From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Lendacky Subject: [RFC PATCH v3 16/20] x86: Do not specify encrypted memory for video mappings Date: Wed, 9 Nov 2016 18:37:53 -0600 Message-ID: <20161110003753.3280.36113.stgit@tlendack-t1.amdoffice.net> References: <20161110003426.3280.2999.stgit@tlendack-t1.amdoffice.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20161110003426.3280.2999.stgit-qCXWGYdRb2BnqfbPTmsdiZQ+2ll4COg0XqFh9Ls21Oc@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kasan-dev-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Cc: Rik van Riel , Radim =?utf-8?b?S3LEjW3DocWZ?= , Arnd Bergmann , Jonathan Corbet , Matt Fleming , Joerg Roedel , Konrad Rzeszutek Wilk , Paolo Bonzini , Larry Woodman , Ingo Molnar , Borislav Petkov , Andy Lutomirski , "H. Peter Anvin" , Andrey Ryabinin , Alexander Potapenko , Thomas Gleixner , Dmitry Vyukov List-Id: linux-efi@vger.kernel.org Since video memory needs to be accessed unencrypted be sure that the memory encryption mask is not set for the video ranges. Signed-off-by: Tom Lendacky --- arch/x86/include/asm/vga.h | 13 +++++++++++++ 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 ++++++++++++ 6 files changed, 40 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/vga.h b/arch/x86/include/asm/vga.h index c4b9dc2..7f944a4 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 + /* * 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 un-encrypted memory. */ +#ifdef CONFIG_AMD_MEM_ENCRYPT +#define VGA_MAP_MEM(x, s) \ +({ \ + unsigned long start = (unsigned long)phys_to_virt(x); \ + sme_set_mem_unenc((void *)start, s); \ + start; \ +}) +#else #define VGA_MAP_MEM(x, s) (unsigned long)phys_to_virt(x) +#endif #define vga_readb(x) (*(x)) #define vga_writeb(x, y) (*(y) = (x)) diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 9134ae1..44f9563 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -36,6 +36,7 @@ #include #include #include +#include #include #include #include @@ -928,6 +929,7 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, vma->vm_ops = dev->driver->gem_vm_ops; vma->vm_private_data = obj; vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); + pgprot_val(vma->vm_page_prot) &= ~sme_me_mask; /* Take a ref for this mapping of the object, so that the fault * handler can dereference the mmap offset's pointer to the object. diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c index caa4e4c..d04752c 100644 --- a/drivers/gpu/drm/drm_vm.c +++ b/drivers/gpu/drm/drm_vm.c @@ -40,6 +40,7 @@ #include #include #endif +#include #include #include "drm_internal.h" #include "drm_legacy.h" @@ -58,6 +59,9 @@ static pgprot_t drm_io_prot(struct drm_local_map *map, { pgprot_t tmp = vm_get_page_prot(vma->vm_flags); + /* We don't want graphics memory to be mapped encrypted */ + pgprot_val(tmp) &= ~sme_me_mask; + #if defined(__i386__) || defined(__x86_64__) || defined(__powerpc__) if (map->type == _DRM_REGISTERS && !(map->flags & _DRM_WRITE_COMBINING)) tmp = pgprot_noncached(tmp); diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index a6ed9d5..f5fbd53 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -39,6 +39,7 @@ #include #include #include +#include #define TTM_BO_VM_NUM_PREFAULT 16 @@ -218,9 +219,11 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) * first page. */ for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) { - if (bo->mem.bus.is_iomem) + if (bo->mem.bus.is_iomem) { + /* Iomem should not be marked encrypted */ + pgprot_val(cvma.vm_page_prot) &= ~sme_me_mask; pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset; - else { + } else { page = ttm->pages[page_offset]; if (unlikely(!page && i == 0)) { retval = VM_FAULT_OOM; diff --git a/drivers/gpu/drm/udl/udl_fb.c b/drivers/gpu/drm/udl/udl_fb.c index 611b6b9..64212ca 100644 --- a/drivers/gpu/drm/udl/udl_fb.c +++ b/drivers/gpu/drm/udl/udl_fb.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include @@ -169,6 +170,9 @@ static int udl_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) pr_notice("mmap() framebuffer addr:%lu size:%lu\n", pos, size); + /* We don't want the framebuffer to be mapped encrypted */ + pgprot_val(vma->vm_page_prot) &= ~sme_me_mask; + while (size > 0) { page = vmalloc_to_pfn((void *)pos); if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED)) diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 76c1ad9..ac51a5e 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -32,6 +32,7 @@ #include #include #include +#include #include @@ -1405,6 +1406,12 @@ fb_mmap(struct file *file, struct vm_area_struct * vma) mutex_lock(&info->mm_lock); if (fb->fb_mmap) { int res; + + /* + * The framebuffer needs to be accessed un-encrypted, be sure + * SME protection is removed ahead of the call + */ + pgprot_val(vma->vm_page_prot) &= ~sme_me_mask; res = fb->fb_mmap(info, vma); mutex_unlock(&info->mm_lock); return res; @@ -1430,6 +1437,11 @@ fb_mmap(struct file *file, struct vm_area_struct * vma) mutex_unlock(&info->mm_lock); vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); + /* + * The framebuffer needs to be accessed un-encrypted, be sure + * SME protection is removed + */ + pgprot_val(vma->vm_page_prot) &= ~sme_me_mask; fb_pgprotect(file, vma, start); return vm_iomap_memory(vma, start, len);