Re: [PATCH 4/7] KVM: TDX: restore host xsave state when exit from the guest TD

[Adrian Hunter]

On 9/01/25 21:11, Sean Christopherson wrote:
> My vote would to KVM_BUG_ON() before entering the guest.

I notice if KVM_BUG_ON() is called with interrupts disabled
smp_call_function_many_cond() generates a warning:

WARNING: CPU: 223 PID: 4213 at kernel/smp.c:807 smp_call_function_many_cond+0x421/0x560

static void smp_call_function_many_cond(const struct cpumask *mask,
					smp_call_func_t func, void *info,
					unsigned int scf_flags,
					smp_cond_func_t cond_func)
{
	int cpu, last_cpu, this_cpu = smp_processor_id();
	struct call_function_data *cfd;
	bool wait = scf_flags & SCF_WAIT;
	int nr_cpus = 0;
	bool run_remote = false;
	bool run_local = false;

	lockdep_assert_preemption_disabled();

	/*
	 * Can deadlock when called with interrupts disabled.
	 * We allow cpu's that are not yet online though, as no one else can
	 * send smp call function interrupt to this cpu and as such deadlocks
	 * can't happen.
	 */
	if (cpu_online(this_cpu) && !oops_in_progress &&
	    !early_boot_irqs_disabled)
		lockdep_assert_irqs_enabled();			<------------- here

Do we need to care about that?