1 files changed, 48 insertions, 36 deletions

diff --git a/hw/intc/pnv_xive.c b/hw/intc/pnv_xive.c
index aae5cb6f60..9b10e90519 100644
--- a/hw/intc/pnv_xive.c
+++ b/hw/intc/pnv_xive.c
@@ -85,28 +85,6 @@ static uint8_t pnv_xive_block_id(PnvXive *xive)
 }
 
 /*
- * Remote access to controllers. HW uses MMIOs. For now, a simple scan
- * of the chips is good enough.
- *
- * TODO: Block scope support
- */
-static PnvXive *pnv_xive_get_remote(uint8_t blk)
-{
-    PnvMachineState *pnv = PNV_MACHINE(qdev_get_machine());
-    int i;
-
-    for (i = 0; i < pnv->num_chips; i++) {
-        Pnv9Chip *chip9 = PNV9_CHIP(pnv->chips[i]);
-        PnvXive *xive = &chip9->xive;
-
-        if (pnv_xive_block_id(xive) == blk) {
-            return xive;
-        }
-    }
-    return NULL;
-}
-
-/*
  * VST accessors for SBE, EAT, ENDT, NVT
  *
  * Indirect VST tables are arrays of VSDs pointing to a page (of same
@@ -209,6 +187,42 @@ static uint64_t pnv_xive_vst_addr_indirect(PnvXive *xive, uint32_t type,
     return pnv_xive_vst_addr_direct(xive, type, vsd, (idx % vst_per_page));
 }
 
+/*
+ * This is a simplified model of operation forwarding on a remote IC.
+ *
+ * A PC MMIO address is built to identify the NVT structure. The load
+ * on the remote IC will return the address of the structure in RAM,
+ * which will then be used by pnv_xive_vst_write/read to perform the
+ * RAM operation.
+ */
+static uint64_t pnv_xive_vst_addr_remote(PnvXive *xive, uint32_t type,
+                                         uint64_t vsd, uint8_t blk,
+                                         uint32_t idx)
+{
+    const XiveVstInfo *info = &vst_infos[type];
+    uint64_t remote_addr = vsd & VSD_ADDRESS_MASK;
+    uint64_t vst_addr;
+    MemTxResult result;
+
+    if (type != VST_TSEL_VPDT) {
+        xive_error(xive, "VST: invalid access on remote VST %s %x/%x !?",
+                   info->name, blk, idx);
+        return 0;
+    }
+
+    remote_addr |= idx << xive->pc_shift;
+
+    vst_addr = address_space_ldq_be(&address_space_memory, remote_addr,
+                                    MEMTXATTRS_UNSPECIFIED, &result);
+    if (result != MEMTX_OK) {
+        xive_error(xive, "VST: read failed at @0x%"  HWADDR_PRIx
+                   " for NVT %x/%x\n", remote_addr, blk, idx);
+        return 0;
+    }
+
+    return vst_addr;
+}
+
 static uint64_t pnv_xive_vst_addr(PnvXive *xive, uint32_t type, uint8_t blk,
                                   uint32_t idx)
 {
@@ -225,14 +239,7 @@ static uint64_t pnv_xive_vst_addr(PnvXive *xive, uint32_t type, uint8_t blk,
 
     /* Remote VST access */
     if (GETFIELD(VSD_MODE, vsd) == VSD_MODE_FORWARD) {
-        if (type != VST_TSEL_VPDT) {
-            xive_error(xive, "VST: invalid access on remote VST %s %x/%x !?",
-                       info->name, blk, idx);
-            return 0;
-        }
-        xive = pnv_xive_get_remote(blk);
-
-        return xive ? pnv_xive_vst_addr(xive, type, blk, idx) : 0;
+        return pnv_xive_vst_addr_remote(xive, type, vsd, blk, idx);
     }
 
     if (VSD_INDIRECT & vsd) {
@@ -1785,16 +1792,20 @@ static const MemoryRegionOps pnv_xive_vc_ops = {
 };
 
 /*
- * Presenter Controller MMIO region. The Virtualization Controller
- * updates the IPB in the NVT table when required. Not modeled.
+ * Presenter Controller MMIO region. Points to the NVT sets.
+ *
+ * HW implements all possible mem ops to the underlying NVT structure
+ * but QEMU does not need to be so precise. The model implementation
+ * simply returns the RAM address of the NVT structure which is then
+ * used by pnv_xive_vst_write/read to perform the RAM operation.
  */
-static uint64_t pnv_xive_pc_read(void *opaque, hwaddr addr,
-                                 unsigned size)
+static uint64_t pnv_xive_pc_read(void *opaque, hwaddr offset, unsigned size)
 {
     PnvXive *xive = PNV_XIVE(opaque);
+    uint32_t nvt_idx = offset >> xive->pc_shift;
+    uint8_t blk = pnv_xive_block_id(xive); /* TODO: VDT -> block xlate */
 
-    xive_error(xive, "PC: invalid read @%"HWADDR_PRIx, addr);
-    return -1;
+    return pnv_xive_vst_addr(xive, VST_TSEL_VPDT, blk, nvt_idx);
 }
 
 static void pnv_xive_pc_write(void *opaque, hwaddr addr,
@@ -2016,6 +2027,7 @@ static void pnv_xive_realize(DeviceState *dev, Error **errp)
     /* Presenter Controller MMIO region (not modeled) */
     memory_region_init_io(&xive->pc_mmio, OBJECT(xive), &pnv_xive_pc_ops, xive,
                           "xive-pc", PNV9_XIVE_PC_SIZE);
+    xive->pc_mmio.disable_reentrancy_guard = true;
 
     /* Thread Interrupt Management Area (Direct) */
     memory_region_init_io(&xive->tm_mmio, OBJECT(xive), &pnv_xive_tm_ops,