From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 22C1A3AAF58 for ; Thu, 30 Jul 2026 17:31:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785432687; cv=none; b=RfEHMAT5N+WxrSrrEYZBtv0TqoiFgnVKiyKgDm1CyF3K9F8RpYzwDj+Z3bdhYFyUWmEBjY/dB0fIyAdXRkQjN04kV6LKRH0VpBBqMNPKhhSSmtYc4m+J8SSZ0NqYaaETCGvgEnFfqvhyLBkvOyLsxKg5oE8En/eBYlAAXJc5ngA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785432687; c=relaxed/simple; bh=xPeLe1CcUsolkLIiJLgN08QJtBG1H3RpJiIrnAT4JBk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=lpQcaLBnFOkpgY1jJ5vLYQ/w4YwQd+CHjCPRzrFXmOJQoTKC3imZiRtAh8GJvpDyMRmjGA7S6I+9UeC81TLykV4ddAvVYu467v/37738yo2QLh0eUk/DbnmTaa6iYmh238A0RfzucysfUzCV2D+F0CmRrlPWgOPs+NTXhCegQlo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=pass smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=b9R0vISN; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="b9R0vISN" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=qppwvJvzalTBoNo2JckKyFvQBCvA/yGZmUxH7n05Ie4=; b=b9R0vISNRyJ/WEhkEa/9pZKRAO Taiz2asLGD2/ZYGYDa6Zx2yd3+MaVkarsWxoGdhHvPZkFMI93MZfXqvRcqwjCBR3bkroJ5tidjmiT utctRviPAPN3xcIR6Xw9gCrU5tBPLjzQ+0R406CDQcfwZ4BTRfSIJkV3VmjFKxCPzfSS4DjMplQxO Gu1wQ2UK+U7Qz3+HQhFGZFsjL87bPynAL+Vih39YI2SteLkgRRfjrtyTWrbK0AHRDpxLIxRGfH+QU ripd/tWJ6qwaG8uQqhiBipurqFKOUihawAuxq44Bh/Z2JIi3L+ppROYyr3S9/kNmlz1Z90IsG0wMT lVhPk1Iw==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.99.2 #2 (Red Hat Linux)) id 1wpUb3-00000006rqP-2O4A; Thu, 30 Jul 2026 17:31:05 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 488D030095A; Thu, 30 Jul 2026 19:31:04 +0200 (CEST) Date: Thu, 30 Jul 2026 19:31:04 +0200 From: Peter Zijlstra To: Borislav Petkov Cc: Rik van Riel , Dave Hansen , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , x86@kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH] add tlbi=off to disable INVLPGB Message-ID: <20260730173104.GB776954@noisy.programming.kicks-ass.net> References: <20260729204341.3eb0b5ea@fangorn> <20260730014412.GEamqsbL46iteL25as@fat_crate.local> <20260730103227.GC751831@noisy.programming.kicks-ass.net> <20260730162318.GAamt6ds0siEVGwWlw@fat_crate.local> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260730162318.GAamt6ds0siEVGwWlw@fat_crate.local> On Thu, Jul 30, 2026 at 09:23:18AM -0700, Borislav Petkov wrote: > On Thu, Jul 30, 2026 at 12:32:27PM +0200, Peter Zijlstra wrote: > > TLBI stands for Translation Lookaside Buffer Invalidation. > > ... instructions." Both ARM and AMD call it this. The usual abbreviation > overload we're suffering from. Same difference, that would mean disabling all TLB instructions :-) Very much including the local invalidation used for IPI based TLB invalidation. But also, nah: https://support.arm.com/documentation/dui0802/b/A64-General-Instructions/TLBI "TLBI - TLB invalidate operation." > > So a command line that says: 'tlbi=off' means no move invalidation *at*all*. > > This seems like a very bad option. > > > > Please rename. > > You suggest one. :-P > > But it needs to be short and relatively easy to type. And "invlpgb" ain't easy > and I can't tell you how many times I've seen it getting typoed. tlbi={ipi,broadcast} Anyway, INVLPGB stands for INVaLidate PaGe Broadcast, ain'ted that hard :-) Also, you know who to complain to for that instruction :-)