Re: [RFC v2 08/32] x86/traps: Add #VE support for TDX guest

[Dave Hansen]

On 4/26/21 11:01 AM, Kuppuswamy Sathyanarayanan wrote:
> +#ifdef CONFIG_INTEL_TDX_GUEST
> +DEFINE_IDTENTRY(exc_virtualization_exception)
> +{
> +	struct ve_info ve;
> +	int ret;
> +
> +	RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
> +
> +	/*
> +	 * Consume #VE info before re-enabling interrupts. It will be
> +	 * re-enabled after executing the TDGETVEINFO TDCALL.
> +	 */
> +	ret = tdg_get_ve_info(&ve);

Is it safe to have *anything* before the tdg_get_ve_info()?  For
instance, say that RCU_LOCKDEP_WARN() triggers.  Will anything in there
do MMIO?