[PATCHv5 12/12] x86/mm: Report unaccepted memory in /proc/meminfo

["Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>]

Track amount of unaccepted memory and report it in /proc/meminfo.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
 arch/x86/include/asm/set_memory.h        |  2 ++
 arch/x86/include/asm/unaccepted_memory.h |  9 ++++++
 arch/x86/mm/init.c                       |  8 ++++++
 arch/x86/mm/pat/set_memory.c             |  2 +-
 arch/x86/mm/unaccepted_memory.c          | 36 +++++++++++++++++++++++-
 5 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
index 78ca53512486..e467f3941d22 100644
--- a/arch/x86/include/asm/set_memory.h
+++ b/arch/x86/include/asm/set_memory.h
@@ -86,6 +86,8 @@ bool kernel_page_present(struct page *page);
 
 extern int kernel_set_to_readonly;
 
+void direct_map_meminfo(struct seq_file *m);
+
 #ifdef CONFIG_X86_64
 /*
  * Prevent speculative access to the page by either unmapping
diff --git a/arch/x86/include/asm/unaccepted_memory.h b/arch/x86/include/asm/unaccepted_memory.h
index a59264ee0ab3..7c93661152a9 100644
--- a/arch/x86/include/asm/unaccepted_memory.h
+++ b/arch/x86/include/asm/unaccepted_memory.h
@@ -3,7 +3,10 @@
 #ifndef _ASM_X86_UNACCEPTED_MEMORY_H
 #define _ASM_X86_UNACCEPTED_MEMORY_H
 
+#include <linux/types.h>
+
 struct boot_params;
+struct seq_file;
 
 void process_unaccepted_memory(struct boot_params *params, u64 start, u64 num);
 
@@ -12,5 +15,11 @@ void process_unaccepted_memory(struct boot_params *params, u64 start, u64 num);
 void accept_memory(phys_addr_t start, phys_addr_t end);
 bool memory_is_unaccepted(phys_addr_t start, phys_addr_t end);
 
+void unaccepted_meminfo(struct seq_file *m);
+
+#else
+
+static inline void unaccepted_meminfo(struct seq_file *m) {}
+
 #endif
 #endif
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index d8cfce221275..7e92a9d93994 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -1065,3 +1065,11 @@ unsigned long max_swapfile_size(void)
 	return pages;
 }
 #endif
+
+#ifdef CONFIG_PROC_FS
+void arch_report_meminfo(struct seq_file *m)
+{
+	direct_map_meminfo(m);
+	unaccepted_meminfo(m);
+}
+#endif
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index abf5ed76e4b7..2880ba01451c 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -105,7 +105,7 @@ static void split_page_count(int level)
 	direct_pages_count[level - 1] += PTRS_PER_PTE;
 }
 
-void arch_report_meminfo(struct seq_file *m)
+void direct_map_meminfo(struct seq_file *m)
 {
 	seq_printf(m, "DirectMap4k:    %8lu kB\n",
 			direct_pages_count[PG_LEVEL_4K] << 2);
diff --git a/arch/x86/mm/unaccepted_memory.c b/arch/x86/mm/unaccepted_memory.c
index 65cd49b93c50..66a6c529bf31 100644
--- a/arch/x86/mm/unaccepted_memory.c
+++ b/arch/x86/mm/unaccepted_memory.c
@@ -3,14 +3,17 @@
 #include <linux/mm.h>
 #include <linux/pfn.h>
 #include <linux/spinlock.h>
+#include <linux/seq_file.h>
 
+#include <asm/e820/api.h>
 #include <asm/io.h>
 #include <asm/setup.h>
 #include <asm/shared/tdx.h>
 #include <asm/unaccepted_memory.h>
 
-/* Protects unaccepted memory bitmap */
+/* Protects unaccepted memory bitmap and nr_unaccepted */
 static DEFINE_SPINLOCK(unaccepted_memory_lock);
+static unsigned long nr_unaccepted;
 
 void accept_memory(phys_addr_t start, phys_addr_t end)
 {
@@ -39,6 +42,12 @@ void accept_memory(phys_addr_t start, phys_addr_t end)
 
 		bitmap_clear(unaccepted_memory, range_start, len);
 		count_vm_events(ACCEPT_MEMORY, len * PMD_SIZE / PAGE_SIZE);
+
+		/* In early boot nr_unaccepted is not yet initialized */
+		if (nr_unaccepted) {
+			WARN_ON(nr_unaccepted < len);
+			nr_unaccepted -= len;
+		}
 	}
 	spin_unlock_irqrestore(&unaccepted_memory_lock, flags);
 }
@@ -62,3 +71,28 @@ bool memory_is_unaccepted(phys_addr_t start, phys_addr_t end)
 
 	return ret;
 }
+
+void unaccepted_meminfo(struct seq_file *m)
+{
+	seq_printf(m, "UnacceptedMem:  %8lu kB\n",
+		   (READ_ONCE(nr_unaccepted) * PMD_SIZE) >> 10);
+}
+
+static int __init unaccepted_meminfo_init(void)
+{
+	unsigned long *unaccepted_memory;
+	unsigned long flags, bitmap_size;
+
+	if (!boot_params.unaccepted_memory)
+		return 0;
+
+	bitmap_size = e820__end_of_ram_pfn() * PAGE_SIZE / PMD_SIZE;
+	unaccepted_memory = __va(boot_params.unaccepted_memory);
+
+	spin_lock_irqsave(&unaccepted_memory_lock, flags);
+	nr_unaccepted = bitmap_weight(unaccepted_memory, bitmap_size);
+	spin_unlock_irqrestore(&unaccepted_memory_lock, flags);
+
+	return 0;
+}
+fs_initcall(unaccepted_meminfo_init);
-- 
2.35.1