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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 3E812C5DF81 for ; Thu, 20 Aug 2026 17:44:50 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6F91810F148; Thu, 20 Aug 2026 17:44:49 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=arm.com header.i=@arm.com header.b="M/XzHRre"; dkim-atps=neutral Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id DC06310F148 for ; Thu, 20 Aug 2026 17:44:48 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 74B511477; Thu, 20 Aug 2026 10:44:44 -0700 (PDT) Received: from arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0F9C43F763; Thu, 20 Aug 2026 10:44:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1787247888; bh=ZM9sg/RSerJOWxKjiA4PYnkNJoiYGKpyXA8LruZG+VE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=M/XzHRrezBOqpp2QoYljfNsuWLo6QApmQ7ZiAInG4n0QLnmZo37eyq/egMLz0msZl NvS4zWlQ6NbWJC9JfVE+ouSxZwRdwNEuLGzeRKFCn8VoThkR+KDSRosyApkLL+ioKC dsNRj5IMAfcmFGkEgCzp4TzBgmXrt7Iu8sLowYm8= Date: Thu, 20 Aug 2026 18:44:43 +0100 From: Catalin Marinas To: Steven Price Cc: Christian =?iso-8859-1?Q?K=F6nig?= , Marc Zyngier , Sumit Semwal , Thomas Gleixner , "T.J. Mercier" , Benjamin Gaignard , Brian Starkey , John Stultz , dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, Jason Gunthorpe , Jiri Pirko , Marek Szyprowski , Suzuki K Poulose , Jason Gunthorpe Subject: Re: [PATCH v2 1/4] irqchip/gic-v3-its: Zero shared pages after conversion Message-ID: References: <20260820150034.88729-1-steven.price@arm.com> <20260820150034.88729-2-steven.price@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260820150034.88729-2-steven.price@arm.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Thu, Aug 20, 2026 at 04:00:30PM +0100, Steven Price wrote: > diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c > index 6f5811aae59c..a055837832bc 100644 > --- a/drivers/irqchip/irq-gic-v3-its.c > +++ b/drivers/irqchip/irq-gic-v3-its.c > @@ -213,16 +213,18 @@ static gfp_t gfp_flags_quirk; > static struct page *its_alloc_pages_node(int node, gfp_t gfp, > unsigned int order) > { > + bool want_zero = gfp & __GFP_ZERO; > struct page *page; > int ret = 0; > > - page = alloc_pages_node(node, gfp | gfp_flags_quirk, order); > + page = alloc_pages_node(node, (gfp & ~__GFP_ZERO) | gfp_flags_quirk, > + order); I don't think pKVM does any scrubbing on set_memory_decrypted(), so it potentially exposes confidential guest data before it reaches clear_pages() below. > > if (!page) > return NULL; > > ret = set_memory_decrypted((unsigned long)page_address(page), > - 1 << order); > + BIT(order)); > /* > * If set_memory_decrypted() fails then we don't know what state the > * page is in, so we can't free it. Instead we leak it. > @@ -231,6 +233,9 @@ static struct page *its_alloc_pages_node(int node, gfp_t gfp, > if (ret) > return NULL; > > + if (want_zero) > + clear_pages(page_address(page), BIT(order)); > + > return page; > } > > -- > 2.43.0 -- Catalin