From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Renaud=20M=C3=A9trich?= <rmetrich@redhat.com>
Date: Tue, 15 Feb 2022 14:05:22 +0100
Subject: [PATCH] efi: new 'connectefi' command
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When efi.quickboot is enabled on VMWare (which is the default for
hardware release 16 and later), it may happen that not all EFI devices
are connected. Due to this, browsing the devices in make_devices() just
fails to find devices, in particular disks or partitions for a given
disk.
This typically happens when network booting, then trying to chainload to
local disk (this is used in deployment tools such as Red Hat Satellite),
which is done through using the following grub.cfg snippet:
-------- 8< ---------------- 8< ---------------- 8< --------
unset prefix
search --file --set=prefix /EFI/redhat/grubx64.efi
if [ -n "$prefix" ]; then
  chainloader ($prefix)/EFI/redhat/grubx64/efi
...
-------- 8< ---------------- 8< ---------------- 8< --------

With efi.quickboot, none of the devices are connected, causing "search"
to fail. Sometimes devices are connected but not the partition of the
disk matching $prefix, causing partition to not be found by
"chainloader".

This patch introduces a new "connectefi pciroot|scsi" command which
recursively connects all EFI devices starting from a given controller
type:
- if 'pciroot' is specified, recursion is performed for all PCI root
  handles
- if 'scsi' is specified, recursion is performed for all SCSI I/O
  handles (recommended usage to avoid connecting unwanted handles which
  may impact Grub performances)

Typical grub.cfg snippet would then be:
-------- 8< ---------------- 8< ---------------- 8< --------
connectefi scsi
unset prefix
search --file --set=prefix /EFI/redhat/grubx64.efi
if [ -n "$prefix" ]; then
  chainloader ($prefix)/EFI/redhat/grubx64/efi
...
-------- 8< ---------------- 8< ---------------- 8< --------

The code is easily extensible to handle other arguments in the future if
needed.

Signed-off-by: Renaud Métrich <rmetrich@redhat.com>
Signed-off-by: Robbie Harwood <rharwood@redhat.com>
(cherry picked from commit cc972c27314c841f80ab0fe8318fae06f078c680)
(cherry picked from commit 84b0c3f965a3918be64ca850139bea7c32d23ae9)
---
 grub-core/Makefile.core.def         |   6 ++
 grub-core/commands/efi/connectefi.c | 205 ++++++++++++++++++++++++++++++++++++
 grub-core/commands/efi/lsefi.c      |   1 +
 grub-core/disk/efi/efidisk.c        |  13 +++
 grub-core/kern/efi/efi.c            |  13 +++
 include/grub/efi/disk.h             |   2 +
 include/grub/efi/efi.h              |   5 +
 NEWS                                |   2 +-
 8 files changed, 246 insertions(+), 1 deletion(-)
 create mode 100644 grub-core/commands/efi/connectefi.c

diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 612df2e9c..ef06f8c95 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -779,6 +779,12 @@ module = {
   enable = efi;
 };
 
