From ca1c4b745779e20711322b3338f3a942a3c1224a Mon Sep 17 00:00:00 2001 From: Dexuan Cui Date: Thu, 13 Aug 2015 17:07:03 -0700 Subject: [PATCH] Drivers: hv: vmbus: fix init_vp_index() for reloading hv_netvsc This fixes the recent commit 3b71107d73b16074afa7658f3f0fcf837aabfe24: Drivers: hv: vmbus: Further improve CPU affiliation logic Without the fix, reloading hv_netvsc hangs the guest. Signed-off-by: Dexuan Cui Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/channel_mgmt.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index 2f9aead4ecfc..652afd11a9ef 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -204,6 +204,8 @@ void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid) spin_lock_irqsave(&vmbus_connection.channel_lock, flags); list_del(&channel->listentry); spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); + + primary_channel = channel; } else { primary_channel = channel->primary_channel; spin_lock_irqsave(&primary_channel->lock, flags); @@ -211,6 +213,14 @@ void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid) primary_channel->num_sc--; spin_unlock_irqrestore(&primary_channel->lock, flags); } + + /* + * We need to free the bit for init_vp_index() to work in the case + * of sub-channel, when we reload drivers like hv_netvsc. + */ + cpumask_clear_cpu(channel->target_cpu, + &primary_channel->alloced_cpus_in_node); + free_channel(channel); } @@ -458,6 +468,13 @@ static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_gui continue; } + /* + * NOTE: in the case of sub-channel, we clear the sub-channel + * related bit(s) in primary->alloced_cpus_in_node in + * hv_process_channel_removal(), so when we reload drivers + * like hv_netvsc in SMP guest, here we're able to re-allocate + * bit from primary->alloced_cpus_in_node. + */ if (!cpumask_test_cpu(cur_cpu, &primary->alloced_cpus_in_node)) { cpumask_set_cpu(cur_cpu, -- 2.39.2