5.4-stable review patch. If anyone has any objections, please let me know.
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From: Jason Andryuk jason.andryuk@amd.com
[ Upstream commit 90989869baae47ee2aa3bcb6f6eb9fbbe4287958 ]
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.
Ideally we'd drop the use of xen_initial_domain() and just check for the event channel instead. However, ARM has a xen,enhanced no-xenstore mode, where the event channel and PFN would both be 0. Retain the xen_initial_domain() check, and use that for an additional check when the event channel is 0.
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.andryuk@amd.com Change-Id: I5506da42e4c6b8e85079fefb2f193c8de17c7437 Reviewed-by: Stefano Stabellini sstabellini@kernel.org Signed-off-by: Juergen Gross jgross@suse.com Message-ID: 20250506204456.5220-1-jason.andryuk@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 fd686b962727a..17705f82f85fd 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -881,9 +881,15 @@ 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; - if (xen_hvm_domain() && xen_initial_domain()) - xen_store_domain_type = XS_LOCAL; + err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v); + if (err) + goto out_error; + xen_store_evtchn = (int)v; + if (!v && xen_initial_domain()) + 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) @@ -902,10 +908,6 @@ 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;