[PATCH v1 12/14] arm/libxl: Emulated PCI device tree node in libxl

[Rahul Singh <rahul.singh@xxxxxxx>]

libxl will create an emulated PCI device tree node in the device tree to
enable the guest OS to discover the virtual PCI during guest boot.
Emulated PCI device tree node will only be created when there is any
device assigned to guest.

A new area has been reserved in the arm guest physical map at
which the VPCI bus is declared in the device tree (reg and ranges
parameters of the node).

Signed-off-by: Rahul Singh <rahul.singh@xxxxxxx>
---
 tools/libs/light/libxl_arm.c          | 109 ++++++++++++++++++++++++++
 tools/libs/light/libxl_types.idl      |   1 +
 tools/xl/xl_parse.c                   |   2 +
 xen/include/public/arch-arm.h         |  11 +++
 xen/include/public/device_tree_defs.h |   1 +
 5 files changed, 124 insertions(+)

diff --git a/tools/libs/light/libxl_arm.c b/tools/libs/light/libxl_arm.c
index e3140a6e00..a091e97e76 100644
--- a/tools/libs/light/libxl_arm.c
+++ b/tools/libs/light/libxl_arm.c
@@ -269,6 +269,58 @@ static int fdt_property_regs(libxl__gc *gc, void *fdt,
     return fdt_property(fdt, "reg", regs, sizeof(regs));
 }
 
+static int fdt_property_values(libxl__gc *gc, void *fdt,
+        const char *name, unsigned num_cells, ...)
+{
+    uint32_t prop[num_cells];
+    be32 *cells = &prop[0];
+    int i;
+    va_list ap;
+    uint32_t arg;
+
+    va_start(ap, num_cells);
+    for (i = 0 ; i < num_cells; i++) {
+        arg = va_arg(ap, uint32_t);
+        set_cell(&cells, 1, arg);
+    }
+    va_end(ap);
+
+    return fdt_property(fdt, name, prop, sizeof(prop));
+}
+
+static int fdt_property_vpci_ranges(libxl__gc *gc, void *fdt,
+                                    unsigned addr_cells,
+                                    unsigned size_cells,
+                                    unsigned num_regs, ...)
+{
+    uint32_t regs[num_regs*((addr_cells*2)+size_cells+1)];
+    be32 *cells = &regs[0];
+    int i;
+    va_list ap;
+    uint64_t arg;
+
+    va_start(ap, num_regs);
+    for (i = 0 ; i < num_regs; i++) {
+        /* Set the memory bit field */
+        arg = va_arg(ap, uint64_t);
+        set_cell(&cells, 1, arg);
+
+        /* Set the vpci bus address */
+        arg = addr_cells ? va_arg(ap, uint64_t) : 0;
+        set_cell(&cells, addr_cells , arg);
+
+        /* Set the cpu bus address where vpci address is mapped */
+        set_cell(&cells, addr_cells, arg);
+
+        /* Set the vpci size requested */
+        arg = size_cells ? va_arg(ap, uint64_t) : 0;
+        set_cell(&cells, size_cells,arg);
+    }
+    va_end(ap);
+
+    return fdt_property(fdt, "ranges", regs, sizeof(regs));
+}
+
 static int make_root_properties(libxl__gc *gc,
                                 const libxl_version_info *vers,
                                 void *fdt)
@@ -668,6 +720,57 @@ static int make_vpl011_uart_node(libxl__gc *gc, void *fdt,
     return 0;
 }
 
+static int make_vpci_node(libxl__gc *gc, void *fdt,
+        const struct arch_info *ainfo,
+        struct xc_dom_image *dom)
+{
+    int res;
+    const uint64_t vpci_ecam_base = GUEST_VPCI_ECAM_BASE;
+    const uint64_t vpci_ecam_size = GUEST_VPCI_ECAM_SIZE;
+    const char *name = GCSPRINTF("pcie@%"PRIx64, vpci_ecam_base);
+
+    res = fdt_begin_node(fdt, name);
+    if (res) return res;
+
+    res = fdt_property_compat(gc, fdt, 1, "pci-host-ecam-generic");
+    if (res) return res;
+
+    res = fdt_property_string(fdt, "device_type", "pci");
+    if (res) return res;
+
+    res = fdt_property_regs(gc, fdt, GUEST_ROOT_ADDRESS_CELLS,
+            GUEST_ROOT_SIZE_CELLS, 1, vpci_ecam_base, vpci_ecam_size);
+    if (res) return res;
+
+    res = fdt_property_values(gc, fdt, "bus-range", 2, 0,17);
+    if (res) return res;
+
+    res = fdt_property_cell(fdt, "#address-cells", 3);
+    if (res) return res;
+
+    res = fdt_property_cell(fdt, "#size-cells", 2);
+    if (res) return res;
+
+    res = fdt_property_string(fdt, "status", "okay");
+    if (res) return res;
+
+    res = fdt_property_vpci_ranges(gc, fdt, GUEST_ROOT_ADDRESS_CELLS,
+        GUEST_ROOT_SIZE_CELLS, 2,
+        GUEST_VPCI_ADDR_TYPE_MEM, GUEST_VPCI_MEM_ADDR, GUEST_VPCI_MEM_SIZE,
+        GUEST_VPCI_ADDR_TYPE_PREFETCH_MEM, GUEST_VPCI_PREFETCH_MEM_ADDR,
+        GUEST_VPCI_PREFETCH_MEM_SIZE);
+    if (res) return res;
+
+    res = fdt_property_values(gc, fdt, "msi-map", 4, 0, GUEST_PHANDLE_ITS,
+                              0, 0x10000);
+    if (res) return res;
+
+    res = fdt_end_node(fdt);
+    if (res) return res;
+
+    return 0;
+}
+
 static const struct arch_info *get_arch_info(libxl__gc *gc,
                                              const struct xc_dom_image *dom)
 {
@@ -971,6 +1074,9 @@ next_resize:
         if (info->tee == LIBXL_TEE_TYPE_OPTEE)
             FDT( make_optee_node(gc, fdt) );
 
