diff --git a/xen/arch/x86/include/asm/pci.h b/xen/arch/x86/include/asm/pci.h
index 0b98081aea..8d8e66928d 100644
--- a/xen/arch/x86/include/asm/pci.h
+++ b/xen/arch/x86/include/asm/pci.h
@@ -36,9 +36,8 @@ struct arch_pci_dev {
     struct page_list_head pgtables_list;
 };
 
-int pci_conf_write_intercept(unsigned int seg, unsigned int bdf,
-                             unsigned int reg, unsigned int size,
-                             uint32_t *data);
+int pci_conf_write_intercept(
+    pci_sbdf_t sbdf, unsigned int reg, unsigned int size, uint32_t *data);
 int pci_msi_conf_write_intercept(struct pci_dev *pdev, unsigned int reg,
                                  unsigned int size, uint32_t *data);
 bool pci_mmcfg_decode(unsigned long mfn, unsigned int *seg,
diff --git a/xen/arch/x86/pci.c b/xen/arch/x86/pci.c
index 4c27987551..0731f7e762 100644
--- a/xen/arch/x86/pci.c
+++ b/xen/arch/x86/pci.c
@@ -72,11 +72,9 @@ void pci_conf_write(uint32_t cf8, uint8_t offset, uint8_t bytes, uint32_t data)
     spin_unlock_irqrestore(&pci_config_lock, flags);
 }
 
-int pci_conf_write_intercept(unsigned int seg, unsigned int bdf,
-                             unsigned int reg, unsigned int size,
-                             uint32_t *data)
+int pci_conf_write_intercept(
+    pci_sbdf_t sbdf, unsigned int reg, unsigned int size, uint32_t *data)
 {
-    pci_sbdf_t sbdf = PCI_SBDF(seg, bdf);
     struct pci_dev *pdev;
     int rc = xsm_pci_config_permission(XSM_HOOK, current->domain, sbdf.sbdf,
                                        reg, reg + size - 1, true);
diff --git a/xen/arch/x86/pv/emul-priv-op.c b/xen/arch/x86/pv/emul-priv-op.c
index dc21515e44..fd9b533e57 100644
--- a/xen/arch/x86/pv/emul-priv-op.c
+++ b/xen/arch/x86/pv/emul-priv-op.c
@@ -228,7 +228,7 @@ static bool admin_io_okay(unsigned int port, unsigned int bytes,
 static bool pci_cfg_ok(struct domain *currd, unsigned int start,
                        unsigned int size, uint32_t *write)
 {
-    uint32_t machine_bdf;
+    pci_sbdf_t sbdf = {}; /* Seg always 0 for IO port CFG accesses. */
 
     if ( !is_hardware_domain(currd) )
         return false;
@@ -236,12 +236,12 @@ static bool pci_cfg_ok(struct domain *currd, unsigned int start,
     if ( !CF8_ENABLED(currd->arch.pci_cf8) )
         return true;
 
-    machine_bdf = CF8_BDF(currd->arch.pci_cf8);
+    sbdf.bdf = CF8_BDF(currd->arch.pci_cf8);
     if ( write )
     {
         const unsigned long *ro_map = pci_get_ro_map(0);
 
-        if ( ro_map && test_bit(machine_bdf, ro_map) )
+        if ( ro_map && test_bit(sbdf.bdf, ro_map) )
             return false;
     }
     start |= CF8_ADDR_LO(currd->arch.pci_cf8);
@@ -259,9 +259,9 @@ static bool pci_cfg_ok(struct domain *currd, unsigned int start,
     }
 
     return !write ?
-           xsm_pci_config_permission(XSM_HOOK, currd, machine_bdf,
+           xsm_pci_config_permission(XSM_HOOK, currd, sbdf.sbdf,
                                      start, start + size - 1, false) == 0 :
-           pci_conf_write_intercept(0, machine_bdf, start, size, write) >= 0;
+           pci_conf_write_intercept(sbdf, start, size, write) >= 0;
 }
 
 static uint32_t guest_io_read(unsigned int port, unsigned int bytes,
diff --git a/xen/arch/x86/pv/ro-page-fault.c b/xen/arch/x86/pv/ro-page-fault.c
index c10541709e..34349e9437 100644
--- a/xen/arch/x86/pv/ro-page-fault.c
+++ b/xen/arch/x86/pv/ro-page-fault.c
@@ -329,8 +329,7 @@ static int cf_check mmcfg_intercept_write(
     }
 
     offset &= 0xfff;
-    if ( pci_conf_write_intercept(mmio_ctxt->sbdf.seg, mmio_ctxt->sbdf.bdf,
-                                  offset, bytes, p_data) >= 0 )
+    if ( pci_conf_write_intercept(mmio_ctxt->sbdf, offset, bytes, p_data) >= 0 )
         pci_mmcfg_write(mmio_ctxt->sbdf, offset, bytes, *(uint32_t *)p_data);
 
     return X86EMUL_OKAY;