From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH] x86: vdso: fix pvclock races with task migration Date: Tue, 07 Apr 2015 13:11:13 +0200 Message-ID: <5523BB51.8090703@redhat.com> References: <1428000263-11892-1-git-send-email-rkrcmar@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: kvm@vger.kernel.org, Marcelo Tosatti , Andy Lutomirski , stable@vger.kernel.org To: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , linux-kernel@vger.kernel.org Return-path: In-Reply-To: <1428000263-11892-1-git-send-email-rkrcmar@redhat.com> Sender: stable-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 02/04/2015 20:44, Radim Kr=C4=8Dm=C3=A1=C5=99 wrote: > If we were migrated right after __getcpu, but before reading the > migration_count, we wouldn't notice that we read TSC of a different > VCPU, nor that KVM's bug made pvti invalid, as only migration_count > on source VCPU is increased. >=20 > Change vdso instead of updating migration_count on destination. >=20 > Fixes: 0a4e6be9ca17 ("x86: kvm: Revert "remove sched notifier for cro= ss-cpu migrations"") > Cc: stable@vger.kernel.org > Signed-off-by: Radim Kr=C4=8Dm=C3=A1=C5=99 Applying this, but removing the "Fixes" tag because a guest patch canno= t fix a host patch (it can work around it or complement it). Paolo