[Qemu-devel] [PATCH 1/2] resolve memory device roll over reporting issues with >32G guests

[Gleb Natapov <gleb@redhat.com>]

The field within the Memory Device type 17 is only a word with the MSB being
used to report MB/KB.  Thereby, a guest with 32G and greater would report
incorrect memory device information rolling over to 0.

This presents more than one memory device and associated memory structures
if the memory is larger than 16G

This is port of commit e65bb0d2bd3a156408996674965555979de3a61b
from qemu pc-bios tree.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
---
 src/smbios.c |   70 +++++++++++++++++++++++++++++-----------------------------
 1 files changed, 35 insertions(+), 35 deletions(-)

diff --git a/src/smbios.c b/src/smbios.c
index c408601..30dc853 100644
--- a/src/smbios.c
+++ b/src/smbios.c
@@ -366,7 +366,7 @@ smbios_type_4_init(void *start, unsigned int cpu_number)
 
 /* Type 16 -- Physical Memory Array */
 static void *
-smbios_type_16_init(void *start)
+smbios_type_16_init(void *start, u32 memory_size_mb, int nr_mem_devs)
 {
     struct smbios_type_16 *p = (struct smbios_type_16*)start;
 
@@ -377,10 +377,9 @@ smbios_type_16_init(void *start)
     p->location = 0x01; /* other */
     p->use = 0x03; /* system memory */
     p->error_correction = 0x01; /* other */
-    u64 memsize = RamSize + RamSizeOver4G;
-    p->maximum_capacity = memsize / 1024;
+    p->maximum_capacity = memory_size_mb * 1024;
     p->memory_error_information_handle = 0xfffe; /* none provided */
-    p->number_of_memory_devices = 1;
+    p->number_of_memory_devices = nr_mem_devs;
 
     start += sizeof(struct smbios_type_16);
     *((u16 *)start) = 0;
@@ -390,21 +389,19 @@ smbios_type_16_init(void *start)
 
 /* Type 17 -- Memory Device */
 static void *
-smbios_type_17_init(void *start)
+smbios_type_17_init(void *start, u32 memory_size_mb, int instance)
 {
     struct smbios_type_17 *p = (struct smbios_type_17 *)start;
 
     p->header.type = 17;
     p->header.length = sizeof(struct smbios_type_17);
-    p->header.handle = 0x1100;
+    p->header.handle = 0x1100 + instance;
 
     p->physical_memory_array_handle = 0x1000;
     p->total_width = 64;
     p->data_width = 64;
-    /* truncate memory_size_mb to 16 bits and clear most significant
-       bit [indicates size in MB] */
-    u64 memsize = RamSize + RamSizeOver4G;
-    p->size = (u16) (memsize / (1024*1024)) & 0x7fff;
+/* TODO: should assert in case something is wrong   ASSERT((memory_size_mb & ~0x7fff) == 0); */
+    p->size = memory_size_mb;
     p->form_factor = 0x09; /* DIMM */
     p->device_set = 0;
     p->device_locator_str = 1;
@@ -413,7 +410,8 @@ smbios_type_17_init(void *start)
     p->type_detail = 0;
 
     start += sizeof(struct smbios_type_17);
-    memcpy((char *)start, "DIMM 1", 7);
+    memcpy((char *)start, "DIMM 0", 7);
+    ((char*)start)[5] += instance;
     start += 7;
     *((u8 *)start) = 0;
 
@@ -422,21 +420,16 @@ smbios_type_17_init(void *start)
 
 /* Type 19 -- Memory Array Mapped Address */
 static void *
-smbios_type_19_init(void *start)
+smbios_type_19_init(void *start, u32 memory_size_mb, int instance)
 {
     struct smbios_type_19 *p = (struct smbios_type_19 *)start;
 
     p->header.type = 19;
     p->header.length = sizeof(struct smbios_type_19);
-    p->header.handle = 0x1300;
+    p->header.handle = 0x1300 + instance;
 
-    p->starting_address = 0;
-    u64 memsize = RamSizeOver4G;
-    if (memsize)
-        memsize += 0x100000000ull;
-    else
-        memsize = RamSize;
-    p->ending_address = memsize / 1024 - 1;
+    p->starting_address = instance << 24;
+    p->ending_address = p->starting_address + (memory_size_mb << 10) - 1;
     p->memory_array_handle = 0x1000;
     p->partition_width = 1;
 
@@ -448,23 +441,18 @@ smbios_type_19_init(void *start)
 
 /* Type 20 -- Memory Device Mapped Address */
 static void *
-smbios_type_20_init(void *start)
+smbios_type_20_init(void *start, u32 memory_size_mb, int instance)
 {
     struct smbios_type_20 *p = (struct smbios_type_20 *)start;
 
     p->header.type = 20;
     p->header.length = sizeof(struct smbios_type_20);
-    p->header.handle = 0x1400;
+    p->header.handle = 0x1400 + instance;
 
-    p->starting_address = 0;
-    u64 memsize = RamSizeOver4G;
-    if (memsize)
-        memsize += 0x100000000ull;
-    else
-        memsize = RamSize;
-    p->ending_address = memsize / 1024 - 1;
-    p->memory_device_handle = 0x1100;
-    p->memory_array_mapped_address_handle = 0x1300;
+    p->starting_address = instance << 24;
+    p->ending_address = p->starting_address + (memory_size_mb << 10) - 1;
+    p->memory_device_handle = 0x1100 + instance;
+    p->memory_array_mapped_address_handle = 0x1300 + instance;
     p->partition_row_position = 1;
     p->interleave_position = 0;
     p->interleaved_data_depth = 0;
@@ -540,10 +528,22 @@ smbios_init(void)
     int cpu_num, smp_cpus = CountCPUs;
     for (cpu_num = 1; cpu_num <= smp_cpus; cpu_num++)
         add_struct(smbios_type_4_init(p, cpu_num));
-    add_struct(smbios_type_16_init(p));
-    add_struct(smbios_type_17_init(p));
-    add_struct(smbios_type_19_init(p));
-    add_struct(smbios_type_20_init(p));
+    u64 memsize = RamSizeOver4G;
+    if (memsize)
+        memsize += 0x100000000ull;
+    else
+        memsize = RamSize;
+    memsize = memsize / (1024 * 1024);
+    int nr_mem_devs = (memsize + 0x3fff) >> 14;
+    add_struct(smbios_type_16_init(p, memsize, nr_mem_devs));
+    int i;
+    for (i = 0; i < nr_mem_devs; i++) {
+        u32 dev_memsize = ((i == (nr_mem_devs - 1))
+                           ? (((memsize-1) & 0x3fff)+1) : 0x4000);
+        add_struct(smbios_type_17_init(p, dev_memsize, i));
+        add_struct(smbios_type_19_init(p, dev_memsize, i));
+        add_struct(smbios_type_20_init(p, dev_memsize, i));
+    }
     add_struct(smbios_type_32_init(p));
     add_struct(smbios_type_127_init(p));
 
-- 
1.6.3.3