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authorAlex Williamson <alex.williamson@redhat.com>2013-02-18 10:11:13 -0700
committerAlex Williamson <alex.williamson@redhat.com>2013-02-18 10:11:13 -0700
commit84237a826b261de7ddd3d09ee53ee68cb4138937 (patch)
treeab0c6d1d07abd74e90db41521258615fc1eaa211 /drivers
parent2dd1194833de133960f286903ce704cb10fa7eb0 (diff)
downloadlinux-84237a826b261de7ddd3d09ee53ee68cb4138937.tar.gz
vfio-pci: Add support for VGA region access
PCI defines display class VGA regions at I/O port address 0x3b0, 0x3c0 and MMIO address 0xa0000. As these are non-overlapping, we can ignore the I/O port vs MMIO difference and expose them both in a single region. We make use of the VGA arbiter around each access to configure chipset access as necessary. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/vfio/pci/Kconfig10
-rw-r--r--drivers/vfio/pci/vfio_pci.c18
-rw-r--r--drivers/vfio/pci/vfio_pci_private.h4
-rw-r--r--drivers/vfio/pci/vfio_pci_rdwr.c61
4 files changed, 93 insertions, 0 deletions
diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
index 5980758563e..e84300b268b 100644
--- a/drivers/vfio/pci/Kconfig
+++ b/drivers/vfio/pci/Kconfig
@@ -6,3 +6,13 @@ config VFIO_PCI
use of PCI drivers using the VFIO framework.
If you don't know what to do here, say N.
+
+config VFIO_PCI_VGA
+ bool "VFIO PCI support for VGA devices"
+ depends on VFIO_PCI && X86 && VGA_ARB && EXPERIMENTAL
+ help
+ Support for VGA extension to VFIO PCI. This exposes an additional
+ region on VGA devices for accessing legacy VGA addresses used by
+ BIOS and generic video drivers.
+
+ If you don't know what to do here, say N.
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index bb8c8c2be96..8189cb6a86a 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -84,6 +84,11 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev)
} else
vdev->msix_bar = 0xFF;
+#ifdef CONFIG_VFIO_PCI_VGA
+ if ((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA)
+ vdev->has_vga = true;
+#endif
+
return 0;
}
@@ -285,6 +290,16 @@ static long vfio_pci_ioctl(void *device_data,
info.flags = VFIO_REGION_INFO_FLAG_READ;
break;
}
+ case VFIO_PCI_VGA_REGION_INDEX:
+ if (!vdev->has_vga)
+ return -EINVAL;
+
+ info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
+ info.size = 0xc0000;
+ info.flags = VFIO_REGION_INFO_FLAG_READ |
+ VFIO_REGION_INFO_FLAG_WRITE;
+
+ break;
default:
return -EINVAL;
}
@@ -386,6 +401,9 @@ static ssize_t vfio_pci_rw(void *device_data, char __user *buf,
case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
+
+ case VFIO_PCI_VGA_REGION_INDEX:
+ return vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite);
}
return -EINVAL;
diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h
index 00d19b953ce..d7e55d03f49 100644
--- a/drivers/vfio/pci/vfio_pci_private.h
+++ b/drivers/vfio/pci/vfio_pci_private.h
@@ -53,6 +53,7 @@ struct vfio_pci_device {
bool reset_works;
bool extended_caps;
bool bardirty;
+ bool has_vga;
struct pci_saved_state *pci_saved_state;
atomic_t refcnt;
};
@@ -77,6 +78,9 @@ extern ssize_t vfio_pci_config_rw(struct vfio_pci_device *vdev,
extern ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf,
size_t count, loff_t *ppos, bool iswrite);
+extern ssize_t vfio_pci_vga_rw(struct vfio_pci_device *vdev, char __user *buf,
+ size_t count, loff_t *ppos, bool iswrite);
+
extern int vfio_pci_init_perm_bits(void);
extern void vfio_pci_uninit_perm_bits(void);
diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c
index e9d78eb91ed..210db24d220 100644
--- a/drivers/vfio/pci/vfio_pci_rdwr.c
+++ b/drivers/vfio/pci/vfio_pci_rdwr.c
@@ -17,6 +17,7 @@
#include <linux/pci.h>
#include <linux/uaccess.h>
#include <linux/io.h>
+#include <linux/vgaarb.h>
#include "vfio_pci_private.h"
@@ -175,3 +176,63 @@ ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf,
return done;
}
+
+ssize_t vfio_pci_vga_rw(struct vfio_pci_device *vdev, char __user *buf,
+ size_t count, loff_t *ppos, bool iswrite)
+{
+ int ret;
+ loff_t off, pos = *ppos & VFIO_PCI_OFFSET_MASK;
+ void __iomem *iomem = NULL;
+ unsigned int rsrc;
+ bool is_ioport;
+ ssize_t done;
+
+ if (!vdev->has_vga)
+ return -EINVAL;
+
+ switch (pos) {
+ case 0xa0000 ... 0xbffff:
+ count = min(count, (size_t)(0xc0000 - pos));
+ iomem = ioremap_nocache(0xa0000, 0xbffff - 0xa0000 + 1);
+ off = pos - 0xa0000;
+ rsrc = VGA_RSRC_LEGACY_MEM;
+ is_ioport = false;
+ break;
+ case 0x3b0 ... 0x3bb:
+ count = min(count, (size_t)(0x3bc - pos));
+ iomem = ioport_map(0x3b0, 0x3bb - 0x3b0 + 1);
+ off = pos - 0x3b0;
+ rsrc = VGA_RSRC_LEGACY_IO;
+ is_ioport = true;
+ break;
+ case 0x3c0 ... 0x3df:
+ count = min(count, (size_t)(0x3e0 - pos));
+ iomem = ioport_map(0x3c0, 0x3df - 0x3c0 + 1);
+ off = pos - 0x3c0;
+ rsrc = VGA_RSRC_LEGACY_IO;
+ is_ioport = true;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (!iomem)
+ return -ENOMEM;
+
+ ret = vga_get_interruptible(vdev->pdev, rsrc);
+ if (ret) {
+ is_ioport ? ioport_unmap(iomem) : iounmap(iomem);
+ return ret;
+ }
+
+ done = do_io_rw(iomem, buf, off, count, 0, 0, iswrite);
+
+ vga_put(vdev->pdev, rsrc);
+
+ is_ioport ? ioport_unmap(iomem) : iounmap(iomem);
+
+ if (done >= 0)
+ *ppos += done;
+
+ return done;
+}