From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D98DB23392F; Thu, 28 May 2026 00:42:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779928961; cv=none; b=q5B+byOdka93Fu4vWtI3ErKZSs+axehudTPEMHwrqkvj0AvfCuCQdl4r8nNd8+0y+POxkT8bQC7jPCX6ZEjbVfr9PX8kvLCGdMJQlAzB1G+wWAyzhHDHrE5MWAfZUscqvWBUFBb74noIj7sPcIWgWARyc++OtVqktON5BOrC958= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779928961; c=relaxed/simple; bh=rx6iKkur0ne2X4SzAyPwfxcKTOWxn5ia5n5lA3O1jng=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qMUj6au/9K9HZMHTOfcM9l5xVfbM0vs2XDNmH2Jn6UKaNkR5HgHnNPKQZMPmmTWHXxV7RT5qQI6UuuzA9xuugi8E6uk0+ttz/sPAVRrIMPD+wEDoOvZdcg+Cd7Nffk+UG21VuYO0Mt9teqxvosfamAUKZ5dsE0aUQ5ElX80w0J8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=bds+T53Y; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="bds+T53Y" Received: by linux.microsoft.com (Postfix, from userid 1241) id EC17820B717A; Wed, 27 May 2026 17:42:23 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com EC17820B717A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1779928943; bh=lTYSobW1vcaiuFaW/ih0lOZTdJfa7tMYIcB/6JUObEE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bds+T53YSwua67KRic1D3xTDVI8g2FG5kFyh9yUH+NKfBwH0s5MxGdFticf7R97vc C6Xh5MCYze42oBrgNFWnDpyid/h5MQYDeNPF/7cyO0UVqYZALjK7f4naGCfMw8KflQ CRrvEG5Kw9ij3UM6KLbWJBmrvJ8vse+aL8vwqdDw= From: Jork Loeser To: linux-hyperv@vger.kernel.org, linux-mm@kvack.org, kexec@lists.infradead.org Cc: "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Long Li , Mike Rapoport , Pasha Tatashin , Pratyush Yadav , Alexander Graf , Jason Miu , Andrew Morton , David Hildenbrand , Muchun Song , Oscar Salvador , Baoquan He , Catalin Marinas , Will Deacon , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Kees Cook , Ran Xiaokai , Justinien Bouron , Sourabh Jain , Pingfan Liu , "Rafael J. Wysocki" , Mario Limonciello , linux-arm-kernel@lists.infradead.org, x86@kernel.org, linux-kernel@vger.kernel.org, Michael Kelley , Jork Loeser Subject: [RFC PATCH 16/20] mshv: Add debugfs interface to page tracker Date: Wed, 27 May 2026 17:41:58 -0700 Message-ID: <20260528004204.1484584-17-jloeser@linux.microsoft.com> X-Mailer: git-send-email 2.43.7 In-Reply-To: <20260528004204.1484584-1-jloeser@linux.microsoft.com> References: <20260528004204.1484584-1-jloeser@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit - expose stats (page-counts for data & metadata) - expose tracked pages - expose scheduler type - add mshv_iterate_preserved() API for walking the radix tree Signed-off-by: Jork Loeser --- drivers/hv/mshv_debugfs.c | 99 +++++++++++++++++++++++++++++++++ drivers/hv/mshv_page_preserve.c | 13 +++++ drivers/hv/mshv_page_preserve.h | 3 + drivers/hv/mshv_root.h | 2 + drivers/hv/mshv_root_main.c | 2 +- 5 files changed, 118 insertions(+), 1 deletion(-) diff --git a/drivers/hv/mshv_debugfs.c b/drivers/hv/mshv_debugfs.c index 3c3e02237ae9..d79898e21b36 100644 --- a/drivers/hv/mshv_debugfs.c +++ b/drivers/hv/mshv_debugfs.c @@ -33,11 +33,18 @@ static struct dentry *mshv_debugfs; static struct dentry *mshv_debugfs_partition; static struct dentry *mshv_debugfs_lp; static struct dentry **parent_vp_stats; + static struct dentry *parent_partition_stats; static u64 mshv_lps_count; static struct hv_stats_page **mshv_lps_stats; +struct mshv_pt_stats { + unsigned long count_data; + unsigned long count_meta; + struct seq_file *stat_file; +}; + static int lp_stats_show(struct seq_file *m, void *v) { const struct hv_stats_page *stats = m->private; @@ -668,8 +675,89 @@ void mshv_debugfs_partition_remove(struct mshv_partition *partition) partition->pt_stats_dentry); } +static int pt_count_data_cb(unsigned long key __maybe_unused, void *stats) +{ + ((struct mshv_pt_stats *)stats)->count_data++; + return 0; +} + +static int pt_count_meta_cb(phys_addr_t phys __maybe_unused, void *stats) +{ + ((struct mshv_pt_stats *)stats)->count_meta++; + return 0; +} + +static int pt_stats_show(struct seq_file *m, void *v) +{ + const struct kho_radix_walk_cb cb = { + .key = pt_count_data_cb, + .table = pt_count_meta_cb, + }; + + struct mshv_pt_stats pt_stats = {0}; + + mshv_iterate_preserved(&cb, &pt_stats); + seq_printf(m, "Data pages: %lu\n", pt_stats.count_data); + seq_printf(m, "Meta pages: %lu\n", pt_stats.count_meta); + return 0; +} +DEFINE_SHOW_ATTRIBUTE(pt_stats); + +static int pt_tree_data_cb(unsigned long key, void *stats) +{ + seq_printf(((struct mshv_pt_stats *)stats)->stat_file, + "data pfn: %#lx\n", key); + return 0; +} + +static int pt_tree_meta_cb(phys_addr_t phys, void *stats) +{ + seq_printf(((struct mshv_pt_stats *)stats)->stat_file, + "meta pfn: %#llx\n", + (unsigned long long)(phys >> PAGE_SHIFT)); + return 0; +} + +static int pt_tree_show(struct seq_file *m, void *v) +{ + const struct kho_radix_walk_cb cb = { + .key = pt_tree_data_cb, + .table = pt_tree_meta_cb, + }; + + struct mshv_pt_stats pt_stats = {.stat_file = m}; + + mshv_iterate_preserved(&cb, &pt_stats); + return 0; +} +DEFINE_SHOW_ATTRIBUTE(pt_tree); + +static int __init mshv_debugfs_pt_create(struct dentry *parent) +{ + struct dentry *d; + + d = debugfs_create_file("pt_stats", 0400, parent, NULL, &pt_stats_fops); + if (IS_ERR(d)) + return PTR_ERR(d); + + d = debugfs_create_file("pt_tree", 0400, parent, NULL, &pt_tree_fops); + if (IS_ERR(d)) + return PTR_ERR(d); + + return 0; +} + +static int scheduler_info_show(struct seq_file *m, void *v) +{ + seq_printf(m, "Scheduler type: %s (%d)\n", + scheduler_type_to_string(hv_scheduler_type), hv_scheduler_type); + return 0; +} +DEFINE_SHOW_ATTRIBUTE(scheduler_info); + int __init mshv_debugfs_init(void) { + struct dentry *d; int err; mshv_debugfs = debugfs_create_dir("mshv", NULL); @@ -694,6 +782,17 @@ int __init mshv_debugfs_init(void) if (err) goto unmap_lp_stats; + err = mshv_debugfs_pt_create(mshv_debugfs); + if (err) + goto unmap_lp_stats; + + d = debugfs_create_file("scheduler_info", 0400, mshv_debugfs, NULL, + &scheduler_info_fops); + if (IS_ERR(d)) { + err = PTR_ERR(d); + goto unmap_lp_stats; + } + return 0; unmap_lp_stats: diff --git a/drivers/hv/mshv_page_preserve.c b/drivers/hv/mshv_page_preserve.c index a79725a74663..bc3a3a688f5b 100644 --- a/drivers/hv/mshv_page_preserve.c +++ b/drivers/hv/mshv_page_preserve.c @@ -52,6 +52,19 @@ int mshv_unregister_preserve_page(struct page *pg) } EXPORT_SYMBOL_GPL(mshv_unregister_preserve_page); +/** + * mshv_iterate_preserved() - Walk all preserved pages + * @cb: callbacks invoked for each key/table entry + * @data: opaque data passed to callbacks + * + * Return: 0 on success, -errno on failure. + */ +int mshv_iterate_preserved(const struct kho_radix_walk_cb *cb, void *data) +{ + return kho_radix_walk_tree(&preserved_pages_tree, cb, data); +} +EXPORT_SYMBOL_GPL(mshv_iterate_preserved); + /* Preserve a single page identified by its PFN key with KHO */ static int preserve_key_cb(unsigned long key, void *data) { diff --git a/drivers/hv/mshv_page_preserve.h b/drivers/hv/mshv_page_preserve.h index 0609002e5f1d..ac99b4e33285 100644 --- a/drivers/hv/mshv_page_preserve.h +++ b/drivers/hv/mshv_page_preserve.h @@ -6,10 +6,13 @@ #ifndef _MSHV_PAGE_PRESERVE_H #define _MSHV_PAGE_PRESERVE_H +#include + struct page; int mshv_preserve_init(void); int mshv_register_preserve_page(struct page *pg); int mshv_unregister_preserve_page(struct page *pg); +int mshv_iterate_preserved(const struct kho_radix_walk_cb *cb, void *data); #endif /* _MSHV_PAGE_PRESERVE_H */ diff --git a/drivers/hv/mshv_root.h b/drivers/hv/mshv_root.h index 362768786c17..216053f8e0ab 100644 --- a/drivers/hv/mshv_root.h +++ b/drivers/hv/mshv_root.h @@ -379,4 +379,6 @@ bool mshv_region_handle_gfn_fault(struct mshv_mem_region *region, u64 gfn); void mshv_region_movable_fini(struct mshv_mem_region *region); bool mshv_region_movable_init(struct mshv_mem_region *region); +const char *scheduler_type_to_string(enum hv_scheduler_type type); + #endif /* _MSHV_ROOT_H_ */ diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c index bd1359eb58dd..5fbd01c12ab8 100644 --- a/drivers/hv/mshv_root_main.c +++ b/drivers/hv/mshv_root_main.c @@ -2134,7 +2134,7 @@ mshv_dev_release(struct inode *inode, struct file *filp) static int mshv_root_sched_online; -static const char *scheduler_type_to_string(enum hv_scheduler_type type) +const char *scheduler_type_to_string(enum hv_scheduler_type type) { switch (type) { case HV_SCHEDULER_TYPE_LP: -- 2.43.0