From patchwork Mon Nov 6 15:58:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haitao Huang X-Patchwork-Id: 13447156 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81727C4167D for ; Mon, 6 Nov 2023 15:59:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232032AbjKFP7t (ORCPT ); Mon, 6 Nov 2023 10:59:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49680 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232375AbjKFP7s (ORCPT ); Mon, 6 Nov 2023 10:59:48 -0500 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F317134; Mon, 6 Nov 2023 07:59:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1699286386; x=1730822386; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=nNLv1SRYuFTxKKGWoPF57npETHhdWVhK7V/evmU3EZ0=; b=ExDgPGp89KgJMJ7spuC4pltQ9hAX5n570J9QAe5UtqbpKYr9axvIObTU 63q9+9MM6moQyzIh3MmK04MxfJGCI7lbFdmwo3oP5PHiuB6d4IMWI0Axs Awmq4y+KSOX9M0YEG4/8SVLCRnGukWBPVw6lEHpKjztAg6Tt8JSDvMEMo CYgtOiCH2SjW+xVmwjltO3AJFqJ3SmKkMN8flR4TNGi9w9ZCsGQa3gLDw WvZQEIo0antl/HlTFUgdT5oZKqBjSF57ClLxRbvd9MKWA8aysSSBjDZ/r ICVhlM2hGuz1tGZUWwiE/QD10b1OZ53hLK0X9aktJLD+WVNdPpv02iEW8 w==; X-IronPort-AV: E=McAfee;i="6600,9927,10886"; a="7935095" X-IronPort-AV: E=Sophos;i="6.03,282,1694761200"; d="scan'208";a="7935095" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Nov 2023 07:59:45 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10886"; a="1093820031" X-IronPort-AV: E=Sophos;i="6.03,282,1694761200"; d="scan'208";a="1093820031" Received: from b4969161e530.jf.intel.com ([10.165.56.46]) by fmsmga005.fm.intel.com with ESMTP; 06 Nov 2023 07:59:43 -0800 From: Haitao Huang To: haitao.huang@linux.intel.com Cc: anakrish@microsoft.com, bp@alien8.de, cgroups@vger.kernel.org, dave.hansen@linux.intel.com, hpa@zytor.com, jarkko@kernel.org, kristen@linux.intel.com, linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org, mikko.ylinen@linux.intel.com, mingo@redhat.com, mkoutny@suse.com, sean.j.christopherson@intel.com, seanjc@google.com, sohil.mehta@intel.com, tglx@linutronix.de, tj@kernel.org, x86@kernel.org, yangjie@microsoft.com, zhanb@microsoft.com, zhiquan1.li@intel.com Subject: [PATCH] x86/sgx: Charge proper mem_cgroup for usage due to EPC reclamation by cgroups Date: Mon, 6 Nov 2023 07:58:59 -0800 Message-Id: <20231106155859.7251-1-haitao.huang@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231030182013.40086-11-haitao.huang@linux.intel.com> References: <20231030182013.40086-11-haitao.huang@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org Enclave Page Cache(EPC) memory can be swapped out to regular system memory, and the consumed memory should be charged to a proper mem_cgroup. Currently the selection of mem_cgroup to charge is done in sgx_encl_get_mem_cgroup(). But it only considers two contexts in which the swapping can be done: normal task and the ksgxd kthread. With the new EPC cgroup implementation, the swapping can also happen in EPC cgroup work-queue threads. In those cases, it improperly selects the root mem_cgroup to charge for the RAM usage. Change sgx_encl_get_mem_cgroup() to handle non-task contexts only and return the mem_cgroup of an mm_struct associated with the enclave. The return is used to charge for EPC backing pages in all kthread cases. Pass a flag into the top level reclamation function, sgx_do_epc_reclamation(), to explicitly indicate whether it is called from a background kthread. Internally, if the flag is true, switch