From 892602338db279204d11212034bc9f359dc4c1c4 Mon Sep 17 00:00:00 2001

From: Laszlo Ersek <lersek@redhat.com>

Date: Mon, 22 Dec 2014 13:11:42 +0100

Subject: [PATCH 11/15] arm: add fw_cfg to "virt" board

fw_cfg already supports exposure over MMIO (used in ppc/mac_newworld.c,

ppc/mac_oldworld.c, sparc/sun4m.c); we can easily add it to the "virt"

board.

Because MMIO access is slow on ARM KVM, we enable the guest, with

fw_cfg_init_mem_wide(), to transfer up to 8 bytes with a single access.

This has been measured to speed up transfers up to 7.5-fold, relative to

single byte data access, on both ARM KVM and x86_64 TCG.

The MMIO register block of fw_cfg is advertized in the device tree. As

base address we pick 0x09020000, which conforms to the comment preceding

"a15memmap": it falls in the miscellaneous device I/O range 128MB..256MB,

and it is aligned at 64KB. The DTB properties follow the documentation in

the Linux source file "Documentation/devicetree/bindings/arm/fw-cfg.txt".

fw_cfg automatically exports a number of files to the guest; for example,

"bootorder" (see fw_cfg_machine_reset()).

Signed-off-by: Laszlo Ersek <lersek@redhat.com>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Message-id: 1419250305-31062-9-git-send-email-pbonzini@redhat.com

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

(cherry picked from commit 578f3c7b083514b4fec0bf8fa0617934cdbdf826)

---

 hw/arm/virt.c | 21 +++++++++++++++++++++

 1 file changed, 21 insertions(+)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c

index 314e55b..8af4aa0 100644

--- a/hw/arm/virt.c

+++ b/hw/arm/virt.c

@@ -68,6 +68,7 @@ enum {

     VIRT_UART,

     VIRT_MMIO,

     VIRT_RTC,

+    VIRT_FW_CFG,

 };

 typedef struct MemMapEntry {

@@ -107,6 +108,7 @@ static const MemMapEntry a15memmap[] = {

     [VIRT_GIC_CPU] =    { 0x08010000, 0x00010000 },

     [VIRT_UART] =       { 0x09000000, 0x00001000 },

     [VIRT_RTC] =        { 0x09010000, 0x00001000 },

+    [VIRT_FW_CFG] =     { 0x09020000, 0x0000000a },

     [VIRT_MMIO] =       { 0x0a000000, 0x00000200 },

     /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */

     /* 0x10000000 .. 0x40000000 reserved for PCI */

@@ -519,6 +521,23 @@ static void create_flash(const VirtBoardInfo *vbi)

     g_free(nodename);

 }

+static void create_fw_cfg(const VirtBoardInfo *vbi)

+{

+    hwaddr base = vbi->memmap[VIRT_FW_CFG].base;

+    hwaddr size = vbi->memmap[VIRT_FW_CFG].size;

+    char *nodename;

+

+    fw_cfg_init_mem_wide(base + 8, base, 8);

+

+    nodename = g_strdup_printf("/fw-cfg@%" PRIx64, base);

+    qemu_fdt_add_subnode(vbi->fdt, nodename);

+    qemu_fdt_setprop_string(vbi->fdt, nodename,

+                            "compatible", "qemu,fw-cfg-mmio");

+    qemu_fdt_setprop_sized_cells(vbi->fdt, nodename, "reg",

+                                 2, base, 2, size);

+    g_free(nodename);

+}

+

 static void *machvirt_dtb(const struct arm_boot_info *binfo, int *fdt_size)

 {

     const VirtBoardInfo *board = (const VirtBoardInfo *)binfo;

@@ -604,6 +623,8 @@ static void machvirt_init(MachineState *machine)

      */

     create_virtio_devices(vbi, pic);

+    create_fw_cfg(vbi);

+

     vbi->bootinfo.ram_size = machine->ram_size;

     vbi->bootinfo.kernel_filename = machine->kernel_filename;

     vbi->bootinfo.kernel_cmdline = machine->kernel_cmdline;

-- 

2.1.0