-----Original Message-----IOFS introducing multiple methods for PR and AFU access.
From: Tom Rix <trix@xxxxxxxxxx>
Sent: Tuesday, February 15, 2022 11:51 PM
To: Zhang, Tianfei <tianfei.zhang@xxxxxxxxx>; Wu, Hao <hao.wu@xxxxxxxxx>;
mdf@xxxxxxxxxx; Xu, Yilun <yilun.xu@xxxxxxxxx>; linux-fpga@xxxxxxxxxxxxxxx;
linux-doc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Cc: corbet@xxxxxxx; Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
Subject: Re: [PATCH v1 4/7] fpga: dfl: fix VF creation when ports have no local
BAR space
On 2/14/22 3:26 AM, Tianfei zhang wrote:
From: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>Similar, how does this fit in with iofs, this looks like it would not be valid for the
When a port is not connected to the same PCIe endpoint as the FME, the
port does not need to be released before being virtualized. Fix VF
creation code to handle this new use
existing cards
1. Legacy Model.
2. Micro-Personas in AFU.
3. Multiple VFs per PR slot.
For 1 and 2 model, there are 1:1 mapping between Port device and PR slot (or entire AFU). In virtualization,
it should release the Port device firstly and then assign to VM. In this models, the DFL driver will track that
the number of port devices has released (cdev->released_port_num in dfl_fpga_cdev_config_ports_vf() function)
are equal with the numbers of SRIOV or not. But in model 3, it has multiple VFs per PR slot, and assign the VF to VM
without release the port device, so the tracking mechanism of cdev->released_port_num is not workable on new
model. This patch want to handle this new model during VF creation.
This code want to handle the " Multiple VFs per PR slot" model as I mentioned above.case.EXPORT_SYMBOL_GPL(dfl_fpga_cdev_config_ports_pf);
Signed-off-by: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
Signed-off-by: Tianfei Zhang <tianfei.zhang@xxxxxxxxx>
---
drivers/fpga/dfl.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c index
26f8cf890700..cfc539a656f0 100644
--- a/drivers/fpga/dfl.c
+++ b/drivers/fpga/dfl.c
@@ -1705,15 +1705,22 @@
int dfl_fpga_cdev_config_ports_vf(struct dfl_fpga_cdev *cdev, int num_vfs)This looks wrong,
{
struct dfl_feature_platform_data *pdata;
- int ret = 0;
+ int ret = 0, port_count = 0;
mutex_lock(&cdev->lock);
+
+ list_for_each_entry(pdata, &cdev->port_dev_list, node) {
+ if (pdata->dev)
pdata->dev is dereferenced below, if there is a case were (!pdata->dev)
here there would be crash later.
+ continue;how does this work when only some of the ports are handled in the new way ?
+ port_count++;
In new model, the port_count want to count that how many port devices have released.
This code looks not good readability, I try to re-write it.
Tom
+ }
+
/*
* can't turn multiple ports into 1 VF device, only 1 port for 1 VF
* device, so if released port number doesn't match VF device number,
* then reject the request with -EINVAL error code.
*/
- if (cdev->released_port_num != num_vfs) {
+ if (port_count && cdev->released_port_num != num_vfs) {
ret = -EINVAL;
goto done;
}