On 17/04/13 13:34, Daniel Kiper wrote: > > kexec -e still does not work. I see in my console: > > I'm in purgatory > sha256 digests do not match :( I have now fixed this. Xen was not probably zeroing out trailing pages (only partial pages) when loading a default image (crash was fine). The kernel does this by allocating and clearing pages and then relocating these as normal but it's wasteful to allocate a bunch of empty pages so I added a IND_ZERO entry type for the indirection pages which gets the relocation code to zero the destination. See the kexec-v5 branch at: http://xenbits.xen.org/gitweb/?p=people/dvrabel/xen.git;a=summary I shall repost this series again once the 4.4 development window is open. --- a/xen/arch/x86/x86_64/kexec_reloc.S +++ b/xen/arch/x86/x86_64/kexec_reloc.S @@ -130,13 +130,18 @@ relocate_pages: jmp 3f 2: testq $0x8, %rcx /* is it the source indicator? */ - jz 0b /* Ignore it otherwise */ + jz 2f movq %rcx, %rsi /* For ever source page do a copy */ andq $0xfffffffffffff000, %rsi - movq $512, %rcx rep movsq - + jmp 0b +2: + testq $0x10, %rcx /* is it the zero indicator? */ + jz 0b /* Ignore it otherwise */ + movq $512, %rcx /* Zero the destination page. */ + xorq %rax, %rax + rep stosq jmp 0b 3: ret diff --git a/xen/common/kimage.c b/xen/common/kimage.c index 86261ca..1cc0ef7 100644 --- a/xen/common/kimage.c +++ b/xen/common/kimage.c @@ -661,7 +661,7 @@ static int kimage_load_normal_segment(struct kexec_image *image, { unsigned long to_copy; unsigned long src_offset; - paddr_t dest; + paddr_t dest, end; int ret; to_copy = segment->buf_size; @@ -675,15 +675,13 @@ static int kimage_load_normal_segment(struct kexec_image *image, while ( to_copy ) { unsigned long dest_mfn; - size_t dest_off; struct page_info *page; void *dest_va; size_t size; dest_mfn = dest >> PAGE_SHIFT; - dest_off = dest & ~PAGE_MASK; - size = min(PAGE_SIZE - dest_off, to_copy); + size = min_t(unsigned long, PAGE_SIZE, to_copy); page = kimage_alloc_page(image, dest); if ( !page ) @@ -693,16 +691,21 @@ static int kimage_load_normal_segment(struct kexec_image *image, return ret; dest_va = __map_domain_page(page); - ret = copy_from_guest_offset(dest_va + dest_off, segment->buf, src_offset, size); + ret = copy_from_guest_offset(dest_va, segment->buf, src_offset, size); unmap_domain_page(dest_va); if ( ret ) return -EFAULT; to_copy -= size; src_offset += size; - dest += size; + dest += PAGE_SIZE; } + /* Remainder of the destination should be zeroed. */ + end = segment->dest_maddr + segment->dest_size; + for ( ; dest < end; dest += PAGE_SIZE ) + kimage_add_entry(image, IND_ZERO); + return 0; } --- a/xen/include/xen/kimage.h +++ b/xen/include/xen/kimage.h @@ -14,6 +14,7 @@ typedef paddr_t kimage_entry_t; #define IND_INDIRECTION 0x2 #define IND_DONE 0x4 #define IND_SOURCE 0x8 +#define IND_ZERO 0x10 struct kexec_image { uint8_t type; David
