From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted Date: Tue, 29 Jan 2019 21:36:08 -0500 Message-ID: <20190129213137-mutt-send-email-mst__34757.132483513$1548826241$gmane$org@kernel.org> References: <87zhrj8kcp.fsf@morokweng.localdomain> <87womn8inf.fsf@morokweng.localdomain> <20190129134750-mutt-send-email-mst@kernel.org> <6c68f7f7-1b28-6eba-9b8b-2c32efac9701@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Content-Disposition: inline In-Reply-To: <6c68f7f7-1b28-6eba-9b8b-2c32efac9701@redhat.com> 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: Jean-Philippe Brucker , Benjamin Herrenschmidt , Alexey Kardashevskiy , Ram Pai , linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, Paul Mackerras , iommu@lists.linux-foundation.org, linuxppc-dev@lists.ozlabs.org, Christoph Hellwig , Thiago Jung Bauermann , David Gibson List-Id: virtualization@lists.linuxfoundation.org T24gV2VkLCBKYW4gMzAsIDIwMTkgYXQgMTA6MjQ6MDFBTSArMDgwMCwgSmFzb24gV2FuZyB3cm90 ZToKPiAKPiBPbiAyMDE5LzEvMzAg5LiK5Y2IMzowMiwgTWljaGFlbCBTLiBUc2lya2luIHdyb3Rl Ogo+ID4gT24gVHVlLCBKYW4gMjksIDIwMTkgYXQgMDM6NDI6NDRQTSAtMDIwMCwgVGhpYWdvIEp1 bmcgQmF1ZXJtYW5uIHdyb3RlOgo+ID4gPiBGaXhpbmcgYWRkcmVzcyBvZiBwb3dlcnBjIG1haWxp bmcgbGlzdC4KPiA+ID4gCj4gPiA+IFRoaWFnbyBKdW5nIEJhdWVybWFubiA8YmF1ZXJtYW5AbGlu dXguaWJtLmNvbT4gd3JpdGVzOgo+ID4gPiAKPiA+ID4gPiBIZWxsbywKPiA+ID4gPiAKPiA+ID4g PiBXaXRoIENocmlzdG9waCdzIHJld29yayBvZiB0aGUgRE1BIEFQSSB0aGF0IHJlY2VudGx5IGxh bmRlZCwgdGhlIHBhdGNoCj4gPiA+ID4gYmVsb3cgaXMgdGhlIG9ubHkgY2hhbmdlIG5lZWRlZCBp biB2aXJ0aW8gdG8gbWFrZSBpdCB3b3JrIGluIGEgUE9XRVIKPiA+ID4gPiBzZWN1cmUgZ3Vlc3Qg dW5kZXIgdGhlIHVsdHJhdmlzb3IuCj4gPiA+ID4gCj4gPiA+ID4gVGhlIG90aGVyIGNoYW5nZSB3 ZSBuZWVkIChtYWtpbmcgc3VyZSB0aGUgZGV2aWNlJ3MgZG1hX21hcF9vcHMgaXMgTlVMTAo+ID4g PiA+IHNvIHRoYXQgdGhlIGRtYS1kaXJlY3Qvc3dpb3RsYiBjb2RlIGlzIHVzZWQpIGNhbiBiZSBt YWRlIGluCj4gPiA+ID4gcG93ZXJwYy1zcGVjaWZpYyBjb2RlLgo+ID4gPiA+IAo+ID4gPiA+IE9m IGNvdXJzZSwgSSBhbHNvIGhhdmUgcGF0Y2hlcyAoc29vbiB0byBiZSBwb3N0ZWQgYXMgUkZDKSB3 aGljaCBob29rIHVwCj4gPiA+ID4gPGxpbnV4L21lbV9lbmNyeXB0Lmg+IHRvIHRoZSBwb3dlcnBj