ppc/xive: Redistribute phys after pulling of pool context

After pulling the pool context, if a pool irq had been presented and
was cleared in the process, there could be a pending irq in phys that
should be presented. Process the phys irq ring after pulling pool ring
to catch this case and avoid losing irqs.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Glenn Miles <milesg@linux.ibm.com>
Reviewed-by: Michael Kowal <kowal@linux.ibm.com>
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Link: https://lore.kernel.org/qemu-devel/20250512031100.439842-43-npiggin@gmail.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

diff --git a/hw/intc/xive.c b/hw/intc/xive.c
index d609d552e89eaf6b1ea44fe90efecf5ed2d887e1..50a38bbf2ef9d2545374cd1b8bd0cb758e96c826 100644 (file)
--- a/hw/intc/xive.c
+++ b/hw/intc/xive.c
@@ -320,6 +320,9 @@ static uint64_t xive_tm_pull_pool_ctx(XivePresenter *xptr, XiveTCTX *tctx,
 
     xive_tctx_reset_signal(tctx, TM_QW1_OS);
     xive_tctx_reset_signal(tctx, TM_QW2_HV_POOL);
+    /* Re-check phys for interrupts if pool was disabled */
+    xive_tctx_pipr_recompute_from_ipb(tctx, TM_QW3_HV_PHYS);
+
     return qw2w2;
 }
 

diff --git a/hw/intc/xive2.c b/hw/intc/xive2.c
index 112397459afed8b812d75ed3e18f5079865f8302..e3f9ff384a1a9ff628ecb044eb9d93598c381465 100644 (file)
--- a/hw/intc/xive2.c
+++ b/hw/intc/xive2.c
@@ -683,6 +683,8 @@ static void xive2_redistribute(Xive2Router *xrtr, XiveTCTX *tctx, uint8_t ring)
     xive_tctx_reset_signal(tctx, ring);
 }
 
+static void xive2_tctx_process_pending(XiveTCTX *tctx, uint8_t sig_ring);
+
 static uint64_t xive2_tm_pull_ctx(XivePresenter *xptr, XiveTCTX *tctx,
                                   hwaddr offset, unsigned size, uint8_t ring)
 {
@@ -739,6 +741,18 @@ static uint64_t xive2_tm_pull_ctx(XivePresenter *xptr, XiveTCTX *tctx,
         }
     }
 
+    if (ring == TM_QW2_HV_POOL) {
+        /* Re-check phys for interrupts if pool was disabled */
+        nsr = tctx->regs[TM_QW3_HV_PHYS + TM_NSR];
+        if (xive_nsr_indicates_exception(TM_QW3_HV_PHYS, nsr)) {
+            /* Ring must be PHYS because POOL would have been redistributed */
+            g_assert(xive_nsr_exception_ring(TM_QW3_HV_PHYS, nsr) ==
+                                                           TM_QW3_HV_PHYS);
+        } else {
+            xive2_tctx_process_pending(tctx, TM_QW3_HV_PHYS);
+        }
+    }
+
     if (xive2_router_get_config(xrtr) & XIVE2_VP_SAVE_RESTORE && do_save) {
         xive2_tctx_save_ctx(xrtr, tctx, ring, nvp_blk, nvp_idx);
     }
@@ -925,8 +939,6 @@ static uint8_t xive2_tctx_restore_ctx(Xive2Router *xrtr, XiveTCTX *tctx,
     return cppr;
 }
 
-static void xive2_tctx_process_pending(XiveTCTX *tctx, uint8_t sig_ring);
-
 static void xive2_tctx_need_resend(Xive2Router *xrtr, XiveTCTX *tctx,
                                    uint8_t nvp_blk, uint32_t nvp_idx,
                                    bool do_restore)