From f58ebdc524d4b3c6bf1ac91bbc85dc37fdc595c5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?= Date: Fri, 18 Oct 2024 03:54:28 +0200 Subject: [PATCH] Update comments/description of the Linux PAT patch --- 1018-x86-Use-Linux-s-PAT.patch | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/1018-x86-Use-Linux-s-PAT.patch b/1018-x86-Use-Linux-s-PAT.patch index d006dfcd..2bfbc9fd 100644 --- a/1018-x86-Use-Linux-s-PAT.patch +++ b/1018-x86-Use-Linux-s-PAT.patch @@ -3,10 +3,8 @@ From: Demi Marie Obenour 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 +Use the same PAT setting as Linux to workaround buggy drivers that have +hardcoded assumptions about it. --- xen/arch/x86/include/asm/page.h | 4 ++-- xen/arch/x86/include/asm/processor.h | 10 +++++----- @@ -35,12 +33,13 @@ diff --git a/xen/arch/x86/include/asm/processor.h b/xen/arch/x86/include/asm/pro index c26ef9090c3a..ec881b880d4d 100644 --- a/xen/arch/x86/include/asm/processor.h +++ b/xen/arch/x86/include/asm/processor.h -@@ -65,16 +65,16 @@ +@@ -65,16 +65,17 @@ /* * 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. ++ * MSR_PAT value, and is and is the same one used by Linux. The proprietary ++ * Nvidia driver (and possibly other kernel code) requires this value. */ #define XEN_MSR_PAT ((_AC(X86_MT_WB, ULL) << 0x00) | \ - (_AC(X86_MT_WT, ULL) << 0x08) | \