From patchwork Tue Jan 30 02:09:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haitao Huang X-Patchwork-Id: 13536700 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) (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 91463376E9; Tue, 30 Jan 2024 02:09:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.10 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706580586; cv=none; b=C7z9Pdj4JcGfRN5mRxpcmCvl1S555kq8Fkx/xvZ8TRhNwbbBsGTFVwdnhjyeFE+SsDAlgsaJiXhWPJ1HR9/VKWy/x5lapCWcLZhzz5wkxpZFHvCVUsTneSgrfLuxTz6ZRYTBf8dpHBfZ+o745jCV3uEIj5xSanqp1x4+newCZ6U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706580586; c=relaxed/simple; bh=PoyVKTX25MY4a35rvXrMVzkJGqAxRZaTOxgth451WqE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=aXzjBANx0gn4EiApZk2VnfRYBuV47W3hyLOhoV4QO/6Z7eJ7Pp2IeEkwDR0uPjJIBvhw5dabBPUe4l7WvVaERWvCBQ0T+BGtUfrIHeA2OpD6WLJ5NuyQiXosZUnOGauFNyRuBKG6qk7hYujrehLMrZNI3D/liMmzWXaFu5A2Z3U= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=ixMKRwEc; arc=none smtp.client-ip=198.175.65.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="ixMKRwEc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1706580585; x=1738116585; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=PoyVKTX25MY4a35rvXrMVzkJGqAxRZaTOxgth451WqE=; b=ixMKRwEcDkCuz20+GaKp3exJZ/88qVusMjKtiJZwRTeGbX8Yub4Mvr6M F8OlQFgERq0uMt7nv+IbxaI8X81PILuJfs6w/1JcVqlQoW53AS2OyGWzD YM7X+UWq3CZgGML38DCS0M0FvxrNA74njz1BSiXn/eYOBWAPB3xzUJ8SY LzTyhySeusxelBvF8fbCmvdUyIzgq/HJ0WLfLE0ZR2gCginWtCXEILRCQ d+Z6pFUmjq/OuZ4iDtXW7RXH2X/m2PryApskU+mGvhgBvpf9zV3gLlKAb Eiq8T33lcDTAyferMD/GdHW861MIjMFn0MMq0AyxItbVnwUiiR2cG59rE A==; X-IronPort-AV: E=McAfee;i="6600,9927,10968"; a="16530968" X-IronPort-AV: E=Sophos;i="6.05,707,1701158400"; d="scan'208";a="16530968" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Jan 2024 18:09:41 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10968"; a="822042339" X-IronPort-AV: E=Sophos;i="6.05,707,1701158400"; d="scan'208";a="822042339" Received: from b4969161e530.jf.intel.com ([10.165.56.46]) by orsmga001.jf.intel.com with ESMTP; 29 Jan 2024 18:09:39 -0800 From: Haitao Huang To: jarkko@kernel.org, dave.hansen@linux.intel.com, tj@kernel.org, mkoutny@suse.com, linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org, x86@kernel.org, cgroups@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, sohil.mehta@intel.com Cc: zhiquan1.li@intel.com, kristen@linux.intel.com, seanjc@google.com, zhanb@microsoft.com, anakrish@microsoft.com, mikko.ylinen@linux.intel.com, yangjie@microsoft.com, chrisyan@microsoft.com Subject: [PATCH v8 07/15] x86/sgx: Expose sgx_reclaim_pages() for cgroup Date: Mon, 29 Jan 2024 18:09:30 -0800 Message-Id: <20240130020938.10025-8-haitao.huang@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240130020938.10025-1-haitao.huang@linux.intel.com> References: <20240130020938.10025-1-haitao.huang@linux.intel.com> Precedence: bulk X-Mailing-List: linux-sgx@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Sean Christopherson Each EPC cgroup will have an LRU structure to track reclaimable EPC pages. When a cgroup usage reaches its limit, the cgroup needs to reclaim pages from its LRU or LRUs of its descendants to make room for any new allocations. To prepare for reclamation per cgroup, expose the top level reclamation function, sgx_reclaim_pages(), in header file for reuse. Add a parameter to the function to pass in an LRU so cgroups can pass in different tracking LRUs later. Add another parameter for passing in the number of pages to scan and make the function return the number of pages reclaimed as a cgroup reclaimer may need to track reclamation progress from its descendants, change number of pages to scan in subsequent calls. Create a wrapper for the global reclaimer, sgx_reclaim_pages_global(), to just call this function with the global LRU passed in. When per-cgroup LRU is added later, the wrapper will perform global reclamation from the root cgroup. Signed-off-by: Sean Christopherson Co-developed-by: Kristen Carlson Accardi Signed-off-by: Kristen Carlson Accardi Co-developed-by: Haitao Huang Signed-off-by: Haitao Huang Reviewed-by: Jarkko Sakkinen --- V8: - Use width of 80 characters in text paragraphs. (Jarkko) V7: - Reworked from patch 9 of V6, "x86/sgx: Restructure top-level EPC reclaim function". Do not split the top level function (Kai) - Dropped patches 7 and 8 of V6. --- arch/x86/kernel/cpu/sgx/main.c | 53 +++++++++++++++++++++++----------- arch/x86/kernel/cpu/sgx/sgx.h | 1 + 2 