vpci: Refactor REGISTER_VPCI_INIT

Refactor REGISTER_VPCI_INIT to contain more capability specific
information, this will benefit further follow-on changes to hide
capability when initialization fails.

What's more, change the definition of init_header() since it is
not a capability and it is needed for all devices' PCI config space.

After refactor, the "priority" of initializing capabilities isn't
needed anymore, so delete its related codes.

Note:
Call vpci_make_msix_hole() in the end of init_msix() since the change
of sequence of init_header() and init_msix().

The cleanup hook is also added in this change, even if it's still
unused. Further changes will make use of it.

Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>

xen/arch/arm/xen.lds.S

@@ -57,6 +57,7 @@ SECTIONS
 
        *(.rodata)
        *(.rodata.*)
+       VPCI_ARRAY
        *(.data.rel.ro)
        *(.data.rel.ro.*)
 
@@ -64,8 +65,6 @@ SECTIONS
        __proc_info_start = .;
        *(.proc.info)
        __proc_info_end = .;
-
-       VPCI_ARRAY
   } :text
 
 #if defined(BUILD_ID)

xen/arch/ppc/xen.lds.S

@@ -51,11 +51,10 @@ SECTIONS
 
         *(.rodata)
         *(.rodata.*)
+        VPCI_ARRAY
         *(.data.rel.ro)
         *(.data.rel.ro.*)
 
-        VPCI_ARRAY
-
         . = ALIGN(POINTER_ALIGN);
     } :text
 

xen/arch/riscv/xen.lds.S

@@ -46,11 +46,10 @@ SECTIONS
 
         *(.rodata)
         *(.rodata.*)
+        VPCI_ARRAY
         *(.data.rel.ro)
         *(.data.rel.ro.*)
 
-        VPCI_ARRAY
-
         . = ALIGN(POINTER_ALIGN);
     } :text
 

xen/arch/x86/xen.lds.S

@@ -135,6 +135,7 @@ SECTIONS
 
        *(.rodata)
        *(.rodata.*)
+       VPCI_ARRAY
        *(.data.rel.ro)
        *(.data.rel.ro.*)
 
@@ -148,7 +149,6 @@ SECTIONS
        *(.note.gnu.build-id)
        __note_gnu_build_id_end = .;
 #endif
-       VPCI_ARRAY
   } PHDR(text)
 
 #if defined(CONFIG_PVH_GUEST) && !defined(EFI)

xen/drivers/vpci/header.c

@@ -858,7 +858,7 @@ static int vpci_init_ext_capability_list(const struct pci_dev *pdev)
     return 0;
 }
 
-static int cf_check init_header(struct pci_dev *pdev)
+int vpci_init_header(struct pci_dev *pdev)
 {
     uint16_t cmd;
     uint64_t addr, size;
@@ -1054,7 +1054,6 @@ static int cf_check init_header(struct pci_dev *pdev)
     pci_conf_write16(pdev->sbdf, PCI_COMMAND, cmd);
     return rc;
 }
-REGISTER_VPCI_INIT(init_header, VPCI_PRIORITY_MIDDLE);
 
 /*
  * Local variables:

xen/drivers/vpci/msi.c

@@ -270,7 +270,7 @@ static int cf_check init_msi(struct pci_dev *pdev)
 
     return 0;
 }
-REGISTER_VPCI_INIT(init_msi, VPCI_PRIORITY_LOW);
+REGISTER_VPCI_CAP(MSI, init_msi, NULL);
 
 void vpci_dump_msi(void)
 {

xen/drivers/vpci/msix.c

@@ -703,9 +703,14 @@ static int cf_check init_msix(struct pci_dev *pdev)
     pdev->vpci->msix = msix;
     list_add(&msix->next, &d->arch.hvm.msix_tables);
 
-    return 0;
+    /*
+     * vPCI header initialization will have mapped the whole BAR into the
+     * p2m, as MSI-X capability was not yet initialized.  Crave a hole for
+     * the MSI-X table here, so that Xen can trap accesses.
+     */
+    return vpci_make_msix_hole(pdev);
 }
-REGISTER_VPCI_INIT(init_msix, VPCI_PRIORITY_HIGH);
+REGISTER_VPCI_CAP(MSIX, init_msix, NULL);
 
 /*
  * Local variables:

xen/drivers/vpci/rebar.c

@@ -118,7 +118,7 @@ static int cf_check init_rebar(struct pci_dev *pdev)
 
     return 0;
 }
-REGISTER_VPCI_INIT(init_rebar, VPCI_PRIORITY_LOW);
+REGISTER_VPCI_EXTCAP(REBAR, init_rebar, NULL);
 
 /*
  * Local variables:

xen/drivers/vpci/vpci.c

@@ -36,8 +36,8 @@ struct vpci_register {
 };
 
