Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH 03/13] x86/HV: Add new hvcall guest address host
 visibility support
To:     Dave Hansen <dave.hansen@intel.com>, kys@microsoft.com,
        haiyangz@microsoft.com, sthemmin@microsoft.com, wei.liu@kernel.org,
        decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com,
        bp@alien8.de, x86@kernel.org, hpa@zytor.com,
        dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org,
        konrad.wilk@oracle.com, boris.ostrovsky@oracle.com,
        jgross@suse.com, sstabellini@kernel.org, joro@8bytes.org,
        will@kernel.org, davem@davemloft.net, kuba@kernel.org,
        jejb@linux.ibm.com, martin.petersen@oracle.com, arnd@arndb.de,
        hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com,
        thomas.lendacky@amd.com, brijesh.singh@amd.com, ardb@kernel.org,
        Tianyu.Lan@microsoft.com, rientjes@google.com,
        martin.b.radev@gmail.com, akpm@linux-foundation.org,
        rppt@kernel.org, kirill.shutemov@linux.intel.com,
        aneesh.kumar@linux.ibm.com, krish.sadhukhan@oracle.com,
        saravanand@fb.com, xen-devel@lists.xenproject.org,
        pgonda@google.com, david@redhat.com, keescook@chromium.org,
        hannes@cmpxchg.org, sfr@canb.auug.org.au,
        michael.h.kelley@microsoft.com
Cc:     iommu@lists.linux-foundation.org, linux-arch@vger.kernel.org,
        linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-scsi@vger.kernel.org, netdev@vger.kernel.org,
        vkuznets@redhat.com, anparri@microsoft.com
References: <20210728145232.285861-1-ltykernel@gmail.com>
 <20210728145232.285861-4-ltykernel@gmail.com>
 <a2444c36-0103-8e1c-7005-d97f77f90e85@intel.com>
 <0d956a05-7d24-57a0-f4a9-dccc849b52fc@gmail.com>
 <ec1d4cfd-bbbc-e27a-7589-e85d9f0438f4@intel.com>
 <8df2845d-ee90-56d0-1228-adebb103ec37@gmail.com>
 <7a2ddcca-e249-ba63-8709-e355fcef2d41@intel.com>
From:   Tianyu Lan <ltykernel@gmail.com>
Message-ID: <fa6cf8b6-7da0-dadf-b137-d90ce3513d5e@gmail.com>
Date:   Fri, 30 Jul 2021 10:52:43 +0800
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
 Thunderbird/78.12.0
MIME-Version: 1.0
In-Reply-To: <7a2ddcca-e249-ba63-8709-e355fcef2d41@intel.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Precedence: bulk

On 7/30/2021 12:05 AM, Dave Hansen wrote:
> On 7/29/21 8:02 AM, Tianyu Lan wrote:
>>>
>>
>> There is x86_hyper_type to identify hypervisor type and we may check
>> this variable after checking X86_FEATURE_HYPERVISOR.
>>
>> static inline bool hv_is_isolation_supported(void)
>> {
>>      if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
>>          return 0;
>>
>>          if (x86_hyper_type != X86_HYPER_MS_HYPERV)
>>                  return 0;
>>
>>      // out of line function call:
>>      return __hv_is_isolation_supported();
>> }
> 
> Looks fine.  You just might want to use this existing helper:
> 
> static inline bool hypervisor_is_type(enum x86_hypervisor_type type)
> {
>          return x86_hyper_type == type;
> }
> 

Yes,thanks for suggestion and will update in the next version.