dmaengine: idxd: make misc interrupt one shot

Current code continuously processes the interrupt as long as the hardware
is setting the status bit. There's no reason to do that since the threaded
handler will get called again if another interrupt is asserted.

Also through testing, it has shown that if a misprogrammed (or malicious)
agent can continuously submit descriptors with bad completion record and
causes errors to be reported via the misc interrupt. Continuous processing
by the thread can cause software hang watchdog to kick off since the thread
isn't giving up the CPU.

Reported-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Tested-by: Tony Zhu <tony.zhu@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lore.kernel.org/r/20230407203143.2189681-2-fenghua.yu@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Dave Jiang 2023-04-07 13:31:28 -07:00 • committed by Vinod Koul
commit 0c40bfb4c2