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:
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/
Signed-off-by: Dongdong Liu <liudongdong3@xxxxxxxxxx>
---
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@xxxxxxxxxx>
+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/
+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
