From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH V4 net-next 1/3] vhost: better detection of available buffers Date: Tue, 10 Jan 2017 01:10:41 +0200 Message-ID: <20170110010957-mutt-send-email-mst@kernel.org> 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> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: 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 To: Jason Wang Cc: kvm@vger.kernel.org, netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, wexu@redhat.com, stefanha@redhat.com List-Id: virtualization@lists.linuxfoundation.org T24gTW9uLCBKYW4gMDksIDIwMTcgYXQgMTA6NTk6MTZBTSArMDgwMCwgSmFzb24gV2FuZyB3cm90 ZToKPiAKPiAKPiBPbiAyMDE35bm0MDHmnIgwN+aXpSAwMzo1NSwgTWljaGFlbCBTLiBUc2lya2lu IHdyb3RlOgo+ID4gT24gRnJpLCBKYW4gMDYsIDIwMTcgYXQgMTA6MTM6MTVBTSArMDgwMCwgSmFz b24gV2FuZyB3cm90ZToKPiA+ID4gVGhpcyBwYXRjaCB0cmllcyB0byBkbyBzZXZlcmFsIHR3ZWFr cyBvbiB2aG9zdF92cV9hdmFpbF9lbXB0eSgpIGZvciBhCj4gPiA+IGJldHRlciBwZXJmb3JtYW5j ZToKPiA+ID4gCj4gPiA+IC0gY2hlY2sgY2FjaGVkIGF2YWlsIGluZGV4IGZpcnN0IHdoaWNoIGNv dWxkIGF2b2lkIHVzZXJzcGFjZSBtZW1vcnkgYWNjZXNzLgo+ID4gPiAtIHVzaW5nIHVubGlrZWx5 KCkgZm9yIHRoZSBmYWlsdXJlIG9mIHVzZXJzcGFjZSBhY2Nlc3MKPiA+ID4gLSBjaGVjayB2cS0+ bGFzdF9hdmFpbF9pZHggaW5zdGVhZCBvZiBjYWNoZWQgYXZhaWwgaW5kZXggYXMgdGhlIGxhc3QK PiA+ID4gICAgc3RlcC4KPiA+ID4gCj4gPiA+IFRoaXMgcGF0Y2ggaXMgbmVlZCBmb3IgYmF0Y2hp bmcgc3VwcG9ydHMgd2hpY2ggbmVlZHMgdG8gcGVlayB3aGV0aGVyCj4gPiA+IG9yIG5vdCB0aGVy ZSdzIHN0aWxsIGF2YWlsYWJsZSBidWZmZXJzIGluIHRoZSByaW5nLgo+ID4gPiAKPiA+ID4gUmV2 aWV3ZWQtYnk6IFN0ZWZhbiBIYWpub2N6aSA8c3RlZmFuaGFAcmVkaGF0LmNvbT4KPiA+ID4gU2ln bmVkLW9mZi1ieTogSmFzb24gV2FuZyA8amFzb3dhbmdAcmVkaGF0LmNvbT4KPiA+ID4gLS0tCj4g PiA+ICAgZHJpdmVycy92aG9zdC92aG9zdC5jIHwgOCArKysrKystLQo+ID4gPiAgIDEgZmlsZSBj aGFuZ2VkLCA2IGluc2VydGlvbnMoKyksIDIgZGVsZXRpb25zKC0pCj4gPiA+IAo+ID4gPiBkaWZm IC0tZ2l0IGEvZHJpdmVycy92aG9zdC92aG9zdC5jIGIvZHJpdmVycy92aG9zdC92aG9zdC5jCj4g PiA+IGluZGV4IGQ2NDMyNjAuLjlmMTE4MzggMTAwNjQ0Cj4gPiA+IC0tLSBhL2RyaXZlcnMvdmhv c3Qvdmhvc3QuYwo+ID4gPiArKysgYi9kcml2ZXJzL3Zob3N0L3Zob3N0LmMKPiA+ID4gQEAgLTIy NDEsMTEgKzIyNDEsMTUgQEAgYm9vbCB2aG9zdF92cV9hdmFpbF9lbXB0eShzdHJ1Y3Qgdmhvc3Rf ZGV2ICpkZXYsIHN0cnVjdCB2aG9zdF92aXJ0cXVldWUgKnZxKQo+ID4gPiAgIAlfX3ZpcnRpbzE2 