From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964781AbcHNUzZ (ORCPT ); Sun, 14 Aug 2016 16:55:25 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:46396 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933169AbcHNUoO (ORCPT ); Sun, 14 Aug 2016 16:44:14 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Toshi Kani , Thomas Gleixner , Andrew Morton , Andy Lutomirski , Borislav Petkov , Borislav Petkov , Brian Gerst , Denys Vlasenko , "H. Peter Anvin" , Juergen Gross , Linus Torvalds , "Luis R. Rodriguez" , Peter Zijlstra , Toshi Kani , elliott@hpe.com, konrad.wilk@oracle.com, paul.gortmaker@windriver.com, xen-devel@lists.xenproject.org, Ingo Molnar Subject: [PATCH 4.6 29/56] x86/pat: Document the PAT initialization sequence Date: Sun, 14 Aug 2016 22:37:33 +0200 Message-Id: <20160814202506.132428006@linuxfoundation.org> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20160814202504.908694181@linuxfoundation.org> References: <20160814202504.908694181@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Toshi Kani commit b6350c21cfe8aa9d65e189509a23c0ea4b8362c2 upstream. Update PAT documentation to describe how PAT is initialized under various configurations. Signed-off-by: Toshi Kani Reviewed-by: Thomas Gleixner Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Juergen Gross Cc: Linus Torvalds Cc: Luis R. Rodriguez Cc: Peter Zijlstra Cc: Toshi Kani Cc: elliott@hpe.com Cc: konrad.wilk@oracle.com Cc: paul.gortmaker@windriver.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1458769323-24491-8-git-send-email-toshi.kani@hpe.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- Documentation/x86/pat.txt | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) --- a/Documentation/x86/pat.txt +++ b/Documentation/x86/pat.txt @@ -196,3 +196,35 @@ Another, more verbose way of getting PAT "debugpat" boot parameter. With this parameter, various debug messages are printed to dmesg log. +PAT Initialization +------------------ + +The following table describes how PAT is initialized under various +configurations. The PAT MSR must be updated by Linux in order to support WC +and WT attributes. Otherwise, the PAT MSR has the value programmed in it +by the firmware. Note, Xen enables WC attribute in the PAT MSR for guests. + + MTRR PAT Call Sequence PAT State PAT MSR + ========================================================= + E E MTRR -> PAT init Enabled OS + E D MTRR -> PAT init Disabled - + D E MTRR -> PAT disable Disabled BIOS + D D MTRR -> PAT disable Disabled - + - np/E PAT -> PAT disable Disabled BIOS + - np/D PAT -> PAT disable Disabled - + E !P/E MTRR -> PAT init Disabled BIOS + D !P/E MTRR -> PAT disable Disabled BIOS + !M !P/E MTRR stub -> PAT disable