arm/libxl: Emulated PCI device tree node in libxl

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).

Note that currently we are using num_pcidevs instead of
c_info->passthrough to decide whether to create a vPCI DT node.
This will be insufficient if and when ARM does PCI hotplug.
Add this note inside libxl_create.c where c_info->passthrough
is set.

Signed-off-by: Rahul Singh <rahul.singh@arm.com>
Signed-off-by: Michal Orzel <michal.orzel@arm.com>
Signed-off-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Acked-by: Ian Jackson <iwj@xenproject.org>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

diff --git a/tools/libs/light/libxl_arm.c b/tools/libs/light/libxl_arm.c
index fdae129605a3616acba5f6b429e56bc4ec581d33..eef1de093914a663444428f1d712e4e7c31840c5 100644 (file)
--- a/tools/libs/light/libxl_arm.c
+++ b/tools/libs/light/libxl_arm.c
@@ -284,6 +284,59 @@ static int fdt_property_reg_placeholder(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, uint32_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)
@@ -687,6 +740,53 @@ 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, 255);
+    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_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)
 {
@@ -991,6 +1091,9 @@ next_resize:
         if (info->tee == LIBXL_TEE_TYPE_OPTEE)
             FDT( make_optee_node(gc, fdt) );
 
+        if (d_config->num_pcidevs)
+            FDT( make_vpci_node(gc, fdt, ainfo, dom) );
+
         if (pfdt)
             FDT( copy_partial_fdt(gc, fdt, pfdt) );
 

diff --git a/tools/libs/light/libxl_create.c b/tools/libs/light/libxl_create.c
index 6ebb2bfc768d060fb898619be907fc973375cce5..5a61d0172213b4ca4001df4417c03a94425d2179 100644 (file)
--- a/tools/libs/light/libxl_create.c
+++ b/tools/libs/light/libxl_create.c
@@ -1096,6 +1096,11 @@ int libxl__domain_config_setdefault(libxl__gc *gc,
         goto error_out;
     }
 
+    /*
+     * Note: libxl_arm directly examines num_pcidevs to decide whether
+     * to create a vPCI DT node, rather than using c_info->passthrough.
+     * This will be insufficient if and when ARM does PCI hotplug.
+     */
     bool need_pt = d_config->num_pcidevs || d_config->num_dtdevs;
     if (c_info->passthrough == LIBXL_PASSTHROUGH_DEFAULT) {
         c_info->passthrough = need_pt

diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h
index b4c615bcdfa4cc644eb99fff985a49f6093a4786..94b31511ddea5558dd0be63e13baef51e7589958 100644 (file)
--- a/xen/include/public/arch-arm.h
+++ b/xen/include/public/arch-arm.h
@@ -433,6 +433,11 @@ typedef uint64_t xen_callback_t;
 #define GUEST_PL011_BASE    xen_mk_ullong(0x22000000)
 #define GUEST_PL011_SIZE    xen_mk_ullong(0x00001000)
 
+/* Guest PCI-PCIe memory space where config space and BAR will be available.*/
+#define GUEST_VPCI_ADDR_TYPE_MEM            xen_mk_ullong(0x02000000)
+#define GUEST_VPCI_MEM_ADDR                 xen_mk_ullong(0x23000000)
+#define GUEST_VPCI_MEM_SIZE                 xen_mk_ullong(0x10000000)
+
 /*
  * 16MB == 4096 pages reserved for guest to use as a region to map its
  * grant table in.
@@ -453,6 +458,11 @@ typedef uint64_t xen_callback_t;
 #define GUEST_RAM0_BASE   xen_mk_ullong(0x40000000) /* 3GB of low RAM @ 1GB */
 #define GUEST_RAM0_SIZE   xen_mk_ullong(0xc0000000)
 
+/* 4GB @ 4GB Prefetch Memory for VPCI */
+#define GUEST_VPCI_ADDR_TYPE_PREFETCH_MEM   xen_mk_ullong(0x42000000)
+#define GUEST_VPCI_PREFETCH_MEM_ADDR        xen_mk_ullong(0x100000000)
+#define GUEST_VPCI_PREFETCH_MEM_SIZE        xen_mk_ullong(0x100000000)
+
 #define GUEST_RAM1_BASE   xen_mk_ullong(0x0200000000) /* 1016GB of RAM @ 8GB */
 #define GUEST_RAM1_SIZE   xen_mk_ullong(0xfe00000000)