Drivers: hv: vmbus: Fix ring buffer signaling
Fix bugs in signaling the Hyper-V host when freeing space in the host->guest ring buffer: 1. The interrupt_mask must not be used to determine whether to signal on the host->guest ring buffer 2. The ring buffer write_index must be read (via hv_get_bytes_to_write) *after* pending_send_sz is read in order to avoid a race condition 3. Comparisons with pending_send_sz must treat the "equals" case as not-enough-space 4. Don't signal if the pending_send_sz feature is not present. Older versions of Hyper-V that don't implement this feature will poll. Fixes: 03bad714 ("vmbus: more host signalling avoidance") Cc: Stable <stable@vger.kernel.org> # 4.14 and above Signed-off-by:Michael Kelley <mhkelley@outlook.com> Signed-off-by:
K. Y. Srinivasan <kys@microsoft.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parent
661e50bc
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