On Tue, Nov 16, 2021 at 12:10:48PM +0100, Borislav Petkov wrote:
On Tue, Nov 16, 2021 at 11:54:46AM +0100, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 541ac97186d9ea88491961a46284de3603c914fd Mon Sep 17 00:00:00 2001 From: Borislav Petkov bp@suse.de Date: Fri, 1 Oct 2021 21:41:20 +0200 Subject: [PATCH] x86/sev: Make the #VC exception stacks part of the default stacks storage
The size of the exception stacks was increased by the commit in Fixes, resulting in stack sizes greater than a page in size. The #VC exception handling was only mapping the first (bottom) page, resulting in an SEV-ES guest failing to boot.
Make the #VC exception stacks part of the default exception stacks storage and allocate them with a CONFIG_AMD_MEM_ENCRYPT=y .config. Map them only when a SEV-ES guest has been detected.
Rip out the custom VC stacks mapping and storage code.
[ bp: Steal and adapt Tom's commit message. ]
Fixes: 7fae4c24a2b8 ("x86: Increase exception stack sizes")
$ git tag --contains 7fae4c24a2b8 | grep -E "^v" v5.16-rc1
Scripts kaputtski?
Nope, planning ahead: $ ~/linux/stable/commit_tree/id_found_in 7fae4c24a2b8 5.16-rc1 queue-4.4 queue-4.9 queue-4.14 queue-4.19 queue-5.4 queue-5.10 queue-5.14 queue-5.15
That commit is in the current -rc releases right now.
The problem with this commit is that the cc_platform_has() function is not present. I thought about backporting it as well, but that seemed odd as I do not think that feature is in the 5.15 and older kernels, right?
Or is it ok to take the cc_platform_has() function?
thanks,
greg k-h