From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0538728FD for ; Sun, 29 Jun 2025 01:42:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.67.55.147 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751161347; cv=none; b=MZt0apkIqqISgyLLW/gtMHIW2x1pnp8bF9kNJB5dZlMYQY9P8DLha2pEXv1FLbb8aQwgFmkot/ErSWaC8ASCWExh+CMP4FNokMu0DxX44jCjpPoh3G2dPgCZrM+7pAwFKu4sWq6jyG0uWbaLDveE0ojs/aoqX01FY7jSWxzfnX4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751161347; c=relaxed/simple; bh=oguTD5d+SzfqkERduYUonzJQRVRzFufZIUOp/nVUstE=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=J2MyjkfxyZJOjIumRMHXg89EWap5MBJcqFagx8wVYkO/u4TOvUwHAalORrpbAYiwP1tGU83nVwYIzVzHBECDiXBnGBkrgwpxa9kdUrpFz5NsebPW6NC7J18drAvO0JiY2PfLdIDrjzpVo95vNHXFg2SQTO4M3B+VXdgKDcttkK0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com; spf=pass smtp.mailfrom=surriel.com; dkim=pass (2048-bit key) header.d=surriel.com header.i=@surriel.com header.b=Ko+asv+J; arc=none smtp.client-ip=96.67.55.147 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=surriel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=surriel.com header.i=@surriel.com header.b="Ko+asv+J" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=surriel.com ; s=mail; h=MIME-Version:Content-Transfer-Encoding:Content-Type:References: In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender:Reply-To: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=HwwWF9GbS2mUvKE0sfHwsiiGHB7p0vJM2njHQCOlwQo=; b=Ko+asv+JGufMfVbRy6LM5tIvHD 9INHe4ikytGO7h57p/mXYrUbh+tNnc6l8MPCWbQ8KeDPGdRFHajMo3Wpt21ZvdM/QZI8XNNlMUp1R PQ0c6SiH147my56+7Aa+M3+LQeSGzOARDiJGkQ2/Xboioi0RyJA8a3KKK6mrg4ymoJ9AU4AdPF6Ie raWkUxIyVxBBen4N+ixxnj6zttqc7HarHON2aovuh+ncivHnL/nqcS57+KQCZ7RCG3MhGivcbkCn6 Pk/z86cgxHIrzJ37LAYekU9xbhv9CdprvbNbw1RK7w+VhYdRwWHHMOb8+jeyViRMdDG1+6cwLPMBx uezreCjw==; Received: from fangorn.home.surriel.com ([10.0.13.7]) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1uVgsB-000000006dB-0ZRd; Sat, 28 Jun 2025 21:30:23 -0400 Message-ID: <7997802c151577c5e681813e121ded3e0d84d3ec.camel@surriel.com> Subject: Re: [RFC PATCH v4 6/8] x86/mm: use RAR for kernel TLB flushes From: Rik van Riel To: "Kirill A. Shutemov" Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, bp@alien8.de, x86@kernel.org, nadav.amit@gmail.com, seanjc@google.com, tglx@linutronix.de, mingo@kernel.org, Rik van Riel Date: Sat, 28 Jun 2025 21:30:23 -0400 In-Reply-To: References: <20250619200442.1694583-1-riel@surriel.com> <20250619200442.1694583-7-riel@surriel.com> Autocrypt: addr=riel@surriel.com; prefer-encrypt=mutual; keydata=mQENBFIt3aUBCADCK0LicyCYyMa0E1lodCDUBf6G+6C5UXKG1jEYwQu49cc/gUBTTk33A eo2hjn4JinVaPF3zfZprnKMEGGv4dHvEOCPWiNhlz5RtqH3SKJllq2dpeMS9RqbMvDA36rlJIIo47 Z/nl6IA8MDhSqyqdnTY8z7LnQHqq16jAqwo7Ll9qALXz4yG1ZdSCmo80VPetBZZPw7WMjo+1hByv/ lvdFnLfiQ52tayuuC1r9x2qZ/SYWd2M4p/f5CLmvG9UcnkbYFsKWz8bwOBWKg1PQcaYHLx06sHGdY dIDaeVvkIfMFwAprSo5EFU+aes2VB2ZjugOTbkkW2aPSWTRsBhPHhV6dABEBAAG0HlJpayB2YW4gU