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charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" T24gVGh1LCBOb3YgMjEsIDIwMTkgYXQgMDc6MzA6NDFQTSAtMDUwMCwgUGF2ZWwgVGF0YXNoaW4g d3JvdGU6Cj4gPiA+ICsjaWZkZWYgQ09ORklHX0NQVV9TV19ET01BSU5fUEFOCj4gPiA+ICtzdGF0 aWMgX19hbHdheXNfaW5saW5lIHZvaWQgdWFjY2Vzc19lbmFibGUodm9pZCkKPiA+ID4gK3sKPiA+ ID4gKyAgICAgdW5zaWduZWQgbG9uZyB2YWwgPSBEQUNSX1VBQ0NFU1NfRU5BQkxFOwo+ID4gPiAr Cj4gPiA+ICsgICAgIGFzbSB2b2xhdGlsZSgibWNyIHAxNSwgMCwgJTAsIGMzLCBjMCwgMCIgOiA6 ICJyIiAodmFsKSk7Cj4gPiA+ICsgICAgIGlzYigpOwo+ID4gPiArfQo+ID4gPiArCj4gPiA+ICtz dGF0aWMgX19hbHdheXNfaW5saW5lIHZvaWQgdWFjY2Vzc19kaXNhYmxlKHZvaWQpCj4gPiA+ICt7 Cj4gPiA+ICsgICAgIHVuc2lnbmVkIGxvbmcgdmFsID0gREFDUl9VQUNDRVNTX0VOQUJMRTsKPiAK PiBPb3BzLCBzaG91bGQgYmUgREFDUl9VQUNDRVNTX0RJU0FCTEUuCj4gCj4gPiA+ICsKPiA+ID4g KyAgICAgYXNtIHZvbGF0aWxlKCJtY3IgcDE1LCAwLCAlMCwgYzMsIGMwLCAwIiA6IDogInIiICh2 YWwpKTsKPiA+ID4gKyAgICAgaXNiKCk7Cj4gPiA+ICt9Cj4gPgo+ID4gUmF0aGVyIHRoYW4gaW52 ZW50aW5nIHRoZXNlLCB3aHkgbm90IHVzZSB1YWNjZXNzX3NhdmVfYW5kX2VuYWJsZSgpLi4KPiA+ IHVhY2Nlc3NfcmVzdG9yZSgpIGFyb3VuZCB0aGUgWGVuIGNhbGw/Cj4gCj4gVGhhbmsgeW91IGZv ciBzdWdnZXN0aW9uOiB1YWNjZXNzX2VuYWJsZSgpIGFuZCB1YWNjZXNzX2Rpc2FibGUoKSBhcmUK PiBjb21tb24gY2FsbHMgd2l0aCBhcm02NCwgc28gSSB3aWxsIG5lZWQgdGhlbSwgYnV0IEkgdGhp bmsgSSBjYW4gdXNlCj4gc2V0X2RvbWFpbigpIHdpdGggREFDUl9VQUNDRVNTX0RJU0FCTEUgL0RB Q1JfVUFDQ0VTU19FTkFCTEUgaW5zaWRlCj4gdGhlc2UgaW5saW5lcy4KClRoYXQgbWF5IGJlLCBi dXQgYmUgdmVyeSBjYXJlZnVsIHRoYXQgeW91IG9ubHkgdXNlIHRoZW0gaW4gQVJNdjctb25seQpj b2RlLiAgVXNpbmcgdGhlbSBlbHNld2hlcmUgaXMgdW5zYWZlIGFzIHRoZSBkb21haW4gcmVnaXN0 ZXIgaXMgdXNlZApmb3Igb3RoZXIgcHVycG9zZXMsIGFuZCBtZXJlbHkgYmxhdHRpbmcgb3ZlciBp dCAoYXMgeW91cgp1YWNjZXNzX2VuYWJsZSBhbmQgdWFjY2Vzc19kaXNhYmxlIGZ1bmN0aW9ucyBk bykgaXMgdW5zYWZlLgoKLS0gClJNSydzIFBhdGNoIHN5c3RlbTogaHR0cHM6Ly93d3cuYXJtbGlu dXgub3JnLnVrL2RldmVsb3Blci9wYXRjaGVzLwpGVFRDIGJyb2FkYmFuZCBmb3IgMC44bWlsZSBs aW5lIGluIHN1YnVyYmlhOiBzeW5jIGF0IDEyLjFNYnBzIGRvd24gNjIya2JwcyB1cApBY2NvcmRp bmcgdG8gc3BlZWR0ZXN0Lm5ldDogMTEuOU1icHMgZG93biA1MDBrYnBzIHVwCgpfX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpYZW4tZGV2ZWwgbWFpbGluZyBs aXN0Clhlbi1kZXZlbEBsaXN0cy54ZW5wcm9qZWN0Lm9yZwpodHRwczovL2xpc3RzLnhlbnByb2pl Y3Qub3JnL21haWxtYW4vbGlzdGluZm8veGVuLWRldmVs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE33CC432C0 for ; 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Fri, 22 Nov 2019 00:34:05 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1iXwtf-0003CX-5J; Fri, 22 Nov 2019 00:34:03 +0000 Date: Fri, 22 Nov 2019 00:34:03 +0000 From: Russell King - ARM Linux admin To: Pavel Tatashin Subject: Re: [PATCH 1/3] arm/arm64/xen: use C inlines for