[PATCH 5/5] kexec: X86: Pass memory ranges via e820 table instead of memmap= boot parameter
Zhang Yanfei
zhangyanfei at cn.fujitsu.com
Fri Apr 12 05:56:08 EDT 2013
于 2013年04月11日 20:26, Thomas Renninger 写道:
> Currently ranges are passed via kernel boot parameters:
> memmap=exactmap memmap=X#Y memmap=
>
> Pass them via e820 table directly instead.
>
> CC: Simon Horman <horms at verge.net.au>
> CC: kexec at lists.infradead.org
> CC: H. Peter Anvin <hpa at zytor.com>
> CC: Eric W. Biederman <ebiederm at xmission.com>
> CC: vgoyal at redhat.com
> CC: yinghai at kernel.org
> CC: cpw at sgi.com
>
> Signed-off-by: Thomas Renninger <trenn at suse.de>
> Signed-off-by: Thomas Renninger <Thomas Renninger" trenn at suse.de>
> ---
> kexec/arch/i386/crashdump-x86.c | 221 ++++++++++++++++++-------------------
> kexec/arch/i386/x86-linux-setup.c | 11 ++-
> 2 files changed, 116 insertions(+), 116 deletions(-)
>
> diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
> index f7821bc..8009efe 100644
> --- a/kexec/arch/i386/crashdump-x86.c
> +++ b/kexec/arch/i386/crashdump-x86.c
> @@ -659,70 +659,6 @@ static void ultoa(unsigned long i, char *str)
> }
> }
>
> -static void cmdline_add_memmap_internal(char *cmdline, unsigned long startk,
> - unsigned long endk, int type)
> -{
> - int cmdlen, len;
> - char str_mmap[256], str_tmp[20];
> -
> - strcpy (str_mmap, " memmap=");
> - ultoa((endk-startk), str_tmp);
> - strcat (str_mmap, str_tmp);
> -
> - if (type == RANGE_RAM)
> - strcat (str_mmap, "K@");
> - else if (type == RANGE_RESERVED)
> - strcat (str_mmap, "K$");
> - else if (type == RANGE_ACPI || type == RANGE_ACPI_NVS)
> - strcat (str_mmap, "K#");
> -
> - ultoa(startk, str_tmp);
> - strcat (str_mmap, str_tmp);
> - strcat (str_mmap, "K");
> - len = strlen(str_mmap);
> - cmdlen = strlen(cmdline) + len;
> - if (cmdlen > (COMMAND_LINE_SIZE - 1))
> - die("Command line overflow\n");
> - strcat(cmdline, str_mmap);
> -}
> -
> -/* Adds the appropriate memmap= options to command line, indicating the
> - * memory regions the new kernel can use to boot into. */
> -static int cmdline_add_memmap(char *cmdline, struct memory_range *memmap_p)
> -{
> - int i, cmdlen, len;
> - unsigned long min_sizek = 100;
> - char str_mmap[256];
> -
> - /* Exact map */
> - strcpy(str_mmap, " memmap=exactmap");
> - len = strlen(str_mmap);
> - cmdlen = strlen(cmdline) + len;
> - if (cmdlen > (COMMAND_LINE_SIZE - 1))
> - die("Command line overflow\n");
> - strcat(cmdline, str_mmap);
> -
> - for (i = 0; i < CRASH_MAX_MEMMAP_NR; i++) {
> - unsigned long startk, endk;
> - startk = (memmap_p[i].start/1024);
> - endk = ((memmap_p[i].end + 1)/1024);
> - if (!startk && !endk)
> - /* All regions traversed. */
> - break;
> -
> - /* A region is not worth adding if region size < 100K. It eats
> - * up precious command line length. */
> - if ((endk - startk) < min_sizek)
> - continue;
> - cmdline_add_memmap_internal(cmdline, startk, endk, RANGE_RAM);
> - }
> -
> - dbgprintf("Command line after adding memmap\n");
> - dbgprintf("%s\n", cmdline);
> -
> - return 0;
> -}
> -
> /* Adds the elfcorehdr= command line parameter to command line. */
> static int cmdline_add_elfcorehdr(char *cmdline, unsigned long addr)
> {
> @@ -803,26 +739,6 @@ static enum coretype get_core_type(struct crash_elf_info *elf_info,
> }
> }
>
> -/* Appends memmap=X#Y commandline for ACPI to command line*/
> -static int cmdline_add_memmap_acpi(char *cmdline, unsigned long start,
> - unsigned long end)
> -{
> - int align = 1024;
> - unsigned long startk, endk;
> -
> - if (!(end - start))
> - return 0;
> -
> - startk = start/1024;
> - endk = (end + align - 1)/1024;
> - cmdline_add_memmap_internal(cmdline, startk, endk, RANGE_ACPI);
> -
> - dbgprintf("Command line after adding acpi memmap\n");
> - dbgprintf("%s\n", cmdline);
> -
> - return 0;
> -}
> -
> /* Appends 'acpi_rsdp=' commandline for efi boot crash dump */
> static void cmdline_add_efi(char *cmdline)
> {
> @@ -881,24 +797,101 @@ static void get_backup_area(struct kexec_info *info,
> info->backup_src_size = BACKUP_SRC_END - BACKUP_SRC_START + 1;
> }
>
> -/* Appends memmap=X$Y commandline for reserved memory to command line*/
> -static int cmdline_add_memmap_reserved(char *cmdline, unsigned long start,
> - unsigned long end)
> +/*
> + * This function takes reserved (all kind of) memory from global
> + * crash_memory_range[] memory ranges and takes memory the kdump/crash
> + * kernel is allowed to use from the passed usable_mem memory ranges.
> + * The passed usable_mem ranges are zero (!start && !end) terminated.
> + *
> + * The final memory map is again written into crash_memory_range[]
> + * and intended to get passed as e820 table to the crash kernel
> + */
> +static int create_final_crash_map(struct memory_range *usable_mem)
> {
> - int align = 1024;
> - unsigned long startk, endk;
> + int i, m, c, tmp_map1_ranges, tmp_map2_ranges;
> + unsigned long min_sizek = 100;
> + /* crash_memory_map with usable memory ranges cut out */
> + struct memory_range tmp_map1[MAX_MEMORY_RANGES];
> + /* merge_map, but small ranges cut out */
> + struct memory_range tmp_map2[MAX_MEMORY_RANGES];
>
> - if (!(end - start))
> - return 0;
> + /*
> + * Ignore usable memory ranges for kdump kernel smaller
> + * than 100k to avoid too much ranges passed
> + * Save the new ranges (exluding lower than 100k ranges) in tmp_map
> + * and store the number of elements in tmp_map_ranges
> + */
> + for (m = 0, i = 0; i < CRASH_MAX_MEMMAP_NR; i++) {
> + unsigned long startk, endk;
> + startk = (usable_mem[i].start/1024);
> + endk = ((usable_mem[i].end + 1)/1024);
> + if (!startk && !endk)
> + /* All regions traversed. */
> + break;
> +
> + /* A region is not worth adding if region size < 100K. It eats
> + * up precious command line length. */
Now you are passing the e820 table directly instead of the commandline, so does
this comment make sense now?
> + if ((endk - startk) < min_sizek) {
> + dbgprintf("Removing: %luk - %luk\n", startk, endk);
> + continue;
> + } else {
> + tmp_map1[m].start = usable_mem[i].start;
> + tmp_map1[m].end = usable_mem[i].end;
> + tmp_map1[m].type = usable_mem[i].type;
> + m++;
> + }
> + }
> + /* No need to check for !start && !end anymore */
> + tmp_map1_ranges = m;
>
> - startk = start/1024;
> - endk = (end + align - 1)/1024;
> - cmdline_add_memmap_internal(cmdline, startk, endk, RANGE_RESERVED);
> + for(i = 0; i < tmp_map1_ranges; ++i)
> + dbgprintf("%016Lx-%016Lx (%d)\n", tmp_map1[i].start,
> + tmp_map1[i].end, tmp_map1[i].type);
> +
> + /*
> + * Cut out RANGE_RAM regions from crash_memory_ranges and store
> + * them in tmp_map2_ranges
> + */
> + for (c = 0, i = 0; i < crash_ranges; i++) {
> + if (crash_memory_range[i].type == RANGE_RAM)
> + continue;
> + tmp_map2[c].start = crash_memory_range[i].start;
> + tmp_map2[c].end = crash_memory_range[i].end;
> + tmp_map2[c].type = crash_memory_range[i].type;
> + c++;
> + }
> + tmp_map2_ranges = c;
> +
> + /*
> + * TBD: Check that no ranges overlap?
> + * Can this happen at all?
> + */
> + for (c = 0, m = 0, i = 0; i < MAX_MEMORY_RANGES; i++) {
> + if (m < tmp_map1_ranges &&
> + (c >= tmp_map2_ranges ||
> + tmp_map2[c].start > tmp_map1[m].start)) {
> + crash_memory_range[i].start = tmp_map1[m].start;
> + crash_memory_range[i].end = tmp_map1[m].end;
> + crash_memory_range[i].type = RANGE_RAM;
> + m++;
> + continue;
> + } else if (c < tmp_map2_ranges) {
> + crash_memory_range[i] = tmp_map2[c];
> + c++;
> + continue;
> + } else
> + break;
> + }
> + crash_ranges = i;
> +
> + /*
> + * End address has to be exlusive for e820 map
> + * x - 00010000
> + * 00010000 - y
> + */
> + for(i = 0; i < crash_ranges; ++i)
> + crash_memory_range[i].end++;
>
> -#ifdef DEBUG
> - printf("Command line after adding reserved memmap\n");
> - printf("%s\n", cmdline);
> -#endif
> return 0;
> }
>
> @@ -944,6 +937,12 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
> return -1;
> }
>
> + /*
> + * From now on the memory regions are stored in crash_memory_range[]
> + * Currently the end address is inclusive at this point:
> + * x - 0000ffff
> + * 00010000 - y
> + */
> if (xen_present()) {
> if (get_crash_memory_ranges_xen(&mem_range, &crash_ranges,
> elf_info.lowmem_limit) < 0)
> @@ -971,7 +970,7 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
>
> get_backup_area(info, mem_range, crash_ranges);
>
> - dbgprintf("CRASH MEMORY RANGES\n");
> + dbgprintf("TEMPORARY CRASH MEMORY RANGES\n");
>
> for(i = 0; i < crash_ranges; ++i)
> dbgprintf("%016Lx-%016Lx (%d)\n", mem_range[i].start,
> @@ -1063,24 +1062,18 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
> dbgprintf("Created elf header segment at 0x%lx\n", elfcorehdr);
> if (delete_memmap(memmap_p, elfcorehdr, memsz) < 0)
> return -1;
> - cmdline_add_memmap(mod_cmdline, memmap_p);
> cmdline_add_efi(mod_cmdline);
> cmdline_add_elfcorehdr(mod_cmdline, elfcorehdr);
>
> - /* Inform second kernel about the presence of ACPI tables. */
> - for (i = 0; i < MAX_MEMORY_RANGES; i++) {
> - unsigned long start, end;
> - if ( !( mem_range[i].type == RANGE_ACPI
> - || mem_range[i].type == RANGE_ACPI_NVS
> - || mem_range[i].type == RANGE_RESERVED) )
> - continue;
> - start = mem_range[i].start;
> - end = mem_range[i].end;
> - if (mem_range[i].type == RANGE_RESERVED)
> - cmdline_add_memmap_reserved(mod_cmdline, start, end);
> - else
> - cmdline_add_memmap_acpi(mod_cmdline, start, end);
> - }
> + /*
> + * Redo crash_memory_range so that it can get passed as e820 info
> + */
> + create_final_crash_map(memmap_p);
> +
> + dbgprintf("FINAL CRASH MEMORY RANGES\n");
> + for(i = 0; i < crash_ranges; ++i)
> + dbgprintf("%016Lx-%016Lx (%d)\n", mem_range[i].start,
> + mem_range[i].end, mem_range[i].type);
> return 0;
> }
>
> diff --git a/kexec/arch/i386/x86-linux-setup.c b/kexec/arch/i386/x86-linux-setup.c
> index c538897..82b4bb9 100644
> --- a/kexec/arch/i386/x86-linux-setup.c
> +++ b/kexec/arch/i386/x86-linux-setup.c
> @@ -505,8 +505,15 @@ void setup_linux_system_parameters(struct kexec_info *info,
> /* another safe default */
> real_mode->aux_device_info = 0;
>
> - range = info->memory_range;
> - ranges = info->memory_ranges;
> + if (info->kexec_flags & KEXEC_ON_CRASH ||
> + info->kexec_flags & KEXEC_PRESERVE_CONTEXT) {
> + range = crash_memory_range;
> + ranges = crash_ranges;
> + } else {
> + range = info->memory_range;
> + ranges = info->memory_ranges;
> + }
> +
> if (ranges > E820MAX) {
> if (!(info->kexec_flags & KEXEC_ON_CRASH))
> /*
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