Re: [PATCH v2 3/5] elf2dmp: introduce merging of physical memory runs

[Peter Maydell]

On Fri, 15 Sept 2023 at 18:02, Viktor Prutyanov  wrote:
>
> DMP supports 42 physical memory runs at most. So, merge adjacent
> physical memory ranges from QEMU ELF when possible to minimize total
> number of runs.
>
> Signed-off-by: Viktor Prutyanov 
> ---
>  contrib/elf2dmp/main.c | 56 --
>  1 file changed, 48 insertions(+), 8 deletions(-)
>
> diff --git a/contrib/elf2dmp/main.c b/contrib/elf2dmp/main.c
> index b7e3930164..b4683575fd 100644
> --- a/contrib/elf2dmp/main.c
> +++ b/contrib/elf2dmp/main.c
> @@ -20,6 +20,7 @@
>  #define PE_NAME "ntoskrnl.exe"
>
>  #define INITIAL_MXCSR   0x1f80
> +#define MAX_NUMBER_OF_RUNS  42
>
>  typedef struct idt_desc {
>  uint16_t offset1;   /* offset bits 0..15 */
> @@ -234,6 +235,42 @@ static int fix_dtb(struct va_space *vs, QEMU_Elf *qe)
>  return 1;
>  }
>
> +static void try_merge_runs(struct pa_space *ps,
> +WinDumpPhyMemDesc64 *PhysicalMemoryBlock)
> +{
> +unsigned int merge_cnt = 0, run_idx = 0;
> +
> +PhysicalMemoryBlock->NumberOfRuns = 0;
> +
> +for (size_t idx = 0; idx < ps->block_nr; idx++) {
> +struct pa_block *blk = ps->block + idx;
> +struct pa_block *next = blk + 1;
> +
> +PhysicalMemoryBlock->NumberOfPages += blk->size / ELF2DMP_PAGE_SIZE;
> +
> +if (idx + 1 != ps->block_nr && blk->paddr + blk->size == 
> next->paddr) {
> +printf("Block #%lu 0x%"PRIx64"+:0x%"PRIx64" and %u previous will 
> be"
> +" merged\n", idx, blk->paddr, blk->size, merge_cnt);
> +merge_cnt++;
> +} else {
> +struct pa_block *first_merged = blk - merge_cnt;
> +
> +printf("Block #%lu 0x%"PRIx64"+:0x%"PRIx64" and %u previous will 
> be"
> +" merged to 0x%"PRIx64"+:0x%"PRIx64" (run #%u)\n",
> +idx, blk->paddr, blk->size, merge_cnt, 
> first_merged->paddr,
> +blk->paddr + blk->size - first_merged->paddr, run_idx);
> +PhysicalMemoryBlock->Run[run_idx] = (WinDumpPhyMemRun64) {
> +.BasePage = first_merged->paddr / ELF2DMP_PAGE_SIZE,
> +.PageCount = (blk->paddr + blk->size - first_merged->paddr) /
> +ELF2DMP_PAGE_SIZE,
> +};

Hi; this fails to build on 32-bit hosts because in both these printf()
statements the format string uses "%lu" to print a size_t. This
doesn't work if size_t is not a 'long'. The right format operator is "%zu".

I have squashed in the relevant change to this patch in target-arm.next.

thanks
-- PMM

[PATCH v2 3/5] elf2dmp: introduce merging of physical memory runs

[Viktor Prutyanov]

DMP supports 42 physical memory runs at most. So, merge adjacent
physical memory ranges from QEMU ELF when possible to minimize total
number of runs.

Signed-off-by: Viktor Prutyanov 
---
 contrib/elf2dmp/main.c | 56 --
 1 file changed, 48 insertions(+), 8 deletions(-)

diff --git a/contrib/elf2dmp/main.c b/contrib/elf2dmp/main.c
index b7e3930164..b4683575fd 100644
--- a/contrib/elf2dmp/main.c
+++ b/contrib/elf2dmp/main.c
@@ -20,6 +20,7 @@
 #define PE_NAME "ntoskrnl.exe"
 
 #define INITIAL_MXCSR   0x1f80
+#define MAX_NUMBER_OF_RUNS  42
 
 typedef struct idt_desc {
 uint16_t offset1;   /* offset bits 0..15 */
@@ -234,6 +235,42 @@ static int fix_dtb(struct va_space *vs, QEMU_Elf *qe)
 return 1;
 }
 
+static void try_merge_runs(struct pa_space *ps,
+WinDumpPhyMemDesc64 *PhysicalMemoryBlock)
+{
+unsigned int merge_cnt = 0, run_idx = 0;
+
+PhysicalMemoryBlock->NumberOfRuns = 0;
+
+for (size_t idx = 0; idx < ps->block_nr; idx++) {
+struct pa_block *blk = ps->block + idx;
+struct pa_block *next = blk + 1;
+
+PhysicalMemoryBlock->NumberOfPages += blk->size / ELF2DMP_PAGE_SIZE;
+
+if (idx + 1 != ps->block_nr && blk->paddr + blk->size == next->paddr) {
+printf("Block #%lu 0x%"PRIx64"+:0x%"PRIx64" and %u previous will 
be"
+" merged\n", idx, blk->paddr, blk->size, merge_cnt);
+merge_cnt++;
+} else {
+struct pa_block *first_merged = blk - merge_cnt;
+
+printf("Block #%lu 0x%"PRIx64"+:0x%"PRIx64" and %u previous will 
be"
+" merged to 0x%"PRIx64"+:0x%"PRIx64" (run #%u)\n",
+idx, blk->paddr, blk->size, merge_cnt, first_merged->paddr,
+blk->paddr + blk->size - first_merged->paddr, run_idx);
+PhysicalMemoryBlock->Run[run_idx] = (WinDumpPhyMemRun64) {
+.BasePage = first_merged->paddr / ELF2DMP_PAGE_SIZE,
+.PageCount = (blk->paddr + blk->size - first_merged->paddr) /
+ELF2DMP_PAGE_SIZE,
+};
+PhysicalMemoryBlock->NumberOfRuns++;
+run_idx++;
+merge_cnt = 0;
+}
+}
+}
+
 static int fill_header(WinDumpHeader64 *hdr, struct pa_space *ps,
 struct va_space *vs, uint64_t KdDebuggerDataBlock,
 KDDEBUGGER_DATA64 *kdbg, uint64_t KdVersionBlock, int nr_cpus)
@@ -244,7 +281,6 @@ static int fill_header(WinDumpHeader64 *hdr, struct 
pa_space *ps,
 KUSD_OFFSET_PRODUCT_TYPE);
 DBGKD_GET_VERSION64 kvb;
 WinDumpHeader64 h;
-size_t i;
 
 QEMU_BUILD_BUG_ON(KUSD_OFFSET_SUITE_MASK >= ELF2DMP_PAGE_SIZE);
 QEMU_BUILD_BUG_ON(KUSD_OFFSET_PRODUCT_TYPE >= ELF2DMP_PAGE_SIZE);
@@ -282,13 +318,17 @@ static int fill_header(WinDumpHeader64 *hdr, struct 
pa_space *ps,
 .RequiredDumpSpace = sizeof(h),
 };
 
-for (i = 0; i < ps->block_nr; i++) {
-h.PhysicalMemoryBlock.NumberOfPages +=
-ps->block[i].size / ELF2DMP_PAGE_SIZE;
-h.PhysicalMemoryBlock.Run[i] = (WinDumpPhyMemRun64) {
-.BasePage = ps->block[i].paddr / ELF2DMP_PAGE_SIZE,
-.PageCount = ps->block[i].size / ELF2DMP_PAGE_SIZE,
-};
+if (h.PhysicalMemoryBlock.NumberOfRuns <= MAX_NUMBER_OF_RUNS) {
+for (size_t idx = 0; idx < ps->block_nr; idx++) {
+h.PhysicalMemoryBlock.NumberOfPages +=
+ps->block[idx].size / ELF2DMP_PAGE_SIZE;
+h.PhysicalMemoryBlock.Run[idx] = (WinDumpPhyMemRun64) {
+.BasePage = ps->block[idx].paddr / ELF2DMP_PAGE_SIZE,
+.PageCount = ps->block[idx].size / ELF2DMP_PAGE_SIZE,
+};
+}
+} else {
+try_merge_runs(ps, &h.PhysicalMemoryBlock);
 }
 
 h.RequiredDumpSpace +=
-- 
2.21.0