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 X-Spam-Level: X-Spam-Status: No, score=-11.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 232D1C2D0A3 for ; Wed, 4 Nov 2020 22:14:06 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7B76D2080D for ; Wed, 4 Nov 2020 22:14:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="NfpCC68e" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7B76D2080D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id DF4BA854DB; Wed, 4 Nov 2020 22:14:04 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id BPct3hLWM9Xe; Wed, 4 Nov 2020 22:14:03 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id B2C9C84FA5; Wed, 4 Nov 2020 22:14:03 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id A1812C088B; Wed, 4 Nov 2020 22:14:03 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 9D727C0051 for ; Wed, 4 Nov 2020 22:14:02 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 927D381420 for ; Wed, 4 Nov 2020 22:14:02 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id rWwjZP65ZcJq for ; Wed, 4 Nov 2020 22:14:00 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from aserp2130.oracle.com (aserp2130.oracle.com [141.146.126.79]) by whitealder.osuosl.org (Postfix) with ESMTPS id 6CE2984D35 for ; Wed, 4 Nov 2020 22:14:00 +0000 (UTC) Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0A4M9ZdN011988; Wed, 4 Nov 2020 22:13:17 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=+MsunikMfk3zwmlZ0LSPh2GGzl34k8yIm00JFMmjECY=; b=NfpCC68eNlmGeU1hKsxqcDfxcfw1IuPh7xNLDlhbpmAM+CmNo9c2I9fIxeG7wI7T1gZm OTIquOzjUJ8PTaP2G7GJ3JcjGpPAPtSKgAm3ZLxerSyHrGSLA/w0lwP+rmmY4Dh2YhXa Vahgvweji9X+c2JcGxz1qC3PPth2+RkrUG4Fizb3AcdzH9U1LGzUeLmcC9zc0oib0Q8Z N+duXDwDHngkEhWcrMG6cILiebYDUkWa9klUqyyMOsTK8cR9s1imTmAzqz7srO1vFw9m Z1VJlXU+3+9Mp7s0p+fw/hybPBoJ9hWPpMmmF1Viljmrxdgeb6nHwaSWgmZzD3/MwLJj sA== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2130.oracle.com with ESMTP id 34hhb295cc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 04 Nov 2020 22:13:17 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0A4MAkn6172262; Wed, 4 Nov 2020 22:13:16 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3020.oracle.com with ESMTP id 34hw0g8t1t-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 04 Nov 2020 22:13:16 +0000 Received: from abhmp0002.oracle.com (abhmp0002.oracle.com [141.146.116.8]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 0A4MD7KL001316; Wed, 4 Nov 2020 22:13:07 GMT Received: from char.us.oracle.com (/10.152.32.25) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 04 Nov 2020 14:13:06 -0800 Received: by char.us.oracle.com (Postfix, from userid 1000) id 312A86A00F4; Wed, 4 Nov 2020 17:14:53 -0500 (EST) Date: Wed, 4 Nov 2020 17:14:52 -0500 From: Konrad Rzeszutek Wilk To: Ashish Kalra Subject: Re: [PATCH v3] swiotlb: Adjust SWIOTBL bounce buffer size for SEV guests. Message-ID: <20201104221452.GA26079@char.us.oracle.com> References: <20201104220804.21026-1-Ashish.Kalra@amd.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201104220804.21026-1-Ashish.Kalra@amd.com> User-Agent: Mutt/1.9.1 (2017-09-22) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9795 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 mlxlogscore=999 phishscore=0 bulkscore=0 spamscore=0 malwarescore=0 mlxscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011040157 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9795 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 phishscore=0 suspectscore=0 clxscore=1011 mlxlogscore=999 impostorscore=0 malwarescore=0 lowpriorityscore=0 adultscore=0 spamscore=0 priorityscore=1501 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011040157 Cc: Thomas.Lendacky@amd.com, brijesh.singh@amd.com, ssg.sos.patches@amd.com, dave.hansen@linux-intel.com, peterz@infradead.org, x86@kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, mingo@redhat.com, bp@alien8.de, luto@kernel.org, hpa@zytor.com, tglx@linutronix.de, hch@lst.de X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Wed, Nov 04, 2020 at 10:08:04PM +0000, Ashish Kalra wrote: > From: Ashish Kalra > > For SEV, all DMA to and from guest has to use shared > (un-encrypted) pages. SEV uses SWIOTLB to make this > happen without requiring changes to device drivers. > However, depending on workload being run, the default > 64MB of SWIOTLB might not be enough and SWIOTLB > may run out of buffers to use for DMA, resulting > in I/O errors and/or performance degradation for > high I/O workloads. > > Increase the default size of SWIOTLB for SEV guests > using a minimum value of 128MB and a maximum value 64MB for a 1GB VM is not enough? > of 512MB, determining on amount of provisioned guest I like the implementation on how this is done.. but the choices of