+module = {
+  name = connectefi;
+  common = commands/efi/connectefi.c;
+  enable = efi;
+};
+
 module = {
   name = blocklist;
   common = commands/blocklist.c;
diff --git a/grub-core/commands/efi/connectefi.c b/grub-core/commands/efi/connectefi.c
new file mode 100644
index 000000000..8ab75bd51
--- /dev/null
+++ b/grub-core/commands/efi/connectefi.c
@@ -0,0 +1,205 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2022  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <grub/types.h>
+#include <grub/mm.h>
+#include <grub/misc.h>
+#include <grub/efi/api.h>
+#include <grub/efi/pci.h>
+#include <grub/efi/efi.h>
+#include <grub/command.h>
+#include <grub/err.h>
+#include <grub/i18n.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+typedef struct handle_list
+{
+  grub_efi_handle_t handle;
+  struct handle_list *next;
+} handle_list_t;
+
+static handle_list_t *already_handled = NULL;
+
+static grub_err_t
+add_handle (grub_efi_handle_t handle)
+{
+  handle_list_t *e;
+  e = grub_malloc (sizeof (*e));
+  if (! e)
+    return grub_errno;
+  e->handle = handle;
+  e->next = already_handled;
+  already_handled = e;
+  return GRUB_ERR_NONE;
+}
+
+static int
+is_in_list (grub_efi_handle_t handle)
+{
+  handle_list_t *e;
+  for (e = already_handled; e != NULL; e = e->next)
+    if (e->handle == handle)
+      return 1;
+  return 0;
+}
+
+static void
+free_handle_list (void)
+{
+  handle_list_t *e;
+  while ((e = already_handled) != NULL)
+    {
+      already_handled = already_handled->next;
+      grub_free (e);
+    }
+}
+
+typedef enum searched_item_flag
+{
+  SEARCHED_ITEM_FLAG_LOOP = 1,
+  SEARCHED_ITEM_FLAG_RECURSIVE = 2
+} searched_item_flags;
+
+typedef struct searched_item
+{
+  grub_efi_guid_t guid;
+  const char *name;
+  searched_item_flags flags;
+} searched_items;
+
+static grub_err_t
+grub_cmd_connectefi (grub_command_t cmd __attribute__ ((unused)),
+		     int argc, char **args)
+{
+  unsigned s;
+  searched_items pciroot_items[] =
+    {
+      { GRUB_EFI_PCI_ROOT_IO_GUID, "PCI root", SEARCHED_ITEM_FLAG_RECURSIVE }
+    };
+  searched_items scsi_items[] =
+    {
+      { GRUB_EFI_PCI_ROOT_IO_GUID, "PCI root", 0 },
+      { GRUB_EFI_PCI_IO_GUID, "PCI", SEARCHED_ITEM_FLAG_LOOP },
+      { GRUB_EFI_SCSI_IO_PROTOCOL_GUID, "SCSI I/O", SEARCHED_ITEM_FLAG_RECURSIVE }
+    };
+  searched_items *items = NULL;
+  unsigned nitems = 0;
+  grub_err_t grub_err = GRUB_ERR_NONE;
+  unsigned total_connected = 0;
+
+  if (argc != 1)
+    return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("one argument expected"));
+
+  if (grub_strcmp(args[0], N_("pciroot")) == 0)
+    {
+      items = pciroot_items;
+      nitems = ARRAY_SIZE (pciroot_items);
+    }
+  else if (grub_strcmp(args[0], N_("scsi")) == 0)
+    {
+      items = scsi_items;
+      nitems = ARRAY_SIZE (scsi_items);
+    }
+  else
+    return grub_error (GRUB_ERR_BAD_ARGUMENT,
+		       N_("unexpected argument `%s'"), args[0]);
+
+  for (s = 0; s < nitems; s++)
+    {
+      grub_efi_handle_t *handles;
+      grub_efi_uintn_t num_handles;
+      unsigned i, connected = 0, loop = 0;
+
+loop:
+      loop++;
+      grub_dprintf ("efi", "step '%s' loop %d:\n", items[s].name, loop);
+
+      handles = grub_efi_locate_handle (GRUB_EFI_BY_PROTOCOL,
+					&items[s].guid, 0, &num_handles);
+
+      if (!handles)
+	continue;
+
+      for (i = 0; i < num_handles; i++)
+	{
+	  grub_efi_handle_t handle = handles[i];
+	  grub_efi_status_t status;
+	  unsigned j;
+
+	  /* Skip already handled handles  */
+	  if (is_in_list (handle))
+	    {
+	      grub_dprintf ("efi", "  handle %p: already processed\n",
+				   handle);
+	      continue;
+	    }
+
+	  status = grub_efi_connect_controller(handle, NULL, NULL,
+			items[s].flags & SEARCHED_ITEM_FLAG_RECURSIVE ? 1 : 0);
+	  if (status == GRUB_EFI_SUCCESS)
+	    {
+	      connected++;
+	      total_connected++;
+	      grub_dprintf ("efi", "  handle %p: connected\n", handle);
+	    }
+	  else
+	    grub_dprintf ("efi", "  handle %p: failed to connect (%d)\n",
+				 handle, (grub_efi_int8_t) status);
+
+	  if ((grub_err = add_handle (handle)) != GRUB_ERR_NONE)
+	    break; /* fatal  */
+	}
+
+      grub_free (handles);
+      if (grub_err != GRUB_ERR_NONE)
+	break; /* fatal  */
+
+      if (items[s].flags & SEARCHED_ITEM_FLAG_LOOP && connected)
+	{
+	  connected = 0;
+	  goto loop;
+	}
+
+      free_handle_list ();
+    }
+
+  free_handle_list ();
+
+  if (total_connected)
+    grub_efidisk_reenumerate_disks ();
+
+  return grub_err;
+}
+
+static grub_command_t cmd;
+
+GRUB_MOD_INIT(connectefi)
+{
+  cmd = grub_register_command ("connectefi", grub_cmd_connectefi,
+			       N_("pciroot|scsi"),
+			       N_("Connect EFI handles."
+				  " If 'pciroot' is specified, connect PCI"
+				  " root EFI handles recursively."
+				  " If 'scsi' is specified, connect SCSI"
+				  " I/O EFI handles recursively."));
+}
+
+GRUB_MOD_FINI(connectefi)
+{
+  grub_unregister_command (cmd);
+}
diff --git a/grub-core/commands/efi/lsefi.c b/grub-core/commands/efi/lsefi.c
index d1ce99af4..f2d2430e6 100644
--- a/grub-core/commands/efi/lsefi.c
+++ b/grub-core/commands/efi/lsefi.c
@@ -19,6 +19,7 @@
 #include <grub/mm.h>
 #include <grub/misc.h>
 #include <grub/efi/api.h>
+#include <grub/efi/disk.h>
 #include <grub/efi/edid.h>
 #include <grub/efi/pci.h>
 #include <grub/efi/efi.h>
diff --git a/grub-core/disk/efi/efidisk.c b/grub-core/disk/efi/efidisk.c
index 5d2400f66..720a23fcc 100644
--- a/grub-core/disk/efi/efidisk.c
+++ b/grub-core/disk/efi/efidisk.c
@@ -390,6 +390,19 @@ enumerate_disks (void)
   free_devices (devices);
 }
 
