apic: disable reentrancy detection for apic-msi

As the code is designed for re-entrant calls to apic-msi, mark apic-msi
as reentrancy-safe.

Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Message-Id: <20230427211013.2994127-9-alxndr@bu.edu>
Signed-off-by: Thomas Huth <thuth@redhat.com>
(cherry picked from commit 50795ee051a342c681a9b45671c552fbd6274db8)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/hw/intc/apic.c b/hw/intc/apic.c
index 3df11c34d6813b9bd207ed04f1a042fb4a068fcc..a7c2b301a87da6906042924ba68fb69f96ff956a 100644 (file)
--- a/hw/intc/apic.c
+++ b/hw/intc/apic.c
@@ -883,6 +883,13 @@ static void apic_realize(DeviceState *dev, Error **errp)
     memory_region_init_io(&s->io_memory, OBJECT(s), &apic_io_ops, s, "apic-msi",
                           APIC_SPACE_SIZE);
 
+    /*
+     * apic-msi's apic_mem_write can call into ioapic_eoi_broadcast, which can
+     * write back to apic-msi. As such mark the apic-msi region re-entrancy
+     * safe.
+     */
+    s->io_memory.disable_reentrancy_guard = true;
+
     s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, apic_timer, s);
     local_apics[s->id] = s;