[libvirt] [RFC v3 PATCH 3/5] PowerPC : Add support for ppc64 qemu

[Stefan Berger]

On 11/29/2011 09:59 AM, Prerna Saxena wrote:
> From: Prerna Saxena<prerna at linux.vnet.ibm.com>
> Date: Mon, 3 Oct 2011 06:01:33 -0700
> Subject: [PATCH 3/5] Add support for ppc64 qemu
>
> This enables libvirt to select the correct qemu binary (qemu-system-ppc64)
> for a guest vm based on arch 'ppc64'.
> Also, libvirt is enabled to correctly parse the list of supported PowerPC
> CPUs, generated by running 'qemu-system-ppc64 -cpu ?'
>
> Signed-off-by: Prerna Saxena<prerna at linux.vnet.ibm.com>
> ---
>   src/qemu/qemu_capabilities.c |   64 ++++++++++++++++++++++++++++++++++++++++++
>   1 files changed, 64 insertions(+), 0 deletions(-)
>
> diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
> index c5fe41d..c2d3d93 100644
> --- a/src/qemu/qemu_capabilities.c
> +++ b/src/qemu/qemu_capabilities.c
> @@ -185,6 +185,7 @@ static const struct qemu_arch_info const arch_info_hvm[] = {
>       {  "mipsel", 32, NULL, "qemu-system-mipsel", NULL, NULL, 0 },
>       {  "sparc",  32, NULL, "qemu-system-sparc",  NULL, NULL, 0 },
>       {  "ppc",    32, NULL, "qemu-system-ppc",    NULL, NULL, 0 },
> +    {  "ppc64",    64, NULL, "qemu-system-ppc64",    NULL, NULL, 0 },
>       {  "itanium", 64, NULL, "qemu-system-ia64",  NULL, NULL, 0 },
>       {  "s390x",  64, NULL, "qemu-system-s390x",  NULL, NULL, 0 },
>   };
> @@ -477,6 +478,67 @@ error:
>       return -1;
>   }
>
> +/* ppc64 parser.
> + * Format : PowerPC<machine>  <description>
> + */
> +static int
> +qemuCapsParsePPCModels(const char *output,
> +                       unsigned int *retcount,
> +                       const char ***retcpus)
> +{
> +    const char *p = output;
> +    const char *next;
> +    unsigned int count = 0;
> +    const char **cpus = NULL;
> +    int i;
> +    do {
> +        const char *t;
> +
> +        if ((next = strchr(p, '\n')))
> +            next++;
> +
> +        if (!STRPREFIX(p, "PowerPC "))
> +            continue;
If what you are parsing here is indeed corrupted, you may end up in an 
endless loop with p not moving anymore. You have to advance 'p' at least 
by 1 and have a check before whether *p == '\0' to get out of it. You 
may also want to put this check before the calculation of 'next'.
> +
> +        /* Skip the preceding sub-string "PowerPC " */
> +        p += 8;
> +
> +        /*Malformed string, does not obey the format 'PowerPC<model>  <desc>'*/
> +        if (!(t = strchr(p, ' ')) || (next&&  t>= next))
> +            continue;
> +
> +        if (*p == '\0' || *p == '\n')
> +            continue;
*p = '\0' presumably is end-of-string -- shouldn't we 'break' here ?
> +
> +        if (retcpus) {
if retcpus is not provided you may want to return -1 earlier
> +            unsigned int len;
> +
> +            if (VIR_REALLOC_N(cpus, count + 1)<  0)
virReportOOMError();
> +                goto error;
> +
> +            if (t)
> +                len = t - p - 1;
len would remain uninitialized if t is not set, but t at this point must 
be set due to the check above. Remove 'if(t)'.
> +
> +            if (!(cpus[count] = strndup(p, len)))
virReportOOMError();
> +                goto error;
> +        }
> +        count++;
> +    } while ((p = next));
> +
> +    if (retcount)
> +        *retcount = count;
> +    if (retcpus)
> +        *retcpus = cpus;
> +    return 0;
> +
> +error:
> +    if (cpus) {
> +        for (i = 0; i<  count; i++)
> +            VIR_FREE(cpus[i]);
> +    }
> +    VIR_FREE(cpus);
> +    return -1;
> +}
>
>   int
>   qemuCapsProbeCPUModels(const char *qemu,
> @@ -497,6 +559,8 @@ qemuCapsProbeCPUModels(const char *qemu,
>
>       if (STREQ(arch, "i686") || STREQ(arch, "x86_64"))
>           parse = qemuCapsParseX86Models;
> +    else if (STREQ(arch, "ppc64"))
> +        parse = qemuCapsParsePPCModels;
>       else {
>           VIR_DEBUG("don't know how to parse %s CPU models", arch);
>           return 0;