On 2025-05-05 16:44, Stefano Stabellini wrote:
On Sat, 3 May 2025, Jason Andryuk wrote:
Make xenbus_init() allow a non-local xenstore for a PVH dom0 - it is
currently forced to XS_LOCAL. With Hyperlaunch booting dom0 and a
xenstore stubdom, dom0 can be handled as a regular XS_HVM following the
late init path.
Drop the use of xen_initial_domain() and just check for the event
channel instead. This matches the PV case where there is no check for
initial domain.
Check the full 64bit HVM_PARAM_STORE_EVTCHN value to catch the off
chance that high bits are set for the 32bit event channel.
Signed-off-by: Jason Andryuk <jason.andr...@amd.com>
Reviewed-by: Stefano Stabellini <sstabell...@kernel.org>
Thanks, Stefano. But I'm wondering if this might break ARM enhanced
no-xenstore.
---
drivers/xen/xenbus/xenbus_probe.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/xen/xenbus/xenbus_probe.c
b/drivers/xen/xenbus/xenbus_probe.c
index 6d32ffb01136..7604f70ee108 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -966,9 +966,15 @@ static int __init xenbus_init(void)
if (xen_pv_domain())
xen_store_domain_type = XS_PV;
if (xen_hvm_domain())
+ {
xen_store_domain_type = XS_HVM;
ARM would have everything set to XS_HVM...
- if (xen_hvm_domain() && xen_initial_domain())
- xen_store_domain_type = XS_LOCAL;
...and only dom0 set to XS_LOCAL.
+ err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
+ if (err)
+ goto out_error;
+ xen_store_evtchn = (int)v;
+ if (!v)
+ xen_store_domain_type = XS_LOCAL;
+ }
if (xen_pv_domain() && !xen_start_info->store_evtchn)
xen_store_domain_type = XS_LOCAL;
if (xen_pv_domain() && xen_start_info->store_evtchn)
@@ -987,10 +993,6 @@ static int __init xenbus_init(void)
xen_store_interface = gfn_to_virt(xen_store_gfn);
break;
case XS_HVM:
- err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
- if (err)
- goto out_error;
- xen_store_evtchn = (int)v;
err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
if (err)
goto out_error;
/*
* Uninitialized hvm_params are zero and return no error.
* Although it is theoretically possible to have
* HVM_PARAM_STORE_PFN set to zero on purpose, in
reality it is
* not zero when valid. If zero, it means that Xenstore
hasn't
* been properly initialized. Instead of attempting to
map a
* wrong guest physical address return error.
*
* Also recognize all bits set as an
invalid/uninitialized value.
*/
if (!v) {
err = -ENOENT;
goto out_error;
}
IIUC, this !v check is for enhanced no-xenstore to end up in XS_UNKNOWN.
I'll have to re-work to handle that case.
Regards,
Jason
--
2.34.1
