Re: [PATCH v2 1/4] xen/arm: Move dom0 creation in domain_build.c

[Julien Grall]

Hi Luca,

On 08/04/2021 10:48, Luca Fancellu wrote:
Move dom0 creation and start from setup.c to domain_build.c
on a dedicate function.
Signed-off-by: Luca Fancellu <luca.fance...@arm.com>
---
  xen/arch/arm/domain_build.c | 36 ++++++++++++++++++++++++++++++++++++
  xen/arch/arm/setup.c        | 29 +----------------------------
  xen/include/asm-arm/setup.h |  1 +
  3 files changed, 38 insertions(+), 28 deletions(-)

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 374bf655ee..d7c9c7f4d1 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -21,6 +21,7 @@
  #include <asm/device.h>
  #include <asm/kernel.h>
  #include <asm/setup.h>
+#include <asm/tee/tee.h>
  #include <asm/platform.h>
  #include <asm/psci.h>
  #include <asm/setup.h>
@@ -2520,6 +2521,41 @@ void __init create_domUs(void)
      }
  }
  
+struct domain* __init create_dom0(void)
+{
+    struct domain *dom0;
+    struct xen_domctl_createdomain dom0_cfg = {
+        .flags = XEN_DOMCTL_CDF_hvm | XEN_DOMCTL_CDF_hap,
+        .max_evtchn_port = -1,
+        .max_grant_frames = gnttab_dom0_frames(),
+        .max_maptrack_frames = -1,
+    };
+
+    /* The vGIC for DOM0 is exactly emulating the hardware GIC */
+    dom0_cfg.arch.gic_version = XEN_DOMCTL_CONFIG_GIC_NATIVE;
+    /*
+     * Xen vGIC supports a maximum of 992 interrupt lines.
+     * 32 are substracted to cover local IRQs.
+     */
+    dom0_cfg.arch.nr_spis = min(gic_number_lines(), (unsigned int) 992) - 32;
+    if ( gic_number_lines() > 992 )
+        printk(XENLOG_WARNING "Maximum number of vGIC IRQs exceeded.\n");
+    dom0_cfg.arch.tee_type = tee_get_type();
+    dom0_cfg.max_vcpus = dom0_max_vcpus();
+
+    if ( iommu_enabled )
+        dom0_cfg.flags |= XEN_DOMCTL_CDF_iommu;
+
+    dom0 = domain_create(0, &dom0_cfg, true);
+    if ( IS_ERR(dom0) || (alloc_dom0_vcpu0(dom0) == NULL) )
+        panic("Error creating domain 0\n");
+
+    if ( construct_dom0(dom0) != 0)
+        panic("Could not set up DOM0 guest OS\n");
+
+    return dom0;
+}
+

I would move the function after...

  int __init construct_dom0(struct domain *d)

... this function so we can mark construct_dom0() static as 
create_dom0() is the only caller.

  {
      struct kernel_info kinfo = {};
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 2532ec9739..b405f58996 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -51,7 +51,6 @@
  #include <asm/platform.h>
  #include <asm/procinfo.h>
  #include <asm/setup.h>
-#include <asm/tee/tee.h>
  #include <xsm/xsm.h>
  #include <asm/acpi.h>
  
@@ -805,12 +804,6 @@ void __init start_xen(unsigned long boot_phys_offset,
      const char *cmdline;
      struct bootmodule *xen_bootmodule;
      struct domain *dom0;
-    struct xen_domctl_createdomain dom0_cfg = {
-        .flags = XEN_DOMCTL_CDF_hvm | XEN_DOMCTL_CDF_hap,
-        .max_evtchn_port = -1,
-        .max_grant_frames = gnttab_dom0_frames(),
-        .max_maptrack_frames = -1,
-    };
      int rc;
  
      dcache_line_bytes = read_dcache_line_bytes();
@@ -965,27 +958,7 @@ void __init start_xen(unsigned long boot_phys_offset,
      enable_errata_workarounds();
  
      /* Create initial domain 0. */
-    /* The vGIC for DOM0 is exactly emulating the hardware GIC */
-    dom0_cfg.arch.gic_version = XEN_DOMCTL_CONFIG_GIC_NATIVE;
-    /*
-     * Xen vGIC supports a maximum of 992 interrupt lines.
-     * 32 are substracted to cover local IRQs.
-     */
-    dom0_cfg.arch.nr_spis = min(gic_number_lines(), (unsigned int) 992) - 32;
-    if ( gic_number_lines() > 992 )
-        printk(XENLOG_WARNING "Maximum number of vGIC IRQs exceeded.\n");
-    dom0_cfg.arch.tee_type = tee_get_type();
-    dom0_cfg.max_vcpus = dom0_max_vcpus();
-
-    if ( iommu_enabled )
-        dom0_cfg.flags |= XEN_DOMCTL_CDF_iommu;
-
-    dom0 = domain_create(0, &dom0_cfg, true);
-    if ( IS_ERR(dom0) || (alloc_dom0_vcpu0(dom0) == NULL) )
-        panic("Error creating domain 0\n");
-
-    if ( construct_dom0(dom0) != 0)
-        panic("Could not set up DOM0 guest OS\n");
+    dom0 = create_dom0();
  
      heap_init_late();
  
diff --git a/xen/include/asm-arm/setup.h b/xen/include/asm-arm/setup.h
index 28bf622aa1..e5f5c7ebc6 100644
--- a/xen/include/asm-arm/setup.h
+++ b/xen/include/asm-arm/setup.h
@@ -95,6 +95,7 @@ int acpi_make_efi_nodes(void *fdt, struct membank tbl_add[]);
  
  int construct_dom0(struct domain *d);
  void create_domUs(void);
+struct domain* create_dom0(void);
  
  void discard_initial_modules(void);
  void fw_unreserved_regions(paddr_t s, paddr_t e,


Cheers,

--
Julien Grall