Disabled BIOS + + Legend + ------------------------------------------------ + E Feature enabled in CPU + D Feature disabled/unsupported in CPU + np "nopat" boot option specified + !P CONFIG_X86_PAT option unset + !M CONFIG_MTRR option unset + Enabled PAT state set to enabled + Disabled PAT state set to disabled + OS PAT initializes PAT MSR with OS setting + BIOS PAT keeps PAT MSR with BIOS setting + From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Kroah-Hartman Subject: [PATCH 4.6 29/56] x86/pat: Document the PAT initialization sequence Date: Sun, 14 Aug 2016 22:37:33 +0200 Message-ID: <20160814202506.132428006@linuxfoundation.org> References: <20160814202504.908694181@linuxfoundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1bZ2GW-0008N8-Sz for xen-devel@lists.xenproject.org; Sun, 14 Aug 2016 20:44:16 +0000 In-Reply-To: <20160814202504.908694181@linuxfoundation.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: linux-kernel@vger.kernel.org Cc: Juergen Gross , Denys Vlasenko , xen-devel@lists.xenproject.org, Toshi Kani , Peter Zijlstra , Greg Kroah-Hartman , "Luis R. Rodriguez" , "H. Peter Anvin" , stable@vger.kernel.org, Andy Lutomirski , paul.gortmaker@windriver.com, Ingo Molnar , Borislav Petkov , Brian Gerst , Toshi Kani , Andrew Morton , Borislav Petkov , Linus Torvalds , Thomas Gleixner , elliott@hpe.com List-Id: xen-devel@lists.xenproject.org NC42LXN0YWJsZSByZXZpZXcgcGF0Y2guICBJZiBhbnlvbmUgaGFzIGFueSBvYmplY3Rpb25zLCBw bGVhc2UgbGV0IG1lIGtub3cuCgotLS0tLS0tLS0tLS0tLS0tLS0KCkZyb206IFRvc2hpIEthbmkg PHRvc2hpLmthbmlAaHBlLmNvbT4KCmNvbW1pdCBiNjM1MGMyMWNmZThhYTlkNjVlMTg5NTA5YTIz YzBlYTRiODM2MmMyIHVwc3RyZWFtLgoKVXBkYXRlIFBBVCBkb2N1bWVudGF0aW9uIHRvIGRlc2Ny aWJlIGhvdyBQQVQgaXMgaW5pdGlhbGl6ZWQgdW5kZXIKdmFyaW91cyBjb25maWd1cmF0aW9ucy4K ClNpZ25lZC1vZmYtYnk6IFRvc2hpIEthbmkgPHRvc2hpLmthbmlAaHBlLmNvbT4KUmV2aWV3ZWQt Ynk6IFRob21hcyBHbGVpeG5lciA8dGdseEBsaW51dHJvbml4LmRlPgpDYzogQW5kcmV3IE1vcnRv biA8YWtwbUBsaW51eC1mb3VuZGF0aW9uLm9yZz4KQ2M6IEFuZHkgTHV0b21pcnNraSA8bHV0b0Bh bWFjYXBpdGFsLm5ldD4KQ2M6IEJvcmlzbGF2IFBldGtvdiA8YnBAYWxpZW44LmRlPgpDYzogQm9y aXNsYXYgUGV0a292IDxicEBzdXNlLmRlPgpDYzogQnJpYW4gR2Vyc3QgPGJyZ2Vyc3RAZ21haWwu Y29tPgpDYzogRGVueXMgVmxhc2Vua28gPGR2bGFzZW5rQHJlZGhhdC5jb20+CkNjOiBILiBQZXRl ciBBbnZpbiA8aHBhQHp5dG9yLmNvbT4KQ2M6IEp1ZXJnZW4gR3Jvc3MgPGpncm9zc0BzdXNlLmNv bT4KQ2M6IExpbnVzIFRvcnZhbGRzIDx0b3J2YWxkc0BsaW51eC1mb3VuZGF0aW9uLm9yZz4KQ2M6 IEx1aXMgUi4gUm9kcmlndWV6IDxtY2dyb2ZAc3VzZS5jb20+CkNjOiBQZXRlciBaaWpsc3RyYSA8 cGV0ZXJ6QGluZnJhZGVhZC5vcmc+CkNjOiBUb3NoaSBLYW5pIDx0b3NoaS5rYW5pQGhwLmNvbT4K Q2M6IGVsbGlvdHRAaHBlLmNvbQpDYzoga29ucmFkLndpbGtAb3JhY2xlLmNvbQpDYzogcGF1bC5n b3J0bWFrZXJAd2luZHJpdmVyLmNvbQpDYzogeGVuLWRldmVsQGxpc3RzLnhlbnByb2plY3Qub3Jn