From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: Re: [PATCH V4 net-next 1/3] vhost: better detection of available buffers Date: Tue, 10 Jan 2017 10:22:42 +0800 Message-ID: <5eb3b349-bbae-6438-d8ea-7df82a7babb4@redhat.com> References: <1483668797-24112-1-git-send-email-jasowang@redhat.com> <1483668797-24112-2-git-send-email-jasowang@redhat.com> <20170106214903-mutt-send-email-mst@kernel.org> <20170110010957-mutt-send-email-mst@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; Format="flowed" Content-Transfer-Encoding: base64 Cc: kvm@vger.kernel.org, netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, wexu@redhat.com, stefanha@redhat.com To: "Michael S. Tsirkin" Return-path: In-Reply-To: <20170110010957-mutt-send-email-mst@kernel.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org CgpPbiAyMDE35bm0MDHmnIgxMOaXpSAwNzoxMCwgTWljaGFlbCBTLiBUc2lya2luIHdyb3RlOgo+ IE9uIE1vbiwgSmFuIDA5LCAyMDE3IGF0IDEwOjU5OjE2QU0gKzA4MDAsIEphc29uIFdhbmcgd3Jv dGU6Cj4+Cj4+IE9uIDIwMTflubQwMeaciDA35pelIDAzOjU1LCBNaWNoYWVsIFMuIFRzaXJraW4g d3JvdGU6Cj4+PiBPbiBGcmksIEphbiAwNiwgMjAxNyBhdCAxMDoxMzoxNUFNICswODAwLCBKYXNv biBXYW5nIHdyb3RlOgo+Pj4+IFRoaXMgcGF0Y2ggdHJpZXMgdG8gZG8gc2V2ZXJhbCB0d2Vha3Mg b24gdmhvc3RfdnFfYXZhaWxfZW1wdHkoKSBmb3IgYQo+Pj4+IGJldHRlciBwZXJmb3JtYW5jZToK Pj4+Pgo+Pj4+IC0gY2hlY2sgY2FjaGVkIGF2YWlsIGluZGV4IGZpcnN0IHdoaWNoIGNvdWxkIGF2 b2lkIHVzZXJzcGFjZSBtZW1vcnkgYWNjZXNzLgo+Pj4+IC0gdXNpbmcgdW5saWtlbHkoKSBmb3Ig dGhlIGZhaWx1cmUgb2YgdXNlcnNwYWNlIGFjY2Vzcwo+Pj4+IC0gY2hlY2sgdnEtPmxhc3RfYXZh aWxfaWR4IGluc3RlYWQgb2YgY2FjaGVkIGF2YWlsIGluZGV4IGFzIHRoZSBsYXN0Cj4+Pj4gICAg IHN0ZXAuCj4+Pj4KPj4+PiBUaGlzIHBhdGNoIGlzIG5lZWQgZm9yIGJhdGNoaW5nIHN1cHBvcnRz IHdoaWNoIG5lZWRzIHRvIHBlZWsgd2hldGhlcgo+Pj4+IG9yIG5vdCB0aGVyZSdzIHN0aWxsIGF2 YWlsYWJsZSBidWZmZXJzIGluIHRoZSByaW5nLgo+Pj4+Cj4+Pj4gUmV2aWV3ZWQtYnk6IFN0ZWZh biBIYWpub2N6aSA8c3RlZmFuaGFAcmVkaGF0LmNvbT4KPj4+PiBTaWduZWQtb2ZmLWJ5OiBKYXNv biBXYW5nIDxqYXNvd2FuZ0ByZWRoYXQuY29tPgo+Pj4+IC0tLQo+Pj4+ICAgIGRyaXZlcnMvdmhv c3Qvdmhvc3QuYyB8IDggKysrKysrLS0KPj4+PiAgICAxIGZpbGUgY2hhbmdlZCwgNiBpbnNlcnRp b25zKCspLCAyIGRlbGV0aW9ucygtKQo+Pj4+Cj4+Pj4gZGlmZiAtLWdpdCBhL2RyaXZlcnMvdmhv c3Qvdmhvc3QuYyBiL2RyaXZlcnMvdmhvc3Qvdmhvc3QuYwo+Pj4+IGluZGV4IGQ2NDMyNjAuLjlm MTE4MzggMTAwNjQ0Cj4+Pj4gLS0tIGEvZHJpdmVycy92aG9zdC92aG9zdC5jCj4+Pj4gKysrIGIv ZHJpdmVycy92aG9zdC92aG9zdC5jCj4+Pj4gQEAgLTIyNDEsMTEgKzIyNDEsMTUgQEAgYm9vbCB2 