linux-kernel - [PATCH v2 09/10] iommu: observability of the IOMMU allocations

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20231130201504.2322355-10-pasha.tatashin@soleen.com>
Date:   Thu, 30 Nov 2023 20:15:03 +0000
From:   Pasha Tatashin <pasha.tatashin@...een.com>
To:     akpm@...ux-foundation.org, alim.akhtar@...sung.com,
        alyssa@...enzweig.io, asahi@...ts.linux.dev,
        baolu.lu@...ux.intel.com, bhelgaas@...gle.com,
        cgroups@...r.kernel.org, corbet@....net, david@...hat.com,
        dwmw2@...radead.org, hannes@...xchg.org, heiko@...ech.de,
        iommu@...ts.linux.dev, jernej.skrabec@...il.com,
        jonathanh@...dia.com, joro@...tes.org,
        krzysztof.kozlowski@...aro.org, linux-doc@...r.kernel.org,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-mm@...ck.org, linux-rockchip@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org, linux-sunxi@...ts.linux.dev,
        linux-tegra@...r.kernel.org, lizefan.x@...edance.com,
        marcan@...can.st, mhiramat@...nel.org, m.szyprowski@...sung.com,
        pasha.tatashin@...een.com, paulmck@...nel.org,
        rdunlap@...radead.org, robin.murphy@....com, samuel@...lland.org,
        suravee.suthikulpanit@....com, sven@...npeter.dev,
        thierry.reding@...il.com, tj@...nel.org, tomas.mudrunka@...il.com,
        vdumpa@...dia.com, wens@...e.org, will@...nel.org,
        yu-cheng.yu@...el.com
Subject: [PATCH v2 09/10] iommu: observability of the IOMMU allocations

Add NR_IOMMU_PAGES into node_stat_item that counts number of pages
that are allocated by the IOMMU subsystem.

The allocations can be view per-node via:
/sys/devices/system/node/nodeN/vmstat.

For example:

$ grep iommu /sys/devices/system/node/node*/vmstat
/sys/devices/system/node/node0/vmstat:nr_iommu_pages 106025
/sys/devices/system/node/node1/vmstat:nr_iommu_pages 3464

The value is in page-count, therefore, in the above example
the iommu allocations amount to ~428M.

Signed-off-by: Pasha Tatashin <pasha.tatashin@...een.com>
---
 drivers/iommu/iommu-pages.h | 30 ++++++++++++++++++++++++++++++
 include/linux/mmzone.h      |  3 +++
 mm/vmstat.c                 |  3 +++
 3 files changed, 36 insertions(+)

diff --git a/drivers/iommu/iommu-pages.h b/drivers/iommu/iommu-pages.h
index 2332f807d514..69895a355c0c 100644
--- a/drivers/iommu/iommu-pages.h
+++ b/drivers/iommu/iommu-pages.h
@@ -17,6 +17,30 @@
  * state can be rather large, i.e. multiple gigabytes in size.
  */
 
+/**
+ * __iommu_alloc_account - account for newly allocated page.
+ * @pages: head struct page of the page.
+ * @order: order of the page
+ */
+static inline void __iommu_alloc_account(struct page *pages, int order)
+{
+	const long pgcnt = 1l << order;
+
+	mod_node_page_state(page_pgdat(pages), NR_IOMMU_PAGES, pgcnt);
+}
+
+/**
+ * __iommu_free_account - account a page that is about to be freed.
+ * @pages: head struct page of the page.
+ * @order: order of the page
+ */
+static inline void __iommu_free_account(struct page *pages, int order)
+{
+	const long pgcnt = 1l << order;
+
+	mod_node_page_state(page_pgdat(pages), NR_IOMMU_PAGES, -pgcnt);
+}
+
 /**
  * __iommu_alloc_pages_node - allocate a zeroed page of a given order from
  * specific NUMA node.
@@ -35,6 +59,8 @@ static inline struct page *__iommu_alloc_pages_node(int nid, gfp_t gfp,
 	if (!pages)
 		return NULL;
 
+	__iommu_alloc_account(pages, order);
+
 	return pages;
 }
 
@@ -53,6 +79,8 @@ static inline struct page *__iommu_alloc_pages(gfp_t gfp, int order)
 	if (!pages)
 		return NULL;
 
+	__iommu_alloc_account(pages, order);
+
 	return pages;
 }
 
@@ -89,6 +117,7 @@ static inline void __iommu_free_pages(struct page *pages, int order)
 	if (!pages)
 		return;
 
+	__iommu_free_account(pages, order);
 	__free_pages(pages, order);
 }
 
@@ -192,6 +221,7 @@ static inline void iommu_free_pages_list(struct list_head *pages)
 		struct page *p = list_entry(pages->prev, struct page, lru);
 
 		list_del(&p->lru);
+		__iommu_free_account(p, 0);
 		put_page(p);
 	}
 }
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 3c25226beeed..1a4d0bba3e8b 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -200,6 +200,9 @@ enum node_stat_item {
 #endif
 	NR_PAGETABLE,		/* used for pagetables */
 	NR_SECONDARY_PAGETABLE, /* secondary pagetables, e.g. KVM pagetables */
+#ifdef CONFIG_IOMMU_SUPPORT
+	NR_IOMMU_PAGES,		/* # of pages allocated by IOMMU */
+#endif
 #ifdef CONFIG_SWAP
 	NR_SWAPCACHE,
 #endif
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 359460deb377..801b58890b6c 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1242,6 +1242,9 @@ const char * const vmstat_text[] = {
 #endif
 	"nr_page_table_pages",
 	"nr_sec_page_table_pages",
+#ifdef CONFIG_IOMMU_SUPPORT
+	"nr_iommu_pages",
+#endif
 #ifdef CONFIG_SWAP
 	"nr_swapcached",
 #endif
-- 
2.43.0.rc2.451.g8631bc7472-goog