Re: [Xen-devel] [PATCH v6 01/12] misc/xenmicrocode: Upload a microcode blob to the hypervisor

[Chao Gao <chao.gao@xxxxxxxxx>]

On Tue, Mar 12, 2019 at 04:27:33PM +0100, Roger Pau Monné wrote:
>On Mon, Mar 11, 2019 at 03:57:25PM +0800, Chao Gao wrote:
>> This patch provides a tool for late microcode update.
>> 
>> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
>> Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
>> ---
>>  tools/libxc/include/xenctrl.h |  1 +
>>  tools/libxc/xc_misc.c         | 20 ++++++++++
>>  tools/misc/Makefile           |  4 ++
>>  tools/misc/xenmicrocode.c     | 89 
>> +++++++++++++++++++++++++++++++++++++++++++
>
>Would you mind naming the tool xen-ucode or xen-microcode?
>
>That seems more inline with the naming schemed used for most of the
>tools in misc/.
>
>> +int main(int argc, char *argv[])
>> +{
>> +    int fd, len, ret;
>> +    char *filename, *buf;
>> +    struct stat st;
>> +    struct xen_platform_op op;
>> +    xc_interface *xch;
>> +    DECLARE_HYPERCALL_BUFFER(struct xenpf_microcode_update, uc);
>> +
>> +    if (argc < 2)
>> +    {
>> +        show_help();
>> +        return 0;
>> +    }
>> +
>> +    filename = argv[1];
>> +    fd = open(filename, O_RDONLY);
>> +    if (fd < 0) {
>> +        fprintf(stderr, "Could not open %s. (err: %s)\n",
>> +                filename, strerror(errno));
>> +        return errno;
>> +    }
>> +
>> +    if (stat(filename, &st) != 0) {
>> +        fprintf(stderr, "Could not get the size of %s. (err: %s)\n",
>> +                filename, strerror(errno));
>> +        return errno;
>> +    }
>> +
>> +    len = st.st_size;
>> +    buf = mmap(0, len, PROT_READ, MAP_PRIVATE, fd, 0);
>> +    if (buf == MAP_FAILED) {
>> +        fprintf(stderr, "mmap failed. (error: %s)\n", strerror(errno));
>> +        return errno;
>> +    }
>
>IMO you could just use fread to read the full contents of the file
>into the buffer you allocate and avoid this mmap dance.

Sure. Will follow your advices.

Thanks
Chao

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