From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46649) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b4s2F-0007uM-HN for qemu-devel@nongnu.org; Mon, 23 May 2016 11:44:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b4s2B-00048M-9d for qemu-devel@nongnu.org; Mon, 23 May 2016 11:44:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35033) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b4s2B-000480-0T for qemu-devel@nongnu.org; Mon, 23 May 2016 11:44:47 -0400 Date: Mon, 23 May 2016 16:44:44 +0100 From: "Richard W.M. Jones" Message-ID: <20160523154444.GU1683@redhat.com> References: <1463000807-18015-1-git-send-email-rjones@redhat.com> <1463000807-18015-4-git-send-email-rjones@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v8 3/3] Add optionrom compatible with fw_cfg DMA version List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: qemu-devel@nongnu.org, marc.mari.barcelo@gmail.com, ehabkost@redhat.com, mst@redhat.com, stefanha@gmail.com, kraxel@redhat.com, lersek@redhat.com, rth@twiddle.net On Mon, May 23, 2016 at 05:05:15PM +0200, Paolo Bonzini wrote: >=20 >=20 > On 11/05/2016 23:06, Richard W.M. Jones wrote: > > From: Marc Mar=ED > >=20 > > This optionrom is based on linuxboot.S. > >=20 > > Signed-off-by: Marc Mar=ED > > Signed-off-by: Richard W.M. Jones >=20 > Hmm, I hadn't noticed that you added -m16. That breaks on even > not-too-old GCC (such as 4.8 on RHEL/CentOS 7). Can you add some > Makefile logic to switch between "-m16" and a "-include code16gcc.h" > that only contains 'asm(".code16gcc");'? I'll note that we did know that -m16 would break on gcc < 4.9. See Stefan's message here: https://lists.gnu.org/archive/html/qemu-devel/2016-05/msg01238.html However you're right we shouldn't break RHEL 7, so I'll try to implement your suggested fix in the next version. > Also, you need to add linuxboot_dma.bin after linuxboot.bin in the > main Makefile. Ah ha, I was wondering why I had to copy the file manually after building it ... Rich. > Thanks, >=20 > Paolo >=20 > > --- > > .gitignore | 4 + > > hw/i386/pc.c | 10 +- > > hw/nvram/fw_cfg.c | 2 +- > > include/hw/nvram/fw_cfg.h | 1 + > > pc-bios/optionrom/Makefile | 13 +- > > pc-bios/optionrom/linuxboot_dma.c | 291 ++++++++++++++++++++++++++++= ++++++++++ > > 6 files changed, 316 insertions(+), 5 deletions(-) > > create mode 100644 pc-bios/optionrom/linuxboot_dma.c > >=20 > > diff --git a/.gitignore b/.gitignore > > index 88a80ff..101d1e0 100644 > > --- a/.gitignore > > +++ b/.gitignore > > @@ -94,6 +94,10 @@ > > /pc-bios/optionrom/linuxboot.bin > > /pc-bios/optionrom/linuxboot.raw > > /pc-bios/optionrom/linuxboot.img > > +/pc-bios/optionrom/linuxboot_dma.asm > > +/pc-bios/optionrom/linuxboot_dma.bin > > +/pc-bios/optionrom/linuxboot_dma.raw > > +/pc-bios/optionrom/linuxboot_dma.img > > /pc-bios/optionrom/multiboot.asm > > /pc-bios/optionrom/multiboot.bin > > /pc-bios/optionrom/multiboot.raw > > diff --git a/hw/i386/pc.c b/hw/i386/pc.c > > index 99437e0..098d571 100644 > > --- a/hw/i386/pc.c > > +++ b/hw/i386/pc.c > > @@ -999,8 +999,13 @@ static void load_linux(PCMachineState *pcms, > > fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_SIZE, setup_size); > > fw_cfg_add_bytes(fw_cfg, FW_CFG_SETUP_DATA, setup, setup_size); > > =20 > > - option_rom[nb_option_roms].name =3D "linuxboot.bin"; > > - option_rom[nb_option_roms].bootindex =3D 0; > > + if (fw_cfg_dma_enabled(fw_cfg)) { > > + option_rom[nb_option_roms].name =3D "linuxboot_dma.bin"; > > + option_rom[nb_option_roms].bootindex =3D 0; > > + } else { > > + option_rom[nb_option_roms].name =3D "linuxboot.bin"; > > + option_rom[nb_option_roms].bootindex =3D 0; > > + } > > nb_option_roms++; > > } > > =20 > > @@ -1263,6 +1268,7 @@ void xen_load_linux(PCMachineState *pcms) > > load_linux(pcms, fw_cfg); > > for (i =3D 0; i < nb_option_roms; i++) { > > assert(!strcmp(option_rom[i].name, "linuxboot.bin") || > > + !strcmp(option_rom[i].name, "linuxboot_dma.bin") || > > !strcmp(option_rom[i].name, "multiboot.bin")); > > rom_add_option(option_rom[i].name, option_rom[i].bootindex); > > } > > diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c > > index 999f480..114aea8 100644 > > --- a/hw/nvram/fw_cfg.c > > +++ b/hw/nvram/fw_cfg.c > > @@ -551,7 +551,7 @@ static bool is_version_1(void *opaque, int versio= n_id) > > return version_id =3D=3D 1; > > } > > =20 > > -static bool fw_cfg_dma_enabled(void *opaque) > > +bool fw_cfg_dma_enabled(void *opaque) > > { > > FWCfgState *s =3D opaque; > > =20 > > diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h > > index d008112..5c27a1f 100644 > > --- a/include/hw/nvram/fw_cfg.h > > +++ b/include/hw/nvram/fw_cfg.h > > @@ -182,5 +182,6 @@ FWCfgState *fw_cfg_init_mem_wide(hwaddr ctl_addr, > > hwaddr dma_addr, AddressSpace *dma_= as); > > =20 > > FWCfgState *fw_cfg_find(void); > > +bool fw_cfg_dma_enabled(void *opaque); > > =20 > > #endif > > diff --git a/pc-bios/optionrom/Makefile b/pc-bios/optionrom/Makefile > > index ce4852a..a51dd6e 100644 > > --- a/pc-bios/optionrom/Makefile > > +++ b/pc-bios/optionrom/Makefile > > @@ -13,15 +13,24 @@ CFLAGS :=3D -Wall -Wstrict-prototypes -Werror -fo= mit-frame-pointer -fno-builtin > > CFLAGS +=3D -I$(SRC_PATH) > > CFLAGS +=3D $(call cc-option, $(CFLAGS), -fno-stack-protector) > > CFLAGS +=3D $(CFLAGS_NOPIE) > > +CFLAGS +=3D -m16 > > QEMU_CFLAGS =3D $(CFLAGS) > > =20 > > -build-all: multiboot.bin linuxboot.bin kvmvapic.bin > > +ASFLAGS +=3D -32 > > + > > +build-all: multiboot.bin linuxboot.bin linuxboot_dma.bin kvmvapic.bi= n > > =20 > > # suppress auto-removal of intermediate files > > .SECONDARY: > > =20 > > +ifdef CONFIG_WIN32 > > +LD_EMULATION =3D i386pe > > +else > > +LD_EMULATION =3D elf_i386 > > +endif > > + > > %.img: %.o > > - $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -Ttext 0 -e _start -s -= o $@ $<," Building $(TARGET_DIR)$@") > > + $(call quiet-command,$(LD) $(LDFLAGS_NOPIE) -m $(LD_EMULATION) -Tte= xt 0 -e _start -s -o $@ $<," Building $(TARGET_DIR)$@") > > =20 > > %.raw: %.img > > $(call quiet-command,$(OBJCOPY) -O binary -j .text $< $@," Buildin= g $(TARGET_DIR)$@") > > diff --git a/pc-bios/optionrom/linuxboot_dma.c b/pc-bios/optionrom/li= nuxboot_dma.c > > new file mode 100644 > > index 0000000..8ebc480 > > --- /dev/null > > +++ b/pc-bios/optionrom/linuxboot_dma.c > > @@ -0,0 +1,291 @@ > > +/* > > + * Linux Boot Option ROM for fw_cfg DMA > > + * > > + * This program is free software; you can redistribute it and/or mod= ify > > + * it under the terms of the GNU General Public License as published= by > > + * the Free Software Foundation; either version 2 of the License, or > > + * (at your option) any later version. > > + * > > + * This program is distributed in the hope that it will be useful, > > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > + * GNU General Public License for more details. > > + * > > + * You should have received a copy of the GNU General Public License > > + * along with this program; if not, see . > > + * > > + * Copyright (c) 2015-2016 Red Hat Inc. > > + * Authors: > > + * Marc Mar=ED > > + * Richard W.M. Jones > > + */ > > + > > +asm( > > +".text\n" > > +".global _start\n" > > +"_start:\n" > > +" .short 0xaa55\n" > > +" .byte 0\n" /* size in 512 units, filled in by signrom.py */ > > +" .byte 0xcb\n" /* far return without prefix */ > > +" .org 0x18\n" > > +" .short 0\n" > > +" .short _pnph\n" > > +"_pnph:\n" > > +" .ascii \"$PnP\"\n" > > +" .byte 0x01\n" > > +" .byte (_pnph_len / 16)\n" > > +" .short 0x0000\n" > > +" .byte 0x00\n" > > +" .byte 0x00\n" > > +" .long 0x00000000\n" > > +" .short _manufacturer\n" > > +" .short _product\n" > > +" .long 0x00000000\n" > > +" .short 0x0000\n" > > +" .short 0x0000\n" > > +" .short _bev\n" > > +" .short 0x0000\n" > > +" .short 0x0000\n" > > +" .equ _pnph_len, . - _pnph\n" > > +"_manufacturer:\n" > > +" .asciz \"QEMU\"\n" > > +"_product:\n" > > +" .asciz \"Linux loader DMA\"\n" > > +" .align 4, 0\n" > > +"_bev:\n" > > +" cli\n" > > +" cld\n" > > +" jmp load_kernel\n" > > +); > > + > > +#include "../../include/hw/nvram/fw_cfg_keys.h" > > + > > +/* QEMU_CFG_DMA_CONTROL bits */ > > +#define BIOS_CFG_DMA_CTL_ERROR 0x01 > > +#define BIOS_CFG_DMA_CTL_READ 0x02 > > +#define BIOS_CFG_DMA_CTL_SKIP 0x04 > > +#define BIOS_CFG_DMA_CTL_SELECT 0x08 > > + > > +#define BIOS_CFG_DMA_ADDR_HIGH 0x514 > > +#define BIOS_CFG_DMA_ADDR_LOW 0x518 > > + > > +#define uint64_t unsigned long long > > +#define uint32_t unsigned int > > +#define uint16_t unsigned short > > + > > +#define barrier() asm("" : : : "memory") > > + > > +typedef struct FWCfgDmaAccess { > > + uint32_t control; > > + uint32_t length; > > + uint64_t address; > > +} __attribute__((packed)) FWCfgDmaAccess; > > + > > +static inline void outl(uint32_t value, uint16_t port) > > +{ > > + asm("outl %0, %w1" : : "a"(value), "Nd"(port)); > > +} > > + > > +static inline void set_es(void *addr) > > +{ > > + uint32_t seg =3D (uint32_t)addr >> 4; > > + asm("movl %0, %%es" : : "r"(seg)); > > +} > > + > > +#ifdef __clang__ > > +#define ADDR32 > > +#else > > +#define ADDR32 "addr32 " > > +#endif > > + > > +static inline uint16_t readw_es(uint16_t offset) > > +{ > > + uint16_t val; > > + asm(ADDR32 "movw %%es:(%1), %0" : "=3Dr"(val) : "r"((uint32_t)of= fset)); > > + barrier(); > > + return val; > > +} > > + > > +static inline uint32_t readl_es(uint16_t offset) > > +{ > > + uint32_t val; > > + asm(ADDR32 "movl %%es:(%1), %0" : "=3Dr"(val) : "r"((uint32_t)of= fset)); > > + barrier(); > > + return val; > > +} > > + > > +static inline void writel_es(uint16_t offset, uint32_t val) > > +{ > > + barrier(); > > + asm(ADDR32 "movl %0, %%es:(%1)" : : "r"(val), "r"((uint32_t)offs= et)); > > +} > > + > > +static inline uint32_t bswap32(uint32_t x) > > +{ > > + return > > + ((x & 0x000000ffU) << 24) | > > + ((x & 0x0000ff00U) << 8) | > > + ((x & 0x00ff0000U) >> 8) | > > + ((x & 0xff000000U) >> 24); > > +} > > + > > +static inline uint64_t bswap64(uint64_t x) > > +{ > > + return > > + ((x & 0x00000000000000ffULL) << 56) | > > + ((x & 0x000000000000ff00ULL) << 40) | > > + ((x & 0x0000000000ff0000ULL) << 24) | > > + ((x & 0x00000000ff000000ULL) << 8) | > > + ((x & 0x000000ff00000000ULL) >> 8) | > > + ((x & 0x0000ff0000000000ULL) >> 24) | > > + ((x & 0x00ff000000000000ULL) >> 40) | > > + ((x & 0xff00000000000000ULL) >> 56); > > +} > > + > > +static inline uint64_t cpu_to_be64(uint64_t x) > > +{ > > + return bswap64(x); > > +} > > + > > +static inline uint32_t cpu_to_be32(uint32_t x) > > +{ > > + return bswap32(x); > > +} > > + > > +static inline uint32_t be32_to_cpu(uint32_t x) > > +{ > > + return bswap32(x); > > +} > > + > > +static void bios_cfg_read_entry(void *buf, uint16_t entry, uint32_t = len) > > +{ > > + FWCfgDmaAccess access; > > + uint32_t control =3D (entry << 16) | BIOS_CFG_DMA_CTL_SELECT > > + | BIOS_CFG_DMA_CTL_READ; > > + > > + access.address =3D cpu_to_be64((uint64_t)(uint32_t)buf); > > + access.length =3D cpu_to_be32(len); > > + access.control =3D cpu_to_be32(control); > > + > > + barrier(); > > + > > + outl(cpu_to_be32((uint32_t)&access), BIOS_CFG_DMA_ADDR_LOW); > > + > > + while (be32_to_cpu(access.control) & ~BIOS_CFG_DMA_CTL_ERROR) { > > + barrier(); > > + } > > +} > > + > > +/* Return top of memory using BIOS function E801. */ > > +static uint32_t get_e801_addr(void) > > +{ > > + uint16_t ax, bx, cx, dx; > > + uint32_t ret; > > + > > + asm("int $0x15\n" > > + : "=3Da"(ax), "=3Db"(bx), "=3Dc"(cx), "=3Dd"(dx) > > + : "a"(0xe801), "b"(0), "c"(0), "d"(0)); > > + > > + /* Not SeaBIOS, but in theory a BIOS could return CX=3DDX=3D0 in= which > > + * case we need to use the result from AX & BX instead. > > + */ > > + if (cx =3D=3D 0 && dx =3D=3D 0) { > > + cx =3D ax; > > + dx =3D bx; > > + } > > + > > + if (dx) { > > + /* DX =3D extended memory above 16M, in 64K units. > > + * Convert it to bytes and return. > > + */ > > + ret =3D ((uint32_t)dx + 256 /* 16M in 64K units */) << 16; > > + } else { > > + /* This is a fallback path for machines with <=3D 16MB of RA= M, > > + * which probably would never be the case, but deal with it > > + * anyway. > > + * > > + * CX =3D extended