 #ifdef __XEN__
-extern vpci_register_init_t *const __start_vpci_array[];
-extern vpci_register_init_t *const __end_vpci_array[];
+extern const vpci_capability_t __start_vpci_array[];
+extern const vpci_capability_t __end_vpci_array[];
 #define NUM_VPCI_INIT (__end_vpci_array - __start_vpci_array)
 
 #ifdef CONFIG_HAS_VPCI_GUEST_SUPPORT
@@ -83,6 +83,32 @@ static int assign_virtual_sbdf(struct pci_dev *pdev)
 
 #endif /* CONFIG_HAS_VPCI_GUEST_SUPPORT */
 
+static int vpci_init_capabilities(struct pci_dev *pdev)
+{
+    for ( unsigned int i = 0; i < NUM_VPCI_INIT; i++ )
+    {
+        const vpci_capability_t *capability = &__start_vpci_array[i];
+        const unsigned int cap = capability->id;
+        const bool is_ext = capability->is_ext;
+        unsigned int pos = 0;
+        int rc;
+
+        if ( !is_ext )
+            pos = pci_find_cap_offset(pdev->sbdf, cap);
+        else if ( is_hardware_domain(pdev->domain) )
+            pos = pci_find_ext_capability(pdev->sbdf, cap);
+
+        if ( !pos )
+            continue;
+
+        rc = capability->init(pdev);
+        if ( rc )
+            return rc;
+    }
+
+    return 0;
+}
+
 void vpci_deassign_device(struct pci_dev *pdev)
 {
     unsigned int i;
@@ -128,7 +154,6 @@ void vpci_deassign_device(struct pci_dev *pdev)
 
 int vpci_assign_device(struct pci_dev *pdev)
 {
-    unsigned int i;
     const unsigned long *ro_map;
     int rc = 0;
 
@@ -159,14 +184,13 @@ int vpci_assign_device(struct pci_dev *pdev)
         goto out;
 #endif
 
-    for ( i = 0; i < NUM_VPCI_INIT; i++ )
-    {
-        rc = __start_vpci_array[i](pdev);
-        if ( rc )
-            break;
-    }
+    rc = vpci_init_header(pdev);
+    if ( rc )
+        goto out;
 
- out: __maybe_unused;
+    rc = vpci_init_capabilities(pdev);
+
+ out:
     if ( rc )
         vpci_deassign_device(pdev);
 

xen/include/xen/vpci.h

@@ -13,11 +13,12 @@ typedef uint32_t vpci_read_t(const struct pci_dev *pdev, unsigned int reg,
 typedef void vpci_write_t(const struct pci_dev *pdev, unsigned int reg,
                           uint32_t val, void *data);
 
-typedef int vpci_register_init_t(struct pci_dev *dev);
-
-#define VPCI_PRIORITY_HIGH      "1"
-#define VPCI_PRIORITY_MIDDLE    "5"
-#define VPCI_PRIORITY_LOW       "9"
+typedef struct {
+    unsigned int id;
+    bool is_ext;
+    int (* init)(struct pci_dev *pdev);
+    int (* cleanup)(const struct pci_dev *pdev);
+} vpci_capability_t;
 
 #define VPCI_ECAM_BDF(addr)     (((addr) & 0x0ffff000) >> 12)
 
@@ -29,9 +30,21 @@ typedef int vpci_register_init_t(struct pci_dev *dev);
  */
 #define VPCI_MAX_VIRT_DEV       (PCI_SLOT(~0) + 1)
 
-#define REGISTER_VPCI_INIT(x, p)                \
-  static vpci_register_init_t *const x##_entry  \
-               __used_section(".data.vpci." p) = (x)
+#define REGISTER_VPCI_CAPABILITY(cap, name, finit, fclean, ext) \
+    static const vpci_capability_t name##_entry \
+        __used_section(".data.rel.ro.vpci") = { \
+        .id = (cap), \
+        .init = (finit), \
+        .cleanup = (fclean), \
+        .is_ext = (ext), \
+    }
+
+#define REGISTER_VPCI_CAP(name, finit, fclean) \
+    REGISTER_VPCI_CAPABILITY(PCI_CAP_ID_##name, name, finit, fclean, false)
+#define REGISTER_VPCI_EXTCAP(name, finit, fclean) \
+    REGISTER_VPCI_CAPABILITY(PCI_EXT_CAP_ID_##name, name, finit, fclean, true)
+
+int __must_check vpci_init_header(struct pci_dev *pdev);
 
 /* Assign vPCI to device by adding handlers. */
 int __must_check vpci_assign_device(struct pci_dev *pdev);

xen/include/xen/xen.lds.h

@@ -188,7 +188,7 @@
 #define VPCI_ARRAY               \
        . = ALIGN(POINTER_ALIGN); \
        __start_vpci_array = .;   \
-       *(SORT(.data.vpci.*))     \
+       *(.data.rel.ro.vpci)      \
        __end_vpci_array = .;
 #else
 #define VPCI_ARRAY