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[efi] Install the HII config access protocol on a child of the SNP handle

In edk2, there are several drivers that associate HII forms (and
corresponding config access protocol instances) with each individual
network device.  (In this context, "network device" means the EFI
handle on which the SNP protocol is installed, and on which the device
path ending with the MAC() node is installed also.)  Such edk2 drivers
are, for example: Ip4Dxe, HttpBootDxe, VlanConfigDxe.

In UEFI, any given handle can carry at most one instance of a specific
protocol (see e.g. the specification of the InstallProtocolInterface()
boot service).  This implies that the class of drivers mentioned above
can't install their EFI_HII_CONFIG_ACCESS_PROTOCOL instances on the
SNP handle directly -- they would conflict with each other.
Accordingly, each of those edk2 drivers creates a "private" child
handle under the SNP handle, and installs its config access protocol
(and corresponding HII package list) on its child handle.

The device path for the child handle is traditionally derived by
appending a Hardware Vendor Device Path node after the MAC() node.
The VenHw() nodes in question consist of a GUID (by definition), and
no trailing data (by choice).  The purpose of these VenHw() nodes is
only that all the child nodes can be uniquely identified by device
path.

At the moment iPXE does not follow this pattern.  It doesn't run into
a conflict when it installs its EFI_HII_CONFIG_ACCESS_PROTOCOL
directly on the SNP handle, but that's only because iPXE is the sole
driver not following the pattern.  This behavior seems risky (one
might call it a "latent bug"); better align iPXE with the edk2 custom.

Cc: Michael Brown <mcb30@ipxe.org>
Cc: Gary Lin <glin@suse.com>
Cc: Ladi Prosek <lprosek@redhat.com>
Ref: http://thread.gmane.org/gmane.comp.bios.edk2.devel/13494/focus=13532
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ladi Prosek <lprosek@redhat.com>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
tags/v1.20.1
Laszlo Ersek 8 år sedan
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2 ändrade filer med 75 tillägg och 4 borttagningar
  1. 4
    0
      src/include/ipxe/efi/efi_snp.h
  2. 71
    4
      src/interface/efi/efi_snp_hii.c

+ 4
- 0
src/include/ipxe/efi/efi_snp.h Visa fil

@@ -57,6 +57,10 @@ struct efi_snp_device {
57 57
 	EFI_HII_CONFIG_ACCESS_PROTOCOL hii;
58 58
 	/** HII package list */
59 59
 	EFI_HII_PACKAGE_LIST_HEADER *package_list;
60
+	/** EFI child handle for HII association */
61
+	EFI_HANDLE hii_child_handle;
62
+	/** Device path of HII child handle */
63
+	EFI_DEVICE_PATH_PROTOCOL *hii_child_path;
60 64
 	/** HII handle */
61 65
 	EFI_HII_HANDLE hii_handle;
62 66
 	/** Device name */

+ 71
- 4
src/interface/efi/efi_snp_hii.c Visa fil

@@ -63,6 +63,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
63 63
 #include <ipxe/efi/efi_hii.h>
64 64
 #include <ipxe/efi/efi_snp.h>
65 65
 #include <ipxe/efi/efi_strings.h>
66
+#include <ipxe/efi/efi_utils.h>
66 67
 #include <config/branding.h>
67 68
 
68 69
 /** EFI platform setup formset GUID */
@@ -653,6 +654,9 @@ static EFI_HII_CONFIG_ACCESS_PROTOCOL efi_snp_device_hii = {
653 654
  */
654 655
 int efi_snp_hii_install ( struct efi_snp_device *snpdev ) {
655 656
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
657
+	VENDOR_DEVICE_PATH *vendor_path;
658
+	EFI_DEVICE_PATH_PROTOCOL *path_end;
659
+	size_t path_prefix_len;
656 660
 	int efirc;
657 661
 	int rc;
658 662
 
@@ -674,9 +678,46 @@ int efi_snp_hii_install ( struct efi_snp_device *snpdev ) {
674 678
 		goto err_build_package_list;
675 679
 	}
676 680
 
