x86/pci: Use pci_sbdf_t in pci_prepare_msix()

Also take the opportunity to clean up a bit PHYSDEVOP_{prepare,release}_msix.

Signed-off-by: Teddy Astie <teddy.astie@vates.tech>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/include/asm/msi.h

@@ -83,7 +83,7 @@ struct msi_desc;
 extern int pci_enable_msi(struct pci_dev *pdev, struct msi_info *msi,
                           struct msi_desc **desc);
 extern void pci_disable_msi(struct msi_desc *msi_desc);
-extern int pci_prepare_msix(u16 seg, u8 bus, u8 devfn, bool off);
+extern int pci_prepare_msix(pci_sbdf_t sbdf, bool off);
 extern void pci_cleanup_msi(struct pci_dev *pdev);
 extern void pci_disable_msi_all(void);
 extern int setup_msi_irq(struct irq_desc *desc, struct msi_desc *msidesc);

xen/arch/x86/msi.c

@@ -1153,7 +1153,7 @@ static void __pci_disable_msix(struct msi_desc *entry)
     _pci_cleanup_msix(dev->msix);
 }
 
-int pci_prepare_msix(u16 seg, u8 bus, u8 devfn, bool off)
+int pci_prepare_msix(pci_sbdf_t sbdf, bool off)
 {
     int rc;
     struct pci_dev *pdev;
@@ -1162,7 +1162,7 @@ int pci_prepare_msix(u16 seg, u8 bus, u8 devfn, bool off)
         return 0;
 
     pcidevs_lock();
-    pdev = pci_get_pdev(NULL, PCI_SBDF(seg, bus, devfn));
+    pdev = pci_get_pdev(NULL, sbdf);
     if ( !pdev )
         rc = -ENODEV;
     else if ( pdev->msix->used_entries != !!off )

xen/arch/x86/physdev.c

@@ -512,15 +512,17 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
     case PHYSDEVOP_prepare_msix:
     case PHYSDEVOP_release_msix: {
         struct physdev_pci_device dev;
+        pci_sbdf_t sbdf;
 
+        ret = -EFAULT;
         if ( copy_from_guest(&dev, arg, 1) )
-            ret = -EFAULT;
-        else
-            ret = xsm_resource_setup_pci(XSM_PRIV,
-                                         (dev.seg << 16) | (dev.bus << 8) |
-                                         dev.devfn) ?:
-                  pci_prepare_msix(dev.seg, dev.bus, dev.devfn,
-                                   cmd != PHYSDEVOP_prepare_msix);
+            break;
+        
+        sbdf = PCI_SBDF(dev.seg, dev.bus, dev.devfn);
+
+        ret = xsm_resource_setup_pci(XSM_PRIV, sbdf.sbdf);
+        if ( !ret )
+            ret = pci_prepare_msix(sbdf, cmd != PHYSDEVOP_prepare_msix);
         break;
     }