2 files changed, 21 insertions, 0 deletions

diff --git a/drivers/misc/cxl/guest.c b/drivers/misc/cxl/guest.c
index a83acf9f8cd9..769971c065b4 100644
--- a/drivers/misc/cxl/guest.c
+++ b/drivers/misc/cxl/guest.c
@@ -552,6 +552,17 @@ static int attach_afu_directed(struct cxl_context *ctx, u64 wed, u64 amr)
 
         elem->common.sstp0  = cpu_to_be64(ctx->sstp0);
         elem->common.sstp1  = cpu_to_be64(ctx->sstp1);
+
+        /*
+         * Ensure we have at least one interrupt allocated to take faults for
+         * kernel contexts that may not have allocated any AFU IRQs at all:
+         */
+        if (ctx->irqs.range[0] == 0) {
+                rc = afu_register_irqs(ctx, 0);
+                if (rc)
+                        goto out_free;
+        }
+
         for (r = 0; r < CXL_IRQ_RANGES; r++) {
                 for (i = 0; i < ctx->irqs.range[r]; i++) {
                         if (r == 0 && i == 0) {
@@ -597,6 +608,7 @@ static int attach_afu_directed(struct cxl_context *ctx, u64 wed, u64 amr)
                 enable_afu_irqs(ctx);
         }
 
+out_free:
         free_page((u64)elem);
         return rc;
 }
diff --git a/drivers/misc/cxl/native.c b/drivers/misc/cxl/native.c
index b8b547a162eb..5d4fb9fd84bc 100644
--- a/drivers/misc/cxl/native.c
+++ b/drivers/misc/cxl/native.c
@@ -534,6 +534,15 @@ static int attach_afu_directed(struct cxl_context *ctx, u64 wed, u64 amr)
         ctx->elem->common.sstp0 = cpu_to_be64(ctx->sstp0);
         ctx->elem->common.sstp1 = cpu_to_be64(ctx->sstp1);
 
+        /*
+         * Ensure we have the multiplexed PSL interrupt set up to take faults
+         * for kernel contexts that may not have allocated any AFU IRQs at all:
+         */
+        if (ctx->irqs.range[0] == 0) {
+                ctx->irqs.offset[0] = ctx->afu->native->psl_hwirq;
+                ctx->irqs.range[0] = 1;
+        }
+
         for (r = 0; r < CXL_IRQ_RANGES; r++) {
                 ctx->elem->ivte_offsets[r] = cpu_to_be16(ctx->irqs.offset[r]);
                 ctx->elem->ivte_ranges[r] = cpu_to_be16(ctx->irqs.range[r]);