Re: [Qemu-devel] [PATCH - V3] Port codes from qemu-kvm to support booting from SCSI disk image

[haishan <haishan.bai@gmail.com>]

Hai Shan Bai wrote:
> The qemu-kvm could boot from SCSI disk image by utilizing seabios, 
> this patch ported codes
> from qemu-kvm to let upstream qemu to support booting from SCSI disk 
> image.
>
> Add 'boot=on' option to qemu command line like following,
> qemu-system-x86_64 -drive file=scsi-disk.img,if=scsi,boot=on
>
>
> Signed-off-by: Shan Hai <haishan.bai@gmail.com 
> <mailto:haishan.bai@gmail.com>>
> ---
>  Makefile.target |    1 +
>  blockdev.c      |   13 ++++++
>  blockdev.h      |    2 +
>  hw/extboot.c    |  123 
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  hw/pc.c         |   17 ++++++++
>  hw/pc.h         |    4 ++
>  qemu-config.c   |    4 ++
>  7 files changed, 164 insertions(+), 0 deletions(-)
>  create mode 100644 hw/extboot.c
>
> diff --git a/Makefile.target b/Makefile.target
> index c8281e9..abba79c 100644
> --- a/Makefile.target
> +++ b/Makefile.target
> @@ -199,6 +199,7 @@ obj-i386-y += mc146818rtc.o i8259.o pc.o
>  obj-i386-y += cirrus_vga.o apic.o ioapic.o piix_pci.o
>  obj-i386-y += vmmouse.o vmport.o hpet.o applesmc.o
>  obj-i386-y += device-hotplug.o pci-hotplug.o smbios.o wdt_ib700.o
> +obj-i386-y += extboot.o
>  obj-i386-y += debugcon.o multiboot.o
>  obj-i386-y += pc_piix.o
>  
> diff --git a/blockdev.c b/blockdev.c
> index 01e402b..78c286c 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -15,6 +15,8 @@
>  #include "qemu-config.h"
>  #include "sysemu.h"
>  
> +DriveInfo *extboot_drive = NULL;
> +
>  static QTAILQ_HEAD(drivelist, DriveInfo) drives = 
> QTAILQ_HEAD_INITIALIZER(drives);
>  
>  /*
> @@ -150,6 +152,7 @@ DriveInfo *drive_init(QemuOpts *opts, int 
> default_to_scsi, int *fatal_error)
>      int on_read_error, on_write_error;
>      const char *devaddr;
>      DriveInfo *dinfo;
> +    int is_extboot = 0;
>      int snapshot = 0;
>      int ret;
>  
> @@ -311,6 +314,12 @@ DriveInfo *drive_init(QemuOpts *opts, int 
> default_to_scsi, int *fatal_error)
>          }
>      }
>  
> +    is_extboot = qemu_opt_get_bool(opts, "boot", 0);
> +    if (is_extboot && extboot_drive) {
> +        fprintf(stderr, "qemu: two bootable drives specified\n");
> +        return NULL;
> +    }
> +
>      on_write_error = BLOCK_ERR_STOP_ENOSPC;
>      if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
>          if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO && 
> type != IF_NONE) {
> @@ -421,6 +430,10 @@ DriveInfo *drive_init(QemuOpts *opts, int 
> default_to_scsi, int *fatal_error)
>          strncpy(dinfo->serial, serial, sizeof(dinfo->serial) - 1);
>      QTAILQ_INSERT_TAIL(&drives, dinfo, next);
>  
> +    if (is_extboot) {
> +        extboot_drive = dinfo;
> +    }
> +
>      bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error);
>  
>      switch(type) {
> diff --git a/blockdev.h b/blockdev.h
> index 37f3a01..e707b87 100644
> --- a/blockdev.h
> +++ b/blockdev.h
> @@ -59,4 +59,6 @@ int do_block_set_passwd(Monitor *mon, const QDict 
> *qdict, QObject **ret_data);
>  int do_change_block(Monitor *mon, const char *device,
>                      const char *filename, const char *fmt);
>  
> +extern DriveInfo *extboot_drive;
> +
>  #endif
> diff --git a/hw/extboot.c b/hw/extboot.c
> new file mode 100644
> index 0000000..8ada21b
> --- /dev/null
> +++ b/hw/extboot.c
> @@ -0,0 +1,123 @@
> +/*
> + * Extended boot option ROM support.
> + *
> + * Copyright IBM, Corp. 2007
> + *
> + * Authors:
> + *  Anthony Liguori   <aliguori@us.ibm.com <mailto:aliguori@us.ibm.com>>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2.  See
> + * the COPYING file in the top-level directory.
> + *
> + */
> +
> +#include "hw.h"
> +#include "pc.h"
> +#include "isa.h"
> +#include "block.h"
> +
> +/* Extended Boot ROM suport */
> +
> +union extboot_cmd
> +{
> +    uint16_t type;
> +    struct {
> +        uint16_t type;
> +        uint16_t cylinders;
> +        uint16_t heads;
> +        uint16_t sectors;
> +        uint64_t nb_sectors;
> +    } query_geometry;
> +    struct {
> +        uint16_t type;
> +        uint16_t nb_sectors;
> +        uint16_t segment;
> +        uint16_t offset;
> +        uint64_t sector;
> +    } xfer;
> +};
> +
> +static void get_translated_chs(BlockDriverState *bs, int *c, int *h, 
> int *s)
> +{
> +    bdrv_get_geometry_hint(bs, c, h, s);
> +
> +    if (*c <= 1024) {
> +        *c >>= 0;
> +        *h <<= 0;
