From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Laight Subject: RE: [PATCH v6] x86: load FPU registers on return to userland Date: Wed, 16 Jan 2019 10:31:08 +0000 Message-ID: References: <20190109114744.10936-1-bigeasy@linutronix.de> <2e396dbcbb1c4cc191b4208626baed07@AcuMS.aculab.com> <39ab2f2b-81bb-636e-933d-f3a5225aa020@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: base64 Cc: "Jason A. Donenfeld" , Sebastian Andrzej Siewior , "linux-kernel@vger.kernel.org" , "x86@kernel.org" , "Paolo Bonzini" , =?utf-8?B?UmFkaW0gS3LEjW3DocWZ?= , "kvm@vger.kernel.org" , "Rik van Riel" , Dave Hansen To: 'Andy Lutomirski' , Dave Hansen Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org RnJvbTogQW5keSBMdXRvbWlyc2tpIFttYWlsdG86bHV0b0BrZXJuZWwub3JnXQ0KPiBPbiBUdWUs IEphbiAxNSwgMjAxOSBhdCAxMjo1NCBQTSBEYXZlIEhhbnNlbiA8ZGF2ZS5oYW5zZW5AaW50ZWwu Y29tPiB3cm90ZToNCj4gPg0KPiA+IE9uIDEvMTUvMTkgMTI6MjYgUE0sIEFuZHkgTHV0b21pcnNr aSB3cm90ZToNCj4gPiA+IEkgZG9uJ3QgdGhpbmsgd2UnZCBldmVyIHdhbnQga2VybmVsX2ZwdV9l bmQoKSB0byByZXN0b3JlIGFueXRoaW5nLA0KPiA+ID4gcmlnaHQ/ICBJJ20gYSBiaXQgY29uZnVz ZWQgYXMgdG8gd2hlbiB0aGlzIG9wdGltaXphdGlvbiB3b3VsZCBhY3R1YWxseQ0KPiA+ID4gYmUg dXNlZnVsLg0KPiA+DQo+ID4gVXNpbmcgQVZYLTUxMiBhcyBhbiBleGFtcGxlLi4uDQo+ID4NCj4g PiBMZXQncyBzYXkgdGhlcmUgd2FzIEFWWC01MTIgc3RhdGUsIGFuZCBhIGtlcm5lbF9mcHVfYmVn aW4oKSB1c2VyIG9ubHkNCj4gPiB1c2VkIEFWWDIuICBXZSBjb3VsZCB0b3RhbGx5IGF2b2lkIGRv aW5nICphbnkqIEFWWC01MTIgc3RhdGUgc2F2ZS9yZXN0b3JlLg0KPiA+DQo+ID4gVGhlIGluaXQg b3B0aW1pemF0aW9uIGRvZXNuJ3QgaGVscCB1cyBpZiB0aGVyZSBfaXNfIEFWWC01MTIgc3RhdGUs IGFuZA0KPiA+IHRoZSBtb2RpZmllZCBvcHRpbWl6YXRpb24gb25seSBoZWxwcyBpZiB3ZSByZWNl bnRseSBkaWQgYSBYUlNUT1IgYXQNCj4gPiBjb250ZXh0IHN3aXRjaCBhbmQgaGF2ZSBub3Qgd3Jp dHRlbiB0byBBVlgtNTEyIHN0YXRlIHNpbmNlIFhSU1RPUi4NCj4gPg0KPiA+IFRoaXMgcHJvYmFi bHkgb25seSBtYXR0ZXJzIGZvciBBVlgtNTEyLXVzaW5nIGFwcHMgdGhhdCBoYXZlIHJ1biBvbiBh DQo+ID4ga2VybmVsIHdpdGggbG90cyBvZiBrZXJuZWxfZnB1X2JlZ2luKClzIHRoYXQgZG9uJ3Qg dXNlIEFWWC01MTIuICBTbywgbm90DQo+ID4gYSBiaWcgZGVhbCByaWdodCBub3cuDQo+IA0KPiBP