diff mbox

[v4,18/19] xen/arm: Prevent slipping hypervisor SError to guest

Message ID 1491383361-22886-19-git-send-email-Wei.Chen@arm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Wei Chen April 5, 2017, 9:09 a.m. UTC 
If there is a pending SError while we're returning from trap. If the
SError handle option is "DIVERSE", we have to prevent slipping this
hypervisor SError to guest. So we have to use the dsb/isb to guarantee
that the pending hypervisor SError would be caught in hypervisor before
return to guest.

In previous patch, we will set SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT to
cpu_hwcaps when option is NOT "DIVERSE". This means we can use the
alternative to skip synchronizing SErrors for other SErrors handle options.

Because we have umasked the Abort/SError bit in previous patch. We have
to disable the Abort/SError before returning to guest as we have done
for IRQ.

Signed-off-by: Wei Chen <Wei.Chen@arm.com>
---
 xen/arch/arm/traps.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Comments

Julien Grall April 5, 2017, 11:17 a.m. UTC | #1 
Hi Wei,

On 05/04/17 10:09, Wei Chen wrote:
> If there is a pending SError while we're returning from trap. If the
> SError handle option is "DIVERSE", we have to prevent slipping this
> hypervisor SError to guest. So we have to use the dsb/isb to guarantee
> that the pending hypervisor SError would be caught in hypervisor before
> return to guest.
>
> In previous patch, we will set SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT to
> cpu_hwcaps when option is NOT "DIVERSE". This means we can use the
> alternative to skip synchronizing SErrors for other SErrors handle options.
>
> Because we have umasked the Abort/SError bit in previous patch. We have
> to disable the Abort/SError before returning to guest as we have done
> for IRQ.
>
> Signed-off-by: Wei Chen <Wei.Chen@arm.com>

Reviewed-by: Julien Grall <julien.grall@arm.com>

Cheers,
diff mbox

Patch

diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index c092e66..c8163db 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -2989,6 +2989,19 @@  asmlinkage void leave_hypervisor_tail(void)
         local_irq_disable();
         if (!softirq_pending(smp_processor_id())) {
             gic_inject();
+
+            /*
+             * If the SErrors handle option is "DIVERSE", we have to prevent
+             * slipping the hypervisor SError to guest. In this option, before
+             * returning from trap, we have to synchronize SErrors to guarantee
+             * that the pending SError would be caught in hypervisor.
+             *
+             * If option is NOT "DIVERSE", SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT
+             * will be set to cpu_hwcaps. This means we can use the alternative
+             * to skip synchronizing SErrors for other SErrors handle options.
+             */
+            SYNCHRONIZE_SERROR(SKIP_SYNCHRONIZE_SERROR_ENTRY_EXIT);
+
             return;
         }
         local_irq_enable();