From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Introduce a helper function, e820_change_type(), that change
the type of subregion of e820 entry.
The following patch uses it.
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
hw/i386/e820_memory_layout.c | 72 ++++++++++++++++++++++++++++++++++++
hw/i386/e820_memory_layout.h | 1 +
2 files changed, 73 insertions(+)
diff --git a/hw/i386/e820_memory_layout.c b/hw/i386/e820_memory_layout.c
index d9bb11c02a..109c4f715a 100644
--- a/hw/i386/e820_memory_layout.c
+++ b/hw/i386/e820_memory_layout.c
@@ -57,6 +57,78 @@ int e820_add_entry(uint64_t address, uint64_t length, uint32_t type)
return e820_entries;
}
+int e820_change_type(uint64_t address, uint64_t length, uint32_t type)
+{
+ size_t i;
+
+ if (type != E820_RAM) {
+ int ret = e820_append_reserve(address, length, type);
+ if (ret) {
+ return ret;
+ }
+ }
+
+ /* new "etc/e820" file -- include ram too */
+ for (i = 0; i < e820_entries; i++) {
+ struct e820_entry *e = &e820_table[i];
+ struct e820_entry tmp = {
+ .address = le64_to_cpu(e->address),
+ .length = le64_to_cpu(e->length),
+ .type = le32_to_cpu(e->type),
+ };
+ /* overlap? */
+ if (address + length < tmp.address ||
+ tmp.address + tmp.length < address) {
+ continue;
+ }
+ /*
+ * partial-overlap is not allowed.
+ * It is assumed that the region is completely contained within
+ * other region.
+ */
+ if (address < tmp.address ||
+ tmp.address + tmp.length < address + length) {
+ return -EINVAL;
+ }
+ /* only real type change is allowed. */
+ if (tmp.type == type) {
+ return -EINVAL;
+ }
+
+ if (tmp.address == address &&
+ tmp.address + tmp.length == address + length) {
+ e->type = cpu_to_le32(type);
+ return e820_entries;
+ } else if (tmp.address == address) {
+ e820_table = g_renew(struct e820_entry,
+ e820_table, e820_entries + 1);
+ e = &e820_table[i];
+ e->address = cpu_to_le64(tmp.address + length);
+ e820_append_entry(address, length, type);
+ return e820_entries;
+ } else if (tmp.address + tmp.length == address + length) {
+ e820_table = g_renew(struct e820_entry,
+ e820_table, e820_entries + 1);
+ e = &e820_table[i];
+ e->length = cpu_to_le64(tmp.length - length);
+ e820_append_entry(address, length, type);
+ return e820_entries;
+ } else {
+ e820_table = g_renew(struct e820_entry,
+ e820_table, e820_entries + 2);
+ e = &e820_table[i];
+ e->length = cpu_to_le64(address - tmp.address);
+ e820_append_entry(address, length, type);
+ e820_append_entry(address + length,
+ tmp.address + tmp.length - (address + length),
+ tmp.type);
+ return e820_entries;
+ }
+ }
+
+ return -EINVAL;
+}
+
int e820_get_num_entries(void)
{
return e820_entries;
diff --git a/hw/i386/e820_memory_layout.h b/hw/i386/e820_memory_layout.h
index 2a0ceb8b9c..5f27cee476 100644
--- a/hw/i386/e820_memory_layout.h
+++ b/hw/i386/e820_memory_layout.h
@@ -33,6 +33,7 @@ extern struct e820_table e820_reserve;
extern struct e820_entry *e820_table;
int e820_add_entry(uint64_t address, uint64_t length, uint32_t type);
+int e820_change_type(uint64_t address, uint64_t length, uint32_t type);
int e820_get_num_entries(void);
bool e820_get_entry(int index, uint32_t type,
uint64_t *address, uint64_t *length);
--
2.25.1
