From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47249) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c5Ttt-0000Ox-ON for qemu-devel@nongnu.org; Sat, 12 Nov 2016 03:43:03 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c5Tto-00031I-Ps for qemu-devel@nongnu.org; Sat, 12 Nov 2016 03:43:01 -0500 Received: from mail-pg0-x244.google.com ([2607:f8b0:400e:c05::244]:33529) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1c5Tto-000318-Er for qemu-devel@nongnu.org; Sat, 12 Nov 2016 03:42:56 -0500 Received: by mail-pg0-x244.google.com with SMTP id 3so3788670pgd.0 for ; Sat, 12 Nov 2016 00:42:56 -0800 (PST) Date: Sat, 12 Nov 2016 16:43:21 +0800 From: "zhunxun@gmail.com" References: <201611051850530152761@gmail.com>, , , , <201611091858142738325@gmail.com>, <20161110103253.GC17332@stefanha-x1.localdomain>, <2016111020163477037720@gmail.com>, <20161111120347.GB8930@stefanha-x1.localdomain> Mime-Version: 1.0 Message-ID: <201611121643189598926@gmail.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: base64 Subject: Re: [Qemu-devel] virtIO question List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: qemu VGhhbmtzLHRoZSBleHByZXNzaW9uIGlzIG5vdCB0aGUga2V5IHByb2JsZW0sSSBqdXN0IHdyaXRl IGl0IHdyb25nLHRoZSBrZXkgcHJvYmxlbSBpcyB0aGF0IHdoYXQgSSBnZXQgZnJvbSB0aGUgY29k ZSBpcyBldmVyeXRpbWUgZGlydmVyIGFkZCBhIHNnICxpdCB3aWxsIGNhbGwgdmlydHF1ZXVlX2tp Y2ssc3VjaCBhcyBuZXR3b3JrIGRyaXZlcixpbiBzdGFydF94bWl0IGZ1bmN0aW9uICxpdCBjYWxs ZWQgeG1pdF9za2IgZ2VuZXJhdGUgYSBzZyBsaXN0IGFuZCBhZGQgaXQgdG8gdGhlIHF1ZXVlLHRo ZW4gY2FsbGVkIHZpcnRxdWV1ZV9raWNrICx3aHkgaXQgaGFuZGxlIGxpa2UgdGhpcz8/Y2FuIHlv dSBleHBsYWluIGl0IHRvIG1lPz90aGFuayB5b3UgdmVyeSBtdWNoISEhDQoNCg0KDQp6aHVueHVu QGdtYWlsLmNvbQ0KIA0KRnJvbTogU3RlZmFuIEhham5vY3ppDQpEYXRlOiAyMDE2LTExLTExIDIw OjAzDQpUbzogemh1bnh1bkBnbWFpbC5jb20NCkNDOiBxZW11DQpTdWJqZWN0OiBSZTogUmU6IFtR ZW11LWRldmVsXSB2aXJ0SU8gcXVlc3Rpb24NCk9uIFRodSwgTm92IDEwLCAyMDE2IGF0IDA4OjE2 OjM4UE0gKzA4MDAsIHpodW54dW5AZ21haWwuY29tIHdyb3RlOg0KPiBGcm9tIHRoaXMgcG9pbnQg b2YgdmlldyAsSSB0aGluayBpdCBtYWtlIHNlbnNlIHdlbGwsIHRoYW5rIHlvdSB2ZXJ5IG11Y2gh DQo+ICBidXQgSSBoYXZlIGFub3RoZXIgcXVlc3Rpb24gYWJvdXQgbm90aWZ5IG1lY2hhbmlzbSBi ZXR3ZWVuIHZpcnRJTyBkcml2ZXIgYW5kIHFlbXUuDQo+IGFjY29yZGluZyB0aGUgc291cmNlIGNv ZGUgb2YgTGludXggYW5kIHFlbXUsDQo+IHdoZW4gZHJpdmVyIGFkZCBhIHNnIGJ1ZmZlciB0byBz ZW5kIHF1ZXVlIG5hbWVkIHNxLA0KPiBzcS0+dnEtPnZyaW5nLmF2YWlsLT5pZHgrKw0KPiB2cS0+ bnVtX2FkZGVkKysNCj4gYW5kIHRoZW4gdXNlIHZpcnRxdWV1ZV9raWNrX3ByZXBhcmUgdG8gbWFr ZSBzdXJlIGlmIG5lZWQgbm90aWZ5IHFlbXUuDQo+IGl0IChuZXdfaWR4LWV2ZW50X2lkeCk8KG5l d19pZHgtb2xkX2lkeCkNCiANClRoaXMgZXhwcmVzc2lvbiBpcyB3cm9uZy4gIFRoZSBzcGVjaWZp Y2F0aW9uIGFuZCBMaW51eCBjb2RlIGJvdGggc2F5Og0KIA0KICAodTE2KShuZXdfaWR4IC0gZXZl bnRfaWR4IC0gMSkgPCAodTE2KShuZXdfaWR4IC0gb2xkX2lkeCkNCiANCkJvdGggdGhlICh1MTYp IGFuZCB0aGUgLTEgbWF0dGVyLiAgTWF5YmUgdGhhdCdzIHdoeSB5b3UgYXJlIGNvbmZ1c2VkIGJ5 DQp0aGlzPw0KIA0KPiBpZiBpdCBpcyB0cnVlLHRoZW4gbm90aWZ5IG90aGVyIHNpZGUuDQo+IEhv d2V2ZXIsZXZlcnkgdGltZSBkcml2ZXIgYWRkIGEgc2csdGhlbiB2aXJ0cXVldWVfa2lja19wcmVw YXJlIGlzIGNhbGxlZCxhbmQgdnEtPm51bV9hZGRlZCAgaXMgcmVzZXRlZCB0byAwLHNvIGluIGZh Y3QgLEkgdGhpbmsgdnEtPm51bV9hZGRlZCBpcyBhbHdheXMgMCBvciAx44CCDQogDQpBIGRyaXZl ciBtYXkgYWRkIG11bHRpcGxlIGJ1ZmZlcnMgdG8gdGhlIHZpcnRxdWV1ZSBieSBjYWxsaW5nDQp2 aXJ0cXVldWVfYWRkX3NncygpIG9yIHNpbWlsYXIgZnVuY3Rpb25zIG11bHRpcGxlIHRpbWVzIGJl Zm9yZSBraWNraW5nLg0KVGhlcmVmb3JlIHZxLT5udW1fYWRkZWQgPiAxIGlzIHBvc3NpYmxlLg0K IA0KPiBhcyB0byBxZW11IHNpZGUsZXZlcnkgdGltZSB3aGVuIHBvcCBhIGVsZW0gZnJvbSB2aXJ0 cXVldWUsaXQgc2V0IFZSaW5nVXNlZC5yaW5nW3ZyaW5nLm51bV0gdG8gdGhlIGxhc3Rlc3QgVlJp bmdBdmFpbC5pZHgsIHRoaXMgYWNjb3JkaW5nIHRoZSBhcml0aG1ldGljICgobmV3X2lkeC1ldmVu dF9pZHgpPChuZXdfaWR4LW9sZF9pZHgpKSxpdCBzZWVtcyB0aGF0IHRoaXMgbWVjaGFuaXNtIGRv ZXMgbm90IG1ha2Ugc2Vuc2UNCiANCllvdSBhcmUgYmFzaWNhbGx5IGFza2luZyAiaG93IGRvZXMg ZXZlbnRfaWR4IHdvcms/Ii4gIFRoZSBzcGVjaWZpY2F0aW9uDQpzYXlzOg0KIA0KICAiVGhlIGRy aXZlciBjYW4gYXNrIHRoZSBkZXZpY2UgdG8gZGVsYXkgaW50ZXJydXB0cyB1bnRpbCBhbiBlbnRy eSB3aXRoDQogIGFuIGluZGV4IHNwZWNpZmllZCBieSB0aGUg4oCcdXNlZF9ldmVudOKAnSBmaWVs ZCBpcyB3cml0dGVuIGluIHRoZSB1c2VkIHJpbmcNCiAgKGVxdWl2YWxlbnRseSwgdW50aWwgdGhl IGlkeCBmaWVsZCBpbiB0aGUgdXNlZCByaW5nIHdpbGwgcmVhY2ggdGhlDQogIHZhbHVlIHVzZWRf ZXZlbnQgKyAxKS4iDQogDQphbmQ6DQogDQogICJUaGUgZGV2aWNlIGNhbiBhc2sgdGhlIGRyaXZl ciB0byBkZWxheSBub3Rp76yBY2F0aW9ucyB1bnRpbCBhbiBlbnRyeQ0KICB3aXRoIGFuIGluZGV4 IHNwZWNpZmllZCBieSB0aGUg4oCcYXZhaWxfZXZlbnTigJ0gZmllbGQgaXMgd3JpdHRlbiBpbiB0 aGUNCiAgYXZhaWxhYmxlIHJpbmcgKGVxdWl2YWxlbnRseSwgdW50aWwgdGhlIGlkeCBmaWVsZCBp biB0aGUgdXNlZCByaW5nIHdpbGwNCiAgcmVhY2ggdGhlIHZhbHVlIGF2YWlsX2V2ZW50ICsgMSku Ig0KIA0KV2hlbmV2ZXIgdGhlIGRldmljZSBvciBkcml2ZXIgd2FudHMgdG8gbm90aWZ5LCBpdCBm aXJzdCBjaGVja3MgaWYgdGhlDQppbmRleCB1cGRhdGUgY3Jvc3NlZCB0aGUgZXZlbnQgaW5kZXgg c2V0IGJ5IHRoZSBvdGhlciBzaWRlLg0K