Re: [PATCH 04/50] ppc/xive2: Remote VSDs need to match on forwarding address

[Mike Kowal]

On 5/11/2025 10:10 PM, Nicholas Piggin wrote:

From: Michael Kowal <ko...@linux.ibm.com>

In a multi chip environment there will be remote/forwarded VSDs.  The check
to find a matching INT controller (XIVE) of the remote block number was
checking the INTs chip number.  Block numbers are not tied to a chip number.
The matching remote INT is the one that matches the forwarded VSD address
with VSD types associated MMIO BAR.

Reviewed-by: Michael Kowal <ko...@linux.ibm.com>

Thanks MAK

Signed-off-by: Michael Kowal <ko...@linux.ibm.com>
---
  hw/intc/pnv_xive2.c | 25 +++++++++++++++++--------
  1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/hw/intc/pnv_xive2.c b/hw/intc/pnv_xive2.c
index d1713b406c..30b4ab2efe 100644
--- a/hw/intc/pnv_xive2.c
+++ b/hw/intc/pnv_xive2.c
@@ -102,12 +102,10 @@ static uint32_t pnv_xive2_block_id(PnvXive2 *xive)
  }

/*

- * Remote access to controllers. HW uses MMIOs. For now, a simple scan
- * of the chips is good enough.
- *
- * TODO: Block scope support
+ * Remote access to INT controllers. HW uses MMIOs(?). For now, a simple
+ * scan of all the chips INT controller is good enough.
   */
-static PnvXive2 *pnv_xive2_get_remote(uint8_t blk)
+static PnvXive2 *pnv_xive2_get_remote(uint32_t vsd_type, hwaddr fwd_addr)
  {
      PnvMachineState *pnv = PNV_MACHINE(qdev_get_machine());
      int i;
@@ -116,10 +114,22 @@ static PnvXive2 *pnv_xive2_get_remote(uint8_t blk)
          Pnv10Chip *chip10 = PNV10_CHIP(pnv->chips[i]);
          PnvXive2 *xive = &chip10->xive;

- if (pnv_xive2_block_id(xive) == blk) {

+        /*
+         * Is this the XIVE matching the forwarded VSD address is for this
+         * VSD type
+         */
+        if ((vsd_type == VST_ESB   && fwd_addr == xive->esb_base) ||
+            (vsd_type == VST_END   && fwd_addr == xive->end_base)  ||
+            ((vsd_type == VST_NVP ||
+              vsd_type == VST_NVG) && fwd_addr == xive->nvpg_base) ||
+            (vsd_type == VST_NVC   && fwd_addr == xive->nvc_base)) {
              return xive;
          }
      }
+
+    qemu_log_mask(LOG_GUEST_ERROR,
+                 "XIVE: >>>>> pnv_xive2_get_remote() vsd_type %u  fwd_addr 0x%lX 
NOT FOUND\n",
+                 vsd_type, fwd_addr);
      return NULL;
  }

@@ -252,8 +262,7 @@ static uint64_t pnv_xive2_vst_addr(PnvXive2 *xive, uint32_t type, uint8_t blk, /* Remote VST access */

      if (GETFIELD(VSD_MODE, vsd) == VSD_MODE_FORWARD) {
-        xive = pnv_xive2_get_remote(blk);
-
+        xive = pnv_xive2_get_remote(type, (vsd & VSD_ADDRESS_MASK));
          return xive ? pnv_xive2_vst_addr(xive, type, blk, idx) : 0;
      }