt_blk, 
uint32_t nvt_idx,
                         XiveNVT *nvt);
 int xive_router_write_nvt(XiveRouter *xrtr, uint8_t nvt_blk, uint32_t nvt_idx,
                           XiveNVT *nvt, uint8_t word_number);
-void xive_router_notify(XiveNotifier *xn, uint32_t lisn);
+void xive_router_notify(XiveNotifier *xn, uint32_t lisn, bool pq_checked);
 
 /*
  * XIVE Presenter
diff --git a/hw/intc/pnv_xive.c b/hw/intc/pnv_xive.c
index 77cacdd6c623..bcfe9dc54e3b 100644
--- a/hw/intc/pnv_xive.c
+++ b/hw/intc/pnv_xive.c
@@ -373,6 +373,34 @@ 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
@@ -469,12 +497,12 @@ 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);
 }
 
 /*
@@ -1316,7 +1344,8 @@ 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,
@@ -1944,6 +1973,8 @@ 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/xive.c b/hw/intc/xive.c
index b8825577f719..894be4b49ba4 100644
--- a/hw/intc/xive.c
+++ b/hw/intc/xive.c
@@ -927,7 +927,7 @@ 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);
     }
 }
 
@@ -1343,6 +1343,24 @@ 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)
 {
@@ -1686,7 +1704,7 @@ 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);
@@ -1699,11 +1717,27 @@ 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/pci-host/pnv_phb4.c b/hw/pci-host/pnv_phb4.c
index ac824f877cf1..c451819bfd52 100644
--- a/hw/pci-host/pnv_phb4.c
+++ b/hw/pci-host/pnv_phb4.c
@@ -1241,14 +1241,19 @@ static const char *pnv_phb4_root_bus_path(PCIHostState 
*host_bridge,
     return phb->bus_path;
 }
 
-static void pnv_phb4_xive_notify(XiveNotifier *xf, uint32_t srcno)
+static void pnv_phb4_xive_notify(XiveNotifier *xf, uint32_t srcno,
+                                 bool pq_checked)
 {
     PnvPHB4 *phb = PNV_PHB4(xf);
     uint64_t notif_port = phb->regs[PHB_INT_NOTIFY_ADDR >> 3];
     uint32_t offset = phb->regs[PHB_INT_NOTIFY_INDEX >> 3];
-    uint64_t data = XIVE_TRIGGER_PQ | offset | srcno;
+    uint64_t data = offset | srcno;
     MemTxResult result;
 
+    if (pq_checked) {
+        data |= XIVE_TRIGGER_PQ;
+    }
+
     address_space_stq_be(&address_space_memory, notif_port, data,
                          MEMTXATTRS_UNSPECIFIED, &result);
     if (result != MEMTX_OK) {
diff --git a/hw/ppc/pnv_psi.c b/hw/ppc/pnv_psi.c
index c34a49b000f2..63804f28f45e 100644
--- a/hw/ppc/pnv_psi.c
+++ b/hw/ppc/pnv_psi.c
@@ -652,7 +652,7 @@ static const TypeInfo pnv_psi_power8_info = {
 #define   PSIHB9_IRQ_STAT_DIO           PPC_BIT(12)
 #define   PSIHB9_IRQ_STAT_PSU           PPC_BIT(13)
 
-static void pnv_psi_notify(XiveNotifier *xf, uint32_t srcno)
+static void pnv_psi_notify(XiveNotifier *xf, uint32_t srcno, bool pq_checked)
 {
     PnvPsi *psi = PNV_PSI(xf);
     uint64_t notif_port = psi->regs[PSIHB_REG(PSIHB9_ESB_NOTIF_ADDR)];
@@ -661,9 +661,13 @@ static void pnv_psi_notify(XiveNotifier *xf, uint32_t 
srcno)
 
     uint32_t offset =
         (psi->regs[PSIHB_REG(PSIHB9_IVT_OFFSET)] >> PSIHB9_IVT_OFF_SHIFT);
-    uint64_t data = XIVE_TRIGGER_PQ | offset | srcno;
+    uint64_t data = offset | srcno;
     MemTxResult result;
 
+    if (pq_checked) {
+        data |= XIVE_TRIGGER_PQ;
+    }
+
     if (!valid) {
         return;
     }
-- 
2.21.1