From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 CAA0222BACA for ; Thu, 16 Jan 2025 22:38:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737067091; cv=none; b=cNPEwy2ScKWJCESbOZufzMe+qXneArQ2iG9YY94+fZ6U8lE7bwQFKkBhWPtdmOOzPZyNZPEAwzPvcHWNxQ6E5Yv+EkddY9YkYKF2CNlvHznvup/Ubh0HxlCfxWL3eo/1vLHBnx7ApR8mrIjx6HVTO/4RUebrMGaumqdam9yqFk0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737067091; c=relaxed/simple; bh=baA3kci9Nwk8+Js0+p7PuVaHWs7BI4E3GbSBfNTgTN4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TffmNWJS+GtbeYgIpiBxSnGBsI2kLGpBalmcDm8+g2wxg17CN5jHf868ai16/Bx/8GeYg8yTLNpe8dcL/wpRwaorrkCFvSR64Kfs6KrlkLE9a6qHu+r43P3U3l6JLsF0WKuimvG66AUPJh65V7VxfCxefgNNvJPvvFm+svEHi9A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=uKmwoAHW; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none 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="uKmwoAHW" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=baA3kci9Nwk8+Js0+p7PuVaHWs7BI4E3GbSBfNTgTN4=; b=uKmwoAHWSuuC5HQtVCfyGNdbHX XJ8luxAnuzLhqgRnOJdybtnnT6VvqWeOsWx6mUDnBS9vWpB2ymWoDvQfYygeN4R0JxV70dsPrZ0lZ +G7PAtzjE0q2UbtENx8dAyp4N7mdTgZaXDTIKBNk2B3Yns64KpVsklQe71OBAN+XrbeCutR9b4gqV 5ubSc3FP6+34wRZ5dlPuNo7QlT+mtda7SGRgcjRo1iTfmI/IL07TfSUOVhNBfM/vOOiROfZxINZKv AE7S7r7qUTWLs07JYMi0nPQ25WllxSsL+R7yjXC4eqczMuXSwlrxxlmgVOSNGyrA6LYmyQV/8iw5A DoD94N/w==; Received: from 77-249-17-89.cable.dynamic.v4.ziggo.nl ([77.249.17.89] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tYYUn-00000003ZcJ-2qka; Thu, 16 Jan 2025 22:37:49 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 91802300777; Thu, 16 Jan 2025 23:37:48 +0100 (CET) Date: Thu, 16 Jan 2025 23:37:48 +0100 From: Peter Zijlstra To: Michael Kelley Cc: "riel@surriel.com" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "zhengqi.arch@bytedance.com" , "nadav.amit@gmail.com" , "thomas.lendacky@amd.com" , "kernel-team@meta.com" , "linux-mm@kvack.org" , "akpm@linux-foundation.org" , "jannh@google.com" , "andrew.cooper3@citrix.com" Subject: Re: [PATCH v5 00/12] AMD broadcast TLB invalidation Message-ID: <20250116223748.GA33629@noisy.programming.kicks-ass.net> References: <20250116023127.1531583-1-riel@surriel.com> 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: On Thu, Jan 16, 2025 at 06:14:00PM +0000, Michael Kelley wrote: > So CoCo > VMs may still use the paravirtualization that makes hypercalls to do > TLB flushes. It's future work to *always* use INVLPGB (if available) > in a CoCo VM. That would place a limit on the number of CPUs, to be no larger than the number of available ASIDs.