[xen staging] vpci/msix: Implement cleanup function for MSI-X

[patchbot@xxxxxxx]

commit 5a733e438f3c8de07c165d9db31e5b37ee39f012
Author:     Jiqian Chen <Jiqian.Chen@xxxxxxx>
AuthorDate: Mon Dec 8 16:18:15 2025 +0800
Commit:     Roger Pau Monne <roger.pau@xxxxxxxxxx>
CommitDate: Mon Feb 2 13:05:32 2026 +0100

    vpci/msix: Implement cleanup function for MSI-X
    
    When MSI-X initialization fails, vPCI hides the capability, but
    removing handlers and datas won't be performed until the device is
    deassigned. So, implement MSI-X cleanup hook that will be called
    to cleanup MSI-X related handlers and free it's associated data when
    initialization fails.
    
    Since cleanup function of MSI-X is implemented, delete the open-code
    in vpci_deassign_device().
    
    Signed-off-by: Jiqian Chen <Jiqian.Chen@xxxxxxx>
    Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 xen/drivers/vpci/msix.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++-
 xen/drivers/vpci/vpci.c |  8 --------
 2 files changed, 50 insertions(+), 9 deletions(-)

diff --git a/xen/drivers/vpci/msix.c b/xen/drivers/vpci/msix.c
index 032e471bb1..516282205a 100644
--- a/xen/drivers/vpci/msix.c
+++ b/xen/drivers/vpci/msix.c
@@ -656,6 +656,55 @@ int vpci_make_msix_hole(const struct pci_dev *pdev)
     return 0;
 }
 
+static int cf_check cleanup_msix(const struct pci_dev *pdev, bool hide)
+{
+    int rc;
+    struct vpci *vpci = pdev->vpci;
+    const unsigned int msix_pos = pdev->msix_pos;
+
+    if ( vpci->msix )
+    {
+        list_del(&vpci->msix->next);
+        for ( unsigned int i = 0; i < ARRAY_SIZE(vpci->msix->table); i++ )
+            if ( vpci->msix->table[i] )
+                iounmap(vpci->msix->table[i]);
+
+        XFREE(vpci->msix);
+    }
+
+    if ( !hide )
+        return 0;
+
+    rc = vpci_remove_registers(vpci, msix_control_reg(msix_pos), 2);
+    if ( rc )
+    {
+        printk(XENLOG_ERR "%pd %pp: fail to remove MSIX handlers rc=%d\n",
+               pdev->domain, &pdev->sbdf, rc);
+        ASSERT_UNREACHABLE();
+        return rc;
+    }
+
+    /*
+     * Unprivileged domains have a deny by default register access policy, no
+     * need to add any further handlers for them.
+     */
+    if ( !is_hardware_domain(pdev->domain) )
+        return 0;
+
+    /*
+     * The driver may not traverse the capability list and think device
+     * supports MSIX by default. So here let the control register of MSIX
+     * be Read-Only is to ensure MSIX disabled.
+     */
+    rc = vpci_add_register(vpci, vpci_hw_read16, NULL,
+                           msix_control_reg(msix_pos), 2, NULL);
+    if ( rc )
+        printk(XENLOG_ERR "%pd %pp: fail to add MSIX ctrl handler rc=%d\n",
+               pdev->domain, &pdev->sbdf, rc);
+
+    return rc;
+}
+
 static int cf_check init_msix(struct pci_dev *pdev)
 {
     struct domain *d = pdev->domain;
@@ -751,7 +800,7 @@ static int cf_check init_msix(struct pci_dev *pdev)
      */
     return vpci_make_msix_hole(pdev);
 }
-REGISTER_VPCI_CAP(MSIX, init_msix, NULL);
+REGISTER_VPCI_CAP(MSIX, init_msix, cleanup_msix);
 
 /*
  * Local variables:
diff --git a/xen/drivers/vpci/vpci.c b/xen/drivers/vpci/vpci.c
index 063adbab9a..f66f50c8ba 100644
--- a/xen/drivers/vpci/vpci.c
+++ b/xen/drivers/vpci/vpci.c
@@ -356,18 +356,10 @@ void vpci_deassign_device(struct pci_dev *pdev)
         xfree(r);
     }
     spin_unlock(&pdev->vpci->lock);
-    if ( pdev->vpci->msix )
-    {
-        list_del(&pdev->vpci->msix->next);
-        for ( i = 0; i < ARRAY_SIZE(pdev->vpci->msix->table); i++ )
-            if ( pdev->vpci->msix->table[i] )
-                iounmap(pdev->vpci->msix->table[i]);
-    }
 
     for ( i = 0; i < ARRAY_SIZE(pdev->vpci->header.bars); i++ )
         rangeset_destroy(pdev->vpci->header.bars[i].mem);
 
-    xfree(pdev->vpci->msix);
     xfree(pdev->vpci);
     pdev->vpci = NULL;
 }
--
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