On 5/16/2017 12:35 PM, Borislav Petkov wrote:
On Tue, Apr 18, 2017 at 04:20:56PM -0500, Tom Lendacky wrote:
Since video memory needs to be accessed decrypted, be sure that the
memory encryption mask is not set for the video ranges.
Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
arch/x86/include/asm/vga.h | 13 +++++++++++++
arch/x86/mm/pageattr.c | 2 ++
drivers/gpu/drm/drm_gem.c | 2 ++
drivers/gpu/drm/drm_vm.c | 4 ++++
drivers/gpu/drm/ttm/ttm_bo_vm.c | 7 +++++--
drivers/gpu/drm/udl/udl_fb.c | 4 ++++
drivers/video/fbdev/core/fbmem.c | 12 ++++++++++++
7 files changed, 42 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/vga.h b/arch/x86/include/asm/vga.h
index c4b9dc2..5c7567a 100644
--- a/arch/x86/include/asm/vga.h
+++ b/arch/x86/include/asm/vga.h
@@ -7,12 +7,25 @@
#ifndef _ASM_X86_VGA_H
#define _ASM_X86_VGA_H
+#include <asm/cacheflush.h>
+
/*
* On the PC, we can just recalculate addresses and then
* access the videoram directly without any black magic.
+ * To support memory encryption however, we need to access
+ * the videoram as decrypted memory.
*/
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+#define VGA_MAP_MEM(x, s) \
+({ \
+ unsigned long start = (unsigned long)phys_to_virt(x); \
+ set_memory_decrypted(start, (s) >> PAGE_SHIFT); \
+ start; \
+})
+#else
#define VGA_MAP_MEM(x, s) (unsigned long)phys_to_virt(x)
+#endif
Can we push the check in and save us the ifdeffery?
#define VGA_MAP_MEM(x, s) \
({ \
unsigned long start = (unsigned long)phys_to_virt(x); \
\
if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) \
set_memory_decrypted(start, (s) >> PAGE_SHIFT); \
\
start; \
})
It does build here. :)
That works for me and it's a lot cleaner. I'll make the change.
Thanks,
Tom
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