On Thu, May 20, 2021 at 04:05:51PM +0200, Joerg M. Sigle wrote:
From: Joerg M. Sigle joerg.sigle@jsigle.com
Odd subject line, what happened?
Patch 416fa531c816 commit 416fa531c8160151090206a51b829b9218b804d9 caused an immediate kernel panic on boot at RIP: 0010:__domain_mapping+0xa7/0x3a0 with longterm kernel 5.10.37 configured w/ CONFIG_INTEL_IOMMU_DEFAULT_ON=y due to removal of a check. Putting the check back in place fixes this. The kernel panic was observed on various Intel Core i7 i5 i3 CPUs from Sandy Bridge, Haswell, Broadwell and Kaby Lake generations (at least). It may NOT be reproducible on some older CPU generations. Suppressing the panic with boot parameter intel_iommu=off is diagnostic. See: https://bugzilla.kernel.org/show_bug.cgi?id=213077 https://bugzilla.kernel.org/show_bug.cgi?id=213087 https://bugzilla.kernel.org/show_bug.cgi?id=213095
Signed-off-by: Joerg M. Sigle joerg.sigle@jsigle.com Acked-by: Lu Baolu baolu.lu@linux.intel.com
Hi Greg, thanks for your response.
Are you sure that 5.10.38 doesn't already fix this issue? We resolved an issue in this area.
Yes, I'm sure.
Did you test 5.10.38?
Your a282b76166b13496967c70bd61ea8f03609d8a76 simply reverts the offending patch.
Yes, and then the next commit in the series applied it back in a different form, hopefully "fixed up" correctly.
My approach corrects it instead.
How so? It does not apply to 5.10.38. Nor to 5.10.39-rc1.
I have submitted that properly before, don't know why it hasn't found you yet.
Where on lore.kernel.org is it shown?
I'm including the "proper" submission info above. The file with the patch is attached again again.
That's not how to submit patches, take a look at the kernel documentaion for all that we need.
But again, are you sure this is needed? If so, can you make it against 5.10.39-rc1?
thanks,
greg k-h