Re: [Qemu-devel] [PATCH v3] qemu-ga: make get-fsinfo work over pci bridges

[Marc-André Lureau]

Hi Michael

On Mon, May 14, 2018 at 2:38 PM, Marc-André Lureau
<address@hidden> wrote:
> Iterate over the PCI bridges to lookup the PCI device associated with
> the block device.
>
> This allows to lookup the driver under the following syspath:
> /sys/devices/pci0000:00/0000:00:02.2/0000:03:00.0/virtio2/block/vda/vda3
>
> It also works with an "old-style" Q35 libvirt hierarchy: root complex
> -> DMI-PCI bridge -> PCI-PCI bridge -> virtio controller, ex:
> /sys/devices/pci0000:00/0000:00:03.0/0000:01:01.0/0000:02:01.0/virtio1/block/vda/vda3
>
> The setup can be reproduced with the following qemu command line
> (Thanks Marcel for help):
>
> qemu-system-x86_64 -M q35 \
>   -device i82801b11-bridge,id=dmi2pci_bridge,bus=pcie.0
>   -device pci-bridge,id=pci_bridge,bus=dmi2pci_bridge,addr=0x1,chassis_nr=1
>   -device 
> virtio-blk-pci,scsi=off,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1,bus=pci_bridge,addr=0x1
>
> For consistency with other syspath-related debug messages, replace a
> \"%s\" in the message with '%s'.
>
> Fixes:
> https://bugzilla.redhat.com/show_bug.cgi?id=1567041
>
> Signed-off-by: Marc-André Lureau <address@hidden>
> Reviewed-by: Laszlo Ersek <address@hidden>
> ---

ping,

are you planning to send a pull request for qga patches

>
> v3:
>  - replace \"%s\" in the debug message with '%s'
>  - simplify the code by getting rid of an "else if"
>
> qga/commands-posix.c | 23 +++++++++++++++++++----
>  1 file changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/qga/commands-posix.c b/qga/commands-posix.c
> index 0dc219dbcf..624b0dc0c3 100644
> --- a/qga/commands-posix.c
> +++ b/qga/commands-posix.c
> @@ -875,13 +875,28 @@ static void build_guest_fsinfo_for_real_device(char 
> const *syspath,
>      p = strstr(syspath, "/devices/pci");
>      if (!p || sscanf(p + 12, "%*x:%*x/%x:%x:%x.%x%n",
>                       pci, pci + 1, pci + 2, pci + 3, &pcilen) < 4) {
> -        g_debug("only pci device is supported: sysfs path \"%s\"", syspath);
> +        g_debug("only pci device is supported: sysfs path '%s'", syspath);
>          return;
>      }
>
> -    driver = get_pci_driver(syspath, (p + 12 + pcilen) - syspath, errp);
> -    if (!driver) {
> -        goto cleanup;
> +    p += 12 + pcilen;
> +    while (true) {
> +        driver = get_pci_driver(syspath, p - syspath, errp);
> +        if (driver && (g_str_equal(driver, "ata_piix") ||
> +                       g_str_equal(driver, "sym53c8xx") ||
> +                       g_str_equal(driver, "virtio-pci") ||
> +                       g_str_equal(driver, "ahci"))) {
> +            break;
> +        }
> +
> +        if (sscanf(p, "/%x:%x:%x.%x%n",
> +                          pci, pci + 1, pci + 2, pci + 3, &pcilen) == 4) {
> +            p += pcilen;
> +            continue;
> +        }
> +
> +        g_debug("unsupported driver or sysfs path '%s'", syspath);
> +        return;
>      }
>
>      p = strstr(syspath, "/target");
> --
> 2.17.0.253.g3dd125b46d
>
>



-- 
Marc-André Lureau