Re: [PATCH 10/11] VMX: work around lacking VNMI support

[Jan Kiszka <jan.kiszka@siemens.com>]

Gleb Natapov wrote:
> On Mon, Sep 22, 2008 at 09:59:07AM +0200, Jan Kiszka wrote:
>> @@ -2356,6 +2384,19 @@ static void vmx_inject_nmi(struct kvm_vc
>>  {
>>  	struct vcpu_vmx *vmx = to_vmx(vcpu);
>>  
>> +	if (!cpu_has_virtual_nmis()) {
>> +		/*
>> +		 * Tracking the NMI-blocked state in software is built upon
>> +		 * finding the next open IRQ window. This, in turn, depends on
>> +		 * well-behaving guests: They have to keep IRQs disabled at
>> +		 * least as long as the NMI handler runs. Otherwise we may
>> +		 * cause NMI nesting, maybe breaking the guest. But as this is
>> +		 * highly unlikely, we can live with the residual risk.
>> +		 */
>> +		vmx->soft_vnmi_blocked = 1;
>> +		vmx->vnmi_blocked_time = 0;
>> +	}
>> +
> We still get here with vmx->soft_vnmi_blocked = 1. Trying to find out
> how.

We should only come along here with vnmi blocked on reinjection (after a
fault on calling the handler).

Jan

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