From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH 4/7] KVM: vmx: Allow the guest to run with dirty debug registers Date: Mon, 10 Mar 2014 13:24:10 +0100 Message-ID: <531DAEEA.8000909@redhat.com> References: <1394192571-11056-1-git-send-email-pbonzini@redhat.com> <1394192571-11056-5-git-send-email-pbonzini@redhat.com> <20140309182639.GA10479@potion.redhat.com> <531CCB15.6070402@redhat.com> <20140310121704.GB16023@potion.brq.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, alex.williamson@redhat.com, mtosatti@redhat.com, gleb@kernel.org, jan.kiszka@siemens.com To: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= Return-path: In-Reply-To: <20140310121704.GB16023@potion.brq.redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Il 10/03/2014 13:17, Radim Kr=C4=8Dm=C3=A1=C5=99 ha scritto: >> > I considered this, but decided that it's unlikely for emulation to >> > be faster than hardware---especially on those AMD CPUs that lack >> > decode assists (and it's good for VMX and SVM code to look as >> > similar as possible). > I meant to move it before the block that exits if there is the > 'exception on access' bit set in cr7, so we wouldn't exit again right > away on the actual access, which is quite likely. > (Exiting without emulation was a great move.) > Ah yes, for the GD bit. I don't know, it's quite unlikely that anyone=20 will use it... It's a feeble attempt at allowing virtualization of the= =20 debug registers without VMX. Paolo