privcmd_call Message-ID: <20191122003403.GG25745@shell.armlinux.org.uk> References: <20191121184805.414758-1-pasha.tatashin@soleen.com> <20191121184805.414758-2-pasha.tatashin@soleen.com> <20191122002258.GD25745@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191121_163417_875781_47543DF0 X-CRM114-Status: GOOD ( 13.01 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Catalin Marinas , stefan@agner.ch, Masahiro Yamada , Will Deacon , boris.ostrovsky@oracle.com, Sasha Levin , sstabellini@kernel.org, James Morris , Linux ARM , xen-devel@lists.xenproject.org, Vladimir Murzin , Marc Zyngier , alexios.zavras@intel.com, Thomas Gleixner , allison@lohutok.net, jgross@suse.com, steve.capper@arm.com, Greg Kroah-Hartman , LKML , James Morse , info@metux.net Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Nov 21, 2019 at 07:30:41PM -0500, Pavel Tatashin wrote: > > > +#ifdef CONFIG_CPU_SW_DOMAIN_PAN > > > +static __always_inline void uaccess_enable(void) > > > +{ > > > + unsigned long val = DACR_UACCESS_ENABLE; > > > + > > > + asm volatile("mcr p15, 0, %0, c3, c0, 0" : : "r" (val)); > > > + isb(); > > > +} > > > + > > > +static __always_inline void uaccess_disable(void) > > > +{ > > > + unsigned long val = DACR_UACCESS_ENABLE; > > Oops, should be DACR_UACCESS_DISABLE. > > > > + > > > + asm volatile("mcr p15, 0, %0, c3, c0, 0" : : "r" (val)); > > > + isb(); > > > +} > > > > Rather than inventing these, why not use uaccess_save_and_enable().. > > uaccess_restore() around the Xen call? > > Thank you for suggestion: uaccess_enable() and uaccess_disable() are > common calls with arm64, so I will need them, but I think I can use > set_domain() with DACR_UACCESS_DISABLE /DACR_UACCESS_ENABLE inside > these inlines. That may be, but be very careful that you only use them in ARMv7-only code. Using them elsewhere is unsafe as the domain register is used for other purposes, and merely blatting over it (as your uaccess_enable and uaccess_disable functions do) is unsafe. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53D9CC432C0 for ; Fri, 22 Nov 2019 00:34:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 21CE420672 for ; Fri, 22 Nov 2019 00:34:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="BLzrPF7J" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726548AbfKVAeN (ORCPT ); Thu, 21 Nov 2019 19:34:13 -0500 Received: from pandora.armlinux.org.uk ([78.32.30.218]:36278 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726265AbfKVAeM (ORCPT ); Thu, 21 Nov 2019 19:34:12 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=YL9UjrFzkCb8yeKfLOoIaW9TGt9+B8/y4tvJ5xKe8SE=; b=BLzrPF7JJVK/eQcSltF4pPT2H