[PATCH v3 01/11] vpci/header: Move emulating cap list logic into new function

[Jiqian Chen <Jiqian.Chen@xxxxxxx>]

No functional changes.
Follow-on changes will benifit from this.

Signed-off-by: Jiqian Chen <Jiqian.Chen@xxxxxxx>
---
cc: "Roger Pau Monné" <roger.pau@xxxxxxxxxx>
---
v2->v3 changes:
new patch.

Best regards,
Jiqian Chen.
---
 xen/drivers/vpci/header.c | 138 ++++++++++++++++++++------------------
 1 file changed, 73 insertions(+), 65 deletions(-)

diff --git a/xen/drivers/vpci/header.c b/xen/drivers/vpci/header.c
index ef6c965c081c..3e9b44454b43 100644
--- a/xen/drivers/vpci/header.c
+++ b/xen/drivers/vpci/header.c
@@ -745,6 +745,75 @@ static int bar_add_rangeset(const struct pci_dev *pdev, 
struct vpci_bar *bar,
     return !bar->mem ? -ENOMEM : 0;
 }
 
+static int vpci_init_capability_list(struct pci_dev *pdev)
+{
+    int rc;
+    bool mask_cap_list = false;
+
+    if ( !is_hardware_domain(pdev->domain) &&
+         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,
+        };
+
+        next = pci_find_next_cap_ttl(pdev->sbdf, PCI_CAPABILITY_LIST,
+                                     supported_caps,
+                                     ARRAY_SIZE(supported_caps), &ttl);
+
+        rc = vpci_add_register(pdev->vpci, vpci_read_val, NULL,
+                               PCI_CAPABILITY_LIST, 1,
+                               (void *)(uintptr_t)next);
+        if ( rc )
+            return rc;
+
+        next &= ~3;
+
+        if ( !next )
+            /*
+             * 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,
+                                         ARRAY_SIZE(supported_caps), &ttl);
+
+            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, NULL,
+                                   pos + PCI_CAP_LIST_NEXT, 1,
+                                   (void *)(uintptr_t)next);
+            if ( rc )
+                return rc;
+
+            next &= ~3;
+        }
+    }
+
+    /* 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 cf_check init_header(struct pci_dev *pdev)
 {
     uint16_t cmd;
@@ -753,7 +822,6 @@ static int cf_check init_header(struct pci_dev *pdev)
     struct vpci_header *header = &pdev->vpci->header;
     struct vpci_bar *bars = header->bars;
     int rc;
-    bool mask_cap_list = false;
     bool is_hwdom = is_hardware_domain(pdev->domain);
 
     ASSERT(rw_is_write_locked(&pdev->domain->pci_lock));
@@ -794,61 +862,12 @@ static int cf_check init_header(struct pci_dev *pdev)
     if ( rc )
         return rc;
 
+    rc = vpci_init_capability_list(pdev);
+    if ( rc )
+        return rc;
+
     if ( !is_hwdom )
     {
-        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,
-            };
-
-            next = pci_find_next_cap_ttl(pdev->sbdf, PCI_CAPABILITY_LIST,
-                                         supported_caps,
-                                         ARRAY_SIZE(supported_caps), &ttl);
-
-            rc = vpci_add_register(pdev->vpci, vpci_read_val, NULL,
-                                   PCI_CAPABILITY_LIST, 1,
-                                   (void *)(uintptr_t)next);
-            if ( rc )
-                return rc;
-
-            next &= ~3;
-
-            if ( !next )
-                /*
-                 * 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,
-                                             ARRAY_SIZE(supported_caps), &ttl);
-
-                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, NULL,
-                                       pos + PCI_CAP_LIST_NEXT, 1,
-                                       (void *)(uintptr_t)next);
-                if ( rc )
-                    return rc;
-
-                next &= ~3;
-            }
-        }
-
         /* Extended capabilities read as zero, write ignore */
         rc = vpci_add_register(pdev->vpci, vpci_read_val, NULL, 0x100, 4,
                                (void *)0);
@@ -856,17 +875,6 @@ static int cf_check init_header(struct pci_dev *pdev)
             return rc;
     }
 
-    /* Utilize rsvdp_mask to hide PCI_STATUS_CAP_LIST from the guest. */
-    rc = 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);
-    if ( rc )
-        return rc;
-
     if ( pdev->ignore_bars )
         return 0;
 
-- 
2.34.1