From 15e33b5493bae40bd1c50413f16ebad3985750f3 Mon Sep 17 00:00:00 2001
From: Mateusz Guzik <mjg@FreeBSD.org>
Date: Tue, 22 Oct 2019 22:54:41 +0000
Subject: [PATCH] amd64 pmap: fixup invlgen lookup for fictitious mappings

Similarly to r353438, use dummy entry.

Reported and tested by:	Neel Chauhan
Sponsored by:	The FreeBSD Foundation
---
 sys/amd64/amd64/pmap.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index de8a47417a1a..73b7d47d90b4 100644
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -951,8 +951,16 @@ SYSCTL_LONG(_vm_pmap, OID_AUTO, invl_wait_slow, CTLFLAG_RD, &invl_wait_slow, 0,
 static u_long *
 pmap_delayed_invl_genp(vm_page_t m)
 {
+	vm_paddr_t pa;
+	u_long *gen;
 
-	return (&pa_to_pmdp(VM_PAGE_TO_PHYS(m))->pv_invl_gen);
+	pa = VM_PAGE_TO_PHYS(m);
+	if (__predict_false((pa) > pmap_last_pa))
+		gen = &pv_dummy_large.pv_invl_gen;
+	else
+		gen = &(pa_to_pmdp(pa)->pv_invl_gen);
+
+	return (gen);
 }
 #else
 static u_long *