Docs on xenopsd: Apply minor fixups to VM.build

.github/workflows/other.yml

@@ -89,8 +89,8 @@ jobs:
       - name: Finish the parallel coverage upload to Coveralls
         uses: coverallsapp/github-action@v2
         with:
+          fail-on-error: false
           parallel-finished: true
-        continue-on-error: true  # Do not fail CI if this step fails
 
   deprecation-test:
     name: Deprecation tests

doc/content/xenopsd/walkthroughs/VM.build/Domain.build.md

@@ -53,21 +53,22 @@ to call:
   - Run `xenguest`
 - `xenguest` to invoke the [xenguest](xenguest) program to setup the domain's system memory.
 
-## Domain Build Preparation using build_pre
+## build_pre: Prepare building the VM
 
-[`Domain.build`](https://github.com/xapi-project/xen-api/blob/master/ocaml/xenopsd/xc/domain.ml#L1111-L1210)
+[Domain.build](https://github.com/xapi-project/xen-api/blob/master/ocaml/xenopsd/xc/domain.ml#L1111-L1210)
 [calls](https://github.com/xapi-project/xen-api/blob/master/ocaml/xenopsd/xc/domain.ml#L1137)
-the [function `build_pre`](https://github.com/xapi-project/xen-api/blob/master/ocaml/xenopsd/xc/domain.ml#L899-L964)
-(which is also used for VM restore). It must:
+[build_pre](https://github.com/xapi-project/xen-api/blob/master/ocaml/xenopsd/xc/domain.ml#L899-L964)
+(which is also used for VM restore) to:
 
 1.  [Call](https://github.com/xapi-project/xen-api/blob/master/ocaml/xenopsd/xc/domain.ml#L902-L911)
     [wait_xen_free_mem](https://github.com/xapi-project/xen-api/blob/master/ocaml/xenopsd/xc/domain.ml#L236-L272)
-    to wait, if necessary, for the Xen memory scrubber to catch up reclaiming memory (CA-39743)
+    to wait (if necessary), for the Xen memory scrubber to catch up reclaiming memory (CA-39743)
 2.  Call the hypercall to set the timer mode
 3.  Call the hypercall to set the number of vCPUs
-4.  As described in the [NUMA feature description](../../toolstack/features/NUMA),
-    when the `xe` configuration option `numa_placement` is set to `Best_effort`,
-    except when the VM has a hard affinity set, invoke the `numa_placement` function:
+4.  Call the `numa_placement` function
+    as described in the [NUMA feature description](/toolstack/features/NUMA)
+    when the `xe` configuration option `numa_placement` is set to `Best_effort`
+    (except when the VM has a hard CPU affinity).
 
     ```ml
     match !Xenops_server.numa_placement with

doc/content/xenopsd/walkthroughs/VM.build/VM_build.md

@@ -45,12 +45,12 @@ must:
 
 1. Run pygrub (or eliloader) to extract the kernel and initrd, if necessary
 2. [Call](https://github.com/xapi-project/xen-api/blob/master/ocaml/xenopsd/xc/xenops_server_xen.ml#L2222-L2225)
-   [Domain.build](Domain.build)
-   to:
+   [Domain.build](Domain.build) to
    - optionally run NUMA placement and
    - invoke [xenguest](VM.build/xenguest) to set up the domain memory.
 
-   See the walk-though on [VM.build](VM.build) for more details on this phase.
+   See the walk-through of the [Domain.build](Domain.build) function
+   for more details on this phase.
 3. Apply the `cpuid` configuration
 4. Store the current domain configuration on disk -- it's important to know
    the difference between the configuration you started with and the configuration

doc/content/xenopsd/walkthroughs/VM.build/xenguest.md

@@ -3,10 +3,9 @@ title: xenguest
 description:
   "Perform building VMs: Allocate and populate the domain's system memory."
 ---
-
-# Flowchart
-
-xenguest is called as part of starting a new domain in VM_build:
+As part of starting a new domain in VM_build, `xenopsd` calls `xenguest`.
+When multiple domain build threads run in parallel,
+also multiple instances of `xenguest` also run in parallel:
 
 ```mermaid
 flowchart
@@ -27,7 +26,8 @@ libxenguest2 --> Xen
 end
 ```
 
-# About xenguest
+## About xenguest
+
 `xenguest` is called by the xenopsd [Domain.build](Domain.build) function
 to perform the build phase for new VMs, which is part of the `xenopsd`
 [VM.start operation](VM.start).
@@ -45,7 +45,7 @@ an individual package once planned changes to the Xen hypercalls are stabilised.
 
 Over time, `xenguest` has evolved to build more of the initial domain state.
 
-# Interface to xenguest
+## Interface to xenguest
 
 ```mermaid
 flowchart
@@ -70,7 +70,8 @@ Xenstore[Xenstore platform data] --> xenguest
 - The amount of system memory of the domain,
 - A number of other parameters that are domain-specific.
 
-Using the Xenstore, the platform data (vCPUs, vCPU affinity, etc) is passed:
+`xenopsd` uses the Xenstore to provide platform data:
+
 - the vCPU affinity
 - the vCPU credit2 weight/cap parameters
 - whether the NX bit is exposed