[RFC 11/38] x86/boot: generalize paging pages calculation

["Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>]

Modeling after libxl__get_required_paging_memory(), refactor
dom0_paging_pages() to calculate the number of paging pages required for a
domain that is not the control or hardware domain. As the function is being
refactored, rename to dom_paging_pages() and move under the domain builder.

Signed-off-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
---
 xen/arch/x86/dom0_build.c                 | 17 +----------------
 xen/arch/x86/domain-builder/domain.c      | 20 ++++++++++++++++++++
 xen/arch/x86/hvm/dom0_build.c             |  3 ++-
 xen/arch/x86/include/asm/dom0_build.h     |  3 ---
 xen/arch/x86/include/asm/domain-builder.h |  3 +++
 xen/arch/x86/pv/dom0_build.c              |  3 ++-
 6 files changed, 28 insertions(+), 21 deletions(-)

diff --git a/xen/arch/x86/dom0_build.c b/xen/arch/x86/dom0_build.c
index a007e424bbe3..1413e8c634a7 100644
--- a/xen/arch/x86/dom0_build.c
+++ b/xen/arch/x86/dom0_build.c
@@ -305,21 +305,6 @@ boolean_param("ro-hpet", ro_hpet);
 
 unsigned int __initdata dom0_memflags = MEMF_no_dma|MEMF_exact_node;
 
-unsigned long __init dom0_paging_pages(const struct domain *d,
-                                       unsigned long nr_pages)
-{
-    /* Keep in sync with libxl__get_required_paging_memory(). */
-    unsigned long memkb = nr_pages * (PAGE_SIZE / 1024);
-
-    memkb = 4 * (256 * d->max_vcpus +
-                 (is_pv_domain(d) ? opt_dom0_shadow || opt_pv_l1tf_hwdom
-                                  : 1 + opt_dom0_shadow) *
-                 (memkb / 1024));
-
-    return DIV_ROUND_UP(memkb, 1024) << (20 - PAGE_SHIFT);
-}
-
-
 /*
  * If allocation isn't specified, reserve 1/16th of available memory for
  * things like DMA buffers. This reservation is clamped to a maximum of 128MB.
@@ -431,7 +416,7 @@ unsigned long __init dom0_compute_nr_pages(
          */
         calculate_dom0_pages(bd, avail);
 
-        cpu_pages = dom0_paging_pages(d, bd->mem_pages);
+        cpu_pages = dom_paging_pages(bd, bd->mem_pages);
 
         if ( !iommu_use_hap_pt(d) )
             avail -= cpu_pages;
diff --git a/xen/arch/x86/domain-builder/domain.c 
b/xen/arch/x86/domain-builder/domain.c
index 619d36ea0b87..87f538ae26c5 100644
--- a/xen/arch/x86/domain-builder/domain.c
+++ b/xen/arch/x86/domain-builder/domain.c
@@ -10,6 +10,26 @@
 
 #include <asm/bootinfo.h>
 #include <asm/dom0_build.h>
+#include <asm/paging.h>
+#include <asm/spec_ctrl.h>
+
+unsigned long __init dom_paging_pages(
+    const struct boot_domain *bd, unsigned long nr_pages)
+{
+    /* Keep in sync with libxl__get_required_paging_memory(). */
+    unsigned long memkb = bd->mem_pages * (PAGE_SIZE / 1024);
+    unsigned long factor = 0;
+
+    if ( bd->capabilities & (BUILD_CAPS_CONTROL | BUILD_CAPS_HARDWARE) )
+        factor = is_pv_domain(bd->d) ? opt_dom0_shadow || opt_pv_l1tf_hwdom
+                                     : 1 + opt_dom0_shadow;
+    else
+        factor = !is_pv_domain(bd->d) + !paging_mode_hap(bd->d);
+
+    memkb = 4 * (256 * bd->d->max_vcpus + (factor * (memkb / 1024)));
+
+    return DIV_ROUND_UP(memkb, 1024) << (20 - PAGE_SHIFT);
+}
 
 unsigned int __init dom_max_vcpus(struct boot_domain *bd)
 {
diff --git a/xen/arch/x86/hvm/dom0_build.c b/xen/arch/x86/hvm/dom0_build.c
index a818a9a772ed..d3ad90348a1f 100644
--- a/xen/arch/x86/hvm/dom0_build.c
+++ b/xen/arch/x86/hvm/dom0_build.c
@@ -19,6 +19,7 @@
 #include <asm/bootinfo.h>
 #include <asm/bzimage.h>
 #include <asm/dom0_build.h>
+#include <asm/domain-builder.h>
 #include <asm/hvm/support.h>
 #include <asm/io_apic.h>
 #include <asm/p2m.h>
@@ -406,7 +407,7 @@ static void __init pvh_init_p2m(struct boot_domain *bd)
     pvh_setup_e820(bd->d, nr_pages);
     do {
         preempted = false;
-        paging_set_allocation(bd->d, dom0_paging_pages(bd->d, nr_pages),
+        paging_set_allocation(bd->d, dom_paging_pages(bd, nr_pages),
                               &preempted);
         process_pending_softirqs();
     } while ( preempted );
diff --git a/xen/arch/x86/include/asm/dom0_build.h 
b/xen/arch/x86/include/asm/dom0_build.h
index dcf71c032a17..81717b49b4ae 100644
--- a/xen/arch/x86/include/asm/dom0_build.h
+++ b/xen/arch/x86/include/asm/dom0_build.h
@@ -19,9 +19,6 @@ unsigned long dom0_compute_nr_pages(
 int dom0_construct_pv(struct boot_domain *bd);
 int dom0_construct_pvh(struct boot_domain *bd);
 
-unsigned long dom0_paging_pages(const struct domain *d,
-                                unsigned long nr_pages);
-
 void dom0_update_physmap(bool compat, unsigned long pfn,
                          unsigned long mfn, unsigned long vphysmap_s);
 
diff --git a/xen/arch/x86/include/asm/domain-builder.h 
b/xen/arch/x86/include/asm/domain-builder.h
index ccfa4bd82acd..8b0b224eba41 100644
--- a/xen/arch/x86/include/asm/domain-builder.h
+++ b/xen/arch/x86/include/asm/domain-builder.h
@@ -8,6 +8,9 @@ int __init builder_get_cmdline(
     struct boot_info *bi, int offset, char *cmdline, size_t size);
 
 void builder_init(struct boot_info *bi);
+
+unsigned long dom_paging_pages(
+    const struct boot_domain *d, unsigned long nr_pages);
 unsigned int dom_max_vcpus(struct boot_domain *bd);
 struct vcpu *alloc_dom_vcpu0(struct boot_domain *bd);
 
diff --git a/xen/arch/x86/pv/dom0_build.c b/xen/arch/x86/pv/dom0_build.c
index 350a60b1e8fd..f8844b858082 100644
--- a/xen/arch/x86/pv/dom0_build.c
+++ b/xen/arch/x86/pv/dom0_build.c
@@ -17,6 +17,7 @@
 #include <asm/bootinfo.h>
 #include <asm/bzimage.h>
 #include <asm/dom0_build.h>
+#include <asm/domain-builder.h>
 #include <asm/guest.h>
 #include <asm/page.h>
 #include <asm/pv/mm.h>
@@ -1043,7 +1044,7 @@ static int __init dom0_construct(struct boot_domain *bd)
     {
         bool preempted;
 
-        nr_pt_pages = dom0_paging_pages(d, nr_pages);
+        nr_pt_pages = dom_paging_pages(bd, nr_pages);
 
         do {
             preempted = false;
-- 
2.30.2