the active mem_cgroup to the one returned from sgx_encl_get_mem_cgroup(), prior to any backing page allocation, in order to ensure that shmem page allocations are charged to the enclave's cgroup. Removed current_is_ksgxd() as it is no longer needed. Signed-off-by: Haitao Huang Reported-by: Mikko Ylinen --- arch/x86/kernel/cpu/sgx/encl.c | 43 ++++++++++++++-------------- arch/x86/kernel/cpu/sgx/encl.h | 3 +- arch/x86/kernel/cpu/sgx/epc_cgroup.c | 8 +++--- arch/x86/kernel/cpu/sgx/main.c | 26 +++++++---------- arch/x86/kernel/cpu/sgx/sgx.h | 2 +- 5 files changed, 38 insertions(+), 44 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 17dc108d3ff7..930f5bd4b752 100644 --- a/arch/x86/kernel/cpu/sgx/encl.c +++ b/arch/x86/kernel/cpu/sgx/encl.c @@ -993,9 +993,7 @@ static int __sgx_encl_get_backing(struct sgx_encl *encl, unsigned long page_inde } /* - * When called from ksgxd, returns the mem_cgroup of a struct mm stored - * in the enclave's mm_list. When not called from ksgxd, just returns - * the mem_cgroup of the current task. + * Returns the mem_cgroup of a struct mm stored in the enclave's mm_list. */ static struct mem_cgroup *sgx_encl_get_mem_cgroup(struct sgx_encl *encl) { @@ -1003,14 +1001,6 @@ static struct mem_cgroup *sgx_encl_get_mem_cgroup(struct sgx_encl *encl) struct sgx_encl_mm *encl_mm; int idx; - /* - * If called from normal task context, return the mem_cgroup - * of the current task's mm. The remainder of the handling is for - * ksgxd. - */ - if (!current_is_ksgxd()) - return get_mem_cgroup_from_mm(current->mm); - /* * Search the enclave's mm_list to find an mm associated with * this enclave to charge the allocation to. @@ -1047,29 +1037,38 @@ static struct mem_cgroup *sgx_encl_get_mem_cgroup(struct sgx_encl *encl) * @encl: an enclave pointer * @page_index: enclave page index * @backing: data for accessing backing storage for the page + * @indirect: in ksgxd or EPC cgroup work queue context + * + * Create a backing page for loading data back into an EPC page with ELDU. This function takes + * a reference on a new backing page which must be dropped with a corresponding call to + * sgx_encl_put_backing(). * - * When called from ksgxd, sets the active memcg from one of the - * mms in the enclave's mm_list prior to any backing page allocation, - * in order to ensure that shmem page allocations are charged to the - * enclave. Create a backing page for loading data back into an EPC page with - * ELDU. This function takes a reference on a new backing page which - * must be dropped with a corresponding call to sgx_encl_put_backing(). + * When @indirect is true, sets the active memcg from one of the mms in the enclave's mm_list + * prior to any backing page allocation, in order to ensure that shmem page allocations are + * charged to the enclave. * * Return: * 0 on success, * -errno otherwise. */ int sgx_encl_alloc_backing(struct sgx_encl *encl, unsigned long page_index, - struct sgx_backing *backing) + struct sgx_backing *backing, bool indirect) { - struct mem_cgroup *encl_memcg = sgx_encl_get_mem_cgroup(encl); - struct mem_cgroup *memcg = set_active_memcg(encl_memcg); + struct mem_cgroup *encl_memcg; + struct mem_cgroup *memcg; int ret; + if (indirect) { + encl_memcg = sgx_encl_get_mem_cgroup(encl); + memcg = set_active_memcg(encl_memcg); + } + ret = __sgx_encl_get_backing(encl, page_index, backing); - set_active_memcg(memcg); - mem_cgroup_put(encl_memcg); + if (indirect) { + set_active_memcg(memcg); + mem_cgroup_put(encl_memcg); + } return ret; } diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h index f94ff14c9486..549cd2e8d98b 100644 --- a/arch/x86/kernel/cpu/sgx/encl.h +++ b/arch/x86/kernel/cpu/sgx/encl.h @@ -103,12 +103,11 @@ static inline int sgx_encl_find(struct mm_struct *mm, unsigned long addr, int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start, unsigned long end, unsigned long vm_flags); -bool current_is_ksgxd(void); void sgx_encl_release(struct kref *ref); int sgx_encl_mm_add(struct sgx_encl *encl, struct mm_struct *mm); const cpumask_t *sgx_encl_cpumask(struct sgx_encl *encl); int sgx_encl_alloc_backing(struct sgx_encl *encl, unsigned long page_index, - struct sgx_backing *backing); + struct sgx_backing *backing, bool indirect); void sgx_encl_put_backing(struct sgx_backing *backing); int sgx_encl_test_and_clear_young(struct mm_struct *mm, struct sgx_encl_page *page); diff --git a/arch/x86/kernel/cpu/sgx/epc_cgroup.c b/arch/x86/kernel/cpu/sgx/epc_cgroup.c index 110d44c0ef7c..9c82bfd531e6 100644 --- a/arch/x86/kernel/cpu/sgx/epc_cgroup.c +++ b/arch/x86/kernel/cpu/sgx/epc_cgroup.c @@ -131,7 +131,7 @@ void sgx_epc_cgroup_isolate_pages(struct misc_cg *root, } static unsigned int sgx_epc_cgroup_reclaim_pages(unsigned int nr_pages, - struct misc_cg *root) + struct misc_cg *root, bool indirect) { LIST_HEAD(iso); /* @@ -143,7 +143,7 @@ static unsigned int sgx_epc_cgroup_reclaim_pages(unsigned int nr_pages, nr_pages = min(nr_pages, SGX_NR_TO_SCAN_MAX); sgx_epc_cgroup_isolate_pages(root, nr_pages, &iso); - return sgx_do_epc_reclamation(&iso); + return sgx_do_epc_reclamation(&iso, indirect); } /* @@ -191,7 +191,7 @@ static void sgx_epc_cgroup_reclaim_work_func(struct work_struct *work) break; /* Keep reclaiming until above condition is met. */ - sgx_epc_cgroup_reclaim_pages((unsigned int)(cur - max), epc_cg->cg); + sgx_epc_cgroup_reclaim_pages((unsigned int)(cur - max), epc_cg->cg, true); } } @@ -214,7 +214,7 @@ static int __sgx_epc_cgroup_try_charge(struct sgx_epc_cgroup *epc_cg, return -EBUSY; } - if (!sgx_epc_cgroup_reclaim_pages(1, epc_cg->cg)) + if (!sgx_epc_cgroup_reclaim_pages(1, epc_cg->cg, false)) /* All pages were too young to reclaim, try again */ schedule(); } diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index c496b8f15b54..45036d41c797 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -274,7 +274,7 @@ static void sgx_encl_ewb(struct sgx_epc_page *epc_page, } static void sgx_reclaimer_write(struct sgx_epc_page *epc_page, - struct sgx_backing *backing) + struct sgx_backing *backing, bool indirect) { struct sgx_encl_page *encl_page = epc_page->owner; struct sgx_encl *encl = encl_page->encl; @@ -290,7 +290,7 @@ static void sgx_reclaimer_write(struct sgx_epc_page *epc_page, if (!encl->secs_child_cnt && test_bit(SGX_ENCL_INITIALIZED, &encl->flags)) { ret = sgx_encl_alloc_backing(encl, PFN_DOWN(encl->size), - &secs_backing); + &secs_backing, indirect); if (ret) goto out; @@ -346,6 +346,7 @@ unsigned int sgx_isolate_epc_pages(struct sgx_epc_lru_list *lru, unsigned int n /** * sgx_do_epc_reclamation() - Perform reclamation for isolated EPC pages. * @iso: List of isolated pages for reclamation + * @indirect: In ksgxd or EPC cgroup workqueue threads * * Take a list of EPC pages and reclaim them to the enclave's private shmem files. Do not * reclaim