Re: [PATCH v4 3/5] hisi_acc_vfio_pci: register debugfs for hisilicon migration driver

liulongfang
2022-12-17T06:44:04Z

On 2022/12/2 23:21, Jason Gunthorpe Wrote:
> On Fri, Dec 02, 2022 at 05:26:23PM +0800, Longfang Liu wrote:
>> On the debugfs framework of VFIO, register the debug function
>> for the live migration driver of the hisilicon accelerator device.
>>
>> On the basis of the original public debug function, a private debug
>> function is added, so that the single-step debugging function
>> during live migration can be realized.
>>
>> Signed-off-by: Longfang Liu <liulongfang@huawei.com>
>> ---
>> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 250 ++++++++++++++++++
>> .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h | 9 +
>> drivers/vfio/pci/vfio_pci_debugfs.c | 10 +-
>> 3 files changed, 268 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>> index eb18edffbd5f..0f35cde6e8ec 100644
>> --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>> +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
>> @@ -15,6 +15,7 @@
>> #include <linux/anon_inodes.h>
>>
>> #include "hisi_acc_vfio_pci.h"
>> +#include "../vfio_pci_debugfs.h"
>>
>> /* Return 0 on VM acc device ready, -ETIMEDOUT hardware timeout */
>> static int qm_wait_dev_not_ready(struct hisi_qm *qm)
>> @@ -609,6 +610,18 @@ hisi_acc_check_int_state(struct hisi_acc_vf_core_device *hisi_acc_vdev)
>> }
>> }
>>
>> +static void hisi_acc_vf_migf_save(struct hisi_acc_vf_migration_file *src_migf,
>> + struct hisi_acc_vf_migration_file *dst_migf)
>> +{
>> + if (!dst_migf)
>> + return;
>> +
>> + dst_migf->disabled = false;
>> + dst_migf->total_length = src_migf->total_length;
>> + memcpy(&dst_migf->vf_data, &src_migf->vf_data,
>> + sizeof(struct acc_vf_data));
>> +}
>> +
>> static void hisi_acc_vf_disable_fd(struct hisi_acc_vf_migration_file *migf)
>> {
>> mutex_lock(&migf->lock);
>> @@ -621,12 +634,16 @@ static void hisi_acc_vf_disable_fd(struct hisi_acc_vf_migration_file *migf)
>> static void hisi_acc_vf_disable_fds(struct hisi_acc_vf_core_device *hisi_acc_vdev)
>> {
>> if (hisi_acc_vdev->resuming_migf) {
>> + hisi_acc_vf_migf_save(hisi_acc_vdev->resuming_migf,
>> + hisi_acc_vdev->debug_migf);
>> hisi_acc_vf_disable_fd(hisi_acc_vdev->resuming_migf);
>> fput(hisi_acc_vdev->resuming_migf->filp);
>> hisi_acc_vdev->resuming_migf = NULL;
>> }
>>
>> if (hisi_acc_vdev->saving_migf) {
>> + hisi_acc_vf_migf_save(hisi_acc_vdev->saving_migf,
>> + hisi_acc_vdev->debug_migf);
>> hisi_acc_vf_disable_fd(hisi_acc_vdev->saving_migf);
>> fput(hisi_acc_vdev->saving_migf->filp);
>> hisi_acc_vdev->saving_migf = NULL;
>> @@ -1188,6 +1205,231 @@ static long hisi_acc_vfio_pci_ioctl(struct vfio_device *core_vdev, unsigned int
>> return vfio_pci_core_ioctl(core_vdev, cmd, arg);
>> }
>>
>> +static int hisi_acc_vf_debug_io(struct vfio_device *vdev)
>> +{
>> + struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(vdev);
>> + struct hisi_qm *vf_qm = &hisi_acc_vdev->vf_qm;
>> + struct device *dev = vdev->dev;
>> + u64 data;
>> + int ret;
>> +
>> + data = readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE);
>> + dev_info(dev, "debug mailbox val: 0x%llx\n", data);
>> +
>> + ret = qm_wait_dev_not_ready(vf_qm);
>> + if (ret)
>> + dev_err(dev, "VF device not ready!\n");
>
> debugfs has helpers for this, you should use debugfs_print_regs32()
>

I analyzed it, and there is no need to replace it here, because it is
a subtype of the "debug" file operation, not an independent debugfs
file operation.

Thanks,
Longfang.

>> +static int hisi_acc_vf_debug_resume(struct vfio_device *vdev)
>> +{
>> + struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(vdev);
>> + struct hisi_acc_vf_migration_file *migf = hisi_acc_vdev->debug_migf;
>> + struct device *dev = vdev->dev;
>> + int ret;
>> +
>> + ret = vf_qm_state_save(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to save device data!\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = vf_qm_check_match(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to match the VF!\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = vf_qm_load_data(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to recover the VF!\n");
>> + return -EINVAL;
>> + }
>> +
>> + vf_qm_fun_reset(&hisi_acc_vdev->vf_qm);
>> + dev_info(dev, "successful to resume device data!\n");
>> +
>> + return 0;
>> +}
>
> This doesn't seem like it belongs in debugfs at all, please just write
> a test progam using normal vfio ioctls to do these steps and put in
> the kernel selftests directory.
>
>> +static int hisi_acc_vf_debug_save(struct vfio_device *vdev)
>> +{
>> + struct hisi_acc_vf_core_device *hisi_acc_vdev = hisi_acc_get_vf_dev(vdev);
>> + struct hisi_acc_vf_migration_file *migf = hisi_acc_vdev->debug_migf;
>> + struct device *dev = vdev->dev;
>> + int ret;
>> +
>> + ret = vf_qm_state_save(hisi_acc_vdev, migf);
>> + if (ret) {
>> + dev_err(dev, "failed to save device data!\n");
>> + return -EINVAL;
>> + }
>> + dev_info(dev, "successful to save device data!\n");
>> +
>> + return 0;
>> +}
>
> Ditto, I don't think debugfs should be accessing the device state
> independently of the main FSM.
>
> Jason
> .
>