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 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 26DD8D3C92E for ; Sat, 19 Oct 2024 22:46:20 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4XWGrp4qvpz2yMv; Sun, 20 Oct 2024 09:46:18 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=139.178.84.217 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1729377978; cv=none; b=RxdoLJiXEWvp8nR00axwQq1oAaSMUc/TIo2Xj3cPfQl2O89apUAuLdbS6V0oJrsaMk1LHIQ/Qt6TU+HF++frCeU9PX5HU5DUWBXzIAwxefG14ZggzUFJbg8NuShspUZE4FOWo8Z5+GYqBtyVPXCGM32ZcBJmx1DDc4B5tZThpynr0l9Su9uA9Q/XDplkA8V6VarDz+OyDeZ8Un7dBq56PMznVAx6GAhqoaWlScGhIk0KSfUZb9YsHXl6d1TNbrlvzCbZQDqjTNsh7Zy1IW/vPWEzJg1JNNPqYweUUGbBIqSK4zwFAV2poRUo7DXkDu+hcDB48S38mZopSD9Q/yI9rA== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1729377978; c=relaxed/relaxed; bh=iHZrlvphzEK5suDumbASFk80vJ39P3mMNbLKT/LkPU0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nikJYyPfjw1OBXZLOowUtW2rYdI3FwctX2fXMfgymkGjfnfqxxRGozuf/DOJc+QHBcZk3NpFUbBCj4a73/Bi43FOckyiBKvzmbswSFu/yHr0cH7248JY0yqVJBsQbpBmMR/uYGtWMx1iy+hPHH/Lgzg+tXlVJVtFoZZhcGSXJYXnntH93DZRKlCPfBTMqN+ISO3BtlI6nHRHV4sRj5cn8raio1yFJ7oE62H3EaDW6G0dVZvzr0Cbu40NCi9cegFmYv75SfrR/TrIe0GUk1rn8wmVraz3NV2jpoDhNztvIl6E2njlrKR2p+kfVbAKQ4RQ0uTDCM0mciH22eCuAkJ0Qg== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=raBET/eq; dkim-atps=neutral; spf=pass (client-ip=139.178.84.217; helo=dfw.source.kernel.org; envelope-from=mcgrof@kernel.org; receiver=lists.ozlabs.org) smtp.mailfrom=kernel.org Authentication-Results: lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=raBET/eq; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=139.178.84.217; helo=dfw.source.kernel.org; envelope-from=mcgrof@kernel.org; receiver=lists.ozlabs.org) Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4XWGrn3pyyz2yMP for ; Sun, 20 Oct 2024 09:46:17 +1100 (AEDT) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id BF9575C5444; Sat, 19 Oct 2024 22:46:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A187C4CEC5; Sat, 19 Oct 2024 22:46:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729377972; bh=cD5eaMzUFo7t+XYDnFM25WIUwCFcdwXaz1SfpP4a6SE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=raBET/eqnMHymvQ7ghoiJNJzhJfHKuWETI4KcodqrLn6OQ/Y9CKtRyA2t4EAlqgdL hZ8GXfGOFi/KBP9oOEyOznfd0G9uHgQFOCCAyoXDyjtw5nXygFTG2CrK0T0RFUBMS3 dw6lBjU8rrQg3O+nhowKfheReV2QdNr7rWdr90u1jL/xItyfqX/Q3Me8KZXxc+SLgs Bgsl1ciX2BowyzgKq/taZpeBj4IacVWutv5wVHimbHiaNsgZE0UEMAbBKocO0BFYoV nD2awtEWshprtgJwrLo1F7dN4Asn2HkQ91l7gW0Dv7NafPgx9Qm2IawXuSLgLc1IAt hvIMZRfR3Mm9A== Date: Sat, 19 Oct 2024 15:46:09 -0700 From: Luis Chamberlain To: Mike Rapoport Cc: Andrew Morton , Andreas Larsson , Andy Lutomirski , Ard Biesheuvel , Arnd Bergmann , Borislav Petkov , Brian Cain , Catalin Marinas , Christoph Hellwig , Christophe Leroy , Dave Hansen , Dinh Nguyen , Geert Uytterhoeven , Guo Ren , Helge Deller , Huacai Chen , Ingo Molnar , Johannes Berg , John Paul Adrian Glaubitz , Kent Overstreet , "Liam R. Howlett" , Mark Rutland , Masami Hiramatsu , Matt Turner , Max Filippov , Michael Ellerman , Michal Simek , Oleg Nesterov , Palmer Dabbelt , Peter Zijlstra , Richard Weinberger , Russell King , Song Liu , Stafford Horne , Steven Rostedt , Suren Baghdasaryan , Thomas Bogendoerfer , Thomas Gleixner , Uladzislau Rezki , Vineet Gupta , Will Deacon , bpf@vger.kernel.org, linux-alpha@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-kernel@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, linux-openrisc@vger.kernel.org, linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-trace-kernel@vger.kernel.org, linux-um@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, loongarch@lists.linux.dev, sparclinux@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH v6 7/8] execmem: add support for cache of large ROX pages Message-ID: References: <20241016122424.1655560-1-rppt@kernel.org> <20241016122424.1655560-8-rppt@kernel.org> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Post: List-Subscribe: , , List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241016122424.1655560-8-rppt@kernel.org> On Wed, Oct 16, 2024 at 03:24:23PM +0300, Mike Rapoport wrote: > From: "Mike Rapoport (Microsoft)" > > Using large pages to map text areas reduces iTLB pressure and improves > performance. > > Extend execmem_alloc() with an ability to use huge pages with ROX > permissions as a cache for smaller allocations. > > To populate the cache, a writable large page is allocated from vmalloc with > VM_ALLOW_HUGE_VMAP, filled with invalid instructions and then remapped as > ROX. > > The direct map alias of that large page is exculded from the direct map. > > Portions of that large page are handed out to execmem_alloc() callers > without any changes to the permissions. > > When the memory is freed with execmem_free() it is invalidated again so > that it won't contain stale instructions. > > An architecture has to implement execmem_fill_trapping_insns() callback > and select ARCH_HAS_EXECMEM_ROX configuration option to be able to use > the ROX cache. > > The cache is enabled on per-range basis when an architecture sets > EXECMEM_ROX_CACHE flag in definition of an execmem_range. > > Signed-off-by: Mike Rapoport (Microsoft) Reviewed-by: Luis Chamberlain Luis