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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 50DF6C25B78 for ; Wed, 22 May 2024 15:53:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=PS535io4xrc/Rki/jpckJhOwbvtuAyH/RKE/pzGfVDc=; b=z6F9do4Wpy7/jJ KOStJrAWs0Lhz6DNTxOoSPVZT2IHiVA2/zFUYyLgu1tJ5ju6taLZPEdmb1M+jRRhrsYrbxGyp7FmL 1sA8K8mUw7wC3rjplfzWvPIyfr7vxSlOk4ty3DaaOy24UrsJ9KnJafkxyJljy3OoJtwCtmEggzMtI YDaZg0C/TKLzHXFCAsXrAlKhrAYQYRhZoLYs/QYetyKmhbandYZZu6TnpTZvNhhHScLsgzqn4ro35 LVO1rydN35YivA4Xelc9SdZfGw1wkK1FjTKEy6DU6CXBnA96XtFWMP5IWLmS/v0InxUMI5aa21fe2 TzJ13LeoDZA3gCbPKhxw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1s9oGu-00000003RVo-1tMY; Wed, 22 May 2024 15:52:56 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1s9oGq-00000003RU1-3Pd2 for linux-arm-kernel@lists.infradead.org; Wed, 22 May 2024 15:52:54 +0000 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 0FC60339; Wed, 22 May 2024 08:53:09 -0700 (PDT) Received: from [10.57.35.73] (unknown [10.57.35.73]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B985F3F766; Wed, 22 May 2024 08:52:41 -0700 (PDT) Message-ID: <74011ac1-34e0-4ee3-a00d-f78ad334fce2@arm.com> Date: Wed, 22 May 2024 16:52:45 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 12/14] arm64: realm: Support nonsecure ITS emulation shared To: Catalin Marinas Cc: kvm@vger.kernel.org, kvmarm@lists.linux.dev, Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni References: <20240412084213.1733764-1-steven.price@arm.com> <20240412084213.1733764-13-steven.price@arm.com> From: Steven Price Content-Language: en-GB In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240522_085253_320642_38A87406 X-CRM114-Status: GOOD ( 19.31 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 15/05/2024 12:01, Catalin Marinas wrote: > On Fri, Apr 12, 2024 at 09:42:11AM +0100, Steven Price wrote: >> @@ -198,6 +201,33 @@ static DEFINE_IDA(its_vpeid_ida); >> #define gic_data_rdist_rd_base() (gic_data_rdist()->rd_base) >> #define gic_data_rdist_vlpi_base() (gic_data_rdist_rd_base() + SZ_128K) >> >> +static struct page *its_alloc_shared_pages_node(int node, gfp_t gfp, >> + unsigned int order) >> +{ >> + struct page *page; >> + >> + if (node == NUMA_NO_NODE) >> + page = alloc_pages(gfp, order); >> + else >> + page = alloc_pages_node(node, gfp, order); > > I think you can just call alloc_pages_node() in both cases. This > function takes care of the NUMA_NO_NODE case itself. > >> + >> + if (page) >> + set_memory_decrypted((unsigned long)page_address(page), >> + 1 << order); >> + return page; >> +} >> + >> +static struct page *its_alloc_shared_pages(gfp_t gfp, unsigned int order) >> +{ >> + return its_alloc_shared_pages_node(NUMA_NO_NODE, gfp, order); >> +} >> + >> +static void its_free_shared_pages(void *addr, unsigned int order) >> +{ >> + set_memory_encrypted((unsigned long)addr, 1 << order); >> + free_pages((unsigned long)addr, order); >> +} > > More of a nitpick on the naming: Are these functions used by the host as > well? The 'shared' part of the name does not make much sense, so maybe > just call them its_alloc_page() etc. Yes, the host is emulating this so the pages need to be in the shared region. However this is only for realms, for a normal guest this functions obviously aren't "sharing" with anything - so perhaps dropping the 'shared' part makes sense. >> @@ -3432,7 +3468,16 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id, >> nr_ites = max(2, nvecs); >> sz = nr_ites * (FIELD_GET(GITS_TYPER_ITT_ENTRY_SIZE, its->typer) + 1); >> sz = max(sz, ITS_ITT_ALIGN) + ITS_ITT_ALIGN - 1; >> - itt = kzalloc_node(sz, GFP_KERNEL, its->numa_node); >> + itt_order = get_order(sz); >> + page = its_alloc_shared_pages_node(its->numa_node, >> + GFP_KERNEL | __GFP_ZERO, >> + itt_order); > > How much do we waste by going for a full page always if this is going to > be used on the host? sz is a minimum of ITS_ITT_ALIGN*2-1 - which is 511 bytes. So potentially PAGE_SIZE-512 bytes could be wasted here (minus kmalloc overhead). >> + if (!page) >> + return NULL; >> + itt = (void *)page_address(page); > > page_address() has the void * type already. > Indeed, the cast is pointless. I'll remove. Thanks, Steve _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel