[RFCv2 11/38] x86/boot: generalize compute number of domain pages

[Daniel P. Smith]

The amount of pages for a domain to be allocated is based on the physical nodes
a domain may be scheduled. For dom0, this can be restricted down from available
nodes via the dom0_nodes command line parameter.

Refactor dom0_compute_nr_pages() such that only apply the dom0_nodes
restriction only if the domain has the control domain or hardware domain
capability flag set. In doing so, also rename the function to
dom_compute_nr_pages().

Signed-off-by: Daniel P. Smith <dpsm...@apertussolutions.com>
---
 xen/arch/x86/dom0_build.c             | 16 +++++++++++++---
 xen/arch/x86/hvm/dom0_build.c         |  2 +-
 xen/arch/x86/include/asm/dom0_build.h |  2 +-
 xen/arch/x86/pv/dom0_build.c          |  2 +-
 4 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/xen/arch/x86/dom0_build.c b/xen/arch/x86/dom0_build.c
index 0bcdfcb97e6c..2a22cd4e125e 100644
--- a/xen/arch/x86/dom0_build.c
+++ b/xen/arch/x86/dom0_build.c
@@ -377,14 +377,23 @@ static void __init dom0_pv_restrict_pages(
     }
 }
 
-unsigned long __init dom0_compute_nr_pages(
+unsigned long __init dom_compute_nr_pages(
     struct boot_domain *bd, struct elf_dom_parms *parms)
 {
     nodeid_t node;
+    nodemask_t nodes = { 0 };
     struct domain *d = bd->d;
     unsigned long avail = 0, iommu_pages = 0;
 
-    for_each_node_mask ( node, dom0_nodes )
+    nodes_or(nodes, nodes, node_online_map);
+
+    /* If building dom0 or hwdom, apply command line restriction. */
+    if ( has_dom0_caps(bd) )
+        nodes_and(nodes, nodes, dom0_nodes);
+
+    ASSERT(nodes_weight(nodes) != 0);
+
+    for_each_node_mask ( node, nodes )
         avail += avail_domheap_pages_region(node, 0, 0) +
                  initial_images_nrpages(node);
 
@@ -396,7 +405,8 @@ unsigned long __init dom0_compute_nr_pages(
         avail -= d->max_vcpus - 1;
 
     /* Reserve memory for iommu_dom0_init() (rough estimate). */
-    if ( is_iommu_enabled(d) && !iommu_hwdom_passthrough )
+    if ( is_hardware_domain(d) && is_iommu_enabled(d)
+         && !iommu_hwdom_passthrough )
     {
         unsigned int s;
 
diff --git a/xen/arch/x86/hvm/dom0_build.c b/xen/arch/x86/hvm/dom0_build.c
index 3f0d157f82c8..1e63e19589a1 100644
--- a/xen/arch/x86/hvm/dom0_build.c
+++ b/xen/arch/x86/hvm/dom0_build.c
@@ -401,7 +401,7 @@ static __init void pvh_setup_e820(struct domain *d, 
unsigned long nr_pages)
 
 static void __init pvh_init_p2m(struct boot_domain *bd)
 {
-    unsigned long nr_pages = dom0_compute_nr_pages(bd, NULL);
+    unsigned long nr_pages = dom_compute_nr_pages(bd, NULL);
     bool preempted;
 
     pvh_setup_e820(bd->d, nr_pages);
diff --git a/xen/arch/x86/include/asm/dom0_build.h 
b/xen/arch/x86/include/asm/dom0_build.h
index 81717b49b4ae..7275bcf9ba6b 100644
--- a/xen/arch/x86/include/asm/dom0_build.h
+++ b/xen/arch/x86/include/asm/dom0_build.h
@@ -13,7 +13,7 @@ void dom0_set_affinity(struct domain *dom0);
 int dom0_setup_permissions(struct domain *d);
 
 struct boot_domain;
-unsigned long dom0_compute_nr_pages(
+unsigned long dom_compute_nr_pages(
     struct boot_domain *bd, struct elf_dom_parms *parms);
 
 int dom0_construct_pv(struct boot_domain *bd);
diff --git a/xen/arch/x86/pv/dom0_build.c b/xen/arch/x86/pv/dom0_build.c
index f8844b858082..ad4d1cc3520c 100644
--- a/xen/arch/x86/pv/dom0_build.c
+++ b/xen/arch/x86/pv/dom0_build.c
@@ -504,7 +504,7 @@ static int __init dom0_construct(struct boot_domain *bd)
         }
     }
 
-    nr_pages = dom0_compute_nr_pages(bd, &parms);
+    nr_pages = dom_compute_nr_pages(bd, &parms);
 
 #ifdef CONFIG_PV32
     if ( elf_32bit(&elf) )
-- 
2.30.2