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* [PATCH v2 0/5] mm/memory_hotplug: full support for add_memory_driver_managed() with CONFIG_ARCH_KEEP_MEMBLOCK
@ 2021-10-04  9:36 David Hildenbrand
  2021-10-04  9:36 ` [PATCH v2 1/5] mm/memory_hotplug: handle memblock_add_node() failures in add_memory_resource() David Hildenbrand
                   ` (4 more replies)
  0 siblings, 5 replies; 10+ messages in thread
From: David Hildenbrand @ 2021-10-04  9:36 UTC (permalink / raw)
  To: linux-kernel
  Cc: David Hildenbrand, Andrew Morton, Mike Rapoport, Michal Hocko,
	Oscar Salvador, Jianyong Wu, Aneesh Kumar K . V, Vineet Gupta,
	Geert Uytterhoeven, Huacai Chen, Jiaxun Yang,
	Thomas Bogendoerfer, Heiko Carstens, Vasily Gorbik,
	Christian Borntraeger, Eric Biederman, Arnd Bergmann,
	linux-snps-arc, linux-ia64, linux-m68k, linux-mips, linux-s390,
	linux-mm, kexec

Architectures that require CONFIG_ARCH_KEEP_MEMBLOCK=y, such as arm64,
don't cleanly support add_memory_driver_managed() yet. Most prominently,
kexec_file can still end up placing kexec images on such driver-managed
memory, resulting in undesired behavior, for example, having kexec images
located on memory not part of the firmware-provided memory map.

Teaching kexec to not place images on driver-managed memory is especially
relevant for virtio-mem. Details can be found in commit 7b7b27214bba
("mm/memory_hotplug: introduce add_memory_driver_managed()").

Extend memblock with a new flag and set it from memory hotplug code
when applicable. This is required to fully support virtio-mem on
arm64, making also kexec_file behave like on x86-64.

v1 -> v2:
- "memblock: improve MEMBLOCK_HOTPLUG documentation"
-- Added
- "memblock: add MEMBLOCK_DRIVER_MANAGED to mimic
   IORESOURCE_SYSRAM_DRIVER_MANAGED"
-- Improve documentation of MEMBLOCK_DRIVER_MANAGED
- Refine patch descriptions

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Jianyong Wu <Jianyong.Wu@arm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-mips@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: kexec@lists.infradead.org

David Hildenbrand (5):
  mm/memory_hotplug: handle memblock_add_node() failures in
    add_memory_resource()
  memblock: improve MEMBLOCK_HOTPLUG documentation
  memblock: allow to specify flags with memblock_add_node()
  memblock: add MEMBLOCK_DRIVER_MANAGED to mimic
    IORESOURCE_SYSRAM_DRIVER_MANAGED
  mm/memory_hotplug: indicate MEMBLOCK_DRIVER_MANAGED with
    IORESOURCE_SYSRAM_DRIVER_MANAGED

 arch/arc/mm/init.c               |  4 ++--
 arch/ia64/mm/contig.c            |  2 +-
 arch/ia64/mm/init.c              |  2 +-
 arch/m68k/mm/mcfmmu.c            |  3 ++-
 arch/m68k/mm/motorola.c          |  6 ++++--
 arch/mips/loongson64/init.c      |  4 +++-
 arch/mips/sgi-ip27/ip27-memory.c |  3 ++-
 arch/s390/kernel/setup.c         |  3 ++-
 include/linux/memblock.h         | 25 +++++++++++++++++++++----
 include/linux/mm.h               |  2 +-
 kernel/kexec_file.c              |  5 +++++
 mm/memblock.c                    | 13 +++++++++----
 mm/memory_hotplug.c              | 11 +++++++++--
 13 files changed, 62 insertions(+), 21 deletions(-)


base-commit: 9e1ff307c779ce1f0f810c7ecce3d95bbae40896
-- 
2.31.1


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^ permalink raw reply	[flat|nested] 10+ messages in thread

* [PATCH v2 1/5] mm/memory_hotplug: handle memblock_add_node() failures in add_memory_resource()
  2021-10-04  9:36 [PATCH v2 0/5] mm/memory_hotplug: full support for add_memory_driver_managed() with CONFIG_ARCH_KEEP_MEMBLOCK David Hildenbrand
@ 2021-10-04  9:36 ` David Hildenbrand
  2021-10-04  9:36 ` [PATCH v2 2/5] memblock: improve MEMBLOCK_HOTPLUG documentation David Hildenbrand
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 10+ messages in thread
From: David Hildenbrand @ 2021-10-04  9:36 UTC (permalink / raw)
  To: linux-kernel
  Cc: David Hildenbrand, Andrew Morton, Mike Rapoport, Michal Hocko,
	Oscar Salvador, Jianyong Wu, Aneesh Kumar K . V, Vineet Gupta,
	Geert Uytterhoeven, Huacai Chen, Jiaxun Yang,
	Thomas Bogendoerfer, Heiko Carstens, Vasily Gorbik,
	Christian Borntraeger, Eric Biederman, Arnd Bergmann,
	linux-snps-arc, linux-ia64, linux-m68k, linux-mips, linux-s390,
	linux-mm, kexec

If memblock_add_node() fails, we're most probably running out of memory.
While this is unlikely to happen, it can happen and having memory added
without a memblock can be problematic for architectures that use
memblock to detect valid memory. Let's fail in a nice way instead of
silently ignoring the error.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 mm/memory_hotplug.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 9fd0be32a281..917b3528636d 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1384,8 +1384,11 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
 
 	mem_hotplug_begin();
 
-	if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
-		memblock_add_node(start, size, nid);
+	if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) {
+		ret = memblock_add_node(start, size, nid);
+		if (ret)
+			goto error_mem_hotplug_end;
+	}
 
 	ret = __try_online_node(nid, false);
 	if (ret < 0)
@@ -1458,6 +1461,7 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
 		rollback_node_hotadd(nid);
 	if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
 		memblock_remove(start, size);
+error_mem_hotplug_end:
 	mem_hotplug_done();
 	return ret;
 }
-- 
2.31.1


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^ permalink raw reply	[flat|nested] 10+ messages in thread

* [PATCH v2 2/5] memblock: improve MEMBLOCK_HOTPLUG documentation
  2021-10-04  9:36 [PATCH v2 0/5] mm/memory_hotplug: full support for add_memory_driver_managed() with CONFIG_ARCH_KEEP_MEMBLOCK David Hildenbrand
  2021-10-04  9:36 ` [PATCH v2 1/5] mm/memory_hotplug: handle memblock_add_node() failures in add_memory_resource() David Hildenbrand
@ 2021-10-04  9:36 ` David Hildenbrand
  2021-10-06  0:35   ` Mike Rapoport
  2021-10-04  9:36 ` [PATCH v2 3/5] memblock: allow to specify flags with memblock_add_node() David Hildenbrand
                   ` (2 subsequent siblings)
  4 siblings, 1 reply; 10+ messages in thread
From: David Hildenbrand @ 2021-10-04  9:36 UTC (permalink / raw)
  To: linux-kernel
  Cc: David Hildenbrand, Andrew Morton, Mike Rapoport, Michal Hocko,
	Oscar Salvador, Jianyong Wu, Aneesh Kumar K . V, Vineet Gupta,
	Geert Uytterhoeven, Huacai Chen, Jiaxun Yang,
	Thomas Bogendoerfer, Heiko Carstens, Vasily Gorbik,
	Christian Borntraeger, Eric Biederman, Arnd Bergmann,
	linux-snps-arc, linux-ia64, linux-m68k, linux-mips, linux-s390,
	linux-mm, kexec

The description of MEMBLOCK_HOTPLUG is currently short and consequently
misleading: we're actually dealing with a memory region that might get
hotunplugged later (i.e., the platform+firmware supports it), yet it is
indicated in the firmware-provided memory map as system ram that will just
get used by the system for any purpose when not taking special care. The
firmware marked this memory region as a hot(un)plugged (e.g., hotplugged
before reboot), implying that it might get hotunplugged again later.

Whether we consider this information depends on the "movable_node" kernel
commandline parameter: only with "movable_node" set, we'll try keeping
this memory hotunpluggable, for example, by not serving early allocations
from this memory region and by letting the buddy manage it using the
ZONE_MOVABLE.

Let's make this clearer by extending the documentation.

Note: kexec *has to* indicate this memory to the second kernel. With
"movable_node" set, we don't want to place kexec-images on this memory.
Without "movable_node" set, we don't care and can place kexec-images on
this memory. In both cases, after successful memory hotunplug, kexec has to
be re-armed to update the memory map for the second kernel and to place the
kexec-images somewhere else.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 include/linux/memblock.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 34de69b3b8ba..4ee8dd2d63a7 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -28,7 +28,11 @@ extern unsigned long long max_possible_pfn;
 /**
  * enum memblock_flags - definition of memory region attributes
  * @MEMBLOCK_NONE: no special request
- * @MEMBLOCK_HOTPLUG: hotpluggable region
+ * @MEMBLOCK_HOTPLUG: memory region indicated in the firmware-provided memory
+ * map during early boot as hot(un)pluggable system RAM (e.g., memory range
+ * that might get hotunplugged later). With "movable_node" set on the kernel
+ * commandline, try keeping this memory region hotunpluggable. Does not apply
+ * to memblocks added ("hotplugged") after early boot.
  * @MEMBLOCK_MIRROR: mirrored region
  * @MEMBLOCK_NOMAP: don't add to kernel direct mapping and treat as
  * reserved in the memory map; refer to memblock_mark_nomap() description
-- 
2.31.1


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^ permalink raw reply	[flat|nested] 10+ messages in thread

* [PATCH v2 3/5] memblock: allow to specify flags with memblock_add_node()
  2021-10-04  9:36 [PATCH v2 0/5] mm/memory_hotplug: full support for add_memory_driver_managed() with CONFIG_ARCH_KEEP_MEMBLOCK David Hildenbrand
  2021-10-04  9:36 ` [PATCH v2 1/5] mm/memory_hotplug: handle memblock_add_node() failures in add_memory_resource() David Hildenbrand
  2021-10-04  9:36 ` [PATCH v2 2/5] memblock: improve MEMBLOCK_HOTPLUG documentation David Hildenbrand
@ 2021-10-04  9:36 ` David Hildenbrand
  2021-10-04 19:31   ` Shahab Vahedi
  2021-10-06  0:36   ` Mike Rapoport
  2021-10-04  9:36 ` [PATCH v2 4/5] memblock: add MEMBLOCK_DRIVER_MANAGED to mimic IORESOURCE_SYSRAM_DRIVER_MANAGED David Hildenbrand
  2021-10-04  9:36 ` [PATCH v2 5/5] mm/memory_hotplug: indicate MEMBLOCK_DRIVER_MANAGED with IORESOURCE_SYSRAM_DRIVER_MANAGED David Hildenbrand
  4 siblings, 2 replies; 10+ messages in thread
From: David Hildenbrand @ 2021-10-04  9:36 UTC (permalink / raw)
  To: linux-kernel
  Cc: David Hildenbrand, Andrew Morton, Mike Rapoport, Michal Hocko,
	Oscar Salvador, Jianyong Wu, Aneesh Kumar K . V, Vineet Gupta,
	Geert Uytterhoeven, Huacai Chen, Jiaxun Yang,
	Thomas Bogendoerfer, Heiko Carstens, Vasily Gorbik,
	Christian Borntraeger, Eric Biederman, Arnd Bergmann,
	linux-snps-arc, linux-ia64, linux-m68k, linux-mips, linux-s390,
	linux-mm, kexec

We want to specify flags when hotplugging memory. Let's prepare to pass
flags to memblock_add_node() by adjusting all existing users.

Note that when hotplugging memory the system is already up and running
and we might have concurrent memblock users: for example, while we're
hotplugging memory, kexec_file code might search for suitable memory
regions to place kexec images. It's important to add the memory directly
to memblock via a single call with the right flags, instead of adding the
memory first and apply flags later: otherwise, concurrent memblock users
might temporarily stumble over memblocks with wrong flags, which will be
important in a follow-up patch that introduces a new flag to properly
handle add_memory_driver_managed().

Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 arch/arc/mm/init.c               | 4 ++--
 arch/ia64/mm/contig.c            | 2 +-
 arch/ia64/mm/init.c              | 2 +-
 arch/m68k/mm/mcfmmu.c            | 3 ++-
 arch/m68k/mm/motorola.c          | 6 ++++--
 arch/mips/loongson64/init.c      | 4 +++-
 arch/mips/sgi-ip27/ip27-memory.c | 3 ++-
 arch/s390/kernel/setup.c         | 3 ++-
 include/linux/memblock.h         | 3 ++-
 include/linux/mm.h               | 2 +-
 mm/memblock.c                    | 9 +++++----
 mm/memory_hotplug.c              | 2 +-
 12 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index 699ecf119641..110eb69e9bee 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -59,13 +59,13 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 
 		low_mem_sz = size;
 		in_use = 1;
-		memblock_add_node(base, size, 0);
+		memblock_add_node(base, size, 0, MEMBLOCK_NONE);
 	} else {
 #ifdef CONFIG_HIGHMEM
 		high_mem_start = base;
 		high_mem_sz = size;
 		in_use = 1;
-		memblock_add_node(base, size, 1);
+		memblock_add_node(base, size, 1, MEMBLOCK_NONE);
 		memblock_reserve(base, size);
 #endif
 	}
diff --git a/arch/ia64/mm/contig.c b/arch/ia64/mm/contig.c
index 42e025cfbd08..24901d809301 100644
--- a/arch/ia64/mm/contig.c
+++ b/arch/ia64/mm/contig.c
@@ -153,7 +153,7 @@ find_memory (void)
 	efi_memmap_walk(find_max_min_low_pfn, NULL);
 	max_pfn = max_low_pfn;
 
-	memblock_add_node(0, PFN_PHYS(max_low_pfn), 0);
+	memblock_add_node(0, PFN_PHYS(max_low_pfn), 0, MEMBLOCK_NONE);
 
 	find_initrd();
 
diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index 5c6da8d83c1a..5d165607bf35 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -378,7 +378,7 @@ int __init register_active_ranges(u64 start, u64 len, int nid)
 #endif
 
 	if (start < end)
-		memblock_add_node(__pa(start), end - start, nid);
+		memblock_add_node(__pa(start), end - start, nid, MEMBLOCK_NONE);
 	return 0;
 }
 
diff --git a/arch/m68k/mm/mcfmmu.c b/arch/m68k/mm/mcfmmu.c
index eac9dde65193..6f1f25125294 100644
--- a/arch/m68k/mm/mcfmmu.c
+++ b/arch/m68k/mm/mcfmmu.c
@@ -174,7 +174,8 @@ void __init cf_bootmem_alloc(void)
 	m68k_memory[0].addr = _rambase;
 	m68k_memory[0].size = _ramend - _rambase;
 
-	memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0);
+	memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0,
+			  MEMBLOCK_NONE);
 
 	/* compute total pages in system */
 	num_pages = PFN_DOWN(_ramend - _rambase);
diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
index 9f3f77785aa7..2b05bb2bac00 100644
--- a/arch/m68k/mm/motorola.c
+++ b/arch/m68k/mm/motorola.c
@@ -410,7 +410,8 @@ void __init paging_init(void)
 
 	min_addr = m68k_memory[0].addr;
 	max_addr = min_addr + m68k_memory[0].size;
-	memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0);
+	memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0,
+			  MEMBLOCK_NONE);
 	for (i = 1; i < m68k_num_memory;) {
 		if (m68k_memory[i].addr < min_addr) {
 			printk("Ignoring memory chunk at 0x%lx:0x%lx before the first chunk\n",
@@ -421,7 +422,8 @@ void __init paging_init(void)
 				(m68k_num_memory - i) * sizeof(struct m68k_mem_info));
 			continue;
 		}
-		memblock_add_node(m68k_memory[i].addr, m68k_memory[i].size, i);
+		memblock_add_node(m68k_memory[i].addr, m68k_memory[i].size, i,
+				  MEMBLOCK_NONE);
 		addr = m68k_memory[i].addr + m68k_memory[i].size;
 		if (addr > max_addr)
 			max_addr = addr;
diff --git a/arch/mips/loongson64/init.c b/arch/mips/loongson64/init.c
index 76e0a9636a0e..4ac5ba80bbf6 100644
--- a/arch/mips/loongson64/init.c
+++ b/arch/mips/loongson64/init.c
@@ -77,7 +77,9 @@ void __init szmem(unsigned int node)
 				(u32)node_id, mem_type, mem_start, mem_size);
 			pr_info("       start_pfn:0x%llx, end_pfn:0x%llx, num_physpages:0x%lx\n",
 				start_pfn, end_pfn, num_physpages);
-			memblock_add_node(PFN_PHYS(start_pfn), PFN_PHYS(node_psize), node);
+			memblock_add_node(PFN_PHYS(start_pfn),
+					  PFN_PHYS(node_psize), node,
+					  MEMBLOCK_NONE);
 			break;
 		case SYSTEM_RAM_RESERVED:
 			pr_info("Node%d: mem_type:%d, mem_start:0x%llx, mem_size:0x%llx MB\n",
diff --git a/arch/mips/sgi-ip27/ip27-memory.c b/arch/mips/sgi-ip27/ip27-memory.c
index 6173684b5aaa..adc2faeecf7c 100644
--- a/arch/mips/sgi-ip27/ip27-memory.c
+++ b/arch/mips/sgi-ip27/ip27-memory.c
@@ -341,7 +341,8 @@ static void __init szmem(void)
 				continue;
 			}
 			memblock_add_node(PFN_PHYS(slot_getbasepfn(node, slot)),
-					  PFN_PHYS(slot_psize), node);
+					  PFN_PHYS(slot_psize), node,
+					  MEMBLOCK_NONE);
 		}
 	}
 }
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 67e5fff96ee0..f3943f15af6e 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -593,7 +593,8 @@ static void __init setup_resources(void)
 	 * part of the System RAM resource.
 	 */
 	if (crashk_res.end) {
-		memblock_add_node(crashk_res.start, resource_size(&crashk_res), 0);
+		memblock_add_node(crashk_res.start, resource_size(&crashk_res),
+				  0, MEMBLOCK_NONE);
 		memblock_reserve(crashk_res.start, resource_size(&crashk_res));
 		insert_resource(&iomem_resource, &crashk_res);
 	}
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 4ee8dd2d63a7..2bc726e43a1b 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -104,7 +104,8 @@ static inline void memblock_discard(void) {}
 #endif
 
 void memblock_allow_resize(void);
-int memblock_add_node(phys_addr_t base, phys_addr_t size, int nid);
+int memblock_add_node(phys_addr_t base, phys_addr_t size, int nid,
+		      enum memblock_flags flags);
 int memblock_add(phys_addr_t base, phys_addr_t size);
 int memblock_remove(phys_addr_t base, phys_addr_t size);
 int memblock_free(phys_addr_t base, phys_addr_t size);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 73a52aba448f..0117cb35b212 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2447,7 +2447,7 @@ static inline unsigned long get_num_physpages(void)
  * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
  * 							 max_highmem_pfn};
  * for_each_valid_physical_page_range()
- * 	memblock_add_node(base, size, nid)
+ *	memblock_add_node(base, size, nid, MEMBLOCK_NONE)
  * free_area_init(max_zone_pfns);
  */
 void free_area_init(unsigned long *max_zone_pfn);
diff --git a/mm/memblock.c b/mm/memblock.c
index 184dcd2e5d99..47a56b223141 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -655,6 +655,7 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
  * @base: base address of the new region
  * @size: size of the new region
  * @nid: nid of the new region
+ * @flags: flags of the new region
  *
  * Add new memblock region [@base, @base + @size) to the "memory"
  * type. See memblock_add_range() description for mode details
@@ -663,14 +664,14 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
  * 0 on success, -errno on failure.
  */
 int __init_memblock memblock_add_node(phys_addr_t base, phys_addr_t size,
-				       int nid)
+				      int nid, enum memblock_flags flags)
 {
 	phys_addr_t end = base + size - 1;
 
-	memblock_dbg("%s: [%pa-%pa] nid=%d %pS\n", __func__,
-		     &base, &end, nid, (void *)_RET_IP_);
+	memblock_dbg("%s: [%pa-%pa] nid=%d flags=%x %pS\n", __func__,
+		     &base, &end, nid, flags, (void *)_RET_IP_);
 
-	return memblock_add_range(&memblock.memory, base, size, nid, 0);
+	return memblock_add_range(&memblock.memory, base, size, nid, flags);
 }
 
 /**
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 917b3528636d..5f873e7f5b29 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1385,7 +1385,7 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
 	mem_hotplug_begin();
 
 	if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) {
-		ret = memblock_add_node(start, size, nid);
+		ret = memblock_add_node(start, size, nid, MEMBLOCK_NONE);
 		if (ret)
 			goto error_mem_hotplug_end;
 	}
-- 
2.31.1


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^ permalink raw reply	[flat|nested] 10+ messages in thread

* [PATCH v2 4/5] memblock: add MEMBLOCK_DRIVER_MANAGED to mimic IORESOURCE_SYSRAM_DRIVER_MANAGED
  2021-10-04  9:36 [PATCH v2 0/5] mm/memory_hotplug: full support for add_memory_driver_managed() with CONFIG_ARCH_KEEP_MEMBLOCK David Hildenbrand
                   ` (2 preceding siblings ...)
  2021-10-04  9:36 ` [PATCH v2 3/5] memblock: allow to specify flags with memblock_add_node() David Hildenbrand
@ 2021-10-04  9:36 ` David Hildenbrand
  2021-10-06  0:35   ` Mike Rapoport
  2021-10-04  9:36 ` [PATCH v2 5/5] mm/memory_hotplug: indicate MEMBLOCK_DRIVER_MANAGED with IORESOURCE_SYSRAM_DRIVER_MANAGED David Hildenbrand
  4 siblings, 1 reply; 10+ messages in thread
From: David Hildenbrand @ 2021-10-04  9:36 UTC (permalink / raw)
  To: linux-kernel
  Cc: David Hildenbrand, Andrew Morton, Mike Rapoport, Michal Hocko,
	Oscar Salvador, Jianyong Wu, Aneesh Kumar K . V, Vineet Gupta,
	Geert Uytterhoeven, Huacai Chen, Jiaxun Yang,
	Thomas Bogendoerfer, Heiko Carstens, Vasily Gorbik,
	Christian Borntraeger, Eric Biederman, Arnd Bergmann,
	linux-snps-arc, linux-ia64, linux-m68k, linux-mips, linux-s390,
	linux-mm, kexec

Let's add a flag that corresponds to IORESOURCE_SYSRAM_DRIVER_MANAGED,
indicating that we're dealing with a memory region that is never
indicated in the firmware-provided memory map, but always detected and
added by a driver.

Similar to MEMBLOCK_HOTPLUG, most infrastructure has to treat such memory
regions like ordinary MEMBLOCK_NONE memory regions -- for example, when
selecting memory regions to add to the vmcore for dumping in the
crashkernel via for_each_mem_range().

However, especially kexec_file is not supposed to select such memblocks via
for_each_free_mem_range() / for_each_free_mem_range_reverse() to place
kexec images, similar to how we handle IORESOURCE_SYSRAM_DRIVER_MANAGED
without CONFIG_ARCH_KEEP_MEMBLOCK.

We'll make sure that memory hotplug code sets the flag where applicable
(IORESOURCE_SYSRAM_DRIVER_MANAGED) next. This prepares architectures
that need CONFIG_ARCH_KEEP_MEMBLOCK, such as arm64, for virtio-mem
support.

Note that kexec *must not* indicate this memory to the second kernel
and *must not* place kexec-images on this memory. Let's add a comment to
kexec_walk_memblock(), documenting how we handle MEMBLOCK_DRIVER_MANAGED
now just like using IORESOURCE_SYSRAM_DRIVER_MANAGED in
locate_mem_hole_callback() for kexec_walk_resources().

Also note that MEMBLOCK_HOTPLUG cannot be reused due to different
semantics:
	MEMBLOCK_HOTPLUG: memory is indicated as "System RAM" in the
	firmware-provided memory map and added to the system early during
	boot; kexec *has to* indicate this memory to the second kernel and
	can place kexec-images on this memory. After memory hotunplug,
	kexec has to be re-armed. We mostly ignore this flag when
	"movable_node" is not set on the kernel command line, because
	then we're told to not care about hotunpluggability of such
	memory regions.

	MEMBLOCK_DRIVER_MANAGED: memory is not indicated as "System RAM" in
	the firmware-provided memory map; this memory is always detected
	and added to the system by a driver; memory might not actually be
	physically hotunpluggable. kexec *must not* indicate this memory to
	the second kernel and *must not* place kexec-images on this memory.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 include/linux/memblock.h | 16 ++++++++++++++--
 kernel/kexec_file.c      |  5 +++++
 mm/memblock.c            |  4 ++++
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 2bc726e43a1b..b3b29ccf91f3 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -37,12 +37,17 @@ extern unsigned long long max_possible_pfn;
  * @MEMBLOCK_NOMAP: don't add to kernel direct mapping and treat as
  * reserved in the memory map; refer to memblock_mark_nomap() description
  * for further details
+ * @MEMBLOCK_DRIVER_MANAGED: memory region that is always detected and added
+ * via a driver, and never indicated in the firmware-provided memory map as
+ * system RAM. This corresponds to IORESOURCE_SYSRAM_DRIVER_MANAGED in the
+ * kernel resource tree.
  */
 enum memblock_flags {
 	MEMBLOCK_NONE		= 0x0,	/* No special request */
 	MEMBLOCK_HOTPLUG	= 0x1,	/* hotpluggable region */
 	MEMBLOCK_MIRROR		= 0x2,	/* mirrored region */
 	MEMBLOCK_NOMAP		= 0x4,	/* don't add to kernel direct mapping */
+	MEMBLOCK_DRIVER_MANAGED = 0x8,	/* always detected via a driver */
 };
 
 /**
@@ -213,7 +218,8 @@ static inline void __next_physmem_range(u64 *idx, struct memblock_type *type,
  */
 #define for_each_mem_range(i, p_start, p_end) \
 	__for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE,	\
-			     MEMBLOCK_HOTPLUG, p_start, p_end, NULL)
+			     MEMBLOCK_HOTPLUG | MEMBLOCK_DRIVER_MANAGED, \
+			     p_start, p_end, NULL)
 
 /**
  * for_each_mem_range_rev - reverse iterate through memblock areas from
@@ -224,7 +230,8 @@ static inline void __next_physmem_range(u64 *idx, struct memblock_type *type,
  */
 #define for_each_mem_range_rev(i, p_start, p_end)			\
 	__for_each_mem_range_rev(i, &memblock.memory, NULL, NUMA_NO_NODE, \
-				 MEMBLOCK_HOTPLUG, p_start, p_end, NULL)
+				 MEMBLOCK_HOTPLUG | MEMBLOCK_DRIVER_MANAGED,\
+				 p_start, p_end, NULL)
 
 /**
  * for_each_reserved_mem_range - iterate over all reserved memblock areas
@@ -254,6 +261,11 @@ static inline bool memblock_is_nomap(struct memblock_region *m)
 	return m->flags & MEMBLOCK_NOMAP;
 }
 
+static inline bool memblock_is_driver_managed(struct memblock_region *m)
+{
+	return m->flags & MEMBLOCK_DRIVER_MANAGED;
+}
+
 int memblock_search_pfn_nid(unsigned long pfn, unsigned long *start_pfn,
 			    unsigned long  *end_pfn);
 void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn,
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 33400ff051a8..8347fc158d2b 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -556,6 +556,11 @@ static int kexec_walk_memblock(struct kexec_buf *kbuf,
 	if (kbuf->image->type == KEXEC_TYPE_CRASH)
 		return func(&crashk_res, kbuf);
 
+	/*
+	 * Using MEMBLOCK_NONE will properly skip MEMBLOCK_DRIVER_MANAGED. See
+	 * IORESOURCE_SYSRAM_DRIVER_MANAGED handling in
+	 * locate_mem_hole_callback().
+	 */
 	if (kbuf->top_down) {
 		for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE,
 						&mstart, &mend, NULL) {
diff --git a/mm/memblock.c b/mm/memblock.c
index 47a56b223141..540a35317fb0 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -979,6 +979,10 @@ static bool should_skip_region(struct memblock_type *type,
 	if (!(flags & MEMBLOCK_NOMAP) && memblock_is_nomap(m))
 		return true;
 
+	/* skip driver-managed memory unless we were asked for it explicitly */
+	if (!(flags & MEMBLOCK_DRIVER_MANAGED) && memblock_is_driver_managed(m))
+		return true;
+
 	return false;
 }
 
-- 
2.31.1


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http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 10+ messages in thread

* [PATCH v2 5/5] mm/memory_hotplug: indicate MEMBLOCK_DRIVER_MANAGED with IORESOURCE_SYSRAM_DRIVER_MANAGED
  2021-10-04  9:36 [PATCH v2 0/5] mm/memory_hotplug: full support for add_memory_driver_managed() with CONFIG_ARCH_KEEP_MEMBLOCK David Hildenbrand
                   ` (3 preceding siblings ...)
  2021-10-04  9:36 ` [PATCH v2 4/5] memblock: add MEMBLOCK_DRIVER_MANAGED to mimic IORESOURCE_SYSRAM_DRIVER_MANAGED David Hildenbrand
@ 2021-10-04  9:36 ` David Hildenbrand
  4 siblings, 0 replies; 10+ messages in thread
From: David Hildenbrand @ 2021-10-04  9:36 UTC (permalink / raw)
  To: linux-kernel
  Cc: David Hildenbrand, Andrew Morton, Mike Rapoport, Michal Hocko,
	Oscar Salvador, Jianyong Wu, Aneesh Kumar K . V, Vineet Gupta,
	Geert Uytterhoeven, Huacai Chen, Jiaxun Yang,
	Thomas Bogendoerfer, Heiko Carstens, Vasily Gorbik,
	Christian Borntraeger, Eric Biederman, Arnd Bergmann,
	linux-snps-arc, linux-ia64, linux-m68k, linux-mips, linux-s390,
	linux-mm, kexec

