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bh=Yhrp7k9I76o0grZ16pUBmgOI5IKl40orUcI3ubcyl24=; b=Pd5sGg3a7US8GWLHBOz31QGN9c3BYhHV7A98yEbPrTaDalKCGzREd6PO SRMNMNhcp7aLNGk2v/8uUe03dpPGdzAGdtkaxSGplmQFjpsTDuEWYFSko lqy1lkuzx4bo+i0/9913ha+9AUAuh9ffLSA5IVz0o2MM0pLeIXOUf8sd0 ym5lXjs/D61vYbEvqgcn5C4f5iGuScGE8kSLgaxEFWJ3Ht+U5VA8bYsX7 3Vj3WkK4ewHC9QromU+8Lx/yzwVlCNhnpNB8NsLQ2v+nS9ubTCrhy2jKD 23O8jOlRNusP0C082B66d93nEoglMSDJjTRszXNrVQ/7FUkLTRW3M+N16 Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10975"; a="11960434" X-IronPort-AV: E=Sophos;i="6.05,245,1701158400"; d="scan'208";a="11960434" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by orvoesa104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Feb 2024 13:06:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.05,245,1701158400"; d="scan'208";a="38245637" Received: from b4969161e530.jf.intel.com ([10.165.56.46]) by orviesa001.jf.intel.com with ESMTP; 05 Feb 2024 13:06:42 -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, tim.c.chen@linux.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 v9 09/15] x86/sgx: Charge mem_cgroup for per-cgroup reclamation Date: Mon, 5 Feb 2024 13:06:32 -0800 Message-Id: <20240205210638.157741-10-haitao.huang@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240205210638.157741-1-haitao.huang@linux.intel.com> References: <20240205210638.157741-1-haitao.huang@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1790102438476857427 X-GMAIL-MSGID: 1790102438476857427 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 tasks 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_reclaim_pages(), 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 --- V9: - Reduce number of if statements. (Tim) V8: - Limit text paragraphs to 80 characters wide. (Jarkko) --- arch/x86/kernel/cpu/sgx/encl.c | 38 +++++++++++++--------------- arch/x86/kernel/cpu/sgx/encl.h | 3 +-- arch/x86/kernel/cpu/sgx/epc_cgroup.c | 7 ++--- arch/x86/kernel/cpu/sgx/main.c | 27 +++++++++----------- arch/x86/kernel/cpu/sgx/sgx.h | 3 ++- 5 files changed, 36 insertions(+), 42 deletions(-) diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c index 279148e72459..4e5948362060 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. @@ -1047,27 +1037,33 @@ 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; - ret = __sgx_encl_get_backing(encl, page_index, backing); + if (!indirect) + return __sgx_encl_get_backing(encl, page_index, backing); + 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); 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 16b6d9f909eb..d399fda2b55e 100644 --- a/arch/x86/kernel/cpu/sgx/epc_cgroup.c +++ b/arch/x86/kernel/cpu/sgx/epc_cgroup.c @@ -93,9 +93,10 @@ bool sgx_epc_cgroup_lru_empty(struct misc_cg *root) /** * sgx_epc_cgroup_reclaim_pages() - walk a cgroup tree and scan LRUs to reclaim pages * @root: Root of the tree to start walking from. + * @indirect: In ksgxd or EPC cgroup work queue context. * Return: Number of pages reclaimed. */ -unsigned int sgx_epc_cgroup_reclaim_pages(struct misc_cg *root) +static unsigned int sgx_epc_cgroup_reclaim_pages(struct misc_cg *root, bool indirect) { /* * Attempting to reclaim only a few pages will often fail and is @@ -119,7 +120,7 @@ unsigned int sgx_epc_cgroup_reclaim_pages(struct misc_cg *root) rcu_read_unlock(); epc_cg = sgx_epc_cgroup_from_misc_cg(css_misc(pos)); - cnt += sgx_reclaim_pages(&epc_cg->lru, &nr_to_scan); + cnt += sgx_reclaim_pages(&epc_cg->lru, &nr_to_scan, indirect); rcu_read_lock(); css_put(pos); @@ -176,7 +177,7 @@ 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(epc_cg->cg); + sgx_epc_cgroup_reclaim_pages(epc_cg->cg, true); } } diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 4f5824c4751d..51904f191b97 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -254,7 +254,7 @@ 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; @@ -270,7 +270,7 @@ 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; @@ -304,9 +304,11 @@ static void sgx_reclaimer_write(struct sgx_epc_page *epc_page, * @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. + * @indirect: In ksgxd or EPC cgroup work queue contexts. * Return: Number of pages reclaimed. */ -unsigned int sgx_reclaim_pages(struct sgx_epc_lru_list *lru, unsigned int *nr_to_scan) +unsigned int sgx_reclaim_pages(struct sgx_epc_lru_list *lru, unsigned int *nr_to_scan, + bool indirect) { struct sgx_epc_page *chunk[SGX_NR_TO_SCAN]; struct sgx_backing backing[SGX_NR_TO_SCAN]; @@ -348,7 +350,7 @@ unsigned int sgx_reclaim_pages(struct sgx_epc_lru_list *lru, unsigned int *nr_to 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; @@ -381,7 +383,7 @@ unsigned int sgx_reclaim_pages(struct sgx_epc_lru_list *lru, unsigned int *nr_to continue; 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); epc_page->flags &= ~SGX_EPC_PAGE_RECLAIMER_TRACKED; @@ -399,11 +401,11 @@ static bool sgx_should_reclaim(unsigned long watermark) !list_empty(&sgx_global_lru.reclaimable); } -static void sgx_reclaim_pages_global(void) +static void sgx_reclaim_pages_global(bool indirect) { unsigned int nr_to_scan = SGX_NR_TO_SCAN; - sgx_reclaim_pages(&sgx_global_lru, &nr_to_scan); + sgx_reclaim_pages(&sgx_global_lru, &nr_to_scan, indirect); } /* @@ -414,7 +416,7 @@ static void sgx_reclaim_pages_global(void) void sgx_reclaim_direct(void) { if (sgx_should_reclaim(SGX_NR_LOW_PAGES)) - sgx_reclaim_pages_global(); + sgx_reclaim_pages_global(false); } static int ksgxd(void *p) @@ -437,7 +439,7 @@ static int ksgxd(void *p) sgx_should_reclaim(SGX_NR_HIGH_PAGES)); if (sgx_should_reclaim(SGX_NR_HIGH_PAGES)) - sgx_reclaim_pages_global(); + sgx_reclaim_pages_global(true); cond_resched(); } @@ -460,11 +462,6 @@ 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]; @@ -623,7 +620,7 @@ 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_global(); + sgx_reclaim_pages_global(false); cond_resched(); } diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index 2593c013d091..cfe906054d85 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -110,7 +110,8 @@ 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); +unsigned int sgx_reclaim_pages(struct sgx_epc_lru_list *lru, unsigned int *nr_to_scan, + bool indirect); void sgx_ipi_cb(void *info);