From afa63fc0e3497b222812eae97e6e5c35cfc9c851 Mon Sep 17 00:00:00 2001 From: Ani Sinha Date: Tue, 14 Apr 2026 10:29:11 +0530 Subject: [PATCH] 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 Reported-by: Gautam Menghani Tested-by: Misbah Anjum N Reviewed-by: Peter Maydell Signed-off-by: Ani Sinha Message-id: 20260414045911.63662-1-anisinha@redhat.com Suggested-by: Fabiano Rosas Suggested-by: Harsh Prateek Bora Tested-by: Misbah Anjum N Reviewed-by: Peter Maydell Signed-off-by: Ani Sinha Signed-off-by: Peter Maydell --- accel/kvm/kvm-all.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) 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); }