Let's communicate driver-managed regions to memblock, to properly
teach kexec_file with CONFIG_ARCH_KEEP_MEMBLOCK to not place images on
these memory regions.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 mm/memory_hotplug.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 5f873e7f5b29..6d90818d4ce8 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1357,6 +1357,7 @@ bool mhp_supports_memmap_on_memory(unsigned long size)
 int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
 {
 	struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) };
+	enum memblock_flags memblock_flags = MEMBLOCK_NONE;
 	struct vmem_altmap mhp_altmap = {};
 	struct memory_group *group = NULL;
 	u64 start, size;
@@ -1385,7 +1386,9 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
 	mem_hotplug_begin();
 
 	if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) {
-		ret = memblock_add_node(start, size, nid, MEMBLOCK_NONE);
+		if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED)
+			memblock_flags = MEMBLOCK_DRIVER_MANAGED;
+		ret = memblock_add_node(start, size, nid, memblock_flags);
 		if (ret)
 			goto error_mem_hotplug_end;
 	}
-- 
2.31.1


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http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v2 3/5] memblock: allow to specify flags with memblock_add_node()
  2021-10-04  9:36 ` [PATCH v2 3/5] memblock: allow to specify flags with memblock_add_node() David Hildenbrand
@ 2021-10-04 19:31   ` Shahab Vahedi
  2021-10-06  0:36   ` Mike Rapoport
  1 sibling, 0 replies; 10+ messages in thread
From: Shahab Vahedi @ 2021-10-04 19:31 UTC (permalink / raw)
  To: David Hildenbrand, linux-kernel
  Cc: Andrew Morton, Mike Rapoport, Michal Hocko, Oscar Salvador,
	Jianyong Wu, Aneesh Kumar K . V, Vineet Gupta,
	Geert Uytterhoeven, Huacai Chen, Jiaxun Yang,
	Thomas Bogendoerfer, Heiko Carstens, Vasily Gorbik,
	Christian Borntraeger, Eric Biederman, Arnd Bergmann,
	linux-snps-arc, linux-ia64, linux-m68k, linux-mips, linux-s390,
	linux-mm, kexec

On 10/4/21 11:36 AM, David Hildenbrand wrote:
> We want to specify flags when hotplugging memory. Let's prepare to pass
> flags to memblock_add_node() by adjusting all existing users.
> 
> Note that when hotplugging memory the system is already up and running
> and we might have concurrent memblock users: for example, while we're
> hotplugging memory, kexec_file code might search for suitable memory
> regions to place kexec images. It's important to add the memory directly
> to memblock via a single call with the right flags, instead of adding the
> memory first and apply flags later: otherwise, concurrent memblock users
> might temporarily stumble over memblocks with wrong flags, which will be
> important in a follow-up patch that introduces a new flag to properly
> handle add_memory_driver_managed().
> 
> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
> Acked-by: Heiko Carstens <hca@linux.ibm.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  arch/arc/mm/init.c               | 4 ++--
>  arch/ia64/mm/contig.c            | 2 +-
>  arch/ia64/mm/init.c              | 2 +-
>  arch/m68k/mm/mcfmmu.c            | 3 ++-
>  arch/m68k/mm/motorola.c          | 6 ++++--
>  arch/mips/loongson64/init.c      | 4 +++-
>  arch/mips/sgi-ip27/ip27-memory.c | 3 ++-
>  arch/s390/kernel/setup.c         | 3 ++-
>  include/linux/memblock.h         | 3 ++-
>  include/linux/mm.h               | 2 +-
>  mm/memblock.c                    | 9 +++++----
>  mm/memory_hotplug.c              | 2 +-
>  12 files changed, 26 insertions(+), 17 deletions(-)
> 
> diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
> index 699ecf119641..110eb69e9bee 100644
> --- a/arch/arc/mm/init.c
> +++ b/arch/arc/mm/init.c
> @@ -59,13 +59,13 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
>  
>  		low_mem_sz = size;
>  		in_use = 1;
> -		memblock_add_node(base, size, 0);
> +		memblock_add_node(base, size, 0, MEMBLOCK_NONE);
>  	} else {
>  #ifdef CONFIG_HIGHMEM
>  		high_mem_start = base;
>  		high_mem_sz = size;
>  		in_use = 1;
> -		memblock_add_node(base, size, 1);
> +		memblock_add_node(base, size, 1, MEMBLOCK_NONE);
>  		memblock_reserve(base, size);
>  #endif

arch/arc part: Acked-by: Shahab Vahedi <shahab@synopsys.com>

-- 
Shahab
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http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v2 4/5] memblock: add MEMBLOCK_DRIVER_MANAGED to mimic IORESOURCE_SYSRAM_DRIVER_MANAGED
  2021-10-04  9:36 ` [PATCH v2 4/5] memblock: add MEMBLOCK_DRIVER_MANAGED to mimic IORESOURCE_SYSRAM_DRIVER_MANAGED David Hildenbrand
@ 2021-10-06  0:35   ` Mike Rapoport
  0 siblings, 0 replies; 10+ messages in thread
From: Mike Rapoport @ 2021-10-06  0:35 UTC (permalink / raw)
  To: David Hildenbrand
  Cc: linux-kernel, Andrew Morton, Michal Hocko, Oscar Salvador,
	Jianyong Wu, Aneesh Kumar K . V, Vineet Gupta,
	Geert Uytterhoeven, Huacai Chen, Jiaxun Yang,
	Thomas Bogendoerfer, Heiko Carstens, Vasily Gorbik,
	Christian Borntraeger, Eric Biederman, Arnd Bergmann,
	linux-snps-arc, linux-ia64, linux-m68k, linux-mips, linux-s390,
	linux-mm, kexec