IGF2YWlsX2lkeDsKPiA+ID4gICAJaW50IHI7Cj4gPiA+ICsJaWYgKHZxLT5hdmFpbF9pZHggIT0g dnEtPmxhc3RfYXZhaWxfaWR4KQo+ID4gPiArCQlyZXR1cm4gZmFsc2U7Cj4gPiA+ICsKPiA+ID4g ICAJciA9IHZob3N0X2dldF91c2VyKHZxLCBhdmFpbF9pZHgsICZ2cS0+YXZhaWwtPmlkeCk7Cj4g PiA+IC0JaWYgKHIpCj4gPiA+ICsJaWYgKHVubGlrZWx5KHIpKQo+ID4gPiAgIAkJcmV0dXJuIGZh bHNlOwo+ID4gPiArCXZxLT5hdmFpbF9pZHggPSB2aG9zdDE2X3RvX2NwdSh2cSwgYXZhaWxfaWR4 KTsKPiA+ID4gLQlyZXR1cm4gdmhvc3QxNl90b19jcHUodnEsIGF2YWlsX2lkeCkgPT0gdnEtPmF2 YWlsX2lkeDsKPiA+ID4gKwlyZXR1cm4gdnEtPmF2YWlsX2lkeCA9PSB2cS0+bGFzdF9hdmFpbF9p ZHg7Cj4gPiA+ICAgfQo+ID4gPiAgIEVYUE9SVF9TWU1CT0xfR1BMKHZob3N0X3ZxX2F2YWlsX2Vt cHR5KTsKPiA+IFNvIGFnYWluLCB0aGlzIGRpZCBub3QgYWRkcmVzcyB0aGUgaXNzdWUgSSBwb2lu dGVkIG91dCBpbiB2MToKPiA+IGlmIHdlIGhhdmUgMSBidWZmZXIgaW4gUlggcXVldWUgYW5kCj4g PiB0aGF0IGlzIG5vdCBlbm91Z2ggdG8gc3RvcmUgdGhlIHdob2xlIHBhY2tldCwKPiA+IHZob3N0 X3ZxX2F2YWlsX2VtcHR5IHJldHVybnMgZmFsc2UsIHRoZW4gd2UgcmUtcmVhZAo+ID4gdGhlIGRl c2NyaXB0b3JzIGFnYWluIGFuZCBhZ2Fpbi4KPiA+IAo+ID4gWW91IGhhdmUgc2F2ZWQgYSBzaW5n bGUgaW5kZXggYWNjZXNzIGJ1dCBub3QgdGhlIG1vcmUgZXhwZW5zaXZlCj4gPiBkZXNjcmlwdG9y IGFjY2Vzcy4KPiAKPiBMb29rcyBub3QsIGlmIEkgdW5kZXJzdGFuZCB0aGUgY29kZSBjb3JyZWN0 bHksIGluIHRoaXMgY2FzZSwgZ2V0X3J4X2J1ZnMoKQo+IHdpbGwgcmV0dXJuIHplcm8sIGFuZCB3 ZSB3aWxsIHRyeSB0byBlbmFibGUgcngga2ljayBhbmQgZXhpdCB0aGUgbG9vcC4KPiAKPiBUaGFu a3MKCkkgbWVhbiB0aGlzOgoKICAgICAgICAgICAgICAgIHdoaWxlICh2aG9zdF9jYW5fYnVzeV9w b2xsKHZxLT5kZXYsIGVuZHRpbWUpICYmCiAgICAgICAgICAgICAgICAgICAgICAgdmhvc3RfdnFf YXZhaWxfZW1wdHkodnEtPmRldiwgdnEpKQogICAgICAgICAgICAgICAgICAgICAgICBjcHVfcmVs YXgoKTsKICAgICAgICAgICAgICAgIHByZWVtcHRfZW5hYmxlKCk7CiAgICAgICAgICAgICAgICBy ID0gdmhvc3RfZ2V0X3ZxX2Rlc2ModnEsIHZxLT5pb3YsIEFSUkFZX1NJWkUodnEtPmlvdiksCiAg ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgb3V0X251bSwgaW5fbnVtLCBOVUxM LCBOVUxMKTsKCgp2aG9zdF92cV9hdmFpbF9lbXB0eSByZXR1cm5zIGZhbHNlIHNvIHdlIGJyZWFr IG91dCBvZiB0aGUgbG9vcAphbmQgY2FsbCB2aG9zdF9nZXRfdnFfZGVzYy4KCgotLSAKTVNUCl9f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fClZpcnR1YWxpemF0 aW9uIG1haWxpbmcgbGlzdApWaXJ0dWFsaXphdGlvbkBsaXN0cy5saW51eC1mb3VuZGF0aW9uLm9y ZwpodHRwczovL2xpc3RzLmxpbnV4Zm91bmRhdGlvbi5vcmcvbWFpbG1hbi9saXN0aW5mby92aXJ0 dWFsaXphdGlvbg==