This is a note to let you know that I've just added the patch titled powerpc/kvm: Fix kvm_use_magic_page to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: powerpc-kvm-fix-kvm_use_magic_page.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 0c8eb2884a42d992c7726539328b7d3568f22143 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher <agruenba@xxxxxxxxxx> Date: Mon, 2 Aug 2021 13:46:19 +0200 Subject: powerpc/kvm: Fix kvm_use_magic_page From: Andreas Gruenbacher <agruenba@xxxxxxxxxx> commit 0c8eb2884a42d992c7726539328b7d3568f22143 upstream. When switching from __get_user to fault_in_pages_readable, commit 9f9eae5ce717 broke kvm_use_magic_page: like __get_user, fault_in_pages_readable returns 0 on success. Fixes: 9f9eae5ce717 ("powerpc/kvm: Prefer fault_in_pages_readable function") Cc: stable@xxxxxxxxxxxxxxx # v4.18+ Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/powerpc/kernel/kvm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/powerpc/kernel/kvm.c +++ b/arch/powerpc/kernel/kvm.c @@ -669,7 +669,7 @@ static void __init kvm_use_magic_page(vo on_each_cpu(kvm_map_magic_page, &features, 1); /* Quick self-test to see if the mapping works */ - if (!fault_in_pages_readable((const char *)KVM_MAGIC_PAGE, sizeof(u32))) { + if (fault_in_pages_readable((const char *)KVM_MAGIC_PAGE, sizeof(u32))) { kvm_patching_worked = false; return; } Patches currently in stable-queue which might be from agruenba@xxxxxxxxxx are queue-5.4/powerpc-kvm-fix-kvm_use_magic_page.patch