memory and how much seems very much random. Could there be some math behind this? > memory. > > Using late_initcall() interface to invoke > swiotlb_adjust() does not work as the size > adjustment needs to be done before mem_encrypt_init() > and reserve_crashkernel() which use the allocated > SWIOTLB buffer size, hence calling it explicitly > from setup_arch(). > > The SWIOTLB default size adjustment is added as an > architecture specific interface/callback to allow > architectures such as those supporting memory > encryption to adjust/expand SWIOTLB size for their > use. > > Signed-off-by: Ashish Kalra > --- > arch/x86/kernel/setup.c | 2 ++ > arch/x86/mm/mem_encrypt.c | 42 +++++++++++++++++++++++++++++++++++++++ > include/linux/swiotlb.h | 1 + > kernel/dma/swiotlb.c | 27 +++++++++++++++++++++++++ > 4 files changed, 72 insertions(+) > > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c > index 3511736fbc74..b073d58dd4a3 100644 > --- a/arch/x86/kernel/setup.c > +++ b/arch/x86/kernel/setup.c > @@ -1166,6 +1166,8 @@ void __init setup_arch(char **cmdline_p) > if (boot_cpu_has(X86_FEATURE_GBPAGES)) > hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT); > > + swiotlb_adjust(); > + > /* > * Reserve memory for crash kernel after SRAT is parsed so that it > * won't consume hotpluggable memory. > diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c > index 3f248f0d0e07..e0deb157cddd 100644 > --- a/arch/x86/mm/mem_encrypt.c > +++ b/arch/x86/mm/mem_encrypt.c > @@ -489,7 +489,49 @@ static void print_mem_encrypt_feature_info(void) > pr_cont("\n"); > } > > +#define TOTAL_MEM_1G 0x40000000UL > +#define TOTAL_MEM_4G 0x100000000UL > + > +#define SIZE_128M (128UL<<20) > +#define SIZE_256M (256UL<<20) > +#define SIZE_512M (512UL<<20) > + > /* Architecture __weak replacement functions */ > +unsigned long __init arch_swiotlb_adjust(unsigned long iotlb_default_size) > +{ > + unsigned long size = 0; > + > + /* > + * For SEV, all DMA has to occur via shared/unencrypted pages. > + * SEV uses SWOTLB to make this happen without changing device > + * drivers. However, depending on the workload being run, the > + * default 64MB of SWIOTLB may not be enough & SWIOTLB may > + * run out of buffers for DMA, resulting in I/O errors and/or > + * performance degradation especially with high I/O workloads. > + * Increase the default size of SWIOTLB for SEV guests using > + * a minimum value of 128MB and a maximum value of 512MB, > + * depending on amount of provisioned guest memory. > + */ > + if (sev_active()) { > + phys_addr_t total_mem = memblock_phys_mem_size(); > + > + if (total_mem <= TOTAL_MEM_1G) > + size = clamp(iotlb_default_size * 2, SIZE_128M, > + SIZE_128M); > + else if (total_mem <= TOTAL_MEM_4G) > + size = clamp(iotlb_default_size * 4, SIZE_256M, > + SIZE_256M); > + else > + size = clamp(iotlb_default_size * 8, SIZE_512M, > + SIZE_512M); > + > + pr_info("SEV adjusted max SWIOTLB size = %luMB", > + size >> 20); > + } > + > + return size; > +} > + > void __init mem_encrypt_init(void) > { > if (!sme_me_mask) > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h > index 046bb94bd4d6..01ae6d891327 100644 > --- a/include/linux/swiotlb.h > +++ b/include/linux/swiotlb.h > @@ -33,6 +33,7 @@ extern void swiotlb_init(int verbose); > int swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose); > extern unsigned long swiotlb_nr_tbl(void); > unsigned long swiotlb_size_or_default(void); > +extern void __init swiotlb_adjust(void); > extern int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs); > extern void __init swiotlb_update_mem_attributes(void); > > diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c > index c19379fabd20..66a9e627bb51 100644 > --- a/kernel/dma/swiotlb.c > +++ b/kernel/dma/swiotlb.c > @@ -163,6 +163,33 @@ unsigned long swiotlb_size_or_default(void) > return size ? size : (IO_TLB_DEFAULT_SIZE); > } > > +unsigned long __init __weak arch_swiotlb_adjust(unsigned long size) > +{ > + return 0; > +} > + > +void __init swiotlb_adjust(void) > +{ > + unsigned long size; > + > + /* > + * If swiotlb parameter has not been specified, give a chance to > + * architectures such as those supporting memory encryption to > + * adjust/expand SWIOTLB size for their use. > + */ > + if (!io_tlb_nslabs) { > + size = arch_swiotlb_adjust(IO_TLB_DEFAULT_SIZE); > + if (size) { > + size = ALIGN(size, 1 << IO_TLB_SHIFT); > + io_tlb_nslabs = size >> IO_TLB_SHIFT; > + io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); > + > + pr_info("architecture adjusted SWIOTLB slabs = %lu\n", > + io_tlb_nslabs); > + } > + } > +} > + > void swiotlb_print_info(void) > { > unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT; > -- > 2.17.1 > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu