From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [RFC][PATCH] KVM: SVM: Sync g_pat with guest-written PAT value Date: Mon, 20 Apr 2015 19:37:27 +0200 Message-ID: <55353957.6010907@siemens.com> References: <552B5128.4010909@siemens.com> <552B6923.3020602@siemens.com> <20150420161401.GB26491@potion.brq.redhat.com> <20150420171635.GC26491@potion.brq.redhat.com> <553535B1.3050901@siemens.com> <20150420173345.GB26478@potion.brq.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: kvm , Joel Schopp To: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= Return-path: Received: from david.siemens.de ([192.35.17.14]:43269 "EHLO david.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751791AbbDTRhh (ORCPT ); Mon, 20 Apr 2015 13:37:37 -0400 In-Reply-To: <20150420173345.GB26478@potion.brq.redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 2015-04-20 19:33, Radim Kr=C4=8Dm=C3=A1=C5=99 wrote: > 2015-04-20 19:21+0200, Jan Kiszka: >> On 2015-04-20 19:16, Radim Kr=C4=8Dm=C3=A1=C5=99 wrote: >>> 2015-04-20 18:14+0200, Radim Kr=C4=8Dm=C3=A1=C5=99: >>>> Tested-by: Radim Kr=C4=8Dm=C3=A1=C5=99 >>> >>> Uncached accesses were roughly 20x slower. >>> In case anyone wanted to reproduce, I used this as a kvm-unit-test: >>> >>> --- > | [code] >> >> Great, thanks. Will you push it to the unit tests? Could raise >> motivations to fix the !NPT/EPT case. >=20 > It can't be included in `run_tests.sh`, because we intenionally ignor= e > PAT for normal RAM on VMX and the test does "fail" ... That ignoring is encoded into the EPT? Hmm... Maybe we can create a ivshmem device and use that as test target. >=20 > I'll think how to make the test use fool-proof first, and also look h= ow > to fix the !NPT/EPT without affecting the case we care about too much= =2E > (And if we can do a similar trick with NPT.) >=20 OK. Jan --=20 Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux