Re: kexec, x86: Need a new e820 type support for kexec

Baoquan He
2015-08-06T08:12:42Z

Hi Toshi,

Does this patch work for you?

There are things I am not sure. When jump to kexec/kdump kernel is this
PMEM still needed by system? And what's the difference between PRAM and
PMEM? I saw in kernel commit ec776ef6 it introduced E820_PRAM for the
non-standard protected e820 type, then in kernel commit ad5fb870 it
introduced E820_PMEM for ACPI 6.0 persistent memory types. While it
doesn't add complete support for E820_PMEM like E820_PRAM if I
understand it correctly. In this patch I simply pass E820_PMEM to kdump
kernel as E820_PRAM when it emerges since kernel can parse E820_PRAM
only in parse_memmap_one(), otherwise E820_PMEM has to be discarded or
need be passed as E820_RESERVED. What do you think about this, need
E820_PMEM be differentiated with E820_PRAM strictly? If yes, I think a
kernel patch need be posted to fix this. If not, this patch is enough
for supporting both of them in kexec.

>From 032f0c2cc89d1cde6d748b2cca90ebb829b4d589 Mon Sep 17 00:00:00 2001
From: Baoquan He <bhe@redhat.com>
Date: Thu, 25 Jun 2015 19:15:49 +0900
Subject: [PATCH] Add persistent memory support

Kernel add E820_PRAM or E820_PMEM type for NVDIMM memory device.
Now support them in kexec too.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
include/x86/x86-linux.h | 2 ++
kexec/arch/i386/crashdump-x86.c | 10 +++++++++-
kexec/arch/i386/kexec-x86-common.c | 10 ++++++++++
kexec/arch/i386/x86-linux-setup.c | 6 ++++++
kexec/firmware_memmap.c | 4 ++++
kexec/kexec.h | 2 ++
6 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/include/x86/x86-linux.h b/include/x86/x86-linux.h
index 50c7324..7834751 100644
--- a/include/x86/x86-linux.h
+++ b/include/x86/x86-linux.h
@@ -21,6 +21,8 @@ struct e820entry {
#define E820_RESERVED 2
#define E820_ACPI 3 /* usable as RAM once ACPI tables have been read */
#define E820_NVS 4
+#define E820_PMEM 7
+#define E820_PRAM 12
} __attribute__((packed));
#endif

diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
index 82bf239..dea42d0 100644
--- a/kexec/arch/i386/crashdump-x86.c
+++ b/kexec/arch/i386/crashdump-x86.c
@@ -301,6 +301,10 @@ static int get_crash_memory_ranges(struct memory_range **range, int *ranges,
type = RANGE_ACPI;
} else if(memcmp(str,"ACPI Non-volatile Storage\n",26) == 0 ) {
type = RANGE_ACPI_NVS;
+ } else if(memcmp(str,"Persistent Memory (legacy)\n",27) == 0 ) {
+ type = RANGE_PRAM;
+ } else if(memcmp(str,"Persistent Memory\n",18) == 0 ) {
+ type = RANGE_PMEM;
} else if(memcmp(str,"reserved\n",9) == 0 ) {
type = RANGE_RESERVED;
} else if (memcmp(str, "GART\n", 5) == 0) {
@@ -640,6 +644,8 @@ static void cmdline_add_memmap_internal(char *cmdline, unsigned long startk,
strcat (str_mmap, "K$");
else if (type == RANGE_ACPI || type == RANGE_ACPI_NVS)
strcat (str_mmap, "K#");
+ else if (type == RANGE_PMEM || type == RANGE_PRAM)
+ strcat (str_mmap, "K!");

ultoa(startk, str_tmp);
strcat (str_mmap, str_tmp);
@@ -997,7 +1003,9 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
unsigned long start, end, size, type;
if ( !( mem_range[i].type == RANGE_ACPI
|| mem_range[i].type == RANGE_ACPI_NVS
- || mem_range[i].type == RANGE_RESERVED))
+ || mem_range[i].type == RANGE_RESERVED
+ || mem_range[i].type == RANGE_PMEM
+ || mem_range[i].type == RANGE_PRAM))
continue;
start = mem_range[i].start;
end = mem_range[i].end;
diff --git a/kexec/arch/i386/kexec-x86-common.c b/kexec/arch/i386/kexec-x86-common.c
index 3624192..90534a8 100644
--- a/kexec/arch/i386/kexec-x86-common.c
+++ b/kexec/arch/i386/kexec-x86-common.c
@@ -94,6 +94,12 @@ static int get_memory_ranges_proc_iomem(struct memory_range **range, int *ranges
else if (memcmp(str, "ACPI Non-volatile Storage\n", 26) == 0) {
type = RANGE_ACPI_NVS;
}
+ else if (memcmp(str, "Persistent Memory (legacy)\n", 27) == 0) {
+ type = RANGE_ACPI_NVS;
+ }
+ else if (memcmp(str, "Persistent Memory\n", 18) == 0) {
+ type = RANGE_ACPI_NVS;
+ }
else {
continue;
}
@@ -149,6 +155,10 @@ unsigned xen_e820_to_kexec_type(uint32_t type)
return RANGE_ACPI;
case E820_NVS:
return RANGE_ACPI_NVS;
+ case E820_PMEM:
+ return RANGE_PMEM;
+ case E820_PRAM:
+ return RANGE_PRAM;
case E820_RESERVED:
default:
return RANGE_RESERVED;
diff --git a/kexec/arch/i386/x86-linux-setup.c b/kexec/arch/i386/x86-linux-setup.c
index 9271c6c..c75adaa 100644
--- a/kexec/arch/i386/x86-linux-setup.c
+++ b/kexec/arch/i386/x86-linux-setup.c
@@ -705,6 +705,12 @@ static void add_e820_map_from_mr(struct x86_linux_param_header *real_mode,
case RANGE_ACPI_NVS:
e820[i].type = E820_NVS;
break;
+ case RANGE_PMEM:
+ e820[i].type = E820_PMEM;
+ break;
+ case RANGE_PRAM:
+ e820[i].type = E820_PRAM;
+ break;
default:
case RANGE_RESERVED:
e820[i].type = E820_RESERVED;
diff --git a/kexec/firmware_memmap.c b/kexec/firmware_memmap.c
index 6be3c7c..4d84f00 100644
--- a/kexec/firmware_memmap.c
+++ b/kexec/firmware_memmap.c
@@ -168,6 +168,10 @@ static int parse_memmap_entry(const char *entry, struct memory_range *range)
range->type = RANGE_ACPI_NVS;
else if (strcmp(type, "Uncached RAM") == 0)
range->type = RANGE_UNCACHED;
+ else if (strcmp(type, "Persistent Memory (legacy)") == 0)
+ range->type = RANGE_PRAM;
+ else if (strcmp(type, "Persistent Memory") == 0)
+ range->type = RANGE_PMEM;
else {
fprintf(stderr, "Unknown type (%s) while parsing %s. Please "
"report this as bug. Using RANGE_RESERVED now.\n",
diff --git a/kexec/kexec.h b/kexec/kexec.h
index b129c15..0fa977f 100644
--- a/kexec/kexec.h
+++ b/kexec/kexec.h
@@ -136,6 +136,8 @@ struct memory_range {
#define RANGE_ACPI 2
#define RANGE_ACPI_NVS 3
#define RANGE_UNCACHED 4
+#define RANGE_PMEM 6
+#define RANGE_PRAM 11
};

struct memory_ranges {
--
2.1.0