Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <1e58e3df-ae9a-607c-cfc3-4f3d033ed531@intel.com>
Date:   Wed, 7 Jun 2023 08:08:48 -0700
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.11.0
Subject: Re: [PATCH v11 06/20] x86/virt/tdx: Handle SEAMCALL running out of
 entropy error
Content-Language: en-US
To:     Kai Huang <kai.huang@intel.com>, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org
Cc:     linux-mm@kvack.org, kirill.shutemov@linux.intel.com,
        tony.luck@intel.com, peterz@infradead.org, tglx@linutronix.de,
        seanjc@google.com, pbonzini@redhat.com, david@redhat.com,
        dan.j.williams@intel.com, rafael.j.wysocki@intel.com,
        ying.huang@intel.com, reinette.chatre@intel.com,
        len.brown@intel.com, ak@linux.intel.com, isaku.yamahata@intel.com,
        chao.gao@intel.com, sathyanarayanan.kuppuswamy@linux.intel.com,
        bagasdotme@gmail.com, sagis@google.com, imammedo@redhat.com
References: <cover.1685887183.git.kai.huang@intel.com>
 <9b3582c9f3a81ae68b32d9997fcd20baecb63b9b.1685887183.git.kai.huang@intel.com>
From:   Dave Hansen <dave.hansen@intel.com>
In-Reply-To: <9b3582c9f3a81ae68b32d9997fcd20baecb63b9b.1685887183.git.kai.huang@intel.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 6/4/23 07:27, Kai Huang wrote:
> Certain SEAMCALL leaf functions may return error due to running out of
> entropy, in which case the SEAMCALL should be retried as suggested by
> the TDX spec.
> 
> Handle this case in SEAMCALL common function.  Mimic the existing
> rdrand_long() to retry RDRAND_RETRY_LOOPS times.

... because who are we kidding?  When the TDX module says it doesn't
have enough entropy it means rdrand.

Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>