[PATCH v2 6/8] vpci/rebar: Remove registers when init_rebar() fails

[Jiqian Chen <Jiqian.Chen@xxxxxxx>]

When init_rebar() fails, the previous new changes will hide Rebar
capability, it can't rely on vpci_deassign_device() to remove all
Rebar related registers anymore, those registers must be removed
in failure path of init_rebar.

To do that, call vpci_remove_registers() to remove all possible
registered registers in the failure patch.

Signed-off-by: Jiqian Chen <Jiqian.Chen@xxxxxxx>
---
cc: "Roger Pau Monné" <roger.pau@xxxxxxxxxx>
---
v1->v2 changes:
* Called vpci_remove_registers() to remove all possible registered registers 
instead of using a array to record all registered register.

Best regards,
Jiqian Chen.
---
 xen/drivers/vpci/rebar.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/xen/drivers/vpci/rebar.c b/xen/drivers/vpci/rebar.c
index 79858e5dc92f..e030937956e3 100644
--- a/xen/drivers/vpci/rebar.c
+++ b/xen/drivers/vpci/rebar.c
@@ -51,6 +51,7 @@ static void cf_check rebar_ctrl_write(const struct pci_dev 
*pdev,
 
 static int cf_check init_rebar(struct pci_dev *pdev)
 {
+    int rc = 0;
     uint32_t ctrl;
     unsigned int nbars;
     unsigned int rebar_offset = pci_find_ext_capability(pdev->sbdf,
@@ -70,7 +71,6 @@ static int cf_check init_rebar(struct pci_dev *pdev)
     nbars = MASK_EXTR(ctrl, PCI_REBAR_CTRL_NBAR_MASK);
     for ( unsigned int i = 0; i < nbars; i++ )
     {
-        int rc;
         struct vpci_bar *bar;
         unsigned int index;
 
@@ -80,7 +80,7 @@ static int cf_check init_rebar(struct pci_dev *pdev)
         {
             printk(XENLOG_ERR "%pd %pp: too big BAR number %u in REBAR_CTRL\n",
                    pdev->domain, &pdev->sbdf, index);
-            continue;
+            goto fail;
         }
 
         bar = &pdev->vpci->header.bars[index];
@@ -88,7 +88,7 @@ static int cf_check init_rebar(struct pci_dev *pdev)
         {
             printk(XENLOG_ERR "%pd %pp: BAR%u is not in memory space\n",
                    pdev->domain, &pdev->sbdf, index);
-            continue;
+            goto fail;
         }
 
         rc = vpci_add_register(pdev->vpci, vpci_hw_read32, rebar_ctrl_write,
@@ -97,14 +97,7 @@ static int cf_check init_rebar(struct pci_dev *pdev)
         {
             printk(XENLOG_ERR "%pd %pp: BAR%u fail to add reg of REBAR_CTRL 
rc=%d\n",
                    pdev->domain, &pdev->sbdf, index, rc);
-            /*
-             * Ideally we would hide the ReBar capability on error, but code
-             * for doing so still needs to be written. Use continue instead
-             * to keep any already setup register hooks, as returning an
-             * error will cause the hardware domain to get unmediated access
-             * to all device registers.
-             */
-            continue;
+            goto fail;
         }
 
         bar->resizable_sizes =
@@ -117,6 +110,16 @@ static int cf_check init_rebar(struct pci_dev *pdev)
     }
 
     return 0;
+
+ fail:
+    /*
+     * Remove all possible registered registers except header.
+     * Header register will be removed in mask function.
+     */
+    vpci_remove_registers(pdev->vpci, rebar_offset + PCI_REBAR_CAP(0),
+                          PCI_REBAR_CTRL(nbars - 1));
+
+    return rc;
 }
 REGISTER_VPCI_EXTEND_CAP(PCI_EXT_CAP_ID_REBAR, init_rebar);
 
-- 
2.34.1