Ckxpbms6IGh0dHA6Ly9sa21sLmtlcm5lbC5vcmcvci8xNDU4NzY5MzIzLTI0NDkxLTgtZ2l0LXNl bmQtZW1haWwtdG9zaGkua2FuaUBocGUuY29tClNpZ25lZC1vZmYtYnk6IEluZ28gTW9sbmFyIDxt aW5nb0BrZXJuZWwub3JnPgpTaWduZWQtb2ZmLWJ5OiBHcmVnIEtyb2FoLUhhcnRtYW4gPGdyZWdr aEBsaW51eGZvdW5kYXRpb24ub3JnPgoKLS0tCiBEb2N1bWVudGF0aW9uL3g4Ni9wYXQudHh0IHwg ICAzMiArKysrKysrKysrKysrKysrKysrKysrKysrKysrKysrKwogMSBmaWxlIGNoYW5nZWQsIDMy IGluc2VydGlvbnMoKykKCi0tLSBhL0RvY3VtZW50YXRpb24veDg2L3BhdC50eHQKKysrIGIvRG9j dW1lbnRhdGlvbi94ODYvcGF0LnR4dApAQCAtMTk2LDMgKzE5NiwzNSBAQCBBbm90aGVyLCBtb3Jl IHZlcmJvc2Ugd2F5IG9mIGdldHRpbmcgUEFUCiAiZGVidWdwYXQiIGJvb3QgcGFyYW1ldGVyLiBX aXRoIHRoaXMgcGFyYW1ldGVyLCB2YXJpb3VzIGRlYnVnIG1lc3NhZ2VzIGFyZQogcHJpbnRlZCB0 byBkbWVzZyBsb2cuCiAKK1BBVCBJbml0aWFsaXphdGlvbgorLS0tLS0tLS0tLS0tLS0tLS0tCisK K1RoZSBmb2xsb3dpbmcgdGFibGUgZGVzY3JpYmVzIGhvdyBQQVQgaXMgaW5pdGlhbGl6ZWQgdW5k ZXIgdmFyaW91cworY29uZmlndXJhdGlvbnMuIFRoZSBQQVQgTVNSIG11c3QgYmUgdXBkYXRlZCBi eSBMaW51eCBpbiBvcmRlciB0byBzdXBwb3J0IFdDCithbmQgV1QgYXR0cmlidXRlcy4gT3RoZXJ3 aXNlLCB0aGUgUEFUIE1TUiBoYXMgdGhlIHZhbHVlIHByb2dyYW1tZWQgaW4gaXQKK2J5IHRoZSBm aXJtd2FyZS4gTm90ZSwgWGVuIGVuYWJsZXMgV0MgYXR0cmlidXRlIGluIHRoZSBQQVQgTVNSIGZv ciBndWVzdHMuCisKKyBNVFJSIFBBVCAgIENhbGwgU2VxdWVuY2UgICAgICAgICAgICAgICBQQVQg U3RhdGUgIFBBVCBNU1IKKyA9PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT0KKyBFICAgIEUgICAgIE1UUlIgLT4gUEFUIGluaXQgICAgICAgICAg ICBFbmFibGVkICAgIE9TCisgRSAgICBEICAgICBNVFJSIC0+IFBBVCBpbml0ICAgICAgICAgICAg RGlzYWJsZWQgICAgLQorIEQgICAgRSAgICAgTVRSUiAtPiBQQVQgZGlzYWJsZSAgICAgICAgIERp c2FibGVkICAgQklPUworIEQgICAgRCAgICAgTVRSUiAtPiBQQVQgZGlzYWJsZSAgICAgICAgIERp c2FibGVkICAgIC0KKyAtICAgIG5wL0UgIFBBVCAgLT4gUEFUIGRpc2FibGUgICAgICAgICBEaXNh YmxlZCAgIEJJT1MKKyAtICAgIG5wL0QgIFBBVCAgLT4gUEFUIGRpc2FibGUgICAgICAgICBEaXNh YmxlZCAgICAtCisgRSAgICAhUC9FICBNVFJSIC0+IFBBVCBpbml0ICAgICAgICAgICAgRGlzYWJs ZWQgICBCSU9TCisgRCAgICAhUC9FICBNVFJSIC0+IFBBVCBkaXNhYmxlICAgICAgICAgRGlzYWJs ZWQgICBCSU9TCisgIU0gICAhUC9FICBNVFJSIHN0dWIgLT4gUEFUIGRpc2FibGUgICAgRGlzYWJs ZWQgICBCSU9TCisKKyBMZWdlbmQKKyAtLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0KKyBFICAgICAgICAgRmVhdHVyZSBlbmFibGVkIGluIENQVQorIEQJICAg RmVhdHVyZSBkaXNhYmxlZC91bnN1cHBvcnRlZCBpbiBDUFUKKyBucAkgICAibm9wYXQiIGJvb3Qg b3B0aW9uIHNwZWNpZmllZAorICFQCSAgIENPTkZJR19YODZfUEFUIG9wdGlvbiB1bnNldAorICFN CSAgIENPTkZJR19NVFJSIG9wdGlvbiB1bnNldAorIEVuYWJsZWQgICBQQVQgc3RhdGUgc2V0IHRv IGVuYWJsZWQKKyBEaXNhYmxlZCAgUEFUIHN0YXRlIHNldCB0byBkaXNhYmxlZAorIE9TICAgICAg ICBQQVQgaW5pdGlhbGl6ZXMgUEFUIE1TUiB3aXRoIE9TIHNldHRpbmcKKyBCSU9TICAgICAgUEFU IGtlZXBzIFBBVCBNU1Igd2l0aCBCSU9TIHNldHRpbmcKKwoKCgpfX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fXwpYZW4tZGV2ZWwgbWFpbGluZyBsaXN0Clhlbi1k ZXZlbEBsaXN0cy54ZW4ub3JnCmh0dHBzOi8vbGlzdHMueGVuLm9yZy94ZW4tZGV2ZWwK