Re: [Xen-devel] Re: [PATCH 2/3] xen: add CPU microcode update driver

[Jeremy Fitzhardinge <jeremy@xxxxxxxx>]

On 11/15/2010 07:59 AM, Konrad Rzeszutek Wilk wrote:
>> +static enum ucode_state xen_request_microcode_user(int cpu,
>> +                                               const void __user *buf, 
>> size_t size)
>> +{
>> +    struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
>> +    struct xen_microcode *uc;
>> +    enum ucode_state ret;
>> +    size_t unread;
>> +
>> +    if (cpu != 0) {
>> +            /* No real firmware for non-zero cpus; just store a
>> +               placeholder */
>> +            size = 0;
>> +    }
>> +
>> +    if (uci->mc != NULL) {
>> +            vfree(uci->mc);
>> +            uci->mc = NULL;
>> +    }
>> +
>> +    ret = UCODE_ERROR;
>> +    uc = vmalloc(sizeof(*uc) + size);
>> +    if (uc == NULL)
>> +            goto out;
>> +
>> +    uc->len = size;
>> +
>> +    ret = UCODE_NFOUND;
>> +
>> +    /* XXX This sporadically returns uncopied bytes, so we return
>> +       EFAULT.  As far as I can see, the usermode code
>            ^^^^^ UCODE_NFOUND.
>> +       (microcode_ctl) isn't doing anything wrong... */
> Is this still valid? Looking at AMD it checks for a magic key and the Intel
> just copies without checks.

Probably not.

    J

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel