From 70f18ea64a1d614d52989612155273b713114bbc Mon Sep 17 00:00:00 2001 From: Wei Chen Date: Wed, 5 Apr 2017 17:09:20 +0800 Subject: [PATCH] xen/arm: Prevent slipping hypervisor SError to guest 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 Reviewed-by: Julien Grall --- xen/arch/arm/traps.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c index c092e662c0..c8163dbfa9 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(); -- 2.39.5