From add19752eb782379610a01ea0d8cfce83cf071b0 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Sun, 8 Oct 2017 21:53:05 -0700 Subject: [PATCH] x86/mm/64: Fix reboot interaction with CR4.PCIDE commit 924c6b900cfdf376b07bccfd80e62b21914f8a5a upstream. Trying to reboot via real mode fails with PCID on: long mode cannot be exited while CR4.PCIDE is set. (No, I have no idea why, but the SDM and actual CPUs are in agreement here.) The result is a GPF and a hang instead of a reboot. I didn't catch this in testing because neither my computer nor my VM reboots this way. I can trigger it with reboot=bios, though. Fixes: 660da7c9228f ("x86/mm: Enable CR4.PCIDE on supported systems") Reported-and-tested-by: Steven Rostedt (VMware) Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Cc: Borislav Petkov Link: https://lkml.kernel.org/r/f1e7d965998018450a7a70c2823873686a8b21c0.1507524746.git.luto@kernel.org Signed-off-by: Hugh Dickins Signed-off-by: Ben Hutchings --- Reading git-format-patch failed