Commit afa63fc0e3 for qemu.org

commit afa63fc0e3497b222812eae97e6e5c35cfc9c851
Author: Ani Sinha <anisinha@redhat.com>
Date:   Tue Apr 14 10:29:11 2026 +0530

    accel/kvm: return early from kvm_irqchip_create if kvm does not support irqchip

    During refactoring of kvm_irqchip_create(), the refactored code was returning
    early from do_kvm_irqchip_create() function if the required essential
    capabilities were not present in KVM. This was not translating to an early
    return from kvm_irqchip_create() as was the case before refactoring.
    This is because, do_kvm_irqchip_create() did not have a means to notify the
    caller of the lack of required kvm capabilities. Fix this by making
    do_notify_irqchip_create() return EOPNOTSUPP error when  capabilities
    are absent and then the caller can check the return code and return early.

    Due to this regression during refactoring, all KVM guests on ppc64le hang
    immediately during startup and this completely breaks all functionality on
    that platform.

    Fixes: 98884e0cc1 ("accel/kvm: add changes required to support KVM VM file descriptor change")
    Message-ID: <20260413090010.60339-1-anisinha@redhat.com>
    Reported-by: Misbah Anjum N <misanjum@linux.ibm.com>
    Reported-by: Gautam Menghani <gautam@linux.ibm.com>
    Tested-by: Misbah Anjum N <misanjum@linux.ibm.com>
    Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
    Signed-off-by: Ani Sinha <anisinha@redhat.com>
    Message-id: 20260414045911.63662-1-anisinha@redhat.com
    Suggested-by: Fabiano Rosas <farosas@suse.de>
    Suggested-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
    Tested-by: Misbah Anjum N <misanjum@linux.ibm.com>
    Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
    Signed-off-by: Ani Sinha <anisinha@redhat.com>
    Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 774499d34f..92af42503b 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -2575,7 +2575,7 @@ void kvm_irqchip_set_qemuirq_gsi(KVMState *s, qemu_irq irq, int gsi)
     g_hash_table_insert(s->gsimap, irq, GINT_TO_POINTER(gsi));
 }

-static void do_kvm_irqchip_create(KVMState *s)
+static int do_kvm_irqchip_create(KVMState *s)
 {
     int ret;
     if (kvm_check_extension(s, KVM_CAP_IRQCHIP)) {
@@ -2587,7 +2587,7 @@ static void do_kvm_irqchip_create(KVMState *s)
             exit(1);
         }
     } else {
-        return;
+        return -EOPNOTSUPP;
     }

     if (kvm_check_extension(s, KVM_CAP_IRQFD) <= 0) {
@@ -2610,13 +2610,17 @@ static void do_kvm_irqchip_create(KVMState *s)
         fprintf(stderr, "Create kernel irqchip failed: %s\n", strerror(-ret));
         exit(1);
     }
+
+    return 0;
 }

 static void kvm_irqchip_create(KVMState *s)
 {
     assert(s->kernel_irqchip_split != ON_OFF_AUTO_AUTO);

-    do_kvm_irqchip_create(s);
+    if (do_kvm_irqchip_create(s) < 0) {
+        return;
+    }
     kvm_kernel_irqchip = true;
     /* If we have an in-kernel IRQ chip then we must have asynchronous
      * interrupt delivery (though the reverse is not necessarily true)
@@ -2835,6 +2839,7 @@ static int kvm_reset_vmfd(MachineState *ms)
     }

     if (s->kernel_irqchip_allowed) {
+        /* ignore return from this function */
         do_kvm_irqchip_create(s);
     }