On Thu, Nov 12, 2020 at 04:24:38PM +0100, Vitaly Kuznetsov wrote:

Wei Liu [off-list ref] writes:

quoted

There is no VMBus and the other infrastructures initialized in
hv_acpi_init when Linux is running as the root partition.

Signed-off-by: Wei Liu <wei.liu@kernel.org>
---
 drivers/hv/vmbus_drv.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 4fad3e6745e5..37c4d3a28309 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c

@@ -2612,6 +2612,9 @@ static int __init hv_acpi_init(void)
 	if (!hv_is_hyperv_initialized())
 		return -ENODEV;
 
+	if (hv_root_partition)
+		return -ENODEV;
+

Nit: any particular reason why we need to return an error from here? I'd
suggest we 'return 0;' if it doesn't break anything (we're still running
on Hyper-V, it's just a coincedence that there's nothing to do here,
eventually we may get some devices/handlers I guess. Also, there's going
to be server-side Vmbus eventually, we may as well initialize it here.

Returning 0 should be fine. It is not likely to make any practical
difference at this stage.

Not sure what you mean by server-side Vmbus. If you mean Vmbus on the
host, yes, there will be. The initialization is, again, a bit different
there.  You will see why when my colleague post /dev/mshv code. The long
term goal is to refactor the Vmbus initialization code to work in all
scenarios.  We are not there yet though.

Wei.

quoted

 	init_completion(&probe_event);
 
 	/*

-- 
Vitaly