On 07/29/2010 06:43 AM, Neil Horman wrote: > On Wed, Jul 28, 2010 at 03:02:19PM -0700, Eric W. Biederman wrote: >> "H. Peter Anvin" <hpa at zytor.com> writes: >> >>> We are getting a claim that the qla driver corrupts memory after a >>> kexec, apparently due to a DMA engine left running in the before-kernel. >>> >>> For an in-place kexec (as opposed to a crash dump kexec, where we switch >>> into dedicated memory), what shutdown paths get executed? >> >> It is the normal reboot path, so the device shutdown method gets >> executed. >> >> Eric >> > Check your iommu. We've had lots of problems with them in the past, and in the > crash path we explicity leave the iommu on now, whereas the normal shutdown path > turns it off. If some other dma-capable device doesn't shut down properly and > keeps dma operations going, you're liable to get memory corruption when the > iommu re-initalizes. > Sorry, can we keep the discussions of kexec-on-crash and kexec-in-place clearly separated, please? The qla driver issue is supposed to be kexec-in-place, and it sounds like you're talking about kexec-on-crash. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
