Miss a comment reply  :).

On 2021/8/5 8:05, Bjorn Helgaas wrote:

On Wed, Aug 04, 2021 at 09:47:07PM +0800, Dongdong Liu wrote:

quoted

PCIe spec 5.0 r1.0 section 2.2.6.2 says that if an Endpoint supports
sending Requests to other Endpoints (as opposed to host memory), the
Endpoint must not send 10-Bit Tag Requests to another given Endpoint
unless an implementation-specific mechanism determines that the
Endpoint supports 10-Bit Tag Completer capability.
Add sriov_vf_10bit_tag file to query the status of VF 10-Bit Tag
Requester Enable. Add sriov_vf_10bit_tag_ctl file to disable the VF
10-Bit Tag Requester. The typical use case is for p2pdma when the peer
device does not support 10-BIT Tag Completer.

Fix the usual spec quoting issue.  Or maybe this is not actually
quoted but is missing blank lines between paragraphs.

s/10-BIT/10-Bit/

quoted

Signed-off-by: Dongdong Liu <redacted>
---
 Documentation/ABI/testing/sysfs-bus-pci | 20 +++++++++++++
 drivers/pci/iov.c                       | 50 +++++++++++++++++++++++++++++++++
 2 files changed, 70 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 0e0c97d..8fdbfae 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci

@@ -421,3 +421,23 @@ Description:
 		to disable 10-Bit Tag Requester when the driver does not bind
 		the deivce. The typical use case is for p2pdma when the peer
 		device does not support 10-BIT Tag Completer.
+
+What:		/sys/bus/pci/devices/.../sriov_vf_10bit_tag
+Date:		August 2021
+Contact:	Dongdong Liu <liudongdong3@huawei.com>
+Description:
+		This file is associated with a SR-IOV physical function (PF).
+		It is visible when the device has VF 10-Bit Tag Requester
+		Supported. It contains the status of VF 10-Bit Tag Requester
+		Enable. The file is only readable.

s/only readable/read-only/

quoted

+What:		/sys/bus/pci/devices/.../sriov_vf_10bit_tag_ctl

Why does this file have "_ctl" on the end when the one in patch 7/9
does not?

PF: 0000:82:00.0  VF:0000:82:10.0
/sys/bus/pci/devices/0000:82:00.0/sriov_vf_10bit_tag
/sys/bus/pci/devices/0000:82:10.0/sriov_vf_10bit_tag_ctl

sriov_vf_10bit_tag is used to qeury the status of VF 10-Bit Tag
Requester Enable,  bind with PF device.

sriov_vf_10bit_tag_ctl is used to disable the VF 10-Bit Tag Requester,
bind with VF device, although in fact it writes PF SR-IOV control 
register, just detect if the VF driver have already bond with the VF deivce.

Thanks,
Dongdong