This series parallelizes the mlx5_vdpa device suspend and resume operations through the firmware async API. The purpose is to reduce live migration downtime. The series starts with changing the VQ suspend and resume commands to the async API. After that, the switch is made to issue multiple commands of the same type in parallel. Then, the an additional improvement is added: keep the notifiers enabled during suspend but make it a NOP. Upon resume make sure that the link state is forwarded. This shaves around 30ms per device constant time. Finally, use parallel VQ suspend and resume during the CVQ MQ command. For 1 vDPA device x 32 VQs (16 VQPs), on a large VM (256 GB RAM, 32 CPUs x 2 threads per core), the improvements are: +-------------------+--------+--------+-----------+ | operation | Before | After | Reduction | |-------------------+--------+--------+-----------| | mlx5_vdpa_suspend | 37 ms | 2.5 ms | 14x | | mlx5_vdpa_resume | 16 ms | 5 ms | 3x | +-------------------+--------+--------+-----------+ --- v2: - Changed to parallel VQ suspend/resume during CVQ MQ command. Support added in the last 2 patches. - Made the fw async command more generic and moved it to resources.c. Did that because the following series (parallel mkey ops) needs this code as well. Dropped Acked-by from Eugenio on modified patches. - Fixed kfree -> kvfree. - Removed extra newline caught during review. - As discussed in the v1, the series can be pulled in completely in the vhost tree [0]. The mlx5_core patch was reviewed by Tariq who is also a maintainer for mlx5_core. [0] - https://lore.kernel.org/virtualization/6582792d-8db2-4bc0-bf3a-248fe5c8fc56@xxxxxxxxxx/T/#maefabb2fde5adfb322d16ca16ae64d540f75b7d2 Dragos Tatulea (10): net/mlx5: Support throttled commands from async API vdpa/mlx5: Introduce error logging function vdpa/mlx5: Introduce async fw command wrapper vdpa/mlx5: Use async API for vq query command vdpa/mlx5: Use async API for vq modify commands vdpa/mlx5: Parallelize device suspend vdpa/mlx5: Parallelize device resume vdpa/mlx5: Keep notifiers during suspend but ignore vdpa/mlx5: Small improvement for change_num_qps() vdpa/mlx5: Parallelize VQ suspend/resume for CVQ MQ command drivers/net/ethernet/mellanox/mlx5/core/cmd.c | 21 +- drivers/vdpa/mlx5/core/mlx5_vdpa.h | 22 + drivers/vdpa/mlx5/core/resources.c | 73 ++++ drivers/vdpa/mlx5/net/mlx5_vnet.c | 396 +++++++++++------- 4 files changed, 361 insertions(+), 151 deletions(-) -- 2.45.1
