From 892602338db279204d11212034bc9f359dc4c1c4 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek 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 Reviewed-by: Peter Maydell Signed-off-by: Paolo Bonzini Message-id: 1419250305-31062-9-git-send-email-pbonzini@redhat.com Signed-off-by: Peter Maydell (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