Re: [PATCH vfio 08/11] vfio/pci: Expose vfio_pci_core_setup_barmap()

[Yishai Hadas via Virtualization]

On 21/09/2023 19:35, Alex Williamson wrote:

On Thu, 21 Sep 2023 15:40:37 +0300
Yishai Hadas <yish...@nvidia.com> wrote:

Expose vfio_pci_core_setup_barmap() to be used by drivers.

This will let drivers to mmap a BAR and re-use it from both vfio and the
driver when it's applicable.

This API will be used in the next patches by the vfio/virtio coming
driver.

Signed-off-by: Yishai Hadas <yish...@nvidia.com>
---
  drivers/vfio/pci/vfio_pci_core.c | 25 +++++++++++++++++++++++++
  drivers/vfio/pci/vfio_pci_rdwr.c | 28 ++--------------------------
  include/linux/vfio_pci_core.h    |  1 +
  3 files changed, 28 insertions(+), 26 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 1929103ee59a..b56111ed8a8c 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -684,6 +684,31 @@ void vfio_pci_core_disable(struct vfio_pci_core_device 
*vdev)
  }
  EXPORT_SYMBOL_GPL(vfio_pci_core_disable);

+int vfio_pci_core_setup_barmap(struct vfio_pci_core_device *vdev, int bar)

+{
+       struct pci_dev *pdev = vdev->pdev;
+       void __iomem *io;
+       int ret;
+
+       if (vdev->barmap[bar])
+               return 0;
+
+       ret = pci_request_selected_regions(pdev, 1 << bar, "vfio");
+       if (ret)
+               return ret;
+
+       io = pci_iomap(pdev, bar, 0);
+       if (!io) {
+               pci_release_selected_regions(pdev, 1 << bar);
+               return -ENOMEM;
+       }
+
+       vdev->barmap[bar] = io;
+
+       return 0;
+}
+EXPORT_SYMBOL(vfio_pci_core_setup_barmap);

Not to endorse the rest of this yet, but minimally _GPL, same for the
following patch.  Thanks,

Alex

Sure, will change to EXPORT_SYMBOL_GPL as part of V1.

Yishai

+
  void vfio_pci_core_close_device(struct vfio_device *core_vdev)
  {
        struct vfio_pci_core_device *vdev =
diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c
index e27de61ac9fe..6f08b3ecbb89 100644
--- a/drivers/vfio/pci/vfio_pci_rdwr.c
+++ b/drivers/vfio/pci/vfio_pci_rdwr.c
@@ -200,30 +200,6 @@ static ssize_t do_io_rw(struct vfio_pci_core_device *vdev, 
bool test_mem,
        return done;
  }

-static int vfio_pci_setup_barmap(struct vfio_pci_core_device *vdev, int bar)

-{
-       struct pci_dev *pdev = vdev->pdev;
-       int ret;
-       void __iomem *io;
-
-       if (vdev->barmap[bar])
-               return 0;
-
-       ret = pci_request_selected_regions(pdev, 1 << bar, "vfio");
-       if (ret)
-               return ret;
-
-       io = pci_iomap(pdev, bar, 0);
-       if (!io) {
-               pci_release_selected_regions(pdev, 1 << bar);
-               return -ENOMEM;
-       }
-
-       vdev->barmap[bar] = io;
-
-       return 0;
-}
-
  ssize_t vfio_pci_bar_rw(struct vfio_pci_core_device *vdev, char __user *buf,
                        size_t count, loff_t *ppos, bool iswrite)
  {
@@ -262,7 +238,7 @@ ssize_t vfio_pci_bar_rw(struct vfio_pci_core_device *vdev, 
char __user *buf,
                }
                x_end = end;
        } else {
-               int ret = vfio_pci_setup_barmap(vdev, bar);
+               int ret = vfio_pci_core_setup_barmap(vdev, bar);
                if (ret) {
                        done = ret;
                        goto out;
@@ -438,7 +414,7 @@ int vfio_pci_ioeventfd(struct vfio_pci_core_device *vdev, 
loff_t offset,
                return -EINVAL;
  #endif

- ret = vfio_pci_setup_barmap(vdev, bar);

+       ret = vfio_pci_core_setup_barmap(vdev, bar);
        if (ret)
                return ret;

diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h

index 562e8754869d..67ac58e20e1d 100644
--- a/include/linux/vfio_pci_core.h
+++ b/include/linux/vfio_pci_core.h
@@ -127,6 +127,7 @@ int vfio_pci_core_match(struct vfio_device *core_vdev, char 
*buf);
  int vfio_pci_core_enable(struct vfio_pci_core_device *vdev);
  void vfio_pci_core_disable(struct vfio_pci_core_device *vdev);
  void vfio_pci_core_finish_enable(struct vfio_pci_core_device *vdev);
+int vfio_pci_core_setup_barmap(struct vfio_pci_core_device *vdev, int bar);
  pci_ers_result_t vfio_pci_core_aer_err_detected(struct pci_dev *pdev,
                                                pci_channel_state_t state);

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