biB0b3Agb2YgdGhpcyBzZXJpZXMsIHRoaXMgZ2V0cyByYXRoZXIgYXdrd2FyZCwgSSB0aGluayAt LSBub3cgd2UNCj4gbmVlZCB0byBiZSBhYmxlIHRvIGtlZXAgdHJhY2sgb2YgYSBzdGF0ZSBpbiB3 aGljaCBzb21lIG9mIHRoZSB1c2VyDQo+IHJlZ2lzdGVycyBsaXZlIGluIHRoZSBDUFUgYW5kIHNv bWUgbGl2ZSBpbiBtZW1vcnksIGFuZCB3ZSBuZWVkIHRvIGJlDQo+IGFibGUgdG8gZG8gdGhlIHBh cnRpYWwgcmVzdG9yZSBpZiB3ZSBnbyBiYWNrIHRvIHVzZXIgbW9kZSBsaWtlIHRoaXMuDQo+IFdl IGFsc28gbmVlZCB0byBiZSBhYmxlIHRvIGRvIGEgcGFydGlhbCBzYXZlIGlmIHdlIGVuZCB1cCBj b250ZXh0DQo+IHN3aXRjaGluZy4gIFRoaXMgc2VlbXMgcmF0aGVyIGNvbXBsaWNhdGVkLg0KDQpJ ZiBrZXJuZWxfZnB1X2JlZ2luKCkgcmVxdWVzdHMgcmVnaXN0ZXJzIHRoYXQgYXJlICdsaXZlJyBm b3IgdXNlcnNwYWNlLA0Kb3IgaWYgdGhlIHVzZXIgcmVnaXN0ZXJzIGhhdmUgYmVlbiBzYXZlZCB0 aGVuIHlvdSAobW9yZSBvciBsZXNzKSBoYXZlDQp0byBkaXNhYmxlIHByZS1lbXB0aW9uLg0KT1RP SCBpZiB0aGUga2VybmVsIHdhbnRzIHRoZSBBVlgyIHJlZ2lzdGVycyBhbmQgdGhlIHVzZXIgb25l cyBhcmUgYWxsIDANCnRoZW4gdGhlIGtlcm5lbCBjYW4ganVzdCB1c2UgdGhlIHJlZ2lzdGVycyBw cm92aWRlZCBrZXJuZWxfZnB1X2VuZCgpDQp6ZXJvZXMgdGhlbS4gSW4gdGhpcyBjYW4geW91IGNh biBhbGxvdyBwcmUtZW1wdGlvbiBiZWNhdXNlIGl0IHdpbGwgc2F2ZQ0KZXZlcnl0aGluZyBhbmQg aXQgd2lsbCBhbGwgZ2V0IHJlc3RvcmVkIGNvcnJlY3RseSAod2lsbCBuZWVkIHRvIGJlDQpyZXN0 b3JlZCB3aGVuIHRoZSBwcm9jZXNzIGlzIHNjaGVkdWxlZCwgbm90IHJldHVybiB0byB1c2VyKS4N ClRoZSByZWdpc3RlciBzYXZlIGFyZWEgbWlnaHQgbmVlZCB6YXBwaW5nIChpZiB1c2VkKSBiZWNh dXNlIGl0IG1pZ2h0DQpiZSByZWFkYWJsZSBmcm9tIHVzZXIgc3BhY2UgKGJ5IGEgZGVidWdnZXIp Lg0KDQpUaGUgb3RoZXIgY2FzZSBpcyBrZXJuZWwgY29kZSB0aGF0IGd1YXJhbnRlZXMgdG8gc2F2 ZSBhbmQgcmVzdG9yZQ0KYW55IHJlZ2lzdGVycyBpcyB1c2VzIChpdCBtaWdodCBvbmx5IHdhbnQg MiByZWdpc3RlcnMgZm9yIGEgQ1JDKS4NClN1Y2ggY29kZSBjYW4gbmVzdCB3aXRoIG90aGVyIGtl cm5lbCB1c2VycyAoZWcgaW4gYW4gSVNSKS4NCkknbSBub3Qgc3VyZSB3aGV0aGVyIGlzIG5lZWRz IGEgc21hbGwgJ3NhdmUgYXJlYScgZm9yIGZwdSBmbGFncz8NCkl0IG1pZ2h0IGJlIHdvcnRoIGFk ZGluZyBzdWNoIGEgc3RydWN0dXJlIHRvIHRoZSBpbnRlcmZhY2UgLSBldmVuDQppZiBpdCBpcyBj dXJyZW50bHkgYSBkdW1teSBzdHJ1Y3R1cmUuDQoNCglEYXZpZA0KDQotDQpSZWdpc3RlcmVkIEFk ZHJlc3MgTGFrZXNpZGUsIEJyYW1sZXkgUm9hZCwgTW91bnQgRmFybSwgTWlsdG9uIEtleW5lcywg TUsxIDFQVCwgVUsNClJlZ2lzdHJhdGlvbiBObzogMTM5NzM4NiAoV2FsZXMpDQo=