diff --git a/1018-x86-Use-Linux-s-PAT.patch b/1018-x86-Use-Linux-s-PAT.patch
new file mode 100644
index 0000000..d006dfc
--- /dev/null
+++ b/1018-x86-Use-Linux-s-PAT.patch
@@ -0,0 +1,81 @@
+From 7f3f94f443f652e4a59c111d4cf8b5fb3b771612 Mon Sep 17 00:00:00 2001
+From: Demi Marie Obenour <demi@invisiblethingslab.com>
+Date: Sun, 4 Dec 2022 07:57:44 -0500
+Subject: [PATCH] x86: Use Linux's PAT
+
+This is purely for testing, to see if it works around a bug in i915.  It
+is not intended to be merged.
+
+NOT-signed-off-by: DO NOT MERGE
+---
+ xen/arch/x86/include/asm/page.h      |  4 ++--
+ xen/arch/x86/include/asm/processor.h | 10 +++++-----
+ xen/arch/x86/mm.c                    |  8 --------
+ 3 files changed, 7 insertions(+), 15 deletions(-)
+
+diff --git a/xen/arch/x86/include/asm/page.h b/xen/arch/x86/include/asm/page.h
+index 350d1fb1100f..2624cc6bdae5 100644
+--- a/xen/arch/x86/include/asm/page.h
++++ b/xen/arch/x86/include/asm/page.h
+@@ -333,11 +333,11 @@ void efi_update_l4_pgtable(unsigned int l4idx, l4_pgentry_t l4e);
+ 
+ /* Memory types, encoded under Xen's choice of MSR_PAT. */
+ #define _PAGE_WB         (                                0)
+-#define _PAGE_WT         (                        _PAGE_PWT)
++#define _PAGE_WC         (                        _PAGE_PWT)
+ #define _PAGE_UCM        (            _PAGE_PCD            )
+ #define _PAGE_UC         (            _PAGE_PCD | _PAGE_PWT)
+-#define _PAGE_WC         (_PAGE_PAT                        )
+ #define _PAGE_WP         (_PAGE_PAT |             _PAGE_PWT)
++#define _PAGE_WT         (_PAGE_PAT | _PAGE_PCD | _PAGE_PWT)
+ 
+ /*
+  * Debug option: Ensure that granted mappings are not implicitly unmapped.
+diff --git a/xen/arch/x86/include/asm/processor.h b/xen/arch/x86/include/asm/processor.h
+index c26ef9090c3a..ec881b880d4d 100644
+--- a/xen/arch/x86/include/asm/processor.h
++++ b/xen/arch/x86/include/asm/processor.h
+@@ -65,16 +65,16 @@
+ 
+ /*
+  * Host IA32_CR_PAT value to cover all memory types.  This is not the default
+- * MSR_PAT value, and is an ABI with PV guests.
++ * MSR_PAT value, and is needed by the Linux i915 driver.
+  */
+ #define XEN_MSR_PAT ((_AC(X86_MT_WB,  ULL) << 0x00) | \
+-                     (_AC(X86_MT_WT,  ULL) << 0x08) | \
++                     (_AC(X86_MT_WC,  ULL) << 0x08) | \
+                      (_AC(X86_MT_UCM, ULL) << 0x10) | \
+                      (_AC(X86_MT_UC,  ULL) << 0x18) | \
+-                     (_AC(X86_MT_WC,  ULL) << 0x20) | \
++                     (_AC(X86_MT_WB,  ULL) << 0x20) | \
+                      (_AC(X86_MT_WP,  ULL) << 0x28) | \
+-                     (_AC(X86_MT_UC,  ULL) << 0x30) | \
+-                     (_AC(X86_MT_UC,  ULL) << 0x38))
++                     (_AC(X86_MT_UCM, ULL) << 0x30) | \
++                     (_AC(X86_MT_WT,  ULL) << 0x38))
+ 
+ #ifndef __ASSEMBLY__
+ 
+diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
+index 702c76a879e5..b30453b9de11 100644
+--- a/xen/arch/x86/mm.c
++++ b/xen/arch/x86/mm.c
+@@ -6365,14 +6365,6 @@ unsigned long get_upper_mfn_bound(void)
+  */
+ static void __init __maybe_unused build_assertions(void)
+ {
+-    /*
+-     * If this trips, any guests that blindly rely on the public API in xen.h
+-     * (instead of reading the PAT from Xen, as Linux 3.19+ does) will be
+-     * broken.  Furthermore, live migration of PV guests between Xen versions
+-     * using different PATs will not work.
+-     */
+-    BUILD_BUG_ON(XEN_MSR_PAT != 0x050100070406ULL);
+-
+     /*
+      * _PAGE_WB must be zero for several reasons, not least because Linux
+      * assumes it.
+-- 
+2.44.0
+
diff --git a/xen.spec.in b/xen.spec.in
index f01b750..593da60 100644
--- a/xen.spec.in
+++ b/xen.spec.in
@@ -162,6 +162,7 @@ Patch1014: 1014-libxl-conditionally-allow-PCI-passthrough-on-PV-with.patch
 Patch1015: 1015-gnttab-disable-grant-tables-v2-by-default.patch
 Patch1016: 1016-cpufreq-enable-HWP-by-default.patch
 Patch1017: 1017-Fix-IGD-passthrough-with-linux-stubdomain.patch
+Patch1018: 1018-x86-Use-Linux-s-PAT.patch
 
 # Reproducible builds
 Patch1100: 1100-Define-build-dates-time-based-on-SOURCE_DATE_EPOCH.patch