With the new allocation strategy of Dom0less DomUs XenStore page,
update the doc of the late XenStore init protocol accordingly.
Signed-off-by: Henry Wang <xin.wa...@amd.com>
---
v3:
- Wording change.
v2:
- New patch.
---
docs/features/dom0less.pandoc | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/docs/features/dom0less.pandoc b/docs/features/dom0less.pandoc
index 725afa0558..8b178edee0 100644
--- a/docs/features/dom0less.pandoc
+++ b/docs/features/dom0less.pandoc
@@ -110,9 +110,10 @@ hotplug PV drivers to dom0less guests. E.g. xl
network-attach domU.
The implementation works as follows:
- Xen allocates the xenstore event channel for each dom0less domU that
has the "xen,enhanced" property, and sets HVM_PARAM_STORE_EVTCHN
-- Xen does *not* allocate the xenstore page and sets HVM_PARAM_STORE_PFN
- to ~0ULL (invalid)
-- Dom0less domU kernels check that HVM_PARAM_STORE_PFN is set to invalid
+- Xen allocates the xenstore page and sets HVM_PARAM_STORE_PFN as well
+ as the connection status to XENSTORE_RECONNECT.
+- Dom0less domU kernels check that HVM_PARAM_STORE_PFN is set to
+ ~0ULL (invalid) or the connection status is *not* XENSTORE_CONNECTED.
- Old kernels will continue without xenstore support (Note: some old
buggy kernels might crash because they don't check the validity of
HVM_PARAM_STORE_PFN before using it! Disable "xen,enhanced" in
@@ -121,13 +122,14 @@ The implementation works as follows:
channel (HVM_PARAM_STORE_EVTCHN) before continuing with the
initialization
- Once dom0 is booted, init-dom0less is executed:
- - it allocates the xenstore shared page and sets HVM_PARAM_STORE_PFN
+ - it gets the xenstore shared page from HVM_PARAM_STORE_PFN
- it calls xs_introduce_domain
- Xenstored notices the new domain, initializes interfaces as usual, and
sends an event channel notification to the domain using the xenstore
event channel (HVM_PARAM_STORE_EVTCHN)
- The Linux domU kernel receives the event channel notification, checks
- HVM_PARAM_STORE_PFN again and continue with the initialization
+ HVM_PARAM_STORE_PFN and the connection status again and continue with
+ the initialization
Limitations
--
2.34.1