IHNlY3VyZSBndWVzdCBzdXBwb3J0IGNvZGUuCj4gPiA+ID4gCj4gPiA+ID4gV2hhdCBkbyB5b3Ug dGhpbms/Cj4gPiA+ID4gCj4gPiA+ID4gIEZyb20gZDA2MjlhMzZhNzVjNjc4YjRhNzJiODUzZjhm N2Y4YzE3ZWVkZDZiMyBNb24gU2VwIDE3IDAwOjAwOjAwIDIwMDEKPiA+ID4gPiBGcm9tOiBUaGlh Z28gSnVuZyBCYXVlcm1hbm4gPGJhdWVybWFuQGxpbnV4LmlibS5jb20+Cj4gPiA+ID4gRGF0ZTog VGh1LCAyNCBKYW4gMjAxOSAyMjowODowMiAtMDIwMAo+ID4gPiA+IFN1YmplY3Q6IFtSRkMgUEFU Q0hdIHZpcnRpb19yaW5nOiBVc2UgRE1BIEFQSSBpZiBndWVzdCBtZW1vcnkgaXMgZW5jcnlwdGVk Cj4gPiA+ID4gCj4gPiA+ID4gVGhlIGhvc3QgY2FuJ3QgYWNjZXNzIHRoZSBndWVzdCBtZW1vcnkg d2hlbiBpdCdzIGVuY3J5cHRlZCwgc28gdXNpbmcKPiA+ID4gPiByZWd1bGFyIG1lbW9yeSBwYWdl cyBmb3IgdGhlIHJpbmcgaXNuJ3QgYW4gb3B0aW9uLiBHbyB0aHJvdWdoIHRoZSBETUEgQVBJLgo+ ID4gPiA+IAo+ID4gPiA+IFNpZ25lZC1vZmYtYnk6IFRoaWFnbyBKdW5nIEJhdWVybWFubiA8YmF1 ZXJtYW5AbGludXguaWJtLmNvbT4KPiA+IFdlbGwgSSB0aGluayB0aGlzIHdpbGwgY29tZSBiYWNr IHRvIGJpdGUgdXMgKHdpdG5lc3MgeGVuIHdoaWNoIGlzIG5vdwo+ID4gcmV3b3JraW5nIHByZWNp c2VseSB0aGlzIHBhdGggLSBidXQgYXQgbGVhc3QgdGhleSBhcmVuJ3QgdG8gYmxhbWUsIHhlbgo+ ID4gY2FtZSBiZWZvcmUgQUNDRVNTX1BMQVRGT1JNKS4KPiA+IAo+ID4gSSBhbHNvIHN0aWxsIHRo aW5rIHRoZSByaWdodCB0aGluZyB3b3VsZCBoYXZlIGJlZW4gdG8gc2V0Cj4gPiBBQ0NFU1NfUExB VEZPUk0gZm9yIGFsbCBzeXN0ZW1zIHdoZXJlIGRldmljZSBjYW4ndCBhY2Nlc3MgYWxsIG1lbW9y eS4KPiA+IAo+ID4gQnV0IEkgYWxzbyB0aGluayBJIGRvbid0IGhhdmUgdGhlIGVuZXJneSB0byBh cmd1ZSBhYm91dCBwb3dlciBzZWN1cmUKPiA+IGd1ZXN0IGFueW1vcmUuICBTbyBiZSBpdCBmb3Ig cG93ZXIgc2VjdXJlIGd1ZXN0IHNpbmNlIHRoZSBpbnZvbHZlZAo+ID4gZW5naW5lZXJzIGRpc2Fn cmVlIHdpdGggbWUuICBIZXkgSSd2ZSBiZWVuIHdyb25nIGluIHRoZSBwYXN0IDspLgo+ID4gCj4g PiBCdXQgdGhlIG5hbWUgInNldl9hY3RpdmUiIG1ha2VzIG1lIHNjYXJlZCBiZWNhdXNlIGF0IGxl YXN0IEFNRCBndXlzIHdobwo+ID4gd2VyZSBkb2luZyB0aGUgc2Vuc2libGUgdGhpbmcgYW5kIHNl dHRpbmcgQUNDRVNTX1BMQVRGT1JNICh1bmxlc3MgSSdtCj4gPiB3cm9uZz8gSSByZWVtZW1iZXIg ZGlzdGluY3RseSB0aGF0J3Mgc28pIHdpbGwgbGlrZWx5IGJlIGFmZmVjdGVkIHRvby4KPiA+IFdl IGRvbid0IHdhbnQgdGhhdC4KPiA+IAo+ID4gU28gbGV0J3MgZmluZCBhIHdheSB0byBtYWtlIHN1 cmUgaXQncyBqdXN0IHBvd2VyIHNlY3VyZSBndWVzdCBmb3Igbm93Cj4gPiBwbHMuCj4gPiAKPiA+ IEkgYWxzbyB0aGluayB3ZSBzaG91bGQgYWRkIGEgZG1hX2FwaSBuZWFyIGZlYXR1cmVzIHVuZGVy IHZpcnRpb19kZXZpY2UKPiA+IHN1Y2ggdGhhdCB0aGVzZSBoYWNrcyBjYW4gbW92ZSBvZmYgZGF0 YSBwYXRoLgo+IAo+IAo+IEFueXdheSB0aGUgY3VycmVudCBYZW4gY29kZSBpcyBjb25mbGljdCB3 aXRoIHNwZWMgd2hpY2ggc2FpZDoKPiAKPiAiSWYgdGhpcyBmZWF0dXJlIGJpdCBpcyBzZXQgdG8g MCwgdGhlbiB0aGUgZGV2aWNlIGhhcyBzYW1lIGFjY2VzcyB0byBtZW1vcnkKPiBhZGRyZXNzZXMg c3VwcGxpZWQgdG8gaXQgYXMgdGhlIGRyaXZlciBoYXMuIEluIHBhcnRpY3VsYXIsIHRoZSBkZXZp Y2Ugd2lsbAo+IGFsd2F5cyB1c2UgcGh5c2ljYWwgYWRkcmVzc2VzIG1hdGNoaW5nIGFkZHJlc3Nl cyB1c2VkIGJ5IHRoZSBkcml2ZXIKPiAodHlwaWNhbGx5IG1lYW5pbmcgcGh5c2ljYWwgYWRkcmVz c2VzIHVzZWQgYnkgdGhlIENQVSkgYW5kIG5vdCB0cmFuc2xhdGVkCj4gZnVydGhlciwgYW5kIGNh biBhY2Nlc3MgYW55IGFkZHJlc3Mgc3VwcGxpZWQgdG8gaXQgYnkgdGhlIGRyaXZlci4gV2hlbgo+ IGNsZWFyLCB0aGlzIG92ZXJyaWRlcyBhbnkgcGxhdGZvcm0tc3BlY2lmaWMgZGVzY3JpcHRpb24g b2Ygd2hldGhlciBkZXZpY2UKPiBhY2Nlc3MgaXMgbGltaXRlZCBvciB0cmFuc2xhdGVkIGluIGFu eSB3YXksIGUuZy4gd2hldGhlciBhbiBJT01NVSBtYXkgYmUKPiBwcmVzZW50LiAiCj4gCj4gSSB3 b25kZXIgaG93IG11Y2ggdmFsdWUgdGhhdCB0aGUgYWJvdmUgZGVzY3JpcHRpb24gY2FuIGdpdmUg dXMuIEl0J3Mga2luZCBvZgo+IG9kZCB0aGF0IHRoZSBiZWhhdmlvciBvZiAid2hlbiB0aGUgZmVh dHVyZSBpcyBub3QgbmVnb3RpYXRlZCIgaXMgZGVzY3JpYmVkCj4gaW4gdGhlIHNwZWMuCgpIbW0g d2hhdCdzIG9kZCBhYm91dCBpdD8gV2UgbmVlZCB0byBkZXNjcmliZSB0aGUgYmVoYXZpb3VyIGlz IGFsbCBjYXNlcy4KCj4gUGVyc29uYWxseSBJIHRoaW5rIHdlIGNhbiByZW1vdmUgdGhlIGFib3Zl IGFuZCB0aGVuIHdlIGNhbgo+IHN3aXRjaCB0byB1c2UgRE1BIEFQSSB1bmNvbmRpdGlvbmFsbHkg aW4gZ3Vlc3QgZHJpdmVyLiBJdCBtYXkgaGF2ZSBzaW5nbGUKPiBkaWdpdCByZWdyZXNzaW9uIHBy b2JhYmx5LCB3ZSBjYW4gdHJ5IHRvIG92ZXJjb21lIGl0Lgo+IAo+IFRoYW5rcwoKVGhpcyBoYXMg YmVlbiBkaXNjdXNzZWQgYWQgbmF1c2V1bS4gdmlydGlvIGlzIGFsbCBhYm91dCBjb21wYXRpYmls aXR5LgpMb3NpbmcgYSBjb3VwbGUgb2YgbGluZXMgb2YgY29kZSBpc24ndCB3b3J0aCBicmVha2lu ZyB3b3JraW5nIHNldHVwcy4KUGVvcGxlIHRoYXQgd2FudCAianVzdCB1c2UgRE1BIEFQSSBubyB0 cmlja3MiIG5vdyBoYXZlIHRoZSBvcHRpb24uClNldHRpbmcgYSBmbGFnIGluIGEgZmVhdHVyZSBi aXQgbWFwIGlzIGxpdGVyYWxseSBhIHNpbmdsZSBsaW5lCm9mIGNvZGUgaW4gdGhlIGh5cGVydmlz b3IuIFNvIHN0b3AgcHVzaGluZyBmb3IgYnJlYWtpbmcgd29ya2luZwpsZWdhY3kgc2V0dXBzIGFu ZCBqdXN0IGZpeCBpdCBpbiB0aGUgcmlnaHQgcGxhY2UuCgo+IAo+ID4gCj4gPiBCeSB0aGUgd2F5 IGNvdWxkIHlvdSBwbGVhc2UgcmVzcG9uZCBhYm91dCB2aXJ0aW8taW9tbXUgYW5kCj4gPiB3aHkg dGhlcmUncyBubyBzdXBwb3J0IGZvciBBQ0NFU1NfUExBVEZPUk0gb24gcG93ZXI/Cj4gPiAKPiA+ IEkgaGF2ZSBDYydkIHlvdSBvbiB0aGVzZSBkaXNjdXNzaW9ucy4KPiA+IAo+ID4gCj4gPiBUaGFu a3MhCj4gPiAKPiA+IAo+ID4gPiA+IC0tLQo+ID4gPiA+ICAgZHJpdmVycy92aXJ0aW8vdmlydGlv X3JpbmcuYyB8IDUgKysrKy0KPiA+ID4gPiAgIDEgZmlsZSBjaGFuZ2VkLCA0IGluc2VydGlvbnMo KyksIDEgZGVsZXRpb24oLSkKPiA+ID4gPiAKPiA+ID4gPiBkaWZmIC0tZ2l0IGEvZHJpdmVycy92 aXJ0aW8vdmlydGlvX3JpbmcuYyBiL2RyaXZlcnMvdmlydGlvL3ZpcnRpb19yaW5nLmMKPiA+ID4g PiBpbmRleCBjZDdlNzU1NDg0ZTMuLjMyMWEyNzA3NTM4MCAxMDA2NDQKPiA+ID4gPiAtLS0gYS9k cml2ZXJzL3ZpcnRpby92aXJ0aW9fcmluZy5jCj4gPiA+ID4gKysrIGIvZHJpdmVycy92aXJ0aW8v dmlydGlvX3JpbmcuYwo+ID4gPiA+IEBAIC0yNTksOCArMjU5LDExIEBAIHN0YXRpYyBib29sIHZy aW5nX3VzZV9kbWFfYXBpKHN0cnVjdCB2aXJ0aW9fZGV2aWNlICp2ZGV2KQo+ID4gPiA+ICAgCSAq IG5vdCB3b3JrIHdpdGhvdXQgYW4gZXZlbiBsYXJnZXIga2x1ZGdlLiAgSW5zdGVhZCwgZW5hYmxl Cj4gPiA+ID4gICAJICogdGhlIERNQSBBUEkgaWYgd2UncmUgYSBYZW4gZ3Vlc3QsIHdoaWNoIGF0 IGxlYXN0IGFsbG93cwo+ID4gPiA+ICAgCSAqIGFsbCBvZiB0aGUgc2Vuc2libGUgWGVuIGNvbmZp Z3VyYXRpb25zIHRvIHdvcmsgY29ycmVjdGx5Lgo+ID4gPiA+ICsJICoKPiA+ID4gPiArCSAqIEFs c28sIGlmIGd1ZXN0IG1lbW9yeSBpcyBlbmNyeXB0ZWQgdGhlIGhvc3QgY2FuJ3QgYWNjZXNzCj4g PiA+ID4gKwkgKiBpdCBkaXJlY3RseS4gSW4gdGhpcyBjYXNlLCB3ZSdsbCBuZWVkIHRvIHVzZSB0 aGUgRE1BIEFQSS4KPiA+ID4gPiAgIAkgKi8KPiA+ID4gPiAtCWlmICh4ZW5fZG9tYWluKCkpCj4g PiA+ID4gKwlpZiAoeGVuX2RvbWFpbigpIHx8IHNldl9hY3RpdmUoKSkKPiA+ID4gPiAgIAkJcmV0 dXJuIHRydWU7Cj4gPiA+ID4gCj4gPiA+ID4gICAJcmV0dXJuIGZhbHNlOwo+ID4gPiAKPiA+ID4g LS0gCj4gPiA+IFRoaWFnbyBKdW5nIEJhdWVybWFubgo+ID4gPiBJQk0gTGludXggVGVjaG5vbG9n eSBDZW50ZXIKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18K VmlydHVhbGl6YXRpb24gbWFpbGluZyBsaXN0ClZpcnR1YWxpemF0aW9uQGxpc3RzLmxpbnV4LWZv dW5kYXRpb24ub3JnCmh0dHBzOi8vbGlzdHMubGludXhmb3VuZGF0aW9uLm9yZy9tYWlsbWFuL2xp c3RpbmZvL3ZpcnR1YWxpemF0aW9u