From: Paolo Bonzini <pbonzini@redhat.com>
To: Bandan Das <bsd@redhat.com>, Nadav Amit <namit@cs.technion.ac.il>
Cc: kvm@vger.kernel.org
Subject: Re: [PATCH v2 1/4] KVM: x86: INIT and reset sequences are different
Date: Tue, 07 Apr 2015 15:23:59 +0200 [thread overview]
Message-ID: <5523DA6F.1050905@redhat.com> (raw)
In-Reply-To: <jpg619f1dfx.fsf@redhat.com>
On 02/04/2015 04:17, Bandan Das wrote:
>> > x86 architecture defines differences between the reset and INIT sequences.
>> > INIT does not initialize the FPU (including MMX, XMM, YMM, etc.), TSC, PMU,
>> > MSRs (in general), MTRRs machine-check, APIC ID, APIC arbitration ID and BSP.
>> >
>> > EFER is supposed NOT to be reset according to the SDM, but leaving the LMA and
>> > LME untouched causes failed VM-entry. Therefore we reset EFER (although it is
>> > unclear whether the rest of EFER bits should be reset).
> Thanks! This was actually in my todo list. #INIT and #RESET are actually separate pins
> on the processor. So, shouldn't we differentiate between the two too by having
> (*vcpu_init) and (*vcpu_reset) separate ?
I think a bool argument is good enough. QEMU has different functions,
and init ends up doing save/reset/restore which is pretty ugly.
Paolo
next prev parent reply other threads:[~2015-04-07 13:24 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-02 0:10 [PATCH v2 0/4] KVM: x86: Reset fixes Nadav Amit
2015-04-02 0:10 ` [PATCH v2 1/4] KVM: x86: INIT and reset sequences are different Nadav Amit
2015-04-02 2:17 ` Bandan Das
2015-04-07 13:23 ` Paolo Bonzini [this message]
2015-04-07 16:17 ` Bandan Das
2015-04-07 16:22 ` Paolo Bonzini
2015-04-07 16:35 ` Bandan Das
2015-04-07 13:23 ` Paolo Bonzini
2015-04-07 13:57 ` Paolo Bonzini
2015-04-02 0:10 ` [PATCH v2 2/4] KVM: x86: BSP in MSR_IA32_APICBASE is writable Nadav Amit
2015-04-02 0:10 ` [PATCH v2 3/4] KVM: x86: DR0-DR3 are not clear on reset Nadav Amit
2015-04-02 0:10 ` [PATCH v2 4/4] KVM: x86: Clear CR2 on VCPU reset Nadav Amit
2015-04-14 10:03 ` Wanpeng Li
2015-04-14 10:31 ` Nadav Amit
2015-04-07 14:01 ` [PATCH v2 0/4] KVM: x86: Reset fixes Paolo Bonzini
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