On Mon, Oct 04, 2021 at 11:36:04AM +0200, David Hildenbrand wrote:
> Let's add a flag that corresponds to IORESOURCE_SYSRAM_DRIVER_MANAGED,
> indicating that we're dealing with a memory region that is never
> indicated in the firmware-provided memory map, but always detected and
> added by a driver.
> 
> Similar to MEMBLOCK_HOTPLUG, most infrastructure has to treat such memory
> regions like ordinary MEMBLOCK_NONE memory regions -- for example, when
> selecting memory regions to add to the vmcore for dumping in the
> crashkernel via for_each_mem_range().
> 
> However, especially kexec_file is not supposed to select such memblocks via
> for_each_free_mem_range() / for_each_free_mem_range_reverse() to place
> kexec images, similar to how we handle IORESOURCE_SYSRAM_DRIVER_MANAGED
> without CONFIG_ARCH_KEEP_MEMBLOCK.
> 
> We'll make sure that memory hotplug code sets the flag where applicable
> (IORESOURCE_SYSRAM_DRIVER_MANAGED) next. This prepares architectures
> that need CONFIG_ARCH_KEEP_MEMBLOCK, such as arm64, for virtio-mem
> support.
> 
> Note that kexec *must not* indicate this memory to the second kernel
> and *must not* place kexec-images on this memory. Let's add a comment to
> kexec_walk_memblock(), documenting how we handle MEMBLOCK_DRIVER_MANAGED
> now just like using IORESOURCE_SYSRAM_DRIVER_MANAGED in
> locate_mem_hole_callback() for kexec_walk_resources().
> 
> Also note that MEMBLOCK_HOTPLUG cannot be reused due to different
> semantics:
> 	MEMBLOCK_HOTPLUG: memory is indicated as "System RAM" in the
> 	firmware-provided memory map and added to the system early during
> 	boot; kexec *has to* indicate this memory to the second kernel and
> 	can place kexec-images on this memory. After memory hotunplug,
> 	kexec has to be re-armed. We mostly ignore this flag when
> 	"movable_node" is not set on the kernel command line, because
> 	then we're told to not care about hotunpluggability of such
> 	memory regions.
> 
> 	MEMBLOCK_DRIVER_MANAGED: memory is not indicated as "System RAM" in
> 	the firmware-provided memory map; this memory is always detected
> 	and added to the system by a driver; memory might not actually be
> 	physically hotunpluggable. kexec *must not* indicate this memory to
> 	the second kernel and *must not* place kexec-images on this memory.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>

Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>

> ---
>  include/linux/memblock.h | 16 ++++++++++++++--
>  kernel/kexec_file.c      |  5 +++++
>  mm/memblock.c            |  4 ++++
>  3 files changed, 23 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
> index 2bc726e43a1b..b3b29ccf91f3 100644
> --- a/include/linux/memblock.h
> +++ b/include/linux/memblock.h
> @@ -37,12 +37,17 @@ extern unsigned long long max_possible_pfn;
>   * @MEMBLOCK_NOMAP: don't add to kernel direct mapping and treat as
>   * reserved in the memory map; refer to memblock_mark_nomap() description
>   * for further details
> + * @MEMBLOCK_DRIVER_MANAGED: memory region that is always detected and added
> + * via a driver, and never indicated in the firmware-provided memory map as
> + * system RAM. This corresponds to IORESOURCE_SYSRAM_DRIVER_MANAGED in the
> + * kernel resource tree.
>   */
>  enum memblock_flags {
>  	MEMBLOCK_NONE		= 0x0,	/* No special request */
>  	MEMBLOCK_HOTPLUG	= 0x1,	/* hotpluggable region */
>  	MEMBLOCK_MIRROR		= 0x2,	/* mirrored region */
>  	MEMBLOCK_NOMAP		= 0x4,	/* don't add to kernel direct mapping */
> +	MEMBLOCK_DRIVER_MANAGED = 0x8,	/* always detected via a driver */
>  };
>  
>  /**
> @@ -213,7 +218,8 @@ static inline void __next_physmem_range(u64 *idx, struct memblock_type *type,
>   */
>  #define for_each_mem_range(i, p_start, p_end) \
>  	__for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE,	\
> -			     MEMBLOCK_HOTPLUG, p_start, p_end, NULL)
> +			     MEMBLOCK_HOTPLUG | MEMBLOCK_DRIVER_MANAGED, \
> +			     p_start, p_end, NULL)
>  
>  /**
>   * for_each_mem_range_rev - reverse iterate through memblock areas from
> @@ -224,7 +230,8 @@ static inline void __next_physmem_range(u64 *idx, struct memblock_type *type,
>   */
>  #define for_each_mem_range_rev(i, p_start, p_end)			\
>  	__for_each_mem_range_rev(i, &memblock.memory, NULL, NUMA_NO_NODE, \
> -				 MEMBLOCK_HOTPLUG, p_start, p_end, NULL)
> +				 MEMBLOCK_HOTPLUG | MEMBLOCK_DRIVER_MANAGED,\
> +				 p_start, p_end, NULL)
>  
>  /**
>   * for_each_reserved_mem_range - iterate over all reserved memblock areas
> @@ -254,6 +261,11 @@ static inline bool memblock_is_nomap(struct memblock_region *m)
>  	return m->flags & MEMBLOCK_NOMAP;
>  }
>  
> +static inline bool memblock_is_driver_managed(struct memblock_region *m)
> +{
> +	return m->flags & MEMBLOCK_DRIVER_MANAGED;
> +}
> +
>  int memblock_search_pfn_nid(unsigned long pfn, unsigned long *start_pfn,
>  			    unsigned long  *end_pfn);
>  void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn,
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index 33400ff051a8..8347fc158d2b 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -556,6 +556,11 @@ static int kexec_walk_memblock(struct kexec_buf *kbuf,
>  	if (kbuf->image->type == KEXEC_TYPE_CRASH)
>  		return func(&crashk_res, kbuf);
>  
> +	/*
> +	 * Using MEMBLOCK_NONE will properly skip MEMBLOCK_DRIVER_MANAGED. See
> +	 * IORESOURCE_SYSRAM_DRIVER_MANAGED handling in
> +	 * locate_mem_hole_callback().
> +	 */
>  	if (kbuf->top_down) {
>  		for_each_free_mem_range_reverse(i, NUMA_NO_NODE, MEMBLOCK_NONE,
>  						&mstart, &mend, NULL) {
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 47a56b223141..540a35317fb0 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -979,6 +979,10 @@ static bool should_skip_region(struct memblock_type *type,
>  	if (!(flags & MEMBLOCK_NOMAP) && memblock_is_nomap(m))
>  		return true;
>  
> +	/* skip driver-managed memory unless we were asked for it explicitly */
> +	if (!(flags & MEMBLOCK_DRIVER_MANAGED) && memblock_is_driver_managed(m))
> +		return true;
> +
>  	return false;
>  }
>  
> -- 
> 2.31.1
> 

-- 
Sincerely yours,
Mike.

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^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v2 2/5] memblock: improve MEMBLOCK_HOTPLUG documentation
  2021-10-04  9:36 ` [PATCH v2 2/5] memblock: improve MEMBLOCK_HOTPLUG documentation David Hildenbrand
@ 2021-10-06  0:35   ` Mike Rapoport
  0 siblings, 0 replies; 10+ messages in thread
From: Mike Rapoport @ 2021-10-06  0:35 UTC (permalink / raw)
  To: David Hildenbrand
  Cc: linux-kernel, Andrew Morton, Michal Hocko, Oscar Salvador,
	Jianyong Wu, Aneesh Kumar K . V, Vineet Gupta,
	Geert Uytterhoeven, Huacai Chen, Jiaxun Yang,
	Thomas Bogendoerfer, Heiko Carstens, Vasily Gorbik,
	Christian Borntraeger, Eric Biederman, Arnd Bergmann,
	linux-snps-arc, linux-ia64, linux-m68k, linux-mips, linux-s390,
	linux-mm, kexec

On Mon, Oct 04, 2021 at 11:36:02AM +0200, David Hildenbrand wrote:
> The description of MEMBLOCK_HOTPLUG is currently short and consequently
> misleading: we're actually dealing with a memory region that might get
> hotunplugged later (i.e., the platform+firmware supports it), yet it is
> indicated in the firmware-provided memory map as system ram that will just
> get used by the system for any purpose when not taking special care. The
> firmware marked this memory region as a hot(un)plugged (e.g., hotplugged
> before reboot), implying that it might get hotunplugged again later.
> 
> Whether we consider this information depends on the "movable_node" kernel
> commandline parameter: only with "movable_node" set, we'll try keeping
> this memory hotunpluggable, for example, by not serving early allocations
> from this memory region and by letting the buddy manage it using the
> ZONE_MOVABLE.
> 
> Let's make this clearer by extending the documentation.
> 
> Note: kexec *has to* indicate this memory to the second kernel. With
> "movable_node" set, we don't want to place kexec-images on this memory.
> Without "movable_node" set, we don't care and can place kexec-images on
> this memory. In both cases, after successful memory hotunplug, kexec has to
> be re-armed to update the memory map for the second kernel and to place the
> kexec-images somewhere else.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>

Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>

> ---
>  include/linux/memblock.h | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
> index 34de69b3b8ba..4ee8dd2d63a7 100644
> --- a/include/linux/memblock.h
> +++ b/include/linux/memblock.h
> @@ -28,7 +28,11 @@ extern unsigned long long max_possible_pfn;
>  /**
>   * enum memblock_flags - definition of memory region attributes
>   * @MEMBLOCK_NONE: no special request
> - * @MEMBLOCK_HOTPLUG: hotpluggable region
> + * @MEMBLOCK_HOTPLUG: memory region indicated in the firmware-provided memory
> + * map during early boot as hot(un)pluggable system RAM (e.g., memory range
> + * that might get hotunplugged later). With "movable_node" set on the kernel
> + * commandline, try keeping this memory region hotunpluggable. Does not apply
> + * to memblocks added ("hotplugged") after early boot.
>   * @MEMBLOCK_MIRROR: mirrored region
>   * @MEMBLOCK_NOMAP: don't add to kernel direct mapping and treat as
>   * reserved in the memory map; refer to memblock_mark_nomap() description
> -- 
> 2.31.1
> 

-- 
Sincerely yours,
Mike.

_______________________________________________
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 10+ messages in thread

* Re: [PATCH v2 3/5] memblock: allow to specify flags with memblock_add_node()
  2021-10-04  9:36 ` [PATCH v2 3/5] memblock: allow to specify flags with memblock_add_node() David Hildenbrand
  2021-10-04 19:31   ` Shahab Vahedi
@ 2021-10-06  0:36   ` Mike Rapoport
  1 sibling, 0 replies; 10+ messages in thread
From: Mike Rapoport @ 2021-10-06  0:36 UTC (permalink / raw)
  To: David Hildenbrand
  Cc: linux-kernel, Andrew Morton, Michal Hocko, Oscar Salvador,
	Jianyong Wu, Aneesh Kumar K . V, Vineet Gupta,
	Geert Uytterhoeven, Huacai Chen, Jiaxun Yang,
	Thomas Bogendoerfer, Heiko Carstens, Vasily Gorbik,
	Christian Borntraeger, Eric Biederman, Arnd Bergmann,
	linux-snps-arc, linux-ia64, linux-m68k, linux-mips, linux-s390,
	linux-mm, kexec

On Mon, Oct 04, 2021 at 11:36:03AM +0200, David Hildenbrand wrote:
> We want to specify flags when hotplugging memory. Let's prepare to pass
> flags to memblock_add_node() by adjusting all existing users.
> 
> Note that when hotplugging memory the system is already up and running
> and we might have concurrent memblock users: for example, while we're
> hotplugging memory, kexec_file code might search for suitable memory
> regions to place kexec images. It's important to add the memory directly
> to memblock via a single call with the right flags, instead of adding the
> memory first and apply flags later: otherwise, concurrent memblock users
> might temporarily stumble over memblocks with wrong flags, which will be
> important in a follow-up patch that introduces a new flag to properly
> handle add_memory_driver_managed().
> 
> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
> Acked-by: Heiko Carstens <hca@linux.ibm.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>

Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>

> ---
>  arch/arc/mm/init.c               | 4 ++--
>  arch/ia64/mm/contig.c            | 2 +-
>  arch/ia64/mm/init.c              | 2 +-
>  arch/m68k/mm/mcfmmu.c            | 3 ++-
>  arch/m68k/mm/motorola.c          | 6 ++++--
>  arch/mips/loongson64/init.c      | 4 +++-
>  arch/mips/sgi-ip27/ip27-memory.c | 3 ++-
>  arch/s390/kernel/setup.c         | 3 ++-
>  include/linux/memblock.h         | 3 ++-
>  include/linux/mm.h               | 2 +-
>  mm/memblock.c                    | 9 +++++----
>  mm/memory_hotplug.c              | 2 +-
>  12 files changed, 26 insertions(+), 17 deletions(-)
> 
> diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
> index 699ecf119641..110eb69e9bee 100644
> --- a/arch/arc/mm/init.c
> +++ b/arch/arc/mm/init.c
> @@ -59,13 +59,13 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
>  
>  		low_mem_sz = size;
>  		in_use = 1;
> -		memblock_add_node(base, size, 0);
> +		memblock_add_node(base, size, 0, MEMBLOCK_NONE);
>  	} else {
>  #ifdef CONFIG_HIGHMEM
>  		high_mem_start = base;
>  		high_mem_sz = size;
>  		in_use = 1;
> -		memblock_add_node(base, size, 1);
> +		memblock_add_node(base, size, 1, MEMBLOCK_NONE);
>  		memblock_reserve(base, size);
>  #endif
>  	}
> diff --git a/arch/ia64/mm/contig.c b/arch/ia64/mm/contig.c
> index 42e025cfbd08..24901d809301 100644
> --- a/arch/ia64/mm/contig.c
> +++ b/arch/ia64/mm/contig.c
> @@ -153,7 +153,7 @@ find_memory (void)
>  	efi_memmap_walk(find_max_min_low_pfn, NULL);
>  	max_pfn = max_low_pfn;
>  
> -	memblock_add_node(0, PFN_PHYS(max_low_pfn), 0);
> +	memblock_add_node(0, PFN_PHYS(max_low_pfn), 0, MEMBLOCK_NONE);
>  
>  	find_initrd();
>  
> diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
> index 5c6da8d83c1a..5d165607bf35 100644
> --- a/arch/ia64/mm/init.c
> +++ b/arch/ia64/mm/init.c
> @@ -378,7 +378,7 @@ int __init register_active_ranges(u64 start, u64 len, int nid)
>  #endif
>  
>  	if (start < end)
> -		memblock_add_node(__pa(start), end - start, nid);
> +		memblock_add_node(__pa(start), end - start, nid, MEMBLOCK_NONE);
>  	return 0;
>  }
>  
> diff --git a/arch/m68k/mm/mcfmmu.c b/arch/m68k/mm/mcfmmu.c
> index eac9dde65193..6f1f25125294 100644
> --- a/arch/m68k/mm/mcfmmu.c
> +++ b/arch/m68k/mm/mcfmmu.c
> @@ -174,7 +174,8 @@ void __init cf_bootmem_alloc(void)
>  	m68k_memory[0].addr = _rambase;
>  	m68k_memory[0].size = _ramend - _rambase;
>  
> -	memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0);
> +	memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0,
> +			  MEMBLOCK_NONE);
>  
>  	/* compute total pages in system */
>  	num_pages = PFN_DOWN(_ramend - _rambase);
> diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
> index 9f3f77785aa7..2b05bb2bac00 100644
> --- a/arch/m68k/mm/motorola.c
> +++ b/arch/m68k/mm/motorola.c
> @@ -410,7 +410,8 @@ void __init paging_init(void)
>  
>  	min_addr = m68k_memory[0].addr;
>  	max_addr = min_addr + m68k_memory[0].size;
> -	memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0);
> +	memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0,
> +			  MEMBLOCK_NONE);
>  	for (i = 1; i < m68k_num_memory;) {
>  		if (m68k_memory[i].addr < min_addr) {
>  			printk("Ignoring memory chunk at 0x%lx:0x%lx before the first chunk\n",
> @@ -421,7 +422,8 @@ void __init paging_init(void)
>  				(m68k_num_memory - i) * sizeof(struct m68k_mem_info));
>  			continue;
>  		}
> -		memblock_add_node(m68k_memory[i].addr, m68k_memory[i].size, i);
> +		memblock_add_node(m68k_memory[i].addr, m68k_memory[i].size, i,
> +				  MEMBLOCK_NONE);
>  		addr = m68k_memory[i].addr + m68k_memory[i].size;
>  		if (addr > max_addr)
>  			max_addr = addr;
> diff --git a/arch/mips/loongson64/init.c b/arch/mips/loongson64/init.c
> index 76e0a9636a0e..4ac5ba80bbf6 100644
> --- a/arch/mips/loongson64/init.c
> +++ b/arch/mips/loongson64/init.c
> @@ -77,7 +77,9 @@ void __init szmem(unsigned int node)
>  				(u32)node_id, mem_type, mem_start, mem_size);
>  			pr_info("       start_pfn:0x%llx, end_pfn:0x%llx, num_physpages:0x%lx\n",
>  				start_pfn, end_pfn, num_physpages);
> -			memblock_add_node(PFN_PHYS(start_pfn), PFN_PHYS(node_psize), node);
> +			memblock_add_node(PFN_PHYS(start_pfn),
> +					  PFN_PHYS(node_psize), node,
> +					  MEMBLOCK_NONE);
>  			break;
>  		case SYSTEM_RAM_RESERVED:
>  			pr_info("Node%d: mem_type:%d, mem_start:0x%llx, mem_size:0x%llx MB\n",
> diff --git a/arch/mips/sgi-ip27/ip27-memory.c b/arch/mips/sgi-ip27/ip27-memory.c
> index 6173684b5aaa..adc2faeecf7c 100644
> --- a/arch/mips/sgi-ip27/ip27-memory.c
> +++ b/arch/mips/sgi-ip27/ip27-memory.c
> @@ -341,7 +341,8 @@ static void __init szmem(void)
>  				continue;
>  			}
>  			memblock_add_node(PFN_PHYS(slot_getbasepfn(node, slot)),
> -					  PFN_PHYS(slot_psize), node);
> +					  PFN_PHYS(slot_psize), node,
> +					  MEMBLOCK_NONE);
>  		}
>  	}
>  }
> diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
> index 67e5fff96ee0..f3943f15af6e 100644
> --- a/arch/s390/kernel/setup.c
> +++ b/arch/s390/kernel/setup.c
> @@ -593,7 +593,8 @@ static void __init setup_resources(void)
>  	 * part of the System RAM resource.
>  	 */
>  	if (crashk_res.end) {
> -		memblock_add_node(crashk_res.start, resource_size(&crashk_res), 0);
> +		memblock_add_node(crashk_res.start, resource_size(&crashk_res),
> +				  0, MEMBLOCK_NONE);
>  		memblock_reserve(crashk_res.start, resource_size(&crashk_res));
>  		insert_resource(&iomem_resource, &crashk_res);
>  	}
> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
> index 4ee8dd2d63a7..2bc726e43a1b 100644
> --- a/include/linux/memblock.h
> +++ b/include/linux/memblock.h
> @@ -104,7 +104,8 @@ static inline void memblock_discard(void) {}
>  #endif
>  
>  void memblock_allow_resize(void);
> -int memblock_add_node(phys_addr_t base, phys_addr_t size, int nid);
> +int memblock_add_node(phys_addr_t base, phys_addr_t size, int nid,
> +		      enum memblock_flags flags);
>  int memblock_add(phys_addr_t base, phys_addr_t size);
>  int memblock_remove(phys_addr_t base, phys_addr_t size);
>  int memblock_free(phys_addr_t base, phys_addr_t size);
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 73a52aba448f..0117cb35b212 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2447,7 +2447,7 @@ static inline unsigned long get_num_physpages(void)
>   * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
>   * 							 max_highmem_pfn};
>   * for_each_valid_physical_page_range()
> - * 	memblock_add_node(base, size, nid)
> + *	memblock_add_node(base, size, nid, MEMBLOCK_NONE)
>   * free_area_init(max_zone_pfns);
>   */
>  void free_area_init(unsigned long *max_zone_pfn);
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 184dcd2e5d99..47a56b223141 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -655,6 +655,7 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
>   * @base: base address of the new region
>   * @size: size of the new region
>   * @nid: nid of the new region
> + * @flags: flags of the new region
>   *
>   * Add new memblock region [@base, @base + @size) to the "memory"
>   * type. See memblock_add_range() description for mode details
> @@ -663,14 +664,14 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
>   * 0 on success, -errno on failure.
>   */
>  int __init_memblock memblock_add_node(phys_addr_t base, phys_addr_t size,
> -				       int nid)
> +				      int nid, enum memblock_flags flags)
>  {
>  	phys_addr_t end = base + size - 1;
>  
> -	memblock_dbg("%s: [%pa-%pa] nid=%d %pS\n", __func__,
> -		     &base, &end, nid, (void *)_RET_IP_);
> +	memblock_dbg("%s: [%pa-%pa] nid=%d flags=%x %pS\n", __func__,
> +		     &base, &end, nid, flags, (void *)_RET_IP_);
>  
> -	return memblock_add_range(&memblock.memory, base, size, nid, 0);
> +	return memblock_add_range(&memblock.memory, base, size, nid, flags);
>  }
>  
>  /**
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 917b3528636d..5f873e7f5b29 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1385,7 +1385,7 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
>  	mem_hotplug_begin();
>  
>  	if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) {
> -		ret = memblock_add_node(start, size, nid);
> +		ret = memblock_add_node(start, size, nid, MEMBLOCK_NONE);
>  		if (ret)
>  			goto error_mem_hotplug_end;
>  	}
> -- 
> 2.31.1
> 

-- 
Sincerely yours,
Mike.

_______________________________________________
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linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc

^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2021-10-06  0:36 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-10-04  9:36 [PATCH v2 0/5] mm/memory_hotplug: full support for add_memory_driver_managed() with CONFIG_ARCH_KEEP_MEMBLOCK David Hildenbrand
2021-10-04  9:36 ` [PATCH v2 1/5] mm/memory_hotplug: handle memblock_add_node() failures in add_memory_resource() David Hildenbrand
2021-10-04  9:36 ` [PATCH v2 2/5] memblock: improve MEMBLOCK_HOTPLUG documentation David Hildenbrand
2021-10-06  0:35   ` Mike Rapoport
2021-10-04  9:36 ` [PATCH v2 3/5] memblock: allow to specify flags with memblock_add_node() David Hildenbrand
2021-10-04 19:31   ` Shahab Vahedi
2021-10-06  0:36   ` Mike Rapoport
2021-10-04  9:36 ` [PATCH v2 4/5] memblock: add MEMBLOCK_DRIVER_MANAGED to mimic IORESOURCE_SYSRAM_DRIVER_MANAGED David Hildenbrand
2021-10-06  0:35   ` Mike Rapoport
2021-10-04  9:36 ` [PATCH v2 5/5] mm/memory_hotplug: indicate MEMBLOCK_DRIVER_MANAGED with IORESOURCE_SYSRAM_DRIVER_MANAGED David Hildenbrand

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