Re: [Xen-devel] [Qemu-devel] [PATCH V4 05/10] Introduce HostPCIDevice to access a pci device on the host.

[Anthony PERARD <anthony.perard@xxxxxxxxxx>]

On Fri, Nov 18, 2011 at 15:06, Konrad Rzeszutek Wilk
<konrad.wilk@xxxxxxxxxx> wrote:
>> +static int host_pci_config_read(HostPCIDevice *d, int pos, void *buf, int 
>> len)
>> +{
>> + Â Âint fd = host_pci_config_fd(d);
>> + Â Âint res = 0;
>> +
>> +again:
>> + Â Âres = pread(fd, buf, len, pos);
>> + Â Âif (res != len) {
>> + Â Â Â Âif (res < 0 && (errno == EINTR || errno == EAGAIN)) {
>> + Â Â Â Â Â Âgoto again;
>> + Â Â Â Â}
>> + Â Â Â Âfprintf(stderr, "host_pci_config: read failed: %s (fd: %i)\n",
>> + Â Â Â Â Â Â Â Âstrerror(errno), fd);
>> + Â Â Â Âreturn -errno;
>> + Â Â}
>> + Â Âreturn 0;
>> +}
>> +static int host_pci_config_write(HostPCIDevice *d,
>> + Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â int pos, const void *buf, int len)
>> +{
>> + Â Âint fd = host_pci_config_fd(d);
>> + Â Âint res = 0;
>> +
>> +again:
>> + Â Âres = pwrite(fd, buf, len, pos);
>> + Â Âif (res != len) {
>> + Â Â Â Âif (res < 0 && (errno == EINTR || errno == EAGAIN)) {
>> + Â Â Â Â Â Âgoto again;
>> + Â Â Â Â}
>> + Â Â Â Âfprintf(stderr, "host_pci_config: write failed: %s\n",
>> + Â Â Â Â Â Â Â Âstrerror(errno));
>> + Â Â Â Âreturn -errno;
>> + Â Â}
>> + Â Âreturn 0;
>> +}
>> +
>> +int host_pci_get_byte(HostPCIDevice *d, int pos, uint8_t *p)
>> +{
>> + Âuint8_t buf;
>> + Âif (host_pci_config_read(d, pos, &buf, 1)) {
>> + Â Â Âreturn -1;
>
> Would it make sense to use the nice enum you decleraed at the
> top of the file? ÂOr not?

I should probably return -errno instead, I mean the return value of
host_pci_config_read/write.

I just introduce the enum to have a differente value than -errno for
some internal function (get_ressource/get_hex_value), so I don't think
that the enum can really by used outside of this file, yet.

(I will change the rest of the patch as you sugest in your comment)

Thanks,

-- 
Anthony PERARD

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