files changed, 37 insertions(+), 17 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index a131aa985c95..4f5824c4751d 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -286,11 +286,13 @@ static void sgx_reclaimer_write(struct sgx_epc_page *epc_page, mutex_unlock(&encl->lock); } -/* - * Take a fixed number of pages from the head of the active page pool and - * reclaim them to the enclave's private shmem files. Skip the pages, which have - * been accessed since the last scan. Move those pages to the tail of active - * page pool so that the pages get scanned in LRU like fashion. +/** + * sgx_reclaim_pages() - Reclaim a fixed number of pages from an LRU + * + * Take a fixed number of pages from the head of a given LRU and reclaim them to + * the enclave's private shmem files. Skip the pages, which have been accessed + * since the last scan. Move those pages to the tail of the list so that the + * pages get scanned in LRU like fashion. * * Batch process a chunk of pages (at the moment 16) in order to degrade amount * of IPI's and ETRACK's potentially required. sgx_encl_ewb() does degrade a bit @@ -298,8 +300,13 @@ static void sgx_reclaimer_write(struct sgx_epc_page *epc_page, * + EWB) but not sufficiently. Reclaiming one page at a time would also be * problematic as it would increase the lock contention too much, which would * halt forward progress. + * + * @lru: The LRU from which pages are reclaimed. + * @nr_to_scan: Pointer to the target number of pages to scan, must be less than + * SGX_NR_TO_SCAN. + * Return: Number of pages reclaimed. */ -static void sgx_reclaim_pages(void) +unsigned int sgx_reclaim_pages(struct sgx_epc_lru_list *lru, unsigned int *nr_to_scan) { struct sgx_epc_page *chunk[SGX_NR_TO_SCAN]; struct sgx_backing backing[SGX_NR_TO_SCAN]; @@ -310,10 +317,10 @@ static void sgx_reclaim_pages(void) int ret; int i; - spin_lock(&sgx_global_lru.lock); - for (i = 0; i < SGX_NR_TO_SCAN; i++) { - epc_page = list_first_entry_or_null(&sgx_global_lru.reclaimable, - struct sgx_epc_page, list); + spin_lock(&lru->lock); + + for (; *nr_to_scan > 0; --(*nr_to_scan)) { + epc_page = list_first_entry_or_null(&lru->reclaimable, struct sgx_epc_page, list); if (!epc_page) break; @@ -328,7 +335,8 @@ static void sgx_reclaim_pages(void) */ epc_page->flags &= ~SGX_EPC_PAGE_RECLAIMER_TRACKED; } - spin_unlock(&sgx_global_lru.lock); + + spin_unlock(&lru->lock); for (i = 0; i < cnt; i++) { epc_page = chunk[i]; @@ -351,9 +359,9 @@ static void sgx_reclaim_pages(void) continue; skip: - spin_lock(&sgx_global_lru.lock); - list_add_tail(&epc_page->list, &sgx_global_lru.reclaimable); - spin_unlock(&sgx_global_lru.lock); + spin_lock(&lru->lock); + list_add_tail(&epc_page->list, &lru->reclaimable); + spin_unlock(&lru->lock); kref_put(&encl_page->encl->refcount, sgx_encl_release); @@ -366,6 +374,7 @@ static void sgx_reclaim_pages(void) sgx_reclaimer_block(epc_page); } + ret = 0; for (i = 0; i < cnt; i++) { epc_page = chunk[i]; if (!epc_page) @@ -378,7 +387,10 @@ static void sgx_reclaim_pages(void) epc_page->flags &= ~SGX_EPC_PAGE_RECLAIMER_TRACKED; sgx_free_epc_page(epc_page); + ret++; } + + return (unsigned int)ret; } static bool sgx_should_reclaim(unsigned long watermark) @@ -387,6 +399,13 @@ static bool sgx_should_reclaim(unsigned long watermark) !list_empty(&sgx_global_lru.reclaimable); } +static void sgx_reclaim_pages_global(void) +{ + unsigned int nr_to_scan = SGX_NR_TO_SCAN; + + sgx_reclaim_pages(&sgx_global_lru, &nr_to_scan); +} + /* * sgx_reclaim_direct() should be called (without enclave's mutex held) * in locations where SGX memory resources might be low and might be @@ -395,7 +414,7 @@ static bool sgx_should_reclaim(unsigned long watermark) void sgx_reclaim_direct(void) { if (sgx_should_reclaim(SGX_NR_LOW_PAGES)) - sgx_reclaim_pages(); + sgx_reclaim_pages_global(); } static int ksgxd(void *p) @@ -418,7 +437,7 @@ static int ksgxd(void *p) sgx_should_reclaim(SGX_NR_HIGH_PAGES)); if (sgx_should_reclaim(SGX_NR_HIGH_PAGES)) - sgx_reclaim_pages(); + sgx_reclaim_pages_global(); cond_resched(); } @@ -604,7 +623,7 @@ 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_pages(); + sgx_reclaim_pages_global(); cond_resched(); } diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index 0e99e9ae3a67..2593c013d091 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -110,6 +110,7 @@ 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_reclaim_pages(struct sgx_epc_lru_list *lru, unsigned int *nr_to_scan); void sgx_ipi_cb(void *info);