[RFC PATCH v4 05/10] vfio/pci: export vfio_pci_get_barmap

From: Yan Zhao <yan.y.zhao@intel.com>
To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: alex.williamson@redhat.com, cohuck@redhat.com,
	zhenyuw@linux.intel.com, zhi.a.wang@intel.com,
	kevin.tian@intel.com, shaopeng.he@intel.com, yi.l.liu@intel.com,
	xin.zeng@intel.com, hang.yuan@intel.com,
	Yan Zhao <yan.y.zhao@intel.com>
Subject: [RFC PATCH v4 05/10] vfio/pci: export vfio_pci_get_barmap
Date: Sun, 17 May 2020 22:50:16 -0400	[thread overview]
Message-ID: <20200518025016.14317-1-yan.y.zhao@intel.com> (raw)
In-Reply-To: <20200518024202.13996-1-yan.y.zhao@intel.com>

This allows vendor driver to read/write to bars directly which is useful
in security checking condition.

Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
---
 drivers/vfio/pci/vfio_pci_rdwr.c | 10 ++++++++++
 include/linux/vfio.h             |  1 +
 2 files changed, 11 insertions(+)

diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c
index a87992892a9f..e4085311ab28 100644
--- a/drivers/vfio/pci/vfio_pci_rdwr.c
+++ b/drivers/vfio/pci/vfio_pci_rdwr.c
@@ -153,6 +153,16 @@ static int vfio_pci_setup_barmap(struct vfio_pci_device *vdev, int bar)
 	return 0;
 }
 
+void __iomem *vfio_pci_get_barmap(void *device_data, int bar)
+{
+	int ret;
+	struct vfio_pci_device *vdev = device_data;
+
+	ret = vfio_pci_setup_barmap(vdev, bar);
+	return ret ? ERR_PTR(ret) : vdev->barmap[bar];
+}
+EXPORT_SYMBOL_GPL(vfio_pci_get_barmap);
+
 ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf,
 			size_t count, loff_t *ppos, bool iswrite)
 {
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 6310c53f9d36..0c786fec4602 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -234,6 +234,7 @@ extern void *vfio_pci_vendor_data(void *device_data);
 extern int vfio_pci_set_vendor_regions(void *device_data,
 				       int num_vendor_regions);
 extern int vfio_pci_set_vendor_irqs(void *device_data, int num_vendor_irqs);
+extern void __iomem *vfio_pci_get_barmap(void *device_data, int bar);
 
 struct vfio_pci_vendor_driver_ops {
 	char			*name;
-- 
2.17.1

