diff options
author | David Hildenbrand <david@redhat.com> | 2020-06-11 11:35:18 +0200 |
---|---|---|
committer | Michael S. Tsirkin <mst@redhat.com> | 2020-06-22 12:34:21 -0400 |
commit | b3562c6087b585abba53d906f127d6fd5a92829c (patch) | |
tree | 11c8ae8bea9be152e900347feca15483cc6abe91 /drivers/virtio/virtio_mem.c | |
parent | 1c3d69ab5348b661616992206357a3ebf19b1008 (diff) |
virtio-mem: add memory via add_memory_driver_managed()
Virtio-mem managed memory is always detected and added by the virtio-mem
driver, never using something like the firmware-provided memory map.
This is the case after an ordinary system reboot, and has to be guaranteed
after kexec. Especially, virtio-mem added memory resources can contain
inaccessible parts ("unblocked memory blocks"), blindly forwarding them
to a kexec kernel is dangerous, as unplugged memory will get accessed
(esp. written).
Let's use the new way of adding special driver-managed memory introduced
in commit 7b7b27214bba ("mm/memory_hotplug: introduce
add_memory_driver_managed()").
This will result in no entries in /sys/firmware/memmap ("raw firmware-
provided memory map"), the memory resource will be flagged
IORESOURCE_MEM_DRIVER_MANAGED (esp., kexec_file_load() will not place
kexec images on this memory), and it is exposed as "System RAM
(virtio_mem)" in /proc/iomem, so esp. kexec-tools can properly handle it.
Example /proc/iomem before this change:
[...]
140000000-333ffffff : virtio0
140000000-147ffffff : System RAM
334000000-533ffffff : virtio1
338000000-33fffffff : System RAM
340000000-347ffffff : System RAM
348000000-34fffffff : System RAM
[...]
Example /proc/iomem after this change:
[...]
140000000-333ffffff : virtio0
140000000-147ffffff : System RAM (virtio_mem)
334000000-533ffffff : virtio1
338000000-33fffffff : System RAM (virtio_mem)
340000000-347ffffff : System RAM (virtio_mem)
348000000-34fffffff : System RAM (virtio_mem)
[...]
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: teawater <teawaterz@linux.alibaba.com>
Fixes: 5f1f79bbc9e26 ("virtio-mem: Paravirtualized memory hotplug")
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200611093518.5737-1-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Diffstat (limited to 'drivers/virtio/virtio_mem.c')
-rw-r--r-- | drivers/virtio/virtio_mem.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index 5210ff0c5681..f26f5f64ae82 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -101,6 +101,11 @@ struct virtio_mem { /* The parent resource for all memory added via this device. */ struct resource *parent_resource; + /* + * Copy of "System RAM (virtio_mem)" to be used for + * add_memory_driver_managed(). + */ + const char *resource_name; /* Summary of all memory block states. */ unsigned long nb_mb_state[VIRTIO_MEM_MB_STATE_COUNT]; @@ -414,8 +419,20 @@ static int virtio_mem_mb_add(struct virtio_mem *vm, unsigned long mb_id) if (nid == NUMA_NO_NODE) nid = memory_add_physaddr_to_nid(addr); + /* + * When force-unloading the driver and we still have memory added to + * Linux, the resource name has to stay. + */ + if (!vm->resource_name) { + vm->resource_name = kstrdup_const("System RAM (virtio_mem)", + GFP_KERNEL); + if (!vm->resource_name) + return -ENOMEM; + } + dev_dbg(&vm->vdev->dev, "adding memory block: %lu\n", mb_id); - return add_memory(nid, addr, memory_block_size_bytes()); + return add_memory_driver_managed(nid, addr, memory_block_size_bytes(), + vm->resource_name); } /* @@ -1890,10 +1907,12 @@ static void virtio_mem_remove(struct virtio_device *vdev) vm->nb_mb_state[VIRTIO_MEM_MB_STATE_OFFLINE_PARTIAL] || vm->nb_mb_state[VIRTIO_MEM_MB_STATE_ONLINE] || vm->nb_mb_state[VIRTIO_MEM_MB_STATE_ONLINE_PARTIAL] || - vm->nb_mb_state[VIRTIO_MEM_MB_STATE_ONLINE_MOVABLE]) + vm->nb_mb_state[VIRTIO_MEM_MB_STATE_ONLINE_MOVABLE]) { dev_warn(&vdev->dev, "device still has system memory added\n"); - else + } else { virtio_mem_delete_resource(vm); + kfree_const(vm->resource_name); + } /* remove all tracking data - no locking needed */ vfree(vm->mb_state); |