681
+	/* Allocate the new device path */
682
+	path_prefix_len = efi_devpath_len ( snpdev->path );
683
+	snpdev->hii_child_path = zalloc ( path_prefix_len +
684
+					  sizeof ( *vendor_path ) +
685
+					  sizeof ( *path_end ) );
686
+	if ( ! snpdev->hii_child_path ) {
687
+		DBGC ( snpdev,
688
+		       "SNPDEV %p could not allocate HII child device path\n",
689
+		       snpdev );
690
+		rc = -ENOMEM;
691
+		goto err_alloc_child_path;
692
+	}
693
+
694
+	/* Populate the device path */
695
+	memcpy ( snpdev->hii_child_path, snpdev->path, path_prefix_len );
696
+	vendor_path = ( ( ( void * ) snpdev->hii_child_path ) +
697
+			path_prefix_len );
698
+	vendor_path->Header.Type = HARDWARE_DEVICE_PATH;
699
+	vendor_path->Header.SubType = HW_VENDOR_DP;
700
+	vendor_path->Header.Length[0] = sizeof ( *vendor_path );
701
+	efi_snp_hii_random_guid ( &vendor_path->Guid );
702
+	path_end = ( ( void * ) ( vendor_path + 1 ) );
703
+	path_end->Type = END_DEVICE_PATH_TYPE;
704
+	path_end->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
705
+	path_end->Length[0] = sizeof ( *path_end );
706
+
707
+	/* Create device path and child handle for HII association */
708
+	if ( ( efirc = bs->InstallMultipleProtocolInterfaces (
709
+			&snpdev->hii_child_handle,
710
+			&efi_device_path_protocol_guid, snpdev->hii_child_path,
711
+			NULL ) ) != 0 ) {
712
+		rc = -EEFI ( efirc );
713
+		DBGC ( snpdev, "SNPDEV %p could not create HII child handle: "
714
+		       "%s\n", snpdev, strerror ( rc ) );
715
+		goto err_hii_child_handle;
716
+	}
717
+
677 718
 	/* Add HII packages */
678 719
 	if ( ( efirc = efihii->NewPackageList ( efihii, snpdev->package_list,
679
-						snpdev->handle,
720
+						snpdev->hii_child_handle,
680 721
 						&snpdev->hii_handle ) ) != 0 ) {
681 722
 		rc = -EEFI ( efirc );
682 723
 		DBGC ( snpdev, "SNPDEV %p could not add HII packages: %s\n",
@@ -686,7 +727,7 @@ int efi_snp_hii_install ( struct efi_snp_device *snpdev ) {
686 727
 
687 728
 	/* Install HII protocol */
688 729
 	if ( ( efirc = bs->InstallMultipleProtocolInterfaces (
689
-			 &snpdev->handle,
730
+			 &snpdev->hii_child_handle,
690 731
 			 &efi_hii_config_access_protocol_guid, &snpdev->hii,
691 732
 			 NULL ) ) != 0 ) {
692 733
 		rc = -EEFI ( efirc );
@@ -695,15 +736,34 @@ int efi_snp_hii_install ( struct efi_snp_device *snpdev ) {
695 736
 		goto err_install_protocol;
696 737
 	}
697 738
 
739
+	/* Add as child of handle with SNP instance */
740
+	if ( ( rc = efi_child_add ( snpdev->handle,
741
+				    snpdev->hii_child_handle ) ) != 0 ) {
742
+		DBGC ( snpdev,
743
+		       "SNPDEV %p could not adopt HII child handle: %s\n",
744
+		       snpdev, strerror ( rc ) );
745
+		goto err_efi_child_add;
746
+	}
747
+
698 748
 	return 0;
699 749
 
750
+	efi_child_del ( snpdev->handle, snpdev->hii_child_handle );
751
+ err_efi_child_add:
700 752
 	bs->UninstallMultipleProtocolInterfaces (
701
-			snpdev->handle,
753
+			snpdev->hii_child_handle,
702 754
 			&efi_hii_config_access_protocol_guid, &snpdev->hii,
703 755
 			NULL );
704 756
  err_install_protocol:
705 757
 	efihii->RemovePackageList ( efihii, snpdev->hii_handle );
706 758
  err_new_package_list:
759
+	bs->UninstallMultipleProtocolInterfaces (
760
+			snpdev->hii_child_handle,
761
+			&efi_device_path_protocol_guid, snpdev->hii_child_path,
762
+			NULL );
763
+ err_hii_child_handle:
764
+	free ( snpdev->hii_child_path );
765
+	snpdev->hii_child_path = NULL;
766
+ err_alloc_child_path:
707 767
 	free ( snpdev->package_list );
708 768
 	snpdev->package_list = NULL;
709 769
  err_build_package_list:
@@ -724,11 +784,18 @@ void efi_snp_hii_uninstall ( struct efi_snp_device *snpdev ) {
724 784
 		return;
725 785
 
726 786
 	/* Uninstall protocols and remove package list */
787
+	efi_child_del ( snpdev->handle, snpdev->hii_child_handle );
727 788
 	bs->UninstallMultipleProtocolInterfaces (
728
-			snpdev->handle,
789
+			snpdev->hii_child_handle,
729 790
 			&efi_hii_config_access_protocol_guid, &snpdev->hii,
730 791
 			NULL );
731 792
 	efihii->RemovePackageList ( efihii, snpdev->hii_handle );
793
+	bs->UninstallMultipleProtocolInterfaces (
794
+			snpdev->hii_child_handle,
795
+			&efi_device_path_protocol_guid, snpdev->hii_child_path,
796
+			NULL );
797
+	free ( snpdev->hii_child_path );
798
+	snpdev->hii_child_path = NULL;
732 799
 	free ( snpdev->package_list );
733 800
 	snpdev->package_list = NULL;
734 801
 }

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