diff options
Diffstat (limited to 'include/linux/hyperv.h')
| -rw-r--r-- | include/linux/hyperv.h | 33 |
1 files changed, 25 insertions, 8 deletions
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 3a3012f57be4..efda23cf32c7 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -89,18 +89,33 @@ struct hv_ring_buffer { u32 interrupt_mask; /* - * Win8 uses some of the reserved bits to implement - * interrupt driven flow management. On the send side - * we can request that the receiver interrupt the sender - * when the ring transitions from being full to being able - * to handle a message of size "pending_send_sz". + * WS2012/Win8 and later versions of Hyper-V implement interrupt + * driven flow management. The feature bit feat_pending_send_sz + * is set by the host on the host->guest ring buffer, and by the + * guest on the guest->host ring buffer. * - * Add necessary state for this enhancement. + * The meaning of the feature bit is a bit complex in that it has + * semantics that apply to both ring buffers. If the guest sets + * the feature bit in the guest->host ring buffer, the guest is + * telling the host that: + * 1) It will set the pending_send_sz field in the guest->host ring + * buffer when it is waiting for space to become available, and + * 2) It will read the pending_send_sz field in the host->guest + * ring buffer and interrupt the host when it frees enough space + * + * Similarly, if the host sets the feature bit in the host->guest + * ring buffer, the host is telling the guest that: + * 1) It will set the pending_send_sz field in the host->guest ring + * buffer when it is waiting for space to become available, and + * 2) It will read the pending_send_sz field in the guest->host + * ring buffer and interrupt the guest when it frees enough space + * + * If either the guest or host does not set the feature bit that it + * owns, that guest or host must do polling if it encounters a full + * ring buffer, and not signal the other end with an interrupt. */ u32 pending_send_sz; - u32 reserved1[12]; - union { struct { u32 feat_pending_send_sz:1; @@ -1046,6 +1061,8 @@ extern int vmbus_establish_gpadl(struct vmbus_channel *channel, extern int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle); +void vmbus_reset_channel_cb(struct vmbus_channel *channel); + extern int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer, u32 bufferlen, |