mllbCA8cmllbEByZWRoYXQuY29tPokBHwQwAQIACQUCW5LcVgIdIAAKCRDOed6ShMTeg05SB/986o gEgdq4byrtaBQKFg5LWfd8e+h+QzLOg/T8mSS3dJzFXe5JBOfvYg7Bj47xXi9I5sM+I9Lu9+1XVb/ r2rGJrU1DwA09TnmyFtK76bgMF0sBEh1ECILYNQTEIemzNFwOWLZZlEhZFRJsZyX+mtEp/WQIygHV WjwuP69VJw+fPQvLOGn4j8W9QXuvhha7u1QJ7mYx4dLGHrZlHdwDsqpvWsW+3rsIqs1BBe5/Itz9o 6y9gLNtQzwmSDioV8KhF85VmYInslhv5tUtMEppfdTLyX4SUKh8ftNIVmH9mXyRCZclSoa6IMd635 Jq1Pj2/Lp64tOzSvN5Y9zaiCc5FucXtB9SaWsgdmFuIFJpZWwgPHJpZWxAc3VycmllbC5jb20+iQE +BBMBAgAoBQJSLd2lAhsjBQkSzAMABgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAAKCRDOed6ShMTe g4PpB/0ZivKYFt0LaB22ssWUrBoeNWCP1NY/lkq2QbPhR3agLB7ZXI97PF2z/5QD9Fuy/FD/jddPx KRTvFCtHcEzTOcFjBmf52uqgt3U40H9GM++0IM0yHusd9EzlaWsbp09vsAV2DwdqS69x9RPbvE/Ne fO5subhocH76okcF/aQiQ+oj2j6LJZGBJBVigOHg+4zyzdDgKM+jp0bvDI51KQ4XfxV593OhvkS3z 3FPx0CE7l62WhWrieHyBblqvkTYgJ6dq4bsYpqxxGJOkQ47WpEUx6onH+rImWmPJbSYGhwBzTo0Mm G1Nb1qGPG+mTrSmJjDRxrwf1zjmYqQreWVSFEt26tBpSaWsgdmFuIFJpZWwgPHJpZWxAZmIuY29tP okBPgQTAQIAKAUCW5LbiAIbIwUJEswDAAYLCQgHAwIGFQgCCQoLBBYCAwECHgECF4AACgkQznneko TE3oOUEQgAsrGxjTC1bGtZyuvyQPcXclap11Ogib6rQywGYu6/Mnkbd6hbyY3wpdyQii/cas2S44N cQj8HkGv91JLVE24/Wt0gITPCH3rLVJJDGQxprHTVDs1t1RAbsbp0XTksZPCNWDGYIBo2aHDwErhI omYQ0Xluo1WBtH/UmHgirHvclsou1Ks9jyTxiPyUKRfae7GNOFiX99+ZlB27P3t8CjtSO831Ij0Ip QrfooZ21YVlUKw0Wy6Ll8EyefyrEYSh8KTm8dQj4O7xxvdg865TLeLpho5PwDRF+/mR3qi8CdGbkE c4pYZQO8UDXUN4S+pe0aTeTqlYw8rRHWF9TnvtpcNzZw== Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.54.3 (3.54.3-1.fc41) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Fri, 2025-06-27 at 16:27 +0300, Kirill A. Shutemov wrote: > On Thu, Jun 19, 2025 at 04:03:58PM -0400, Rik van Riel wrote: > > From: Rik van Riel > >=20 > > Use Intel RAR for kernel TLB flushes, when enabled. > >=20 > > Pass in PCID 0 to smp_call_rar_many() to flush the specified > > addresses, > > regardless of which PCID they might be cached under in any > > destination CPU. > >=20 > > Signed-off-by: Rik van Riel > > --- > > =C2=A0arch/x86/mm/tlb.c | 38 ++++++++++++++++++++++++++++++++++++++ > > =C2=A01 file changed, 38 insertions(+) > >=20 > > diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c > > index 39f80111e6f1..8931f7029d6c 100644 > > --- a/arch/x86/mm/tlb.c > > +++ b/arch/x86/mm/tlb.c > > @@ -21,6 +21,7 @@ > > =C2=A0#include > > =C2=A0#include > > =C2=A0#include > > +#include > > =C2=A0#include > > =C2=A0 > > =C2=A0#include "mm_internal.h" > > @@ -1468,6 +1469,18 @@ static void do_flush_tlb_all(void *info) > > =C2=A0 __flush_tlb_all(); > > =C2=A0} > > =C2=A0 > > +static void rar_full_flush(const cpumask_t *cpumask) > > +{ > > + guard(preempt)(); > > + smp_call_rar_many(cpumask, 0, 0, TLB_FLUSH_ALL); > > + invpcid_flush_all(); >=20 > I don't follow why do we need to call invpcid_flush_all() here in > addition > to smp_call_rar_many(). Hm? >=20 We shouldn't have to. Once we figure out why the RAR flush isn't working right (despite the RAR transitioning from RAR_PENDING to RAR_SUCCESS) we should be able to get rid of this call. --=20 All Rights Reversed.