linux-kernel - Re: KVM Nested L2 guest startup problems

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Message-ID: <5369F5B0.7050307@redhat.com>
Date:	Wed, 07 May 2014 10:58:24 +0200
From:	Paolo Bonzini <pbonzini@...hat.com>
To:	Hu Yaohui <loki2441@...il.com>, Abel Gordon <abel@...atoscale.com>
CC:	Bandan Das <bsd@...hat.com>, kvm <kvm@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Muli Ben-Yehuda <muli@...atoscale.com>
Subject: Re: KVM Nested L2 guest startup problems

Il 04/05/2014 18:33, Hu Yaohui ha scritto:
>> I experienced a similar problem that was related to nested code
>> having some bugs related to apicv and other new vmx features.
>>
>> For example, the code enabled posted interrupts to run L2 even when the
>> feature was not exposed to L1 and L1 didn't use it.
>>
>> Try changing prepare_vmcs02  to force disabling posted_interrupts,
>> code should looks like:
>>
>> ....
>> ....
>> exec_control = vmcs12->pin_based_vm_exec_control;
>> exec_control |= vmcs_config.pin_based_exec_ctrl;
>> exec_control &= ~(PIN_BASED_VMX_PREEMPTION_TIMER|PIN_BASED_POSTED_INTR);
>> vmcs_write32(PIN_BASED_VM_EXEC_CONTROL, exec_control);
>> ....
>> ...
>>
>> and also
>>
>> ...
>> ...
>> exec_control &= ~(SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
>>      SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY |
>>      SECONDARY_EXEC_APIC_REGISTER_VIRT |
>>      SECONDARY_EXEC_PAUSE_LOOP_EXITING);

PLE should be left enabled, I think.

Apart from that, I'll change the suggestion into a patch.

Thanks!

Paolo

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