mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-11 21:38:32 +08:00
Drivers: hv: vmbus: Cleanup hv_post_message()
Minimize failures in this function by pre-allocating the buffer for posting messages. The hypercall for posting the message can fail for a number of reasons: 1. Transient resource related issues 2. Buffer alignment 3. Buffer cannot span a page boundry We address issues 2 and 3 by preallocating a per-cpu page for the buffer. Transient resource related failures are handled by retrying by the callers of this function. This patch is based on the investigation done by Dexuan Cui <decui@microsoft.com>. I would like to thank Sitsofe Wheeler <sitsofe@yahoo.com> for reporting the issue and helping in debuggging. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com> Cc: <stable@vger.kernel.org> Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
98d731bb06
commit
b29ef3546a
@ -138,6 +138,8 @@ int hv_init(void)
|
||||
memset(hv_context.synic_event_page, 0, sizeof(void *) * NR_CPUS);
|
||||
memset(hv_context.synic_message_page, 0,
|
||||
sizeof(void *) * NR_CPUS);
|
||||
memset(hv_context.post_msg_page, 0,
|
||||
sizeof(void *) * NR_CPUS);
|
||||
memset(hv_context.vp_index, 0,
|
||||
sizeof(int) * NR_CPUS);
|
||||
memset(hv_context.event_dpc, 0,
|
||||
@ -217,26 +219,18 @@ int hv_post_message(union hv_connection_id connection_id,
|
||||
enum hv_message_type message_type,
|
||||
void *payload, size_t payload_size)
|
||||
{
|
||||
struct aligned_input {
|
||||
u64 alignment8;
|
||||
struct hv_input_post_message msg;
|
||||
};
|
||||
|
||||
struct hv_input_post_message *aligned_msg;
|
||||
u16 status;
|
||||
unsigned long addr;
|
||||
|
||||
if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
|
||||
return -EMSGSIZE;
|
||||
|
||||
addr = (unsigned long)kmalloc(sizeof(struct aligned_input), GFP_ATOMIC);
|
||||
if (!addr)
|
||||
return -ENOMEM;
|
||||
|
||||
aligned_msg = (struct hv_input_post_message *)
|
||||
(ALIGN(addr, HV_HYPERCALL_PARAM_ALIGN));
|
||||
hv_context.post_msg_page[get_cpu()];
|
||||
|
||||
aligned_msg->connectionid = connection_id;
|
||||
aligned_msg->reserved = 0;
|
||||
aligned_msg->message_type = message_type;
|
||||
aligned_msg->payload_size = payload_size;
|
||||
memcpy((void *)aligned_msg->payload, payload, payload_size);
|
||||
@ -244,8 +238,7 @@ int hv_post_message(union hv_connection_id connection_id,
|
||||
status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
|
||||
& 0xFFFF;
|
||||
|
||||
kfree((void *)addr);
|
||||
|
||||
put_cpu();
|
||||
return status;
|
||||
}
|
||||
|
||||
@ -294,6 +287,14 @@ int hv_synic_alloc(void)
|
||||
pr_err("Unable to allocate SYNIC event page\n");
|
||||
goto err;
|
||||
}
|
||||
|
||||
hv_context.post_msg_page[cpu] =
|
||||
(void *)get_zeroed_page(GFP_ATOMIC);
|
||||
|
||||
if (hv_context.post_msg_page[cpu] == NULL) {
|
||||
pr_err("Unable to allocate post msg page\n");
|
||||
goto err;
|
||||
}
|
||||
}
|
||||
|
||||
return 0;
|
||||
@ -308,6 +309,8 @@ static void hv_synic_free_cpu(int cpu)
|
||||
free_page((unsigned long)hv_context.synic_event_page[cpu]);
|
||||
if (hv_context.synic_message_page[cpu])
|
||||
free_page((unsigned long)hv_context.synic_message_page[cpu]);
|
||||
if (hv_context.post_msg_page[cpu])
|
||||
free_page((unsigned long)hv_context.post_msg_page[cpu]);
|
||||
}
|
||||
|
||||
void hv_synic_free(void)
|
||||
|
@ -515,6 +515,10 @@ struct hv_context {
|
||||
* per-cpu list of the channels based on their CPU affinity.
|
||||
*/
|
||||
struct list_head percpu_list[NR_CPUS];
|
||||
/*
|
||||
* buffer to post messages to the host.
|
||||
*/
|
||||
void *post_msg_page[NR_CPUS];
|
||||
};
|
||||
|
||||
extern struct hv_context hv_context;
|
||||
|
Loading…
Reference in New Issue
Block a user