memory between 1M and 16M, in kilobytes > > + * Convert it to bytes and return. > > + */ > > + ret =3D ((uint32_t)cx + 1024 /* 1M in K */) << 10; > > + } > > + > > + return ret; > > +} > > + > > +void load_kernel(void) > > +{ > > + void *setup_addr; > > + void *initrd_addr; > > + void *kernel_addr; > > + void *cmdline_addr; > > + uint32_t setup_size; > > + uint32_t initrd_size; > > + uint32_t kernel_size; > > + uint32_t cmdline_size; > > + uint32_t initrd_end_page, max_allowed_page; > > + uint32_t segment_addr, stack_addr; > > + > > + bios_cfg_read_entry(&setup_addr, FW_CFG_SETUP_ADDR, 4); > > + bios_cfg_read_entry(&setup_size, FW_CFG_SETUP_SIZE, 4); > > + bios_cfg_read_entry(setup_addr, FW_CFG_SETUP_DATA, setup_size); > > + > > + set_es(setup_addr); > > + > > + /* For protocol < 0x203 we don't have initrd_max ... */ > > + if (readw_es(0x206) < 0x203) { > > + /* ... so we assume initrd_max =3D 0x37ffffff. */ > > + writel_es(0x22c, 0x37ffffff); > > + } > > + > > + bios_cfg_read_entry(&initrd_addr, FW_CFG_INITRD_ADDR, 4); > > + bios_cfg_read_entry(&initrd_size, FW_CFG_INITRD_SIZE, 4); > > + > > + initrd_end_page =3D ((uint32_t)(initrd_addr + initrd_size) & -40= 96); > > + max_allowed_page =3D (readl_es(0x22c) & -4096); > > + > > + if (initrd_end_page !=3D 0 && max_allowed_page !=3D 0 && > > + initrd_end_page !=3D max_allowed_page) { > > + /* Initrd at the end of memory. Compute better initrd addres= s > > + * based on e801 data > > + */ > > + initrd_addr =3D (void *)((get_e801_addr() - initrd_size) & -= 4096); > > + writel_es(0x218, (uint32_t)initrd_addr); > > + > > + } > > + > > + bios_cfg_read_entry(initrd_addr, FW_CFG_INITRD_DATA, initrd_size= ); > > + > > + bios_cfg_read_entry(&kernel_addr, FW_CFG_KERNEL_ADDR, 4); > > + bios_cfg_read_entry(&kernel_size, FW_CFG_KERNEL_SIZE, 4); > > + bios_cfg_read_entry(kernel_addr, FW_CFG_KERNEL_DATA, kernel_size= ); > > + > > + bios_cfg_read_entry(&cmdline_addr, FW_CFG_CMDLINE_ADDR, 4); > > + bios_cfg_read_entry(&cmdline_size, FW_CFG_CMDLINE_SIZE, 4); > > + bios_cfg_read_entry(cmdline_addr, FW_CFG_CMDLINE_DATA, cmdline_s= ize); > > + > > + /* Boot linux */ > > + segment_addr =3D ((uint32_t)setup_addr >> 4); > > + stack_addr =3D (uint32_t)(cmdline_addr - setup_addr - 16); > > + > > + /* As we are changing critical registers, we cannot leave freedo= m to the > > + * compiler. > > + */ > > + asm("movw %%ax, %%ds\n" > > + "movw %%ax, %%es\n" > > + "movw %%ax, %%fs\n" > > + "movw %%ax, %%gs\n" > > + "movw %%ax, %%ss\n" > > + "movl %%ebx, %%esp\n" > > + "addw $0x20, %%ax\n" > > + "pushw %%ax\n" /* CS */ > > + "pushw $0\n" /* IP */ > > + /* Clear registers and jump to Linux */ > > + "xor %%ebx, %%ebx\n" > > + "xor %%ecx, %%ecx\n" > > + "xor %%edx, %%edx\n" > > + "xor %%edi, %%edi\n" > > + "xor %%ebp, %%ebp\n" > > + "lretw\n" > > + : : "a"(segment_addr), "b"(stack_addr)); > > +} > >=20 --=20 Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rj= ones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into KVM guests. http://libguestfs.org/virt-v2v