aG9zdF92cV9hdmFpbF9lbXB0eShzdHJ1Y3Qgdmhvc3RfZGV2ICpkZXYsIHN0cnVjdCB2aG9zdF92 aXJ0cXVldWUgKnZxKQo+Pj4+ICAgIAlfX3ZpcnRpbzE2IGF2YWlsX2lkeDsKPj4+PiAgICAJaW50 IHI7Cj4+Pj4gKwlpZiAodnEtPmF2YWlsX2lkeCAhPSB2cS0+bGFzdF9hdmFpbF9pZHgpCj4+Pj4g KwkJcmV0dXJuIGZhbHNlOwo+Pj4+ICsKPj4+PiAgICAJciA9IHZob3N0X2dldF91c2VyKHZxLCBh dmFpbF9pZHgsICZ2cS0+YXZhaWwtPmlkeCk7Cj4+Pj4gLQlpZiAocikKPj4+PiArCWlmICh1bmxp a2VseShyKSkKPj4+PiAgICAJCXJldHVybiBmYWxzZTsKPj4+PiArCXZxLT5hdmFpbF9pZHggPSB2 aG9zdDE2X3RvX2NwdSh2cSwgYXZhaWxfaWR4KTsKPj4+PiAtCXJldHVybiB2aG9zdDE2X3RvX2Nw dSh2cSwgYXZhaWxfaWR4KSA9PSB2cS0+YXZhaWxfaWR4Owo+Pj4+ICsJcmV0dXJuIHZxLT5hdmFp bF9pZHggPT0gdnEtPmxhc3RfYXZhaWxfaWR4Owo+Pj4+ICAgIH0KPj4+PiAgICBFWFBPUlRfU1lN Qk9MX0dQTCh2aG9zdF92cV9hdmFpbF9lbXB0eSk7Cj4+PiBTbyBhZ2FpbiwgdGhpcyBkaWQgbm90 IGFkZHJlc3MgdGhlIGlzc3VlIEkgcG9pbnRlZCBvdXQgaW4gdjE6Cj4+PiBpZiB3ZSBoYXZlIDEg YnVmZmVyIGluIFJYIHF1ZXVlIGFuZAo+Pj4gdGhhdCBpcyBub3QgZW5vdWdoIHRvIHN0b3JlIHRo ZSB3aG9sZSBwYWNrZXQsCj4+PiB2aG9zdF92cV9hdmFpbF9lbXB0eSByZXR1cm5zIGZhbHNlLCB0 aGVuIHdlIHJlLXJlYWQKPj4+IHRoZSBkZXNjcmlwdG9ycyBhZ2FpbiBhbmQgYWdhaW4uCj4+Pgo+ Pj4gWW91IGhhdmUgc2F2ZWQgYSBzaW5nbGUgaW5kZXggYWNjZXNzIGJ1dCBub3QgdGhlIG1vcmUg ZXhwZW5zaXZlCj4+PiBkZXNjcmlwdG9yIGFjY2Vzcy4KPj4gTG9va3Mgbm90LCBpZiBJIHVuZGVy c3RhbmQgdGhlIGNvZGUgY29ycmVjdGx5LCBpbiB0aGlzIGNhc2UsIGdldF9yeF9idWZzKCkKPj4g d2lsbCByZXR1cm4gemVybywgYW5kIHdlIHdpbGwgdHJ5IHRvIGVuYWJsZSByeCBraWNrIGFuZCBl eGl0IHRoZSBsb29wLgo+Pgo+PiBUaGFua3MKPiBJIG1lYW4gdGhpczoKPgo+ICAgICAgICAgICAg ICAgICAgd2hpbGUgKHZob3N0X2Nhbl9idXN5X3BvbGwodnEtPmRldiwgZW5kdGltZSkgJiYKPiAg ICAgICAgICAgICAgICAgICAgICAgICB2aG9zdF92cV9hdmFpbF9lbXB0eSh2cS0+ZGV2LCB2cSkp Cj4gICAgICAgICAgICAgICAgICAgICAgICAgIGNwdV9yZWxheCgpOwo+ICAgICAgICAgICAgICAg ICAgcHJlZW1wdF9lbmFibGUoKTsKPiAgICAgICAgICAgICAgICAgIHIgPSB2aG9zdF9nZXRfdnFf ZGVzYyh2cSwgdnEtPmlvdiwgQVJSQVlfU0laRSh2cS0+aW92KSwKPiAgICAgICAgICAgICAgICAg ICAgICAgICAgICAgICAgICAgICAgICBvdXRfbnVtLCBpbl9udW0sIE5VTEwsIE5VTEwpOwo+Cj4K PiB2aG9zdF92cV9hdmFpbF9lbXB0eSByZXR1cm5zIGZhbHNlIHNvIHdlIGJyZWFrIG91dCBvZiB0 aGUgbG9vcAo+IGFuZCBjYWxsIHZob3N0X2dldF92cV9kZXNjLgo+Cj4KCkJ1dCB0aGlzIGlzIHRo ZSBjb2RlIGZvciBwb2xsaW5nIHR4IHZxIG5vdCByeCBJIHRoaW5rPwoKVGhhbmtzCgpfX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpWaXJ0dWFsaXphdGlvbiBt YWlsaW5nIGxpc3QKVmlydHVhbGl6YXRpb25AbGlzdHMubGludXgtZm91bmRhdGlvbi5vcmcKaHR0 cHM6Ly9saXN0cy5saW51eGZvdW5kYXRpb24ub3JnL21haWxtYW4vbGlzdGluZm8vdmlydHVhbGl6 YXRpb24=