[PATCH v3 38/40] efi: Avoid using sandbox virtio devices

[Simon Glass]

While sandbox supports virtio it cannot support actually using the block
devices to read files, since there is nothing on the other end of the
'virtqueue'.

A recent change makes EFI probe all block devices, whether used or not.
This is apparently required by EFI, although it violates U-Boot's
lazy-init principle.

We cannot just drop the virtio devices as they are used in sandbox tests.

So for now just add a special case to work around this.

The eventual fix is likely adding an implementation of
virtio_sandbox_notify() to actually do the block read. That is tracked
in [1].

Signed-off-by: Simon Glass <sjg at chromium.org>
Fixes: d5391bf02b9 ("efi_loader: ensure all block devices are probed")
[1] https://source.denx.de/u-boot/u-boot/-/issues/37
---

Changes in v3:
- Add a Fixes tag
- Mention the issue created for this problem

 lib/efi_loader/efi_disk.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
index 93a9a5ac025..2e1d37848fc 100644
--- a/lib/efi_loader/efi_disk.c
+++ b/lib/efi_loader/efi_disk.c
@@ -838,8 +838,20 @@ efi_status_t efi_disk_get_device_name(const efi_handle_t handle, char *buf, int
 efi_status_t efi_disks_register(void)
 {
 	struct udevice *dev;
+	struct uclass *uc;
 
-	uclass_foreach_dev_probe(UCLASS_BLK, dev) {
+	uclass_id_foreach_dev(UCLASS_BLK, dev, uc) {
+		/*
+		 * The virtio block-device hangs on sandbox when accessed since
+		 * there is nothing listening to the mailbox
+		 */
+		if (IS_ENABLED(CONFIG_SANDBOX)) {
+			struct blk_desc *desc = dev_get_uclass_plat(dev);
+
+			if (desc->uclass_id == UCLASS_VIRTIO)
+				continue;
+		}
+		device_probe(dev);
 	}
 
 	return EFI_SUCCESS;
-- 
2.34.1