[kvm-unit-tests PATCH v2 3/6] x86: efi_main: Get EFI memory map and exit boot services

Varad Gautam
2021-08-19T11:35:17Z

The largest EFI_CONVENTIONAL_MEMORY chunk is passed over to
alloc_phys for the testcase.

Signed-off-by: Varad Gautam <varad.gautam@suse.com>
---
x86/efi_main.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 92 insertions(+)

diff --git a/x86/efi_main.c b/x86/efi_main.c
index 00e7086..237d4e7 100644
--- a/x86/efi_main.c
+++ b/x86/efi_main.c
@@ -1,11 +1,103 @@
+#include <alloc_phys.h>
#include <linux/uefi.h>

unsigned long __efiapi efi_main(efi_handle_t handle, efi_system_table_t *sys_tab);
efi_system_table_t *efi_system_table = NULL;

+static void efi_free_pool(void *ptr)
+{
+ efi_bs_call(free_pool, ptr);
+}
+
+static efi_status_t efi_get_memory_map(struct efi_boot_memmap *map)
+{
+ efi_memory_desc_t *m = NULL;
+ efi_status_t status;
+ unsigned long key = 0, map_size = 0, desc_size = 0;
+
+ status = efi_bs_call(get_memory_map, &map_size,
+ NULL, &key, &desc_size, NULL);
+ if (status != EFI_BUFFER_TOO_SMALL || map_size == 0)
+ goto out;
+
+ /* Pad map_size with additional descriptors so we don't need to
+ * retry. */
+ map_size += 4 * desc_size;
+ *map->buff_size = map_size;
+ status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
+ map_size, (void **)&m);
+ if (status != EFI_SUCCESS)
+ goto out;
+
+ /* Get the map. */
+ status = efi_bs_call(get_memory_map, &map_size,
+ m, &key, &desc_size, NULL);
+ if (status != EFI_SUCCESS) {
+ efi_free_pool(m);
+ goto out;
+ }
+
+ *map->desc_size = desc_size;
+ *map->map_size = map_size;
+ *map->key_ptr = key;
+out:
+ *map->map = m;
+ return status;
+}
+
+static efi_status_t efi_exit_boot_services(void *handle,
+ struct efi_boot_memmap *map)
+{
+ return efi_bs_call(exit_boot_services, handle, *map->key_ptr);
+}
+
+static efi_status_t exit_efi(void *handle)
+{
+ unsigned long map_size = 0, key = 0, desc_size = 0, buff_size;
+ efi_memory_desc_t *mem_map, *md, *conventional = NULL;
+ efi_status_t status;
+ unsigned num_ents, i;
+ unsigned long pages = 0;
+ struct efi_boot_memmap map;
+
+ map.map = &mem_map;
+ map.map_size = &map_size;
+ map.desc_size = &desc_size;
+ map.desc_ver = NULL;
+ map.key_ptr = &key;
+ map.buff_size = &buff_size;
+
+ status = efi_get_memory_map(&map);
+ if (status != EFI_SUCCESS)
+ return status;
+
+ status = efi_exit_boot_services(handle, &map);
+ if (status != EFI_SUCCESS) {
+ efi_free_pool(mem_map);
+ return status;
+ }
+
+ /* Use the largest EFI_CONVENTIONAL_MEMORY range for phys_alloc_init. */
+ num_ents = map_size / desc_size;
+ for (i = 0; i < num_ents; i++) {
+ md = (efi_memory_desc_t *) (((u8 *) mem_map) + i * (desc_size));
+
+ if (md->type == EFI_CONVENTIONAL_MEMORY && md->num_pages > pages) {
+ conventional = md;
+ pages = md->num_pages;
+ }
+ }
+ phys_alloc_init(conventional->phys_addr,
+ conventional->num_pages << EFI_PAGE_SHIFT);
+
+ return EFI_SUCCESS;
+}
+
unsigned long __efiapi efi_main(efi_handle_t handle, efi_system_table_t *sys_tab)
{
efi_system_table = sys_tab;

+ exit_efi(handle);
+
return 0;
}
--
2.30.2