lkml.org 
[lkml]   [2017]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH v5 26/32] x86, drm, fbdev: Do not specify encrypted memory for video mappings
    From
    Date
    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@amd.com>
    >> ---
    >> 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

    \
     
     \ /
      Last update: 2017-05-30 22:08    [W:4.238 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site