[v2,2/5] elf2dmp: introduce physical block alignment

Commit Message

Viktor Prutyanov Sept. 15, 2023, 5:01 p.m. UTC

Physical memory ranges may not be aligned to page size in QEMU ELF, but
DMP can only contain page-aligned runs. So, align them.

Signed-off-by: Viktor Prutyanov <[e-mail]>
---
 contrib/elf2dmp/addrspace.c | 31 +++++++++++++++++++++++++++++--
 contrib/elf2dmp/addrspace.h |  1 +
 contrib/elf2dmp/main.c      |  5 +++--
 3 files changed, 33 insertions(+), 4 deletions(-)

Patch

diff --git a/contrib/elf2dmp/addrspace.c b/contrib/elf2dmp/addrspace.c
index 0b04cba00e..64b5d680ad 100644
--- a/contrib/elf2dmp/addrspace.c
+++ b/contrib/elf2dmp/addrspace.c
@@ -14,7 +14,7 @@  static struct pa_block *pa_space_find_block(struct pa_space *ps, uint64_t pa)
 
     for (i = 0; i < ps->block_nr; i++) {
         if (ps->block[i].paddr <= pa &&
-                pa <= ps->block[i].paddr + ps->block[i].size) {
+                pa < ps->block[i].paddr + ps->block[i].size) {
             return ps->block + i;
         }
     }
@@ -33,6 +33,30 @@  static uint8_t *pa_space_resolve(struct pa_space *ps, uint64_t pa)
     return block->addr + (pa - block->paddr);
 }
 
+static void pa_block_align(struct pa_block *b)
+{
+    uint64_t low_align = ((b->paddr - 1) | ELF2DMP_PAGE_MASK) + 1 - b->paddr;
+    uint64_t high_align = (b->paddr + b->size) & ELF2DMP_PAGE_MASK;
+
+    if (low_align == 0 && high_align == 0) {
+        return;
+    }
+
+    if (low_align + high_align < b->size) {
+        printf("Block 0x%"PRIx64"+:0x%"PRIx64" will be aligned to "
+                "0x%"PRIx64"+:0x%"PRIx64"\n", b->paddr, b->size,
+                b->paddr + low_align, b->size - low_align - high_align);
+        b->size -= low_align + high_align;
+    } else {
+        printf("Block 0x%"PRIx64"+:0x%"PRIx64" is too small to align\n",
+                b->paddr, b->size);
+        b->size = 0;
+    }
+
+    b->addr += low_align;
+    b->paddr += low_align;
+}
+
 int pa_space_create(struct pa_space *ps, QEMU_Elf *qemu_elf)
 {
     Elf64_Half phdr_nr = elf_getphdrnum(qemu_elf->map);
@@ -60,10 +84,13 @@  int pa_space_create(struct pa_space *ps, QEMU_Elf *qemu_elf)
                 .paddr = phdr[i].p_paddr,
                 .size = phdr[i].p_filesz,
             };
-            block_i++;
+            pa_block_align(&ps->block[block_i]);
+            block_i = ps->block[block_i].size ? (block_i + 1) : block_i;
         }
     }
 
+    ps->block_nr = block_i;
+
     return 0;
 }
 
diff --git a/contrib/elf2dmp/addrspace.h b/contrib/elf2dmp/addrspace.h
index 00b44c1218..039c70c5b0 100644
--- a/contrib/elf2dmp/addrspace.h
+++ b/contrib/elf2dmp/addrspace.h
@@ -12,6 +12,7 @@ 
 
 #define ELF2DMP_PAGE_BITS 12
 #define ELF2DMP_PAGE_SIZE (1ULL << ELF2DMP_PAGE_BITS)
+#define ELF2DMP_PAGE_MASK (ELF2DMP_PAGE_SIZE - 1)
 #define ELF2DMP_PFN_MASK (~(ELF2DMP_PAGE_SIZE - 1))
 
 #define INVALID_PA  UINT64_MAX
diff --git a/contrib/elf2dmp/main.c b/contrib/elf2dmp/main.c
index bb6744c0cd..b7e3930164 100644
--- a/contrib/elf2dmp/main.c
+++ b/contrib/elf2dmp/main.c
@@ -400,9 +400,10 @@  static int write_dump(struct pa_space *ps,
     for (i = 0; i < ps->block_nr; i++) {
         struct pa_block *b = &ps->block[i];
 
-        printf("Writing block #%zu/%zu to file...\n", i, ps->block_nr);
+        printf("Writing block #%zu/%zu of %"PRIu64" bytes to file...\n", i,
+                ps->block_nr, b->size);
         if (fwrite(b->addr, b->size, 1, dmp_file) != 1) {
-            eprintf("Failed to write dump header\n");
+            eprintf("Failed to write block\n");
             fclose(dmp_file);
             return 1;
         }