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From: Tao Xu <tao3.xu@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: rkrcmar@redhat.com, corbet@lwn.net, tglx@linutronix.de,
	mingo@redhat.com, bp@alien8.de, hpa@zytor.com,
	sean.j.christopherson@intel.com, x86@kernel.org,
	kvm@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, jingqi.liu@intel.com
Subject: Re: [PATCH v2 3/3] KVM: vmx: handle vm-exit for UMWAIT and TPAUSE
Date: Wed, 29 May 2019 10:25:14 +0800	[thread overview]
Message-ID: <a2b463ee-c032-555e-b012-184e4f4753f1@intel.com> (raw)
In-Reply-To: <b0958339-b23c-dd9d-8673-aae098769738@redhat.com>

On 29/05/2019 09:28, Paolo Bonzini wrote:
> On 24/05/19 09:56, Tao Xu wrote:
>> As the latest Intel 64 and IA-32 Architectures Software Developer's
>> Manual, UMWAIT and TPAUSE instructions cause a VM exit if the
>> “RDTSC exiting” and “enable user wait and pause” VM-execution controls
>> are both 1.
>>
>> This patch is to handle the vm-exit for UMWAIT and TPAUSE as invalid_op.
> 
> KVM never enables RDTSC exiting, so this is not necessary.
> 
> Paolo
> 
OK, but should we just drop this patch?
Or add the VMX_EXIT_REASONS bits of UMWAIT and TPAUSE and handle like 
XSAVES/XRSTORS:
"kvm_skip_emulated_instruction(vcpu);"
"WARN(1, "this should never happen\n");"

Looking forward to your reply.

Tao

  reply	other threads:[~2019-05-29  2:27 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-24  7:56 [PATCH v2 0/3] KVM: x86: Enable user wait instructions Tao Xu
2019-05-24  7:56 ` [PATCH v2 1/3] KVM: x86: add support for " Tao Xu
2019-05-27 10:30   ` Peter Zijlstra
2019-05-28  5:11     ` Tao Xu
2019-05-28  6:11       ` Wanpeng Li
2019-05-28  7:19         ` Tao Xu
2019-05-29  1:26           ` Paolo Bonzini
2019-05-29  1:25     ` Paolo Bonzini
2019-05-29  1:24   ` Paolo Bonzini
2019-05-29  2:05     ` Tao Xu
2019-05-29  2:38       ` Paolo Bonzini
2019-05-29  3:12         ` Tao Xu
2019-05-24  7:56 ` [PATCH v2 2/3] KVM: vmx: Emulate MSR IA32_UMWAIT_CONTROL Tao Xu
2019-05-29  1:29   ` Paolo Bonzini
2019-05-29  1:38     ` Tao Xu
2019-05-24  7:56 ` [PATCH v2 3/3] KVM: vmx: handle vm-exit for UMWAIT and TPAUSE Tao Xu
2019-05-29  1:28   ` Paolo Bonzini
2019-05-29  2:25     ` Tao Xu [this message]
2019-05-29  2:39       ` Paolo Bonzini

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