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

Kirill A. Shutemov
2022-04-25T03:40:12Z

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

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
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