PNsjDKHbMyIPQt75OFD/xgt3Tran+t5t0JIl5n6NN5YV+rxoah/hQUcmbGwTcSHpVcL8gAB0ZqiSR 3LqM+kxQu/0Oku48ZcpF17NSbkzCJmq5Vwcd8iGwI8tAxol1gULqUV8XJ1m924k97RK9bv/kGXFqb uKWRfp0mFUtW70cmQpzJSn8pqHW+NhtKzsSeMGZ1Qkwjc8tEbfYH6pv6aE+rZdLv8Io+sskEYleRZ rXGierSb3mbTZWA/k+2Mr4QKfJSorBdj9NjjUl56cMpEgCbwNXsOh0MU7deZIV5PBv7LQKlaozHFA ADu5Y77EA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:42888) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1iXwth-0001eL-2J; Fri, 22 Nov 2019 00:34:05 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1iXwtf-0003CX-5J; Fri, 22 Nov 2019 00:34:03 +0000 Date: Fri, 22 Nov 2019 00:34:03 +0000 From: Russell King - ARM Linux admin To: Pavel Tatashin Cc: James Morris , Sasha Levin , LKML , Catalin Marinas , Will Deacon , steve.capper@arm.com, Linux ARM , Marc Zyngier , James Morse , Vladimir Murzin , Mark Rutland , Thomas Gleixner , Greg Kroah-Hartman , allison@lohutok.net, info@metux.net, alexios.zavras@intel.com, sstabellini@kernel.org, boris.ostrovsky@oracle.com, jgross@suse.com, stefan@agner.ch, Masahiro Yamada , xen-devel@lists.xenproject.org Subject: Re: [PATCH 1/3] arm/arm64/xen: use C inlines for privcmd_call Message-ID: <20191122003403.GG25745@shell.armlinux.org.uk> References: <20191121184805.414758-1-pasha.tatashin@soleen.com> <20191121184805.414758-2-pasha.tatashin@soleen.com> <20191122002258.GD25745@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 21, 2019 at 07:30:41PM -0500, Pavel Tatashin wrote: > > > +#ifdef CONFIG_CPU_SW_DOMAIN_PAN > > > +static __always_inline void uaccess_enable(void) > > > +{ > > > + unsigned long val = DACR_UACCESS_ENABLE; > > > + > > > + asm volatile("mcr p15, 0, %0, c3, c0, 0" : : "r" (val)); > > > + isb(); > > > +} > > > + > > > +static __always_inline void uaccess_disable(void) > > > +{ > > > + unsigned long val = DACR_UACCESS_ENABLE; > > Oops, should be DACR_UACCESS_DISABLE. > > > > + > > > + asm volatile("mcr p15, 0, %0, c3, c0, 0" : : "r" (val)); > > > + isb(); > > > +} > > > > Rather than inventing these, why not use uaccess_save_and_enable().. > > uaccess_restore() around the Xen call? > > Thank you for suggestion: uaccess_enable() and uaccess_disable() are > common calls with arm64, so I will need them, but I think I can use > set_domain() with DACR_UACCESS_DISABLE /DACR_UACCESS_ENABLE inside > these inlines. That may be, but be very careful that you only use them in ARMv7-only code. Using them elsewhere is unsafe as the domain register is used for other purposes, and merely blatting over it (as your uaccess_enable and uaccess_disable functions do) is unsafe. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up