diff mbox series

[V3,2/4] mm: introduce memory type MEMORY_DEVICE_DEV_DAX

Message ID 01aaca83694c3b0093fcb2f48af1dff0b147a4b2.1533811181.git.yi.z.zhang@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series Fix kvm misconceives NVDIMM pages as reserved mmio | expand

Commit Message

Zhang, Yi Aug. 9, 2018, 10:53 a.m. UTC
Currently, NVDIMM pages will be marked 'PageReserved'. However, unlike
other reserved PFNs, pages on NVDIMM shall still behave like normal ones
in many cases, i.e. when used as backend memory of KVM guest. This patch
introduces a new memory type, MEMORY_DEVICE_DEV_DAX. And set this flag
while dax driver hotplug the device memory.

Signed-off-by: Zhang Yi <yi.z.zhang@linux.intel.com>
Signed-off-by: Zhang Yu <yu.c.zhang@linux.intel.com>
---
 drivers/dax/pmem.c       | 1 +
 include/linux/memremap.h | 8 ++++++++
 2 files changed, 9 insertions(+)

Comments

Jan Kara Aug. 9, 2018, 8:59 a.m. UTC | #1
On Thu 09-08-18 18:53:08, Zhang Yi wrote:
> Currently, NVDIMM pages will be marked 'PageReserved'. However, unlike
> other reserved PFNs, pages on NVDIMM shall still behave like normal ones
> in many cases, i.e. when used as backend memory of KVM guest. This patch
> introduces a new memory type, MEMORY_DEVICE_DEV_DAX. And set this flag
> while dax driver hotplug the device memory.
> 
> Signed-off-by: Zhang Yi <yi.z.zhang@linux.intel.com>
> Signed-off-by: Zhang Yu <yu.c.zhang@linux.intel.com>

Looks good to me now. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  drivers/dax/pmem.c       | 1 +
>  include/linux/memremap.h | 8 ++++++++
>  2 files changed, 9 insertions(+)
> 
> diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c
> index fd49b24..fb3f363 100644
> --- a/drivers/dax/pmem.c
> +++ b/drivers/dax/pmem.c
> @@ -111,6 +111,7 @@ static int dax_pmem_probe(struct device *dev)
>  		return rc;
>  
>  	dax_pmem->pgmap.ref = &dax_pmem->ref;
> +	dax_pmem->pgmap.type = MEMORY_DEVICE_DEV_DAX;
>  	addr = devm_memremap_pages(dev, &dax_pmem->pgmap);
>  	if (IS_ERR(addr))
>  		return PTR_ERR(addr);
> diff --git a/include/linux/memremap.h b/include/linux/memremap.h
> index f91f9e7..cd07ca8 100644
> --- a/include/linux/memremap.h
> +++ b/include/linux/memremap.h
> @@ -53,11 +53,19 @@ struct vmem_altmap {
>   * wakeup event whenever a page is unpinned and becomes idle. This
>   * wakeup is used to coordinate physical address space management (ex:
>   * fs truncate/hole punch) vs pinned pages (ex: device dma).
> + *
> + * MEMORY_DEVICE_DEV_DAX:
> + * Device memory that support raw access to persistent memory. Without need
> + * of an intervening filesystem, it could be directed mapped via an mmap
> + * capable character device. Together with the type MEMORY_DEVICE_FS_DAX,
> + * we could distinguish the persistent memory pages from normal ZONE_DEVICE
> + * pages.
>   */
>  enum memory_type {
>  	MEMORY_DEVICE_PRIVATE = 1,
>  	MEMORY_DEVICE_PUBLIC,
>  	MEMORY_DEVICE_FS_DAX,
> +	MEMORY_DEVICE_DEV_DAX,
>  };
>  
>  /*
> -- 
> 2.7.4
>
diff mbox series

Patch

diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c
index fd49b24..fb3f363 100644
--- a/drivers/dax/pmem.c
+++ b/drivers/dax/pmem.c
@@ -111,6 +111,7 @@  static int dax_pmem_probe(struct device *dev)
 		return rc;
 
 	dax_pmem->pgmap.ref = &dax_pmem->ref;
+	dax_pmem->pgmap.type = MEMORY_DEVICE_DEV_DAX;
 	addr = devm_memremap_pages(dev, &dax_pmem->pgmap);
 	if (IS_ERR(addr))
 		return PTR_ERR(addr);
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index f91f9e7..cd07ca8 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -53,11 +53,19 @@  struct vmem_altmap {
  * wakeup event whenever a page is unpinned and becomes idle. This
  * wakeup is used to coordinate physical address space management (ex:
  * fs truncate/hole punch) vs pinned pages (ex: device dma).
+ *
+ * MEMORY_DEVICE_DEV_DAX:
+ * Device memory that support raw access to persistent memory. Without need
+ * of an intervening filesystem, it could be directed mapped via an mmap
+ * capable character device. Together with the type MEMORY_DEVICE_FS_DAX,
+ * we could distinguish the persistent memory pages from normal ZONE_DEVICE
+ * pages.
  */
 enum memory_type {
 	MEMORY_DEVICE_PRIVATE = 1,
 	MEMORY_DEVICE_PUBLIC,
 	MEMORY_DEVICE_FS_DAX,
+	MEMORY_DEVICE_DEV_DAX,
 };
 
 /*