[PATCH V7 vfio 8/9] vfio/pci: Expose vfio_pci_core_iowrite/read##size()

Yishai Hadas
2023-12-07T10:29:44Z

Expose vfio_pci_core_iowrite/read##size() to let it be used by drivers.

This functionality is needed to enable direct access to some physical
BAR of the device with the proper locks/checks in place.

The next patches from this series will use this functionality on a data
path flow when a direct access to the BAR is needed.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
---
drivers/vfio/pci/vfio_pci_rdwr.c | 50 +++++++++++++++++---------------
include/linux/vfio_pci_core.h | 19 ++++++++++++
2 files changed, 45 insertions(+), 24 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c
index a9887fd6de46..07fea08ea8a2 100644
--- a/drivers/vfio/pci/vfio_pci_rdwr.c
+++ b/drivers/vfio/pci/vfio_pci_rdwr.c
@@ -38,7 +38,7 @@
#define vfio_iowrite8 iowrite8

#define VFIO_IOWRITE(size) \
-static int vfio_pci_iowrite##size(struct vfio_pci_core_device *vdev, \
+int vfio_pci_core_iowrite##size(struct vfio_pci_core_device *vdev, \
bool test_mem, u##size val, void __iomem *io) \
{ \
if (test_mem) { \
@@ -55,7 +55,8 @@ static int vfio_pci_iowrite##size(struct vfio_pci_core_device *vdev, \
up_read(&vdev->memory_lock); \
\
return 0; \
-}
+} \
+EXPORT_SYMBOL_GPL(vfio_pci_core_iowrite##size);

VFIO_IOWRITE(8)
VFIO_IOWRITE(16)
@@ -65,7 +66,7 @@ VFIO_IOWRITE(64)
#endif

#define VFIO_IOREAD(size) \
-static int vfio_pci_ioread##size(struct vfio_pci_core_device *vdev, \
+int vfio_pci_core_ioread##size(struct vfio_pci_core_device *vdev, \
bool test_mem, u##size *val, void __iomem *io) \
{ \
if (test_mem) { \
@@ -82,7 +83,8 @@ static int vfio_pci_ioread##size(struct vfio_pci_core_device *vdev, \
up_read(&vdev->memory_lock); \
\
return 0; \
-}
+} \
+EXPORT_SYMBOL_GPL(vfio_pci_core_ioread##size);

VFIO_IOREAD(8)
VFIO_IOREAD(16)
@@ -119,13 +121,13 @@ static ssize_t do_io_rw(struct vfio_pci_core_device *vdev, bool test_mem,
if (copy_from_user(&val, buf, 4))
return -EFAULT;

- ret = vfio_pci_iowrite32(vdev, test_mem,
- val, io + off);
+ ret = vfio_pci_core_iowrite32(vdev, test_mem,
+ val, io + off);
if (ret)
return ret;
} else {
- ret = vfio_pci_ioread32(vdev, test_mem,
- &val, io + off);
+ ret = vfio_pci_core_ioread32(vdev, test_mem,
+ &val, io + off);
if (ret)
return ret;

@@ -141,13 +143,13 @@ static ssize_t do_io_rw(struct vfio_pci_core_device *vdev, bool test_mem,
if (copy_from_user(&val, buf, 2))
return -EFAULT;

- ret = vfio_pci_iowrite16(vdev, test_mem,
- val, io + off);
+ ret = vfio_pci_core_iowrite16(vdev, test_mem,
+ val, io + off);
if (ret)
return ret;
} else {
- ret = vfio_pci_ioread16(vdev, test_mem,
- &val, io + off);
+ ret = vfio_pci_core_ioread16(vdev, test_mem,
+ &val, io + off);
if (ret)
return ret;

@@ -163,13 +165,13 @@ static ssize_t do_io_rw(struct vfio_pci_core_device *vdev, bool test_mem,
if (copy_from_user(&val, buf, 1))
return -EFAULT;

- ret = vfio_pci_iowrite8(vdev, test_mem,
- val, io + off);
+ ret = vfio_pci_core_iowrite8(vdev, test_mem,
+ val, io + off);
if (ret)
return ret;
} else {
- ret = vfio_pci_ioread8(vdev, test_mem,
- &val, io + off);
+ ret = vfio_pci_core_ioread8(vdev, test_mem,
+ &val, io + off);
if (ret)
return ret;

@@ -364,21 +366,21 @@ static void vfio_pci_ioeventfd_do_write(struct vfio_pci_ioeventfd *ioeventfd,
{
switch (ioeventfd->count) {
case 1:
- vfio_pci_iowrite8(ioeventfd->vdev, test_mem,
- ioeventfd->data, ioeventfd->addr);
+ vfio_pci_core_iowrite8(ioeventfd->vdev, test_mem,
+ ioeventfd->data, ioeventfd->addr);
break;
case 2:
- vfio_pci_iowrite16(ioeventfd->vdev, test_mem,
- ioeventfd->data, ioeventfd->addr);
+ vfio_pci_core_iowrite16(ioeventfd->vdev, test_mem,
+ ioeventfd->data, ioeventfd->addr);
break;
case 4:
- vfio_pci_iowrite32(ioeventfd->vdev, test_mem,
- ioeventfd->data, ioeventfd->addr);
+ vfio_pci_core_iowrite32(ioeventfd->vdev, test_mem,
+ ioeventfd->data, ioeventfd->addr);
break;
#ifdef iowrite64
case 8:
- vfio_pci_iowrite64(ioeventfd->vdev, test_mem,
- ioeventfd->data, ioeventfd->addr);
+ vfio_pci_core_iowrite64(ioeventfd->vdev, test_mem,
+ ioeventfd->data, ioeventfd->addr);
break;
#endif
}
diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
index 67ac58e20e1d..85e84b92751b 100644
--- a/include/linux/vfio_pci_core.h
+++ b/include/linux/vfio_pci_core.h
@@ -131,4 +131,23 @@ 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);

+#define VFIO_IOWRITE_DECLATION(size) \
+int vfio_pci_core_iowrite##size(struct vfio_pci_core_device *vdev, \
+ bool test_mem, u##size val, void __iomem *io);
+
+VFIO_IOWRITE_DECLATION(8)
+VFIO_IOWRITE_DECLATION(16)
+VFIO_IOWRITE_DECLATION(32)
+#ifdef iowrite64
+VFIO_IOWRITE_DECLATION(64)
+#endif
+
+#define VFIO_IOREAD_DECLATION(size) \
+int vfio_pci_core_ioread##size(struct vfio_pci_core_device *vdev, \
+ bool test_mem, u##size *val, void __iomem *io);
+
+VFIO_IOREAD_DECLATION(8)
+VFIO_IOREAD_DECLATION(16)
+VFIO_IOREAD_DECLATION(32)
+
#endif /* VFIO_PCI_CORE_H */
--
2.27.0