From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (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 29B6E757E4 for ; Thu, 29 Feb 2024 17:52:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709229160; cv=none; b=E/BfOWAm5Js/6tN4K+/CsTH1rkToiVQO3TXXWlkvO4t9U36pQFDBeAUifIAhrN6g5zYBXJW6j5g3zP2DdQpiXjEwspJ+QoWmLKdbko/+raJKhDhPqAnVT9swZiuw7tdd0Sef6NRWnMq8LkqPhbvoG1adhOgHXUmOxb9Kpn2rR0M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709229160; c=relaxed/simple; bh=3XHzcDQ3BdpugAYo88NvzKpQxuXlSOu6WO/2FPWINJE=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=hvJ8YkFeR7KwVzkvAza+gnTT73ObKy11tVhWhiAyfQZ/exTJ0he8XfAeRh27YIFYnMP6SgmuttXgzz8ffCrwVcyUQNWMgl59ss0RSQ7EfOCERXligkUVI4VHWV9K7sfYlUlEFqr2aEfBoihrYbe+LbzPVBT0iTqj2s55FtMACvA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.216]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4TlzGF3GXlz6K647; Fri, 1 Mar 2024 01:48:05 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 3394F140B67; Fri, 1 Mar 2024 01:52:34 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Thu, 29 Feb 2024 17:52:33 +0000 Date: Thu, 29 Feb 2024 17:52:32 +0000 From: Jonathan Cameron To: Gregory Price CC: Liu Jingqi , , , "Michael S . Tsirkin" , Igor Mammedov , Ani Sinha , , Markus Armbruster , Daniel Black , Subject: Re: [PATCH 1/2] hmat acpi: Do not add Memory Proximity Domain Attributes Structure targetting non existent memory. Message-ID: <20240229175232.000017d2@Huawei.com> In-Reply-To: References: <20240229162545.7887-1-Jonathan.Cameron@huawei.com> <20240229162545.7887-2-Jonathan.Cameron@huawei.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml100004.china.huawei.com (7.191.162.219) To lhrpeml500005.china.huawei.com (7.191.163.240) On Thu, 29 Feb 2024 12:28:51 -0500 Gregory Price wrote: > On Thu, Feb 29, 2024 at 04:25:44PM +0000, Jonathan Cameron wrote: > > If qemu is started with a proximity node containing CPUs alone, > > it will provide one of these structures to say memory in this > > node is directly connected to itself. > > > > This description is arguably pointless even if there is memory > > in the node. If there is no memory present, and hence no SRAT > > entry it breaks Linux HMAT passing and the table is rejected. > > > > https://elixir.bootlin.com/linux/latest/source/drivers/acpi/numa/hmat.c#L444 > > > > Nit: This link becomes out of date pretty much immediately, consider > using a versioned link. Good point. https://elixir.bootlin.com/linux/v6.7/source/drivers/acpi/numa/hmat.c#L444 > > > Signed-off-by: Jonathan Cameron > > --- > > hw/acpi/hmat.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/hw/acpi/hmat.c b/hw/acpi/hmat.c > > index 3042d223c8..723ae28d32 100644 > > --- a/hw/acpi/hmat.c > > +++ b/hw/acpi/hmat.c > > @@ -204,6 +204,13 @@ static void hmat_build_table_structs(GArray *table_data, NumaState *numa_state) > > build_append_int_noprefix(table_data, 0, 4); /* Reserved */ > > > > for (i = 0; i < numa_state->num_nodes; i++) { > > + /* > > + * Linux rejects whole HMAT table if a node with no memory > > + * has one of these structures listing it as a target. > > + */ > > + if (!numa_state->nodes[i].node_mem) { > > + continue; > > + } > > flags = 0; > > > > if (numa_state->nodes[i].initiator < MAX_NODES) { > > -- > > 2.39.2 > > > >