diff mbox series

apic: disable reentrancy detection for apic-msi

Message ID 20230427135233.2973922-1-alxndr@bu.edu (mailing list archive)
State New, archived
Headers show
Series apic: disable reentrancy detection for apic-msi | expand

Commit Message

Alexander Bulekov April 27, 2023, 1:52 p.m. UTC
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>
---
Based-on: <20230426161951.2948996-1-alxndr@bu.edu>

 hw/intc/apic.c | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Darren Kenny April 27, 2023, 2:05 p.m. UTC | #1
On Thursday, 2023-04-27 at 09:52:33 -04, Alexander Bulekov wrote:
> 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>

> ---
> Based-on: <20230426161951.2948996-1-alxndr@bu.edu>
>
>  hw/intc/apic.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/hw/intc/apic.c b/hw/intc/apic.c
> index 20b5a94073..ac3d47d231 100644
> --- a/hw/intc/apic.c
> +++ b/hw/intc/apic.c
> @@ -885,6 +885,13 @@ 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;
>  
> -- 
> 2.39.0
diff mbox series

Patch

diff --git a/hw/intc/apic.c b/hw/intc/apic.c
index 20b5a94073..ac3d47d231 100644
--- a/hw/intc/apic.c
+++ b/hw/intc/apic.c
@@ -885,6 +885,13 @@  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;