+        if (libxl_defbool_val(info->arch_arm.vpci))
+            FDT( make_vpci_node(gc, fdt, ainfo, dom) );
+
         if (pfdt)
             FDT( copy_partial_fdt(gc, fdt, pfdt) );
 
@@ -1189,6 +1295,9 @@ void libxl__arch_domain_build_info_setdefault(libxl__gc 
*gc,
     /* ACPI is disabled by default */
     libxl_defbool_setdefault(&b_info->acpi, false);
 
+    /* VPCI is disabled by default */
+    libxl_defbool_setdefault(&b_info->arch_arm.vpci, false);
+
     if (b_info->type != LIBXL_DOMAIN_TYPE_PV)
         return;
 
diff --git a/tools/libs/light/libxl_types.idl b/tools/libs/light/libxl_types.idl
index 3f9fff653a..78b1ddf0b8 100644
--- a/tools/libs/light/libxl_types.idl
+++ b/tools/libs/light/libxl_types.idl
@@ -644,6 +644,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
 
     ("arch_arm", Struct(None, [("gic_version", libxl_gic_version),
                                ("vuart", libxl_vuart_type),
+                               ("vpci", libxl_defbool),
                               ])),
     ("arch_x86", Struct(None, [("msr_relaxed", libxl_defbool),
                               ])),
diff --git a/tools/xl/xl_parse.c b/tools/xl/xl_parse.c
index 17dddb4cd5..ffafbeffb4 100644
--- a/tools/xl/xl_parse.c
+++ b/tools/xl/xl_parse.c
@@ -1497,6 +1497,8 @@ void parse_config_data(const char *config_source,
         }
         if (d_config->num_pcidevs && c_info->type == LIBXL_DOMAIN_TYPE_PV)
             libxl_defbool_set(&b_info->u.pv.e820_host, true);
+        if (d_config->num_pcidevs)
+            libxl_defbool_set(&b_info->arch_arm.vpci, true);
     }
 
     if (!xlu_cfg_get_list (config, "dtdev", &dtdevs, 0, 0)) {
diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h
index 0a9749e768..01d13e669e 100644
--- a/xen/include/public/arch-arm.h
+++ b/xen/include/public/arch-arm.h
@@ -426,6 +426,17 @@ typedef uint64_t xen_callback_t;
 #define GUEST_VPCI_ECAM_BASE    xen_mk_ullong(0x10000000)
 #define GUEST_VPCI_ECAM_SIZE    xen_mk_ullong(0x10000000)
 
+/* PCI-PCIe memory space types */
+#define GUEST_VPCI_ADDR_TYPE_PREFETCH_MEM xen_mk_ullong(0x42000000)
+#define GUEST_VPCI_ADDR_TYPE_MEM          xen_mk_ullong(0x02000000)
+
+/* Guest PCI-PCIe memory space where config space and BAR will be available.*/
+#define GUEST_VPCI_PREFETCH_MEM_ADDR  xen_mk_ullong(0x900000000)
+#define GUEST_VPCI_MEM_ADDR           xen_mk_ullong(0x20000000)
+
+#define GUEST_VPCI_PREFETCH_MEM_SIZE      xen_mk_ullong(0x2000000000)
+#define GUEST_VPCI_MEM_SIZE               xen_mk_ullong(0x04000000)
+
 /*
  * 16MB == 4096 pages reserved for guest to use as a region to map its
  * grant table in.
diff --git a/xen/include/public/device_tree_defs.h 
b/xen/include/public/device_tree_defs.h
index 209d43de3f..d24d86b1fc 100644
--- a/xen/include/public/device_tree_defs.h
+++ b/xen/include/public/device_tree_defs.h
@@ -7,6 +7,7 @@
  * onwards. Reserve a high value for the GIC phandle.
  */
 #define GUEST_PHANDLE_GIC (65000)
+#define GUEST_PHANDLE_ITS (64999)
 
 #define GUEST_ROOT_ADDRESS_CELLS 2
 #define GUEST_ROOT_SIZE_CELLS 2
-- 
2.17.1