0029-x86-mm-account-for-PGT_pae_xen_l2-in-recently-added-.patch


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From 0b4e62847c5af1a59eea8d17093feccd550d1c26 Mon Sep 17 00:00:00 2001
From: Jan Beulich <jbeulich@suse.com>
Date: Fri, 10 Jun 2022 10:28:28 +0200
Subject: [PATCH 29/32] x86/mm: account for PGT_pae_xen_l2 in recently added
 assertion

While PGT_pae_xen_l2 will be zapped once the type refcount of an L2 page
reaches zero, it'll be retained as long as the type refcount is non-
zero. Hence any checking against the requested type needs to either zap
the bit from the type or include it in the used mask.

Fixes: 9186e96b199e ("x86/pv: Clean up _get_page_type()")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
master commit: c2095ac76be0f4a1940346c9ffb49fb967345060
master date: 2022-06-10 10:21:06 +0200
---
 xen/arch/x86/mm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index bab9624fabb7..c1b9a3bb102a 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -2928,7 +2928,8 @@ static int _get_page_type(struct page_info *page, unsigned long type,
              * The page is in one of two states (depending on PGT_partial),
              * and should have exactly one reference.
              */
-            ASSERT((x & (PGT_type_mask | PGT_count_mask)) == (type | 1));
+            ASSERT((x & (PGT_type_mask | PGT_pae_xen_l2 | PGT_count_mask)) ==
+                   (type | 1));
 
             if ( !(x & PGT_partial) )
             {
-- 
2.35.1