virtio-mem: generalize check for added memory (989ff825) · Commits · 戴 / test

Let's check by traversing busy system RAM resources instead, to avoid relying on memory block states. Don't use walk_system_ram_range(), as that works on pages and we want to use the bare addresses we have easily at hand. This is a preparation for Big Block Mode (BBM), which won't have memory block states. Reviewed-by:

Wei Yang <richard.weiyang@linux.alibaba.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by:

David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-12-david@redhat.com Signed-off-by:

Michael S. Tsirkin <mst@redhat.com>

drivers/virtio/virtio_mem.c

+15 −4

Original line number	Diff line number	Diff line
		@@ -1833,6 +1833,20 @@ static void virtio_mem_delete_resource(struct virtio_mem *vm)
		vm->parent_resource = NULL;
		}

		static int virtio_mem_range_has_system_ram(struct resource res, void arg)
		{
		return 1;
		}

		static bool virtio_mem_has_memory_added(struct virtio_mem *vm)
		{
		const unsigned long flags = IORESOURCE_SYSTEM_RAM \| IORESOURCE_BUSY;

		return walk_iomem_res_desc(IORES_DESC_NONE, flags, vm->addr,
		vm->addr + vm->region_size, NULL,
		virtio_mem_range_has_system_ram) == 1;
		}

		static int virtio_mem_probe(struct virtio_device *vdev)
		{
		struct virtio_mem *vm;
		@@ -1954,10 +1968,7 @@ static void virtio_mem_remove(struct virtio_device *vdev)
		* the system. And there is no way to stop the driver/device from going
		* away. Warn at least.
		*/
		if (vm->nb_mb_state[VIRTIO_MEM_MB_STATE_OFFLINE] \|\|
		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]) {
		if (virtio_mem_has_memory_added(vm)) {
		dev_warn(&vdev->dev, "device still has system memory added\n");
		} else {
		virtio_mem_delete_resource(vm);

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