+void
+grub_efidisk_reenumerate_disks (void)
+{
+  free_devices (fd_devices);
+  free_devices (hd_devices);
+  free_devices (cd_devices);
+  fd_devices = 0;
+  hd_devices = 0;
+  cd_devices = 0;
+
+  enumerate_disks ();
+}
+
 static int
 grub_efidisk_iterate (grub_disk_dev_iterate_hook_t hook, void *hook_data,
 		      grub_disk_pull_t pull)
diff --git a/grub-core/kern/efi/efi.c b/grub-core/kern/efi/efi.c
index 4b95a4004..286395645 100644
--- a/grub-core/kern/efi/efi.c
+++ b/grub-core/kern/efi/efi.c
@@ -95,6 +95,19 @@ grub_efi_locate_handle (grub_efi_locate_search_type_t search_type,
   return buffer;
 }
 
+grub_efi_status_t
+grub_efi_connect_controller (grub_efi_handle_t controller_handle,
+			     grub_efi_handle_t *driver_image_handle,
+			     grub_efi_device_path_protocol_t *remaining_device_path,
+			     grub_efi_boolean_t recursive)
+{
+  grub_efi_boot_services_t *b;
+
+  b = grub_efi_system_table->boot_services;
+  return efi_call_4 (b->connect_controller, controller_handle,
+		     driver_image_handle, remaining_device_path, recursive);
+}
+
 void *
 grub_efi_open_protocol (grub_efi_handle_t handle,
 			grub_efi_guid_t *protocol,
diff --git a/include/grub/efi/disk.h b/include/grub/efi/disk.h
index 254475c84..6845c2f1f 100644
--- a/include/grub/efi/disk.h
+++ b/include/grub/efi/disk.h
@@ -27,6 +27,8 @@ grub_efi_handle_t
 EXPORT_FUNC(grub_efidisk_get_device_handle) (grub_disk_t disk);
 char *EXPORT_FUNC(grub_efidisk_get_device_name) (grub_efi_handle_t *handle);
 
+void EXPORT_FUNC(grub_efidisk_reenumerate_disks) (void);
+
 void grub_efidisk_init (void);
 void grub_efidisk_fini (void);
 
diff --git a/include/grub/efi/efi.h b/include/grub/efi/efi.h
index 570a69361..4411ffa16 100644
--- a/include/grub/efi/efi.h
+++ b/include/grub/efi/efi.h
@@ -36,6 +36,11 @@ EXPORT_FUNC(grub_efi_locate_handle) (grub_efi_locate_search_type_t search_type,
 				     grub_efi_guid_t *protocol,
 				     void *search_key,
 				     grub_efi_uintn_t *num_handles);
+grub_efi_status_t
+EXPORT_FUNC(grub_efi_connect_controller) (grub_efi_handle_t controller_handle,
+					  grub_efi_handle_t *driver_image_handle,
+					  grub_efi_device_path_protocol_t *remaining_device_path,
+					  grub_efi_boolean_t recursive);
 void *EXPORT_FUNC(grub_efi_open_protocol) (grub_efi_handle_t handle,
 					   grub_efi_guid_t *protocol,
 					   grub_efi_uint32_t attributes);
diff --git a/NEWS b/NEWS
index 2ebd54e78..b04041507 100644
--- a/NEWS
+++ b/NEWS
@@ -66,7 +66,7 @@ New in 2.02:
   * Prefer pmtimer for TSC calibration.
 
 * New/improved platform support:
-  * New `efifwsetup' and `lsefi' commands on EFI platforms.
+  * New `efifwsetup', `lsefi' and `connectefi` commands on EFI platforms.
   * New `cmosdump' and `cmosset' commands on platforms with CMOS support.
   * New command `pcidump' for PCI platforms.
   * Improve opcode parsing in ACPI halt implementation.
