From patchwork Mon Feb 1 23:26:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Andrew Cooper X-Patchwork-Id: 12060221 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 EBC51C433E0 for ; Mon, 1 Feb 2021 23:27:48 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 9756364E2E for ; Mon, 1 Feb 2021 23:27:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9756364E2E Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=citrix.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.80191.146512 (Exim 4.92) (envelope-from ) id 1l6ibb-0007UN-VW; Mon, 01 Feb 2021 23:27:39 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 80191.146512; Mon, 01 Feb 2021 23:27:39 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l6ibb-0007UB-P4; Mon, 01 Feb 2021 23:27:39 +0000 Received: by outflank-mailman (input) for mailman id 80191; Mon, 01 Feb 2021 23:27:38 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l6iba-0007PB-S1 for xen-devel@lists.xenproject.org; Mon, 01 Feb 2021 23:27:38 +0000 Received: from esa3.hc3370-68.iphmx.com (unknown [216.71.145.155]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 530ec581-18cd-4167-be04-6ebe22ae1b1a; Mon, 01 Feb 2021 23:27:33 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 530ec581-18cd-4167-be04-6ebe22ae1b1a DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1612222053; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=ndDeJS/U1dfYy3KhxJrt2mDw759yVCsV1w6A2jxC4Vc=; b=ONwkkz4bp/Rs/aDmWEzl3ejg2gfVuUGHPmueZ8g+Y0eohiCZ9YSzCSvy x6RI8SyEU9dObXAgtHppbolQJk2VYQCkKWu6zRvbggnNtXpZUySDJOsRC AIVTcG3E8V/LhFACCqWdwyTKXCE8O3bxv9jD6ZZuh6tM0r50meMvFiW75 Q=; Authentication-Results: esa3.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: qPaTmDrkP1LKm8wqBC3XVmHClBioSLKitKOvQ8gdeQSj8QZTBSD0gl6IF4SE3Jk6eaauqodLPf XeAAr0udY8Y/XhFkyeew+ppbCt3K4DrTK8SQVhInP7O29toYZdCSQagGB67guO7cxm+C0NKqp/ rv8MFkIvoCSWNEEw0sPtuejPeiHoMs7vhYjvPXAgOwdoLcySy2iAShIBmLfgwwFvjlkqoIlD3C bKWkohFeKuCfe5aJbhnBrE+7bhd1hGuI44pzxwYMICvfuAEnZORRz+WBWlQPkaA8gsO5S8UJzD 6hc= X-SBRS: 5.1 X-MesageID: 36319797 X-Ironport-Server: esa3.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.79,393,1602561600"; d="scan'208";a="36319797" From: Andrew Cooper To: Xen-devel CC: =?utf-8?q?Micha=C5=82_Leszczy=C5=84ski?= , Andrew Cooper , Jan Beulich , =?utf-8?q?Roger_Pau_Monn=C3=A9?= , Wei Liu , Anthony PERARD , Tamas K Lengyel Subject: [PATCH v9 02/11] xen/domain: Add vmtrace_size domain creation parameter Date: Mon, 1 Feb 2021 23:26:54 +0000 Message-ID: <20210201232703.29275-3-andrew.cooper3@citrix.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20210201232703.29275-1-andrew.cooper3@citrix.com> References: <20210201232703.29275-1-andrew.cooper3@citrix.com> MIME-Version: 1.0 From: Michał Leszczyński To use vmtrace, buffers of a suitable size need allocating, and different tasks will want different sizes. Add a domain creation parameter, and audit it appropriately in the {arch_,}sanitise_domain_config() functions. For now, the x86 specific auditing is tuned to Processor Trace running in Single Output mode, which requires a single contiguous range of memory. The size is given an arbitrary limit of 64M which is expected to be enough for anticipated usecases, but not large enough to get into long-running-hypercall problems. Signed-off-by: Michał Leszczyński Signed-off-by: Andrew Cooper Reviewed-by: Roger Pau Monné Acked-by: Jan Beulich --- CC: Jan Beulich CC: Roger Pau Monné CC: Wei Liu CC: Anthony PERARD CC: Michał Leszczyński CC: Tamas K Lengyel When support for later generations of IPT get added, we can in principle start to use ToTP which is a scatter list of smaller trace regions to use, if we need to massively up the buffer size available. v9: * Drop misleading comments in vmtrace_alloc_buffer(). Memory still gets leaked in theoretical corner cases, but the pattern needs fixing across the board when we figure out a solution. v8: * Rename vmtrace_frames to vmtrace_size. Reposition to fill a hole. * Rename vmtrace.buf to vmtrace.pg. * Rework the refcounting logic and comment it *very* clearly. v7: * Major chop&change within the series. * Use the name 'vmtrace' consistently. * Use the (new) common vcpu_teardown() functionality, rather than leaving a latent memory leak on ARM. --- xen/arch/x86/domain.c | 23 ++++++++++++++++ xen/common/domain.c | 64 +++++++++++++++++++++++++++++++++++++++++++++ xen/include/public/domctl.h | 3 +++ xen/include/xen/sched.h | 6 +++++ 4 files changed, 96 insertions(+) diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c index b9ba04633e..6c7ee25f3b 100644 --- a/xen/arch/x86/domain.c +++ b/xen/arch/x86/domain.c @@ -660,6 +660,29 @@ int arch_sanitise_domain_config(struct xen_domctl_createdomain *config) return -EINVAL; } + if ( config->vmtrace_size ) + { + unsigned int size = config->vmtrace_size; + + ASSERT(vmtrace_available); /* Checked by common code. */ + + /* + * For now, vmtrace is restricted to HVM guests, and using a + * power-of-2 buffer between 4k and 64M in size. + */ + if ( !hvm ) + { + dprintk(XENLOG_INFO, "vmtrace not supported for PV\n"); + return -EINVAL; + } + + if ( size < PAGE_SIZE || size > MB(64) || (size & (size - 1)) ) + { + dprintk(XENLOG_INFO, "Unsupported vmtrace size: %#x\n", size); + return -EINVAL; + } + } + return 0; } diff --git a/xen/common/domain.c b/xen/common/domain.c index d1e94d88cf..b6f8d2f536 100644 --- a/xen/common/domain.c +++ b/xen/common/domain.c @@ -132,6 +132,56 @@ static void vcpu_info_reset(struct vcpu *v) v->vcpu_info_mfn = INVALID_MFN; } +static void vmtrace_free_buffer(struct vcpu *v) +{ + const struct domain *d = v->domain; + struct page_info *pg = v->vmtrace.pg; + unsigned int i; + + if ( !pg ) + return; + + v->vmtrace.pg = NULL; + + for ( i = 0; i < (d->vmtrace_size >> PAGE_SHIFT); i++ ) + { + put_page_alloc_ref(&pg[i]); + put_page_and_type(&pg[i]); + } +} + +static int vmtrace_alloc_buffer(struct vcpu *v) +{ + struct domain *d = v->domain; + struct page_info *pg; + unsigned int i; + + if ( !d->vmtrace_size ) + return 0; + + pg = alloc_domheap_pages(d, get_order_from_bytes(d->vmtrace_size), + MEMF_no_refcount); + if ( !pg ) + return -ENOMEM; + + for ( i = 0; i < (d->vmtrace_size >> PAGE_SHIFT); i++ ) + if ( unlikely(!get_page_and_type(&pg[i], d, PGT_writable_page)) ) + goto refcnt_err; + + /* + * We must only let vmtrace_free_buffer() take any action in the success + * case when we've taken all the refs it intends to drop. + */ + v->vmtrace.pg = pg; + return 0; + + refcnt_err: + while ( i-- ) + put_page_and_type(&pg[i]); + + return -ENODATA; +} + /* * Release resources held by a vcpu. There may or may not be live references * to the vcpu, and it may or may not be fully constructed. @@ -140,6 +190,8 @@ static void vcpu_info_reset(struct vcpu *v) */ static int vcpu_teardown(struct vcpu *v) { + vmtrace_free_buffer(v); + return 0; } @@ -201,6 +253,9 @@ struct vcpu *vcpu_create(struct domain *d, unsigned int vcpu_id) if ( sched_init_vcpu(v) != 0 ) goto fail_wq; + if ( vmtrace_alloc_buffer(v) != 0 ) + goto fail_wq; + if ( arch_vcpu_create(v) != 0 ) goto fail_sched; @@ -449,6 +504,12 @@ static int sanitise_domain_config(struct xen_domctl_createdomain *config) } } + if ( config->vmtrace_size && !vmtrace_available ) + { + dprintk(XENLOG_INFO, "vmtrace requested but not available\n"); + return -EINVAL; + } + return arch_sanitise_domain_config(config); } @@ -474,7 +535,10 @@ struct domain *domain_create(domid_t domid, ASSERT(is_system_domain(d) ? config == NULL : config != NULL); if ( config ) + { d->options = config->flags; + d->vmtrace_size = config->vmtrace_size; + } /* Sort out our idea of is_control_domain(). */ d->is_privileged = is_priv; diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h index 666aeb71bf..88a5b1ef5d 100644 --- a/xen/include/public/domctl.h +++ b/xen/include/public/domctl.h @@ -95,6 +95,9 @@ struct xen_domctl_createdomain { int32_t max_grant_frames; int32_t max_maptrack_frames; + /* Per-vCPU buffer size in bytes. 0 to disable. */ + uint32_t vmtrace_size; + struct xen_arch_domainconfig arch; }; diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h index 06dba1a397..bc78a09a53 100644 --- a/xen/include/xen/sched.h +++ b/xen/include/xen/sched.h @@ -272,6 +272,10 @@ struct vcpu /* vPCI per-vCPU area, used to store data for long running operations. */ struct vpci_vcpu vpci; + struct { + struct page_info *pg; /* One contiguous allocation of d->vmtrace_size */ + } vmtrace; + struct arch_vcpu arch; #ifdef CONFIG_IOREQ_SERVER @@ -547,6 +551,8 @@ struct domain unsigned int guest_request_sync : 1; } monitor; + unsigned int vmtrace_size; /* Buffer size in bytes, or 0 to disable. */ + #ifdef CONFIG_ARGO /* Argo interdomain communication support */ struct argo_domain *argo;