From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH v2] arm64: KVM: VHE: Context switch MDSCR_EL1 Date: Thu, 21 Jul 2016 14:53:46 +0100 Message-ID: <20160721145346.470fea00@arm.com> References: <1468933014-26966-1-git-send-email-marc.zyngier@arm.com> <20160721131720.GA32739@potion> <20160721142451.2ee990ce@arm.com> <20160721134937.GA4603@potion> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 0C56C49B36 for ; Thu, 21 Jul 2016 09:47:40 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id tG3iuKfoJAPa for ; Thu, 21 Jul 2016 09:47:39 -0400 (EDT) Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 332144998D for ; Thu, 21 Jul 2016 09:47:38 -0400 (EDT) In-Reply-To: <20160721134937.GA4603@potion> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: Radim =?UTF-8?Q?Kr=C4=8Dm=C3=A1=C5=99?= Cc: kvm@vger.kernel.org, Tirumalesh Chalamarla , Paolo Bonzini , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org List-Id: kvmarm@lists.cs.columbia.edu T24gVGh1LCAyMSBKdWwgMjAxNiAxNTo0OTozOCArMDIwMApSYWRpbSBLcsSNbcOhxZkgPHJrcmNt YXJAcmVkaGF0LmNvbT4gd3JvdGU6Cgo+IDIwMTYtMDctMjEgMTQ6MjQrMDEwMCwgTWFyYyBaeW5n aWVyOgo+ID4gT24gVGh1LCAyMSBKdWwgMjAxNiAxNToxNzoyMCArMDIwMAo+ID4gUmFkaW0gS3LE jW3DocWZIDxya3JjbWFyQHJlZGhhdC5jb20+IHdyb3RlOgo+ID4gCj4gPiBIaSBSYWRpbSwKPiA+ ICAgCj4gPj4gMjAxNi0wNy0xOSAxMzo1NiswMTAwLCBNYXJjIFp5bmdpZXI6ICAKPiA+PiA+IFRo ZSBrcHJvYmUgZW5hYmxlbWVudCB3b3JrIGhhcyB1bmNvdmVyZWQgdGhhdCBjaGFuZ2VzIG1hZGUg YnkKPiA+PiA+IGEgZ3Vlc3QgdG8gTURTQ1JfRUwxIHdlcmUgcHJvcGFnYXRlZCB0byB0aGUgaG9z dCB3aGVuIFZIRSB3YXMKPiA+PiA+IGVuYWJsZWQsIGxlYWRpbmcgdG8gdW5leHBlY3RlZCBleGNl cHRpb24gYmVpbmcgZGVsaXZlcmVkLgo+ID4+ID4gCj4gPj4gPiBNb3ZpbmcgdGhpcyByZWdpc3Rl ciB0byB0aGUgbGlzdCBvZiByZWdpc3RlcnMgdGhhdCBhcmUgYWx3YXlzCj4gPj4gPiBjb250ZXh0 LXN3aXRjaGVkIGZpeGVzIHRoZSBpc3N1ZS4KPiA+PiA+IAo+ID4+ID4gRml4ZXM6IDljNmMzNTY4 MzI4NiAoImFybTY0OiBLVk06IFZIRTogU3BsaXQgc2F2ZS9yZXN0b3JlIG9mIHJlZ2lzdGVycyBz aGFyZWQgYmV0d2VlbiBndWVzdCBhbmQgaG9zdCIpCj4gPj4gPiBDYzogc3RhYmxlQHZnZXIua2Vy bmVsLm9yZyAjNC42Cj4gPj4gPiBSZXBvcnRlZC1ieTogVGlydW1hbGVzaCBDaGFsYW1hcmxhIDxU aXJ1bWFsZXNoLkNoYWxhbWFybGFAY2F2aXVtLmNvbT4KPiA+PiA+IFRlc3RlZC1ieTogVGlydW1h bGVzaCBDaGFsYW1hcmxhIDxUaXJ1bWFsZXNoLkNoYWxhbWFybGFAY2F2aXVtLmNvbT4KPiA+PiA+ IFNpZ25lZC1vZmYtYnk6IE1hcmMgWnluZ2llciA8bWFyYy56eW5naWVyQGFybS5jb20+Cj4gPj4g PiAtLS0gICAgCj4gPj4gCj4gPj4gSSB3b3VsZCB0YWtlIHRoaXMgcGF0Y2ggdG8gNC43IGRpcmVj dGx5IHRocm91Z2ggdGhlIG1haW4gdHJlZS4KPiA+PiBBcmUgeW91ciBwbGFucyBkaWZmZXJlbnQ/ ICAKPiA+IAo+ID4gSWYgeW91J3JlIGhhcHB5IHRvIHRha2UgaXQgbm93LCB0aGF0IHdvcmtzIGZv ciBtZS4gIAo+IAo+IFRoZSBmaXggaXMgY2xlYXIsIHRlc3RlZCwgYW5kIHdvdWxkIGdvIHRvIDQu Ny5zdGFibGUuICBCZXR0ZXIgdG8gaGF2ZSBpdAo+IGluIDQuNywgSU1PLgoKQWdyZWVkLgoKPiA+ ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgIEkgY2Fu IGVpdGhlciBzZW5kIGEKPiA+IFBSIHJpZ2h0IGF3YXksIG9yIHlvdSBjYW4gYXBwbHkgaXQgZGly ZWN0bHksIHdoaWNoZXZlciB3b3JrcyBiZXN0IGZvcgo+ID4geW91LiAgCj4gCj4gSXQgaXMganVz dCBvbmUgcGF0Y2ggc28gSSdsbCBhcHBseSBpdCBhbmQgc2VuZCBhIHB1bGwgcmVxdWVzdCB0byBM aW51cwo+IG9uIFNhdHVyZGF5OyAgbGVzcyBjdW1tdWxhdGl2ZSB3b3JrIHRoYXQgd2F5LiA6KQoK QnJpbGxpYW50LiBUaGFua3MgUmFkaW0uCgoJTS4KLS0gCkphenogaXMgbm90IGRlYWQuIEl0IGp1 c3Qgc21lbGxzIGZ1bm55LgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fXwprdm1hcm0gbWFpbGluZyBsaXN0Cmt2bWFybUBsaXN0cy5jcy5jb2x1bWJpYS5lZHUK aHR0cHM6Ly9saXN0cy5jcy5jb2x1bWJpYS5lZHUvbWFpbG1hbi9saXN0aW5mby9rdm1hcm0K From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Thu, 21 Jul 2016 14:53:46 +0100 Subject: [PATCH v2] arm64: KVM: VHE: Context switch MDSCR_EL1 In-Reply-To: <20160721134937.GA4603@potion> References: <1468933014-26966-1-git-send-email-marc.zyngier@arm.com> <20160721131720.GA32739@potion> <20160721142451.2ee990ce@arm.com> <20160721134937.GA4603@potion> Message-ID: <20160721145346.470fea00@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, 21 Jul 2016 15:49:38 +0200 Radim Kr?m?? wrote: > 2016-07-21 14:24+0100, Marc Zyngier: > > On Thu, 21 Jul 2016 15:17:20 +0200 > > Radim Kr?m?? wrote: > > > > Hi Radim, > > > >> 2016-07-19 13:56+0100, Marc Zyngier: > >> > The kprobe enablement work has uncovered that changes made by > >> > a guest to MDSCR_EL1 were propagated to the host when VHE was > >> > enabled, leading to unexpected exception being delivered. > >> > > >> > Moving this register to the list of registers that are always > >> > context-switched fixes the issue. > >> > > >> > Fixes: 9c6c35683286 ("arm64: KVM: VHE: Split save/restore of registers shared between guest and host") > >> > Cc: stable at vger.kernel.org #4.6 > >> > Reported-by: Tirumalesh Chalamarla > >> > Tested-by: Tirumalesh Chalamarla > >> > Signed-off-by: Marc Zyngier > >> > --- > >> > >> I would take this patch to 4.7 directly through the main tree. > >> Are your plans different? > > > > If you're happy to take it now, that works for me. > > The fix is clear, tested, and would go to 4.7.stable. Better to have it > in 4.7, IMO. Agreed. > > I can either send a > > PR right away, or you can apply it directly, whichever works best for > > you. > > It is just one patch so I'll apply it and send a pull request to Linus > on Saturday; less cummulative work that way. :) Brilliant. Thanks Radim. M. -- Jazz is not dead. It just smells funny.