... both for when the functions are invoked and where they live in source.
Don't invoke them directly in vpci_init_header(), but instead first thing
in vpci_init_capabilities().

Suggested-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
v4: New.

--- a/xen/drivers/vpci/cap.c
+++ b/xen/drivers/vpci/cap.c
@@ -159,15 +159,150 @@ static int vpci_ext_capability_hide(
     return 0;
 }
 
+static int vpci_init_capability_list(struct pci_dev *pdev)
+{
+    int rc;
+    bool mask_cap_list = false;
+    bool is_hwdom = is_hardware_domain(pdev->domain);
+
+    if ( pci_conf_read16(pdev->sbdf, PCI_STATUS) & PCI_STATUS_CAP_LIST )
+    {
+        /* Only expose capabilities to the guest that vPCI can handle. */
+        unsigned int next, ttl = 48;
+        static const unsigned int supported_caps[] = {
+            PCI_CAP_ID_MSI,
+            PCI_CAP_ID_MSIX,
+        };
+        /*
+         * For dom0, we should expose all capabilities instead of a fixed
+         * capabilities array, so setting n to 0 here is to get the next
+         * capability position directly in pci_find_next_cap_ttl.
+         */
+        const unsigned int n = is_hwdom ? 0 : ARRAY_SIZE(supported_caps);
+
+        next = pci_find_next_cap_ttl(pdev->sbdf, PCI_CAPABILITY_LIST,
+                                     supported_caps, n, &ttl);
+
+        rc = vpci_add_register(pdev->vpci, vpci_read_val,
+                               is_hwdom ? vpci_hw_write8 : NULL,
+                               PCI_CAPABILITY_LIST, 1,
+                               (void *)(uintptr_t)next);
+        if ( rc )
+            return rc;
+
+        next &= ~3;
+
+        if ( !next && !is_hwdom )
+            /*
+             * If we don't have any supported capabilities to expose to the
+             * guest, mask the PCI_STATUS_CAP_LIST bit in the status
+             * register.
+             */
+            mask_cap_list = true;
+
+        while ( next && ttl )
+        {
+            unsigned int pos = next;
+
+            next = pci_find_next_cap_ttl(pdev->sbdf,
+                                         pos + PCI_CAP_LIST_NEXT,
+                                         supported_caps, n, &ttl);
+
+            if ( !is_hwdom )
+            {
+                rc = vpci_add_register(pdev->vpci, vpci_hw_read8, NULL,
+                                       pos + PCI_CAP_LIST_ID, 1, NULL);
+                if ( rc )
+                    return rc;
+            }
+
+            rc = vpci_add_register(pdev->vpci, vpci_read_val,
+                                   is_hwdom ? vpci_hw_write8 : NULL,
+                                   pos + PCI_CAP_LIST_NEXT, 1,
+                                   (void *)(uintptr_t)next);
+            if ( rc )
+                return rc;
+
+            next &= ~3;
+        }
+    }
+
+    /* Return early for the hw domain, no masking of PCI_STATUS. */
+    if ( is_hwdom )
+        return 0;
+
+    /* Utilize rsvdp_mask to hide PCI_STATUS_CAP_LIST from the guest. */
+    return vpci_add_register_mask(pdev->vpci, vpci_hw_read16, vpci_hw_write16,
+                                  PCI_STATUS, 2, NULL,
+                                  PCI_STATUS_RO_MASK &
+                                    ~(mask_cap_list ? PCI_STATUS_CAP_LIST : 0),
+                                  PCI_STATUS_RW1C_MASK,
+                                  mask_cap_list ? PCI_STATUS_CAP_LIST : 0,
+                                  PCI_STATUS_RSVDZ_MASK);
+}
+
+static int vpci_init_ext_capability_list(const struct pci_dev *pdev)
+{
+    unsigned int pos = PCI_CFG_SPACE_SIZE;
+
+    if ( !pdev->ext_cfg )
+        return 0;
+
+    if ( !is_hardware_domain(pdev->domain) )
+        /* Extended capabilities read as zero, write ignore for DomU */
+        return vpci_add_register(pdev->vpci, vpci_read_val, NULL,
+                                 pos, 4, (void *)0);
+
+    do
+    {
+        uint32_t header = pci_conf_read32(pdev->sbdf, pos);
+        int rc;
+
+        if ( header == 0xffffffffU )
+        {
+            printk(XENLOG_WARNING
+                   "%pd %pp: broken extended cap list, offset %#x\n",
+                   pdev->domain, &pdev->sbdf, pos);
+            return 0;
+        }
+
+        rc = vpci_add_register(pdev->vpci, vpci_read_val, NULL,
+                               pos, 4, (void *)(uintptr_t)header);
+        if ( rc == -EEXIST )
+        {
+            printk(XENLOG_WARNING
+                   "%pd %pp: overlap in extended cap list, offset %#x\n",
+                   pdev->domain, &pdev->sbdf, pos);
+            return 0;
+        }
+
+        if ( rc )
+            return rc;
+
+        pos = PCI_EXT_CAP_NEXT(header);
+    } while ( pos >= PCI_CFG_SPACE_SIZE );
+
+    return 0;
+}
+
 int vpci_init_capabilities(struct pci_dev *pdev)
 {
+    int rc;
+
+    rc = vpci_init_capability_list(pdev);
+    if ( rc )
+        return rc;
+
+    rc = vpci_init_ext_capability_list(pdev);
+    if ( rc )
+        return rc;
+
     for ( unsigned int i = 0; i < NUM_VPCI_INIT; i++ )
     {
         const vpci_capability_t *capability = &__start_vpci_array[i];
         const unsigned int cap = capability->id;
         const bool is_ext = capability->is_ext;
         unsigned int pos = 0;
-        int rc;
 
         if ( !is_ext )
             pos = pci_find_cap_offset(pdev->sbdf, cap);
--- a/xen/drivers/vpci/header.c
+++ b/xen/drivers/vpci/header.c
@@ -744,132 +744,6 @@ static int bar_add_rangeset(const struct
     return !bar->mem ? -ENOMEM : 0;
 }
 
