From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCHv2] KVM: emulator: do not needlesly sync registers from emulator ctxt to vcpu Date: Thu, 14 Apr 2011 04:08:56 -0300 Message-ID: <20110414070856.GB14370@amt.cnet> References: <20110331100641.GL7766@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: avi@redhat.com, kvm@vger.kernel.org To: Gleb Natapov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:1026 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757816Ab1DNHck (ORCPT ); Thu, 14 Apr 2011 03:32:40 -0400 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p3E7We9a012778 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 14 Apr 2011 03:32:40 -0400 Content-Disposition: inline In-Reply-To: <20110331100641.GL7766@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Mar 31, 2011 at 12:06:41PM +0200, Gleb Natapov wrote: > Currently we sync registers back and forth before/after exiting > to userspace for IO, but during IO device model shouldn't need to > read/write the registers, so we can as well skip those sync points. The > only exaception is broken vmware backdor interface. The new code sync > registers content during IO only if registers are read from/written to > by userspace in the middle of the IO operation and this almost never > happens in practise. > > Signed-off-by: Gleb Natapov > --- > v1->v2 > - rebased onto see emulation patchset. Applied, thanks.