FAILED: patch "[PATCH] MIPS: KVM: Check for pfn noslot case" failed to apply to 4.4-stable tree

FAILED: patch "[PATCH] MIPS: KVM: Check for pfn noslot case" failed to apply to 4.4-stable tree

[gregkh]

The patch below does not apply to the 4.4-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 ba913e4f72fc9cfd03dad968dfb110eb49211d80 Mon Sep 17 00:00:00 2001
From: James Hogan <james.hogan@imgtec.com>
Date: Fri, 19 Aug 2016 14:30:29 +0100
Subject: [PATCH] MIPS: KVM: Check for pfn noslot case
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

When mapping a page into the guest we error check using is_error_pfn(),
however this doesn't detect a value of KVM_PFN_NOSLOT, indicating an
error HVA for the page. This can only happen on MIPS right now due to
unusual memslot management (e.g. being moved / removed / resized), or
with an Enhanced Virtual Memory (EVA) configuration where the default
KVM_HVA_ERR_* and kvm_is_error_hva() definitions are unsuitable (fixed
in a later patch). This case will be treated as a pfn of zero, mapping
the first page of physical memory into the guest.

It would appear the MIPS KVM port wasn't updated prior to being merged
(in v3.10) to take commit 81c52c56e2b4 ("KVM: do not treat noslot pfn as
a error pfn") into account (merged v3.8), which converted a bunch of
is_error_pfn() calls to is_error_noslot_pfn(). Switch to using
is_error_noslot_pfn() instead to catch this case properly.

Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: <stable@vger.kernel.org> # 3.10.y-
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
index 6cfdcf55572d..121008c0fcc9 100644
--- a/arch/mips/kvm/mmu.c
+++ b/arch/mips/kvm/mmu.c
@@ -40,7 +40,7 @@ static int kvm_mips_map_page(struct kvm *kvm, gfn_t gfn)
 	srcu_idx = srcu_read_lock(&kvm->srcu);
 	pfn = gfn_to_pfn(kvm, gfn);
 
-	if (is_error_pfn(pfn)) {
+	if (is_error_noslot_pfn(pfn)) {
 		kvm_err("Couldn't get pfn for gfn %#llx!\n", gfn);
 		err = -EFAULT;
 		goto out;