the pages that have been accessed since the last scan, and move each of those pages @@ -362,7 +363,7 @@ unsigned int sgx_isolate_epc_pages(struct sgx_epc_lru_list *lru, unsigned int n * * Return: number of pages successfully reclaimed. */ -unsigned int sgx_do_epc_reclamation(struct list_head *iso) +unsigned int sgx_do_epc_reclamation(struct list_head *iso, bool indirect) { struct sgx_backing backing[SGX_NR_TO_SCAN_MAX]; struct sgx_epc_page *epc_page, *tmp; @@ -384,7 +385,7 @@ unsigned int sgx_do_epc_reclamation(struct list_head *iso) page_index = PFN_DOWN(encl_page->desc - encl_page->encl->base); mutex_lock(&encl_page->encl->lock); - ret = sgx_encl_alloc_backing(encl_page->encl, page_index, &backing[i]); + ret = sgx_encl_alloc_backing(encl_page->encl, page_index, &backing[i], indirect); if (ret) { mutex_unlock(&encl_page->encl->lock); goto skip; @@ -411,7 +412,7 @@ unsigned int sgx_do_epc_reclamation(struct list_head *iso) i = 0; list_for_each_entry_safe(epc_page, tmp, iso, list) { encl_page = epc_page->owner; - sgx_reclaimer_write(epc_page, &backing[i++]); + sgx_reclaimer_write(epc_page, &backing[i++], indirect); kref_put(&encl_page->encl->refcount, sgx_encl_release); sgx_epc_page_reset_state(epc_page); @@ -422,7 +423,7 @@ unsigned int sgx_do_epc_reclamation(struct list_head *iso) return i; } -static void sgx_reclaim_epc_pages_global(void) +static void sgx_reclaim_epc_pages_global(bool indirect) { unsigned int nr_to_scan = SGX_NR_TO_SCAN; LIST_HEAD(iso); @@ -432,7 +433,7 @@ static void sgx_reclaim_epc_pages_global(void) else sgx_isolate_epc_pages(&sgx_global_lru, nr_to_scan, &iso); - sgx_do_epc_reclamation(&iso); + sgx_do_epc_reclamation(&iso, indirect); } static bool sgx_should_reclaim(unsigned long watermark) @@ -449,7 +450,7 @@ static bool sgx_should_reclaim(unsigned long watermark) void sgx_reclaim_direct(void) { if (sgx_should_reclaim(SGX_NR_LOW_PAGES)) - sgx_reclaim_epc_pages_global(); + sgx_reclaim_epc_pages_global(false); } static int ksgxd(void *p) @@ -472,7 +473,7 @@ static int ksgxd(void *p) sgx_should_reclaim(SGX_NR_HIGH_PAGES)); if (sgx_should_reclaim(SGX_NR_HIGH_PAGES)) - sgx_reclaim_epc_pages_global(); + sgx_reclaim_epc_pages_global(true); cond_resched(); } @@ -495,11 +496,6 @@ static bool __init sgx_page_reclaimer_init(void) return true; } -bool current_is_ksgxd(void) -{ - return current == ksgxd_tsk; -} - static struct sgx_epc_page *__sgx_alloc_epc_page_from_node(int nid) { struct sgx_numa_node *node = &sgx_numa_nodes[nid]; @@ -653,7 +649,7 @@ struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim) * Need to do a global reclamation if cgroup was not full but free * physical pages run out, causing __sgx_alloc_epc_page() to fail. */ - sgx_reclaim_epc_pages_global(); + sgx_reclaim_epc_pages_global(false); cond_resched(); } diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index 6a40f70ed96f..377625e2ba1d 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -167,7 +167,7 @@ void sgx_reclaim_direct(void); void sgx_mark_page_reclaimable(struct sgx_epc_page *page); int sgx_unmark_page_reclaimable(struct sgx_epc_page *page); struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim); -unsigned int sgx_do_epc_reclamation(struct list_head *iso); +unsigned int sgx_do_epc_reclamation(struct list_head *iso, bool indirect); unsigned int sgx_isolate_epc_pages(struct sgx_epc_lru_list *lru, unsigned int nr_to_scan, struct list_head *dst);