[libvirt PATCH v7 1/5] Add a PCI/PCIe device VPD Parser

[Daniel P. Berrangé]

On Wed, Oct 20, 2021 at 11:30:31AM +0300, Dmitrii Shcherbakov wrote:
> Add support for deserializing the binary PCI/PCIe VPD format and storing
> results in memory.
> 
> The VPD format is specified in "I.3. VPD Definitions" in PCI specs
> (2.2+) and "6.28.1 VPD Format" PCIe 4.0. As section 6.28 in PCIe 4.0
> notes, the PCI Local Bus and PCIe VPD formats are binary compatible
> and PCIe 4.0 merely started incorporating what was already present in
> PCI specs.
> 
> Linux kernel exposes a binary blob in the VPD format via sysfs since
> v2.6.26 (commit 94e6108803469a37ee1e3c92dafdd1d59298602f) which requires
> a parser to interpret.
> 
> Signed-off-by: Dmitrii Shcherbakov <dmitrii.shcherbakov at canonical.com>
> ---
>  build-aux/syntax-check.mk |   4 +-
>  po/POTFILES.in            |   1 +
>  src/libvirt_private.syms  |  18 +
>  src/util/meson.build      |   1 +
>  src/util/virpcivpd.c      | 754 +++++++++++++++++++++++++++++++++++
>  src/util/virpcivpd.h      |  76 ++++
>  src/util/virpcivpdpriv.h  |  83 ++++
>  tests/meson.build         |   1 +
>  tests/testutils.c         |  35 ++
>  tests/testutils.h         |   4 +
>  tests/virpcivpdtest.c     | 809 ++++++++++++++++++++++++++++++++++++++
>  11 files changed, 1784 insertions(+), 2 deletions(-)
>  create mode 100644 src/util/virpcivpd.c
>  create mode 100644 src/util/virpcivpd.h
>  create mode 100644 src/util/virpcivpdpriv.h
>  create mode 100644 tests/virpcivpdtest.c


> +size_t
> +virPCIVPDReadVPDBytes(int vpdFileFd, uint8_t *buf, size_t count, off_t offset, uint8_t *csum)
> +{
> +    ssize_t numRead = pread(vpdFileFd, buf, count, offset);
> +
> +    if (numRead == -1) {
> +        VIR_DEBUG("Unable to read %zu bytes at offset %ld from fd: %d", count, offset, vpdFileFd);

%ld isn't portable to 32-bit, so we need %zd here.

> +    } else if (numRead) {
> +        /*
> +         * Update the checksum for every byte read. Per the PCI(e) specs
> +         * the checksum is correct if the sum of all bytes in VPD from
> +         * VPD address 0 up to and including the VPD-R RV field's first
> +         * data byte is zero.
> +         */
> +        while (count--) {
> +            *csum += *buf;
> +            buf++;
> +        }
> +    }
> +    return numRead;
> +}

Regards,
Daniel
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