From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <pbonzini@redhat.com>
X-Google-Smtp-Source: AH8x227+TkleZ8ZK5r8g6uWuf0IQ/Qxft1Sc54GIiVMEuz1NQX0GwYuygV48BNgBsNGZ6fqRk0qb
ARC-Seal: i=1; a=rsa-sha256; t=1517354522; cv=none;
        d=google.com; s=arc-20160816;
        b=cOfkZLFbz/1fi0sZ1Us7ZuG2dsfQR/hyjmKI5tXPcV3w8nBFynbabp2PUL0Ba6/xLl
         skcBOPrFrU8TLZINWwWLpf7bo5uE3RimYI0KyaX3ALWvp02BQcEoUR5XMlkuZlOS+iOe
         jyxEmEcaHvjVYdBQYc7J0x0PYfnkR91Xi5AKM40qo0UTwAgFsaFV/duBvex/1DACahCk
         1sxeRvty3gjI6ERd9u0lD5tGUp/yrO8iWcYgei9PvfmiFbtlngQ5ttu/VbPjSug5HS20
         ipHkS5nkU3ZtNkvGQ/Uy0GavmWe/DlnjbJ4pA9rBE2xCUP8Dk9wE/BZBGTq5Egwqygd0
         n3ig==
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816;
        h=content-transfer-encoding:content-language:in-reply-to:mime-version
         :user-agent:date:message-id:from:references:cc:to:subject
         :arc-authentication-results;
        bh=VPDGW2zWjIdkWJItEHfqPltK+BvheVuLpqfUq6GTqkc=;
        b=dCapa1VptbwUn4ampdypAosXm9ZwySmJjTsXxl+RM/SQ7mLPhLFDgp0vTUk10XAHE5
         9AoHkBCq9daoyuA6cNCA4yCJQMR2bNAW9vwgWq0puopn2TQgU+ZEETPrs3XvTZqN77Pn
         gu7L5jb0YmMZRrhs4p/A4fkyCmw15N2QtX5DRhzolzCCrgA35pohcvUxbGRS3EJic1wm
         EamGeA1mWpckXR3JGCCKYehSKbpfGkUq17V1sgmrGZVJFYhfdBsb5bdtqgpEI3AfgJkp
         u8F1qIALfPgM3jhTLeZ4ZmGW1sKav2fs4iKTijaSWolLmcOhUiERx3IJOmuhk3kBofSn
         qJww==
ARC-Authentication-Results: i=1; mx.google.com;
       spf=pass (google.com: domain of pbonzini@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=pbonzini@redhat.com;
       dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com
Authentication-Results: mx.google.com;
       spf=pass (google.com: domain of pbonzini@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=pbonzini@redhat.com;
       dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com
Subject: Re: [PATCH v3 3/4] KVM: VMX: Emulate MSR_IA32_ARCH_CAPABILITIES
To: KarimAllah Ahmed <karahmed@amazon.com>, "Raj, Ashok"
 <ashok.raj@intel.com>, KarimAllah Ahmed <karahmed@amazon.de>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org,
 Asit Mallick <asit.k.mallick@intel.com>, Dave Hansen
 <dave.hansen@intel.com>, Arjan Van De Ven <arjan.van.de.ven@intel.com>,
 Tim Chen <tim.c.chen@linux.intel.com>,
 Linus Torvalds <torvalds@linux-foundation.org>,
 Andrea Arcangeli <aarcange@redhat.com>, Andi Kleen <ak@linux.intel.com>,
 Thomas Gleixner <tglx@linutronix.de>, Dan Williams
 <dan.j.williams@intel.com>, Jun Nakajima <jun.nakajima@intel.com>,
 Andy Lutomirski <luto@kernel.org>, Greg KH <gregkh@linuxfoundation.org>,
 David Woodhouse <dwmw@amazon.co.uk>
References: <1517271028-15916-1-git-send-email-karahmed@amazon.de>
 <1517271028-15916-4-git-send-email-karahmed@amazon.de>
 <20180130002218.GA112596@otc-nc-03>
 <87b28856-c477-283f-695c-daed42b31287@amazon.com>
From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <2aaedc76-b407-15f9-7712-535e08153a26@redhat.com>
Date: Tue, 30 Jan 2018 18:21:47 -0500
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.5.2
MIME-Version: 1.0
In-Reply-To: <87b28856-c477-283f-695c-daed42b31287@amazon.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 8bit
X-getmail-retrieved-from-mailbox: INBOX
X-GMAIL-THRID: =?utf-8?q?1590974072319856252?=
X-GMAIL-MSGID: =?utf-8?q?1591061535871687088?=
X-Mailing-List: linux-kernel@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>

On 29/01/2018 19:25, KarimAllah Ahmed wrote:
>>> +    case MSR_IA32_ARCH_CAPABILITIES:
>>> +        if (!msr_info->host_initiated)
>>> +            return 1;
>>> +        vmx->arch_capabilities = data;
>>> +        break;
>>
>> arch capabilities is read only. You don't need the set_msr handling
>> for this.
> 
> This is only for host driven writes. This would allow QEMU/whatever to
> override the default value (i.e. the value from the hardware).

Agreed.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>