This support allows the DRTM launch to be initiated after and EFI stub
launch of the Linux kernel is done. This is accomplished by providing
a handler to jump to when a Secure Launch is in progress.

Signed-off-by: Ross Philipson <ross.philip...@oracle.com>
---
 drivers/firmware/efi/libstub/x86-stub.c | 55 +++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/drivers/firmware/efi/libstub/x86-stub.c 
b/drivers/firmware/efi/libstub/x86-stub.c
index a0bfd31..66ff922 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -9,6 +9,7 @@
 #include <linux/efi.h>
 #include <linux/pci.h>
 #include <linux/stddef.h>
+#include <linux/slr_table.h>
 
 #include <asm/efi.h>
 #include <asm/e820/types.h>
@@ -760,6 +761,57 @@ static efi_status_t exit_boot(struct boot_params 
*boot_params, void *handle)
        return EFI_SUCCESS;
 }
 
+static void efi_secure_launch(struct boot_params *boot_params)
+{
+       struct slr_entry_uefi_config *uefi_config;
+       struct slr_uefi_cfg_entry *uefi_entry;
+       struct slr_entry_dl_info *dlinfo;
+       efi_guid_t guid = SLR_TABLE_GUID;
+       struct slr_table *slrt;
+       u64 memmap_hi;
+       void *table;
+       u8 buf[64] = {0};
+
+       table = get_efi_config_table(guid);
+
+       /*
+        * The presence of this table indicated a Secure Launch
+        * is being requested.
+        */
+       if (!table)
+               return;
+
+       slrt = (struct slr_table *)table;
+
+       if (slrt->magic != SLR_TABLE_MAGIC)
+               return;
+
+       /* Add config information to measure the UEFI memory map */
+       uefi_config = (struct slr_entry_uefi_config *)buf;
+       uefi_config->hdr.tag = SLR_ENTRY_UEFI_CONFIG;
+       uefi_config->hdr.size = sizeof(*uefi_config) + sizeof(*uefi_entry);
+       uefi_config->revision = SLR_UEFI_CONFIG_REVISION;
+       uefi_config->nr_entries = 1;
+       uefi_entry = (struct slr_uefi_cfg_entry *)(buf + sizeof(*uefi_config));
+       uefi_entry->pcr = 18;
+       uefi_entry->cfg = boot_params->efi_info.efi_memmap;
+       memmap_hi = boot_params->efi_info.efi_memmap_hi;
+       uefi_entry->cfg |= memmap_hi << 32;
+       uefi_entry->size = boot_params->efi_info.efi_memmap_size;
+       memcpy(&uefi_entry->evt_info[0], "Measured UEFI memory map",
+               strlen("Measured UEFI memory map"));
+
+       if (slr_add_entry(slrt, (struct slr_entry_hdr *)uefi_config))
+               return;
+
+       /* Jump through DL stub to initiate Secure Launch */
+       dlinfo = (struct slr_entry_dl_info *)
+               slr_next_entry_by_tag(slrt, NULL, SLR_ENTRY_DL_INFO);
+
+       asm volatile ("jmp *%%rax"
+                     : : "a" (dlinfo->dl_handler), "D" (&dlinfo->bl_context));
+}
+
 /*
  * On success, we return the address of startup_32, which has potentially been
  * relocated by efi_relocate_kernel.
@@ -905,6 +957,9 @@ asmlinkage unsigned long efi_main(efi_handle_t handle,
                goto fail;
        }
 
+       /* If a secure launch is in progress, this never returns */
+       efi_secure_launch(boot_params);
+
        return bzimage_addr;
 fail:
        efi_err("efi_main() failed!\n");
-- 
1.8.3.1


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