From faa45ff4ce885af93a3233a408c5a74b2943226b Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 12 Nov 2020 14:38:12 +0100 Subject: virtio-mem: allow to force Big Block Mode (BBM) and set the big block size Let's allow to force BBM, even if subblocks would be possible. Take care of properly calculating the first big block id, because the start address might no longer be aligned to the big block size. Also, allow to manually configure the size of Big Blocks. Reviewed-by: Wei Yang Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Pankaj Gupta Cc: Michal Hocko Cc: Oscar Salvador Cc: Wei Yang Cc: Andrew Morton Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20201112133815.13332-27-david@redhat.com Signed-off-by: Michael S. Tsirkin --- drivers/virtio/virtio_mem.c | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) (limited to 'drivers/virtio') diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index 8a4f735360ac..861149acafe5 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -27,6 +27,16 @@ static bool unplug_online = true; module_param(unplug_online, bool, 0644); MODULE_PARM_DESC(unplug_online, "Try to unplug online memory"); +static bool force_bbm; +module_param(force_bbm, bool, 0444); +MODULE_PARM_DESC(force_bbm, + "Force Big Block Mode. Default is 0 (auto-selection)"); + +static unsigned long bbm_block_size; +module_param(bbm_block_size, ulong, 0444); +MODULE_PARM_DESC(bbm_block_size, + "Big Block size in bytes. Default is 0 (auto-detection)."); + /* * virtio-mem currently supports the following modes of operation: * @@ -2164,7 +2174,7 @@ static int virtio_mem_init(struct virtio_mem *vm) pageblock_nr_pages) * PAGE_SIZE; sb_size = max_t(uint64_t, vm->device_block_size, sb_size); - if (sb_size < memory_block_size_bytes()) { + if (sb_size < memory_block_size_bytes() && !force_bbm) { /* SBM: At least two subblocks per Linux memory block. */ vm->in_sbm = true; vm->sbm.sb_size = sb_size; @@ -2177,9 +2187,24 @@ static int virtio_mem_init(struct virtio_mem *vm) vm->sbm.next_mb_id = vm->sbm.first_mb_id; } else { /* BBM: At least one Linux memory block. */ - vm->bbm.bb_size = vm->device_block_size; + vm->bbm.bb_size = max_t(uint64_t, vm->device_block_size, + memory_block_size_bytes()); + + if (bbm_block_size) { + if (!is_power_of_2(bbm_block_size)) { + dev_warn(&vm->vdev->dev, + "bbm_block_size is not a power of 2"); + } else if (bbm_block_size < vm->bbm.bb_size) { + dev_warn(&vm->vdev->dev, + "bbm_block_size is too small"); + } else { + vm->bbm.bb_size = bbm_block_size; + } + } - vm->bbm.first_bb_id = virtio_mem_phys_to_bb_id(vm, vm->addr); + /* Round up to the next aligned big block */ + addr = vm->addr + vm->bbm.bb_size - 1; + vm->bbm.first_bb_id = virtio_mem_phys_to_bb_id(vm, addr); vm->bbm.next_bb_id = vm->bbm.first_bb_id; } -- cgit v1.2.3