Re: [Qemu-devel] [RFC Patch 01/12] PCI: Add virtfn_index for struct pci_device

[Lan, Tianyu]

On 10/22/2015 2:07 AM, Alexander Duyck wrote:

On 10/21/2015 09:37 AM, Lan Tianyu wrote:

Add "virtfn_index" member in the struct pci_device to record VF sequence
of PF. This will be used in the VF sysfs node handle.

Signed-off-by: Lan Tianyu 
---
  drivers/pci/iov.c   | 1 +
  include/linux/pci.h | 1 +
  2 files changed, 2 insertions(+)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index ee0ebff..065b6bb 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -136,6 +136,7 @@ static int virtfn_add(struct pci_dev *dev, int id,
int reset)
  virtfn->physfn = pci_dev_get(dev);
  virtfn->is_virtfn = 1;
  virtfn->multifunction = 0;
+virtfn->virtfn_index = id;
  for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
  res = >resource[i + PCI_IOV_RESOURCES];
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 353db8d..85c5531 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -356,6 +356,7 @@ struct pci_dev {
  unsigned intio_window_1k:1;/* Intel P2P bridge 1K I/O
windows */
  unsigned intirq_managed:1;
  pci_dev_flags_t dev_flags;
+unsigned intvirtfn_index;
  atomic_tenable_cnt;/* pci_enable_device has been called */
  u32saved_config_space[16]; /* config space saved at
suspend time */



Can't you just calculate the VF index based on the VF BDF number
combined with the information in the PF BDF number and VF
offset/stride?  Seems kind of pointless to add a variable that is only
used by one driver and is in a slowpath when you can just calculate it
pretty quickly.


Good suggestion. Will try it.



- Alex

[Qemu-devel] [RFC Patch 01/12] PCI: Add virtfn_index for struct pci_device

[Lan Tianyu]

Add "virtfn_index" member in the struct pci_device to record VF sequence
of PF. This will be used in the VF sysfs node handle.

Signed-off-by: Lan Tianyu 
---
 drivers/pci/iov.c   | 1 +
 include/linux/pci.h | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index ee0ebff..065b6bb 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -136,6 +136,7 @@ static int virtfn_add(struct pci_dev *dev, int id, int 
reset)
virtfn->physfn = pci_dev_get(dev);
virtfn->is_virtfn = 1;
virtfn->multifunction = 0;
+   virtfn->virtfn_index = id;
 
for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
res = >resource[i + PCI_IOV_RESOURCES];
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 353db8d..85c5531 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -356,6 +356,7 @@ struct pci_dev {
unsigned intio_window_1k:1; /* Intel P2P bridge 1K I/O windows */
unsigned intirq_managed:1;
pci_dev_flags_t dev_flags;
+   unsigned intvirtfn_index;
atomic_tenable_cnt; /* pci_enable_device has been called */
 
u32 saved_config_space[16]; /* config space saved at 
suspend time */
-- 
1.8.4.rc0.1.g8f6a3e5.dirty

Re: [Qemu-devel] [RFC Patch 01/12] PCI: Add virtfn_index for struct pci_device

[Alexander Duyck]

On 10/21/2015 09:37 AM, Lan Tianyu wrote:

Add "virtfn_index" member in the struct pci_device to record VF sequence
of PF. This will be used in the VF sysfs node handle.

Signed-off-by: Lan Tianyu 
---
  drivers/pci/iov.c   | 1 +
  include/linux/pci.h | 1 +
  2 files changed, 2 insertions(+)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index ee0ebff..065b6bb 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -136,6 +136,7 @@ static int virtfn_add(struct pci_dev *dev, int id, int 
reset)
virtfn->physfn = pci_dev_get(dev);
virtfn->is_virtfn = 1;
virtfn->multifunction = 0;
+   virtfn->virtfn_index = id;
  
  	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {

res = >resource[i + PCI_IOV_RESOURCES];
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 353db8d..85c5531 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -356,6 +356,7 @@ struct pci_dev {
unsigned intio_window_1k:1; /* Intel P2P bridge 1K I/O windows */
unsigned intirq_managed:1;
pci_dev_flags_t dev_flags;
+   unsigned intvirtfn_index;
atomic_tenable_cnt; /* pci_enable_device has been called */
  
  	u32		saved_config_space[16]; /* config space saved at suspend time */




Can't you just calculate the VF index based on the VF BDF number 
combined with the information in the PF BDF number and VF 
offset/stride?  Seems kind of pointless to add a variable that is only 
used by one driver and is in a slowpath when you can just calculate it 
pretty quickly.


- Alex