Re: [PATCH 16/28] kvm tools: Allow load_flat_binary() to load an

Pekka Enberg
2011-12-06T10:29:48Z

On Tue, Dec 6, 2011 at 5:41 AM, Matt Evans <matt@ozlabs.org> wrote:
> This patch passes the initrd fd and commandline to load_flat_binary(), which may
> be used to load both the kernel & an initrd (stashing or inserting the
> commandline as appropriate) in the same way that load_bzimage() does.  This is
> especially useful when load_bzimage() is unused for a particular
> architecture. :-)
>
> Signed-off-by: Matt Evans <matt@ozlabs.org>
> ---
>  tools/kvm/include/kvm/kvm.h |    2 +-
>  tools/kvm/kvm.c             |   10 ++++++----
>  tools/kvm/x86/kvm.c         |   12 +++++++++---
>  3 files changed, 16 insertions(+), 8 deletions(-)
>
> diff --git a/tools/kvm/include/kvm/kvm.h b/tools/kvm/include/kvm/kvm.h
> index fae2ba9..5fe6e75 100644
> --- a/tools/kvm/include/kvm/kvm.h
> +++ b/tools/kvm/include/kvm/kvm.h
> @@ -59,7 +59,7 @@ void kvm__arch_setup_firmware(struct kvm *kvm);
>  bool kvm__arch_cpu_supports_vm(void);
>  void kvm__arch_periodic_poll(struct kvm *kvm);
>
> -int load_flat_binary(struct kvm *kvm, int fd);
> +int load_flat_binary(struct kvm *kvm, int fd_kernel, int fd_initrd, const char *kernel_cmdline);
>  bool load_bzimage(struct kvm *kvm, int fd_kernel, int fd_initrd, const char *kernel_cmdline, u16 vidmode);
>
>  /*
> diff --git a/tools/kvm/kvm.c b/tools/kvm/kvm.c
> index 457de1a..6f33e1a 100644
> --- a/tools/kvm/kvm.c
> +++ b/tools/kvm/kvm.c
> @@ -354,23 +354,25 @@ bool kvm__load_kernel(struct kvm *kvm, const char *kernel_filename,
>
>        ret = load_bzimage(kvm, fd_kernel, fd_initrd, kernel_cmdline, vidmode);
>
> -       if (initrd_filename)
> -               close(fd_initrd);
> -
>        if (ret)
>                goto found_kernel;
>
>        pr_warning("%s is not a bzImage. Trying to load it as a flat binary...", kernel_filename);
>
> -       ret = load_flat_binary(kvm, fd_kernel);
> +       ret = load_flat_binary(kvm, fd_kernel, fd_initrd, kernel_cmdline);
> +
>        if (ret)
>                goto found_kernel;
>
> +       if (initrd_filename)
> +               close(fd_initrd);
>        close(fd_kernel);
>
>        die("%s is not a valid bzImage or flat binary", kernel_filename);
>
>  found_kernel:
> +       if (initrd_filename)
> +               close(fd_initrd);
>        close(fd_kernel);
>
>        return ret;
> diff --git a/tools/kvm/x86/kvm.c b/tools/kvm/x86/kvm.c
> index 7071dc6..4ac21c0 100644
> --- a/tools/kvm/x86/kvm.c
> +++ b/tools/kvm/x86/kvm.c
> @@ -227,17 +227,23 @@ void kvm__irq_trigger(struct kvm *kvm, int irq)
>  #define BOOT_PROTOCOL_REQUIRED 0x206
>  #define LOAD_HIGH              0x01
>
> -int load_flat_binary(struct kvm *kvm, int fd)
> +int load_flat_binary(struct kvm *kvm, int fd_kernel, int fd_initrd, const char *kernel_cmdline)
>  {
>        void *p;
>        int nr;
>
> -       if (lseek(fd, 0, SEEK_SET) < 0)
> +       /* Some architectures may support loading an initrd alongside the flat kernel,
> +        * but we do not.
> +        */

Minor nit - we use comment format where the first line is left empty from text:

/*
* Some architectures may support loading an initrd alongside
the flat kernel,
* but we do not.
*/

> +       if (fd_initrd != -1)
> +               pr_warning("Loading initrd with flat binary not supported.");
> +
> +       if (lseek(fd_kernel, 0, SEEK_SET) < 0)
>                die_perror("lseek");
>
>        p = guest_real_to_host(kvm, BOOT_LOADER_SELECTOR, BOOT_LOADER_IP);
>
> -       while ((nr = read(fd, p, 65536)) > 0)
> +       while ((nr = read(fd_kernel, p, 65536)) > 0)
>                p += nr;
>
>        kvm->boot_selector      = BOOT_LOADER_SELECTOR;
> --
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Otherwise looks OK to me. Cyrill?