> +    } else if (*c <= 2048) {
> +        *c >>= 1;
> +        *h <<= 1;
> +    } else if (*c <= 4096) {
> +        *c >>= 2;
> +        *h <<= 2;
> +    } else if (*c <= 8192) {
> +        *c >>= 3;
> +        *h <<= 3;
> +    } else {
> +        *c >>= 4;
> +        *h <<= 4;
> +    }
> +
> +    /* what is the correct algorithm for this?? */
> +    if (*h == 256) {
> +        *h = 255;
> +        *c = *c + 1;
> +    }
> +}
> +
> +static void extboot_write_cmd(void *opaque, uint32_t addr, uint32_t 
> value)
> +{
> +    union extboot_cmd cmd;
> +    BlockDriverState *bs = opaque;
> +    int cylinders, heads, sectors, err;
> +    uint64_t nb_sectors;
> +    target_phys_addr_t pa = 0;
> +    int blen = 0;
> +    void *buf = NULL;
> +
> +    cpu_physical_memory_read((value & 0xFFFF) << 4, (uint8_t *)&cmd,
> +                             sizeof(cmd));
> +
> +    if (cmd.type == 0x01 || cmd.type == 0x02) {
> +        pa = cmd.xfer.segment * 16 + cmd.xfer.offset;
> +        blen = cmd.xfer.nb_sectors * 512;
> +        buf = qemu_memalign(512, blen);
> +    }
> +
> +    switch (cmd.type) {
> +    case 0x00:
> +        get_translated_chs(bs, &cylinders, &heads, &sectors);
> +        bdrv_get_geometry(bs, &nb_sectors);
> +        cmd.query_geometry.cylinders = cylinders;
> +        cmd.query_geometry.heads = heads;
> +        cmd.query_geometry.sectors = sectors;
> +        cmd.query_geometry.nb_sectors = nb_sectors;
> +        break;
> +    case 0x01:
> +        err = bdrv_read(bs, cmd.xfer.sector, buf, cmd.xfer.nb_sectors);
> +        if (err)
> +            printf("Read failed\n");
> +
> +        cpu_physical_memory_write(pa, buf, blen);
> +
> +        break;
> +    case 0x02:
> +        cpu_physical_memory_read(pa, buf, blen);
> +
> +        err = bdrv_write(bs, cmd.xfer.sector, buf, cmd.xfer.nb_sectors);
> +        if (err)
> +            printf("Write failed\n");
> +
> +        break;
> +    }
> +
> +    cpu_physical_memory_write((value & 0xFFFF) << 4, (uint8_t *)&cmd,
> +                              sizeof(cmd));
> +    if (buf)
> +        qemu_free(buf);
> +}
> +
> +void extboot_init(BlockDriverState *bs)
> +{
> +    register_ioport_write(0x405, 1, 2, extboot_write_cmd, bs);
> +}
> diff --git a/hw/pc.c b/hw/pc.c
> index 58dea57..88f43aa 100644
> --- a/hw/pc.c
> +++ b/hw/pc.c
> @@ -54,6 +54,7 @@
>  #endif
>  
>  #define BIOS_FILENAME "bios.bin"
> +#define EXTBOOT_FILENAME "extboot.bin"
>  
>  #define PC_MAX_BIOS_SIZE (4 * 1024 * 1024)
>  
> @@ -953,6 +954,10 @@ void pc_memory_init(ram_addr_t ram_size,
>                                   isa_bios_size,
>                                   (bios_offset + bios_size - 
> isa_bios_size) | IO_MEM_ROM);
>  
> +    if (extboot_drive) {
> +        option_rom[nb_option_roms++] = qemu_strdup(EXTBOOT_FILENAME);
> +    }
> +   
>      option_rom_offset = qemu_ram_alloc(NULL, "pc.rom", PC_ROM_SIZE);
>      cpu_register_physical_memory(PC_ROM_MIN_VGA, PC_ROM_SIZE, 
> option_rom_offset);
>  
> @@ -1074,4 +1079,16 @@ void pc_pci_device_init(PCIBus *pci_bus)
>      for (bus = 0; bus <= max_bus; bus++) {
>          pci_create_simple(pci_bus, -1, "lsi53c895a");
>      }
> +
> +    if (extboot_drive) {
> +        DriveInfo *info = extboot_drive;
> +        int cyls, heads, secs;
> +
> +        if (info->type != IF_IDE && info->type != IF_VIRTIO) {
> +            bdrv_guess_geometry(info->bdrv, &cyls, &heads, &secs);
> +            bdrv_set_geometry_hint(info->bdrv, cyls, heads, secs);
> +        }
> +
> +        extboot_init(info->bdrv);
> +    }
>  }
> diff --git a/hw/pc.h b/hw/pc.h
> index 63b0249..61882db 100644
> --- a/hw/pc.h
> +++ b/hw/pc.h
> @@ -167,6 +167,10 @@ void isa_cirrus_vga_init(void);
>  
>  void isa_ne2000_init(int base, int irq, NICInfo *nd);
>  
> +/* extboot.c */
> +       
> +void extboot_init(BlockDriverState *bs);
> +
>  /* e820 types */
>  #define E820_RAM        1
>  #define E820_RESERVED   2
> diff --git a/qemu-config.c b/qemu-config.c
> index 95abe61..08ee553 100644
> --- a/qemu-config.c
> +++ b/qemu-config.c
> @@ -79,6 +79,10 @@ QemuOptsList qemu_drive_opts = {
>          },{
>              .name = "readonly",
>              .type = QEMU_OPT_BOOL,
> +        },{
> +            .name = "boot",
> +            .type = QEMU_OPT_BOOL,
> +            .help = "make this a boot drive",
>          },
>          { /* end if list */ }
>      },
> -- 
> 1.7.0.4
>

This version just corrected the code indentation errors in previous 
versions.

Thanks
Shan Hai