From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
To: "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>
Cc: <joro@8bytes.org>, <alex.williamson@redhat.com>,
<gleb@kernel.org>, <kvm@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <wei@redhat.com>,
<sherry.hurwitz@amd.com>, "Wu, Feng" <feng.wu@intel.com>
Subject: Re: [PART1 RFC 5/9] svm: Add VMEXIT handlers for AVIC
Date: Fri, 19 Feb 2016 18:39:52 +0700 [thread overview]
Message-ID: <56C6FF08.6050408@amd.com> (raw)
In-Reply-To: <56C5FCCF.5010802@redhat.com>
Hi,
On 2/19/16 00:18, Paolo Bonzini wrote:
>
>
> On 18/02/2016 17:27, Radim Krčmář wrote:
>> 2016-02-18 16:53+0100, Paolo Bonzini:
>>> Patch 9 is okay, but it is also necessary to clear IsRunning in
>>> kvm_arch_vcpu_blocking and set it in kvm_arch_vcpu_unblocking. In
>>> addition, vcpu_put/vcpu_load should not modify IsRunning between
>>> kvm_arch_vcpu_blocking and kvm_arch_vcpu_unblocking. Do you agree?
>>
>> Yes.
>>
>> I think we don't need to clear IsRunning on preemption, which would
>> simplify the protection. (I haven't thought much about userspace exit,
>> so maybe we could skip that one as well, but we don't need to now.)
>>
>> The reason for that is that KVM knows that the VCPU was scheduled out,
>> so it couldn't do much in the AVIC VMEXIT.
>> (KVM could force scheduler to pritioritize the VCPU, but our kick
>> doesn't do that now and it seems like a bad idea.)
>>
>> Does it seem reasonable?
>
> Yes, and in fact it wouldn't need to clear and set IsRunning on
> vcpu_put/vcpu_load; only on vcpu_blocking/vcpu_unblocking.
>
> The IsRunning flag is more of a IsNotHalted flag, in the end.
>
> Paolo
>
Good point. I have made the change by introducing new function pointer,
kvm_x86_ops.vcpu_blocking() and kvm_x86_ops.vcpu_unblocking(). Then
provides the hook to set/unset the IsRunningBit here. Also, I no longer
set the bit in the vcpu_load/vcpu_put.
If this is okay. I'll send out V2 soon.
Thanks,
Suravee
next prev parent reply other threads:[~2016-02-19 11:40 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-12 13:59 [PART1 RFC 0/9] KVM: x86: Introduce SVM AVIC support Suravee Suthikulpanit
2016-02-12 13:59 ` [PART1 RFC 1/9] KVM: x86: Misc LAPIC changes to exposes helper functions Suravee Suthikulpanit
2016-02-12 13:59 ` [PART1 RFC 2/9] svm: Introduce new AVIC VMCB registers Suravee Suthikulpanit
2016-02-12 13:59 ` [PART1 RFC 3/9] svm: clean up V_TPR, V_IRQ, V_INTR_PRIO, and V_INTR_MASKING Suravee Suthikulpanit
2016-02-12 13:59 ` [PART1 RFC 4/9] KVM: x86: Detect and Initialize AVIC support Suravee Suthikulpanit
2016-02-12 14:13 ` Borislav Petkov
2016-02-12 15:46 ` Suravee Suthikulpanit
2016-02-12 13:59 ` [PART1 RFC 5/9] svm: Add VMEXIT handlers for AVIC Suravee Suthikulpanit
2016-02-12 15:38 ` Paolo Bonzini
2016-02-15 19:22 ` Radim Krčmář
2016-02-16 6:29 ` Suravee Suthikulpanit
2016-02-16 12:15 ` Paolo Bonzini
2016-02-16 14:13 ` Radim Krčmář
2016-02-16 16:56 ` Paolo Bonzini
2016-02-16 18:06 ` Radim Krčmář
2016-02-18 2:25 ` Suravee Suthikulpanit
2016-02-18 14:18 ` Radim Krčmář
2016-02-18 14:51 ` Paolo Bonzini
2016-02-18 15:43 ` Radim Krčmář
2016-02-18 15:53 ` Paolo Bonzini
2016-02-18 16:27 ` Radim Krčmář
2016-02-18 17:18 ` Paolo Bonzini
2016-02-19 11:39 ` Suravee Suthikulpanit [this message]
2016-02-19 11:44 ` Paolo Bonzini
2016-02-19 11:59 ` Suravee Suthikulpanit
2016-03-03 10:42 ` Suravee Suthikulpanit
2016-03-03 10:50 ` Paolo Bonzini
2016-02-19 11:32 ` Suravee Suthikulpanit
2016-02-12 13:59 ` [PART1 RFC 6/9] svm: Add interrupt injection via AVIC Suravee Suthikulpanit
2016-02-12 14:16 ` Borislav Petkov
2016-02-12 15:54 ` Suravee Suthikulpanit
2016-02-12 17:14 ` Borislav Petkov
2016-02-12 18:21 ` Paolo Bonzini
2016-02-12 18:30 ` Borislav Petkov
2016-02-12 18:56 ` Paolo Bonzini
2016-02-12 19:33 ` Borislav Petkov
2016-02-16 7:50 ` Ingo Molnar
2016-02-16 8:39 ` [PATCH] x86/msr: Document msr-index.h rule for addition Borislav Petkov
2016-02-12 15:55 ` [PART1 RFC 6/9] svm: Add interrupt injection via AVIC Paolo Bonzini
2016-02-12 16:21 ` Suravee Suthikulpanit
2016-02-12 18:19 ` Paolo Bonzini
2016-02-12 19:36 ` Suravee Suthikulpanit
2016-02-19 11:57 ` Suravee Suthikulpanit
2016-02-12 13:59 ` [PART1 RFC 7/9] svm: Do not expose x2APIC when enable AVIC Suravee Suthikulpanit
2016-02-12 13:59 ` [PART1 RFC 8/9] svm: Do not intercept CR8 " Suravee Suthikulpanit
2016-02-12 15:48 ` Paolo Bonzini
2016-02-12 13:59 ` [PART1 RFC 9/9] svm: Manage vcpu load/unload " Suravee Suthikulpanit
2016-02-12 15:46 ` Paolo Bonzini
2016-02-12 18:13 ` [PART1 RFC 0/9] KVM: x86: Introduce SVM AVIC support Paolo Bonzini
2016-02-12 19:55 ` Suravee Suthikulpanit
2016-02-12 20:05 ` Paolo Bonzini
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