[PATCH v7 2/8] vpci: Refactor REGISTER_VPCI_INIT

[Jiqian Chen <Jiqian.Chen@xxxxxxx>]

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(). And delete the call of
vpci_make_msix_hole() in modify_decoding() since it is not needed.

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@xxxxxxx>
---
There is a byte alignment problem in the array __start_vpci_array, which can be 
solved after
"[PATCH] x86: don't have gcc over-align data" is merged.
---
cc: "Roger Pau Monné" <roger.pau@xxxxxxxxxx>
cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
cc: Anthony PERARD <anthony.perard@xxxxxxxxxx>
cc: Michal Orzel <michal.orzel@xxxxxxx>
cc: Jan Beulich <jbeulich@xxxxxxxx>
cc: Julien Grall <julien@xxxxxxx>
cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
v6->v7 changes:
* Change the pointer parameter of cleanup hook of vpci_capability_t to be const.
  If change parameter of init hook to be const will affect init_msix, and it 
assigns pdev
  to struct vpci_msix, so keep no const to expanding the impact.
* Delete the vpci_make_msix_hole() call in modify_decoding().
* Change __start_vpci_array from vpci_capability_t* array to vpci_capability_t 
array.
* Change the name "finit##_t" to be "name##_entry" and add a "name" parameter 
to macro
  REGISTER_VPCI_CAPABILITY.

v5->v6 changes:
* Rename REGISTER_PCI_CAPABILITY to REGISTER_VPCI_CAPABILITY.
* Move vpci_capability_t entry from ".data.vpci" to ".data.rel.ro.vpci" and
  move the instances of VPCI_ARRAY in the linker scripts before *(.data.rel.ro).
* Change _start/end_vpci_array[] to be const pointer array.

v4->v5 changes:
* Rename REGISTER_VPCI_CAP to REGISTER_PCI_CAPABILITY, rename 
REGISTER_VPCI_LEGACY_CAP to
  REGISTER_VPCI_CAP, rename REGISTER_VPCI_EXTENDED_CAP to REGISTER_VPCI_EXTCAP.
* Change cleanup hook of vpci_capability_t from void to int.

v3->v4 changes
* Delete the useless trailing dot of section ".data.vpci".
* Add description about priority since this patch removes the initializing 
priority of
  capabilities and priority is not needed anymore.
* Change the hook name from fini to cleanup.
* Change the name x and y to be finit and fclean.
* Remove the unnecessary check "!capability->init"

v2->v3 changes:
* This is separated from patch "vpci: Hide capability when it fails to 
initialize" of v2.
* Delete __maybe_unused attribute of "out" in function vpci_assign_devic().
* Rename REGISTER_VPCI_EXTEND_CAP to REGISTER_VPCI_EXTENDED_CAP.

v1->v2 changes:
* Removed the "priorities" of initializing capabilities since it isn't used 
anymore.
* Added new function vpci_capability_mask() and vpci_ext_capability_mask() to 
remove
  failed capability from list.
* Called vpci_make_msix_hole() in the end of init_msix().

Best regards,
Jiqian Chen.
---
 xen/arch/arm/xen.lds.S    |  3 +--
 xen/arch/ppc/xen.lds.S    |  3 +--
 xen/arch/riscv/xen.lds.S  |  3 +--
 xen/arch/x86/xen.lds.S    |  2 +-
 xen/drivers/vpci/header.c | 16 +-------------
 xen/drivers/vpci/msi.c    |  2 +-
 xen/drivers/vpci/msix.c   | 11 +++++++---
 xen/drivers/vpci/rebar.c  |  2 +-
 xen/drivers/vpci/vpci.c   | 44 ++++++++++++++++++++++++++++++---------
 xen/include/xen/vpci.h    | 32 ++++++++++++++++++----------
 xen/include/xen/xen.lds.h |  2 +-
 11 files changed, 71 insertions(+), 49 deletions(-)

diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
index 5bfbe1e92c1e..9f30c3a13ed1 100644
--- a/xen/arch/arm/xen.lds.S
+++ b/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)
diff --git a/xen/arch/ppc/xen.lds.S b/xen/arch/ppc/xen.lds.S
index 1366e2819eed..1de0b77fc6b9 100644
--- a/xen/arch/ppc/xen.lds.S
+++ b/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
 
diff --git a/xen/arch/riscv/xen.lds.S b/xen/arch/riscv/xen.lds.S
index 8c3c06de01f6..edcadff90bfe 100644
--- a/xen/arch/riscv/xen.lds.S
+++ b/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
 
diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S
index 636c7768aa3c..8e9cac75b09e 100644
--- a/xen/arch/x86/xen.lds.S
+++ b/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)
diff --git a/xen/drivers/vpci/header.c b/xen/drivers/vpci/header.c
index 8ee8052cd4a3..069253b5f721 100644
--- a/xen/drivers/vpci/header.c
+++ b/xen/drivers/vpci/header.c
@@ -122,19 +122,6 @@ static void modify_decoding(const struct pci_dev *pdev, 
uint16_t cmd,
     bool map = cmd & PCI_COMMAND_MEMORY;
     unsigned int i;
 
-    /*
-     * Make sure there are no mappings in the MSIX MMIO areas, so that accesses
-     * can be trapped (and emulated) by Xen when the memory decoding bit is
-     * enabled.
-     *
-     * FIXME: punching holes after the p2m has been set up might be racy for
-     * DomU usage, needs to be revisited.
-     */
-#ifdef CONFIG_HAS_PCI_MSI
-    if ( map && !rom_only && vpci_make_msix_hole(pdev) )
-        return;
-#endif
-
     for ( i = 0; i < ARRAY_SIZE(header->bars); i++ )
     {
         struct vpci_bar *bar = &header->bars[i];
@@ -869,7 +856,7 @@ 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;
@@ -1065,7 +1052,6 @@ 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:
diff --git a/xen/drivers/vpci/msi.c b/xen/drivers/vpci/msi.c
index 66e5a8a116be..c3eba4e14870 100644
--- a/xen/drivers/vpci/msi.c
+++ b/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)
 {
diff --git a/xen/drivers/vpci/msix.c b/xen/drivers/vpci/msix.c
index 74211301ba10..a1692b9d9f6a 100644
--- a/xen/drivers/vpci/msix.c
+++ b/xen/drivers/vpci/msix.c
@@ -589,7 +589,8 @@ static const struct hvm_mmio_ops vpci_msix_table_ops = {
     .write = msix_write,
 };
 
-int vpci_make_msix_hole(const struct pci_dev *pdev)
+/* Make sure there's a hole in the p2m for the MSIX mmio areas. */
+static int vpci_make_msix_hole(const struct pci_dev *pdev)
 {
     struct domain *d = pdev->domain;
     unsigned int i;
@@ -703,9 +704,13 @@ 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;
+    spin_lock(&pdev->vpci->lock);
+    rc = vpci_make_msix_hole(pdev);
+    spin_unlock(&pdev->vpci->lock);
+
+    return rc;
 }
-REGISTER_VPCI_INIT(init_msix, VPCI_PRIORITY_HIGH);
+REGISTER_VPCI_CAP(MSIX, init_msix, NULL);
 
 /*
  * Local variables:
diff --git a/xen/drivers/vpci/rebar.c b/xen/drivers/vpci/rebar.c
index 793937449af7..3c18792d9bcd 100644
--- a/xen/drivers/vpci/rebar.c
+++ b/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:
diff --git a/xen/drivers/vpci/vpci.c b/xen/drivers/vpci/vpci.c
index 8474c0e3b995..e7e5b64f1be4 100644
--- a/xen/drivers/vpci/vpci.c
+++ b/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;
+
+    rc = vpci_init_capabilities(pdev);
 
- out: __maybe_unused;
+ out:
     if ( rc )
         vpci_deassign_device(pdev);
 
diff --git a/xen/include/xen/vpci.h b/xen/include/xen/vpci.h
index 61d16cc8b897..61287e5d2e12 100644
--- a/xen/include/xen/vpci.h
+++ b/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);
@@ -206,9 +219,6 @@ struct vpci_vcpu {
 #ifdef __XEN__
 void vpci_dump_msi(void);
 
-/* Make sure there's a hole in the p2m for the MSIX mmio areas. */
-int vpci_make_msix_hole(const struct pci_dev *pdev);
-
 /* Arch-specific vPCI MSI helpers. */
 void vpci_msi_arch_mask(struct vpci_msi *msi, const struct pci_dev *pdev,
                         unsigned int entry, bool mask);
diff --git a/xen/include/xen/xen.lds.h b/xen/include/xen/xen.lds.h
index 793d0e11450c..eb86305c11c7 100644
--- a/xen/include/xen/xen.lds.h
+++ b/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
-- 
2.34.1