-static int vpci_init_capability_list(struct pci_dev *pdev)
-{
-    int rc;
-    bool mask_cap_list = false;
-    bool is_hwdom = is_hardware_domain(pdev->domain);
-
-    if ( pci_conf_read16(pdev->sbdf, PCI_STATUS) & PCI_STATUS_CAP_LIST )
-    {
-        /* Only expose capabilities to the guest that vPCI can handle. */
-        unsigned int next, ttl = 48;
-        static const unsigned int supported_caps[] = {
-            PCI_CAP_ID_MSI,
-            PCI_CAP_ID_MSIX,
-        };
-        /*
-         * For dom0, we should expose all capabilities instead of a fixed
-         * capabilities array, so setting n to 0 here is to get the next
-         * capability position directly in pci_find_next_cap_ttl.
-         */
-        const unsigned int n = is_hwdom ? 0 : ARRAY_SIZE(supported_caps);
-
-        next = pci_find_next_cap_ttl(pdev->sbdf, PCI_CAPABILITY_LIST,
-                                     supported_caps, n, &ttl);
-
-        rc = vpci_add_register(pdev->vpci, vpci_read_val,
-                               is_hwdom ? vpci_hw_write8 : NULL,
-                               PCI_CAPABILITY_LIST, 1,
-                               (void *)(uintptr_t)next);
-        if ( rc )
-            return rc;
-
-        next &= ~3;
-
-        if ( !next && !is_hwdom )
-            /*
-             * If we don't have any supported capabilities to expose to the
-             * guest, mask the PCI_STATUS_CAP_LIST bit in the status
-             * register.
-             */
-            mask_cap_list = true;
-
-        while ( next && ttl )
-        {
-            unsigned int pos = next;
-
-            next = pci_find_next_cap_ttl(pdev->sbdf,
-                                         pos + PCI_CAP_LIST_NEXT,
-                                         supported_caps, n, &ttl);
-
-            if ( !is_hwdom )
-            {
-                rc = vpci_add_register(pdev->vpci, vpci_hw_read8, NULL,
-                                       pos + PCI_CAP_LIST_ID, 1, NULL);
-                if ( rc )
-                    return rc;
-            }
-
-            rc = vpci_add_register(pdev->vpci, vpci_read_val,
-                                   is_hwdom ? vpci_hw_write8 : NULL,
-                                   pos + PCI_CAP_LIST_NEXT, 1,
-                                   (void *)(uintptr_t)next);
-            if ( rc )
-                return rc;
-
-            next &= ~3;
-        }
-    }
-
-    /* Return early for the hw domain, no masking of PCI_STATUS. */
-    if ( is_hwdom )
-        return 0;
-
-    /* Utilize rsvdp_mask to hide PCI_STATUS_CAP_LIST from the guest. */
-    return vpci_add_register_mask(pdev->vpci, vpci_hw_read16, vpci_hw_write16,
-                                  PCI_STATUS, 2, NULL,
-                                  PCI_STATUS_RO_MASK &
-                                    ~(mask_cap_list ? PCI_STATUS_CAP_LIST : 0),
-                                  PCI_STATUS_RW1C_MASK,
-                                  mask_cap_list ? PCI_STATUS_CAP_LIST : 0,
-                                  PCI_STATUS_RSVDZ_MASK);
-}
-
-static int vpci_init_ext_capability_list(const struct pci_dev *pdev)
-{
-    unsigned int pos = PCI_CFG_SPACE_SIZE;
-
-    if ( !pdev->ext_cfg )
-        return 0;
-
-    if ( !is_hardware_domain(pdev->domain) )
-        /* Extended capabilities read as zero, write ignore for DomU */
-        return vpci_add_register(pdev->vpci, vpci_read_val, NULL,
-                                 pos, 4, (void *)0);
-
-    do
-    {
-        uint32_t header = pci_conf_read32(pdev->sbdf, pos);
-        int rc;
-
-        if ( header == 0xffffffffU )
-        {
-            printk(XENLOG_WARNING
-                   "%pd %pp: broken extended cap list, offset %#x\n",
-                   pdev->domain, &pdev->sbdf, pos);
-            return 0;
-        }
-
-        rc = vpci_add_register(pdev->vpci, vpci_read_val, NULL,
-                               pos, 4, (void *)(uintptr_t)header);
-        if ( rc == -EEXIST )
-        {
-            printk(XENLOG_WARNING
-                   "%pd %pp: overlap in extended cap list, offset %#x\n",
-                   pdev->domain, &pdev->sbdf, pos);
-            return 0;
-        }
-
-        if ( rc )
-            return rc;
-
-        pos = PCI_EXT_CAP_NEXT(header);
-    } while ( pos >= PCI_CFG_SPACE_SIZE );
-
-    return 0;
-}
-
 int vpci_init_header(struct pci_dev *pdev)
 {
     uint16_t cmd;
@@ -918,14 +792,6 @@ int vpci_init_header(struct pci_dev *pde
     if ( rc )
         return rc;
 
-    rc = vpci_init_capability_list(pdev);
-    if ( rc )
-        return rc;
-
-    rc = vpci_init_ext_capability_list(pdev);
-    if ( rc )
-        return rc;
-
     if ( pdev->ignore_bars )
         return 0;