vfio/pci: Intel IGD OpRegion support

This is the first consumer of vfio device specific resource support,
providing read-only access to the OpRegion for Intel graphics devices.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
index 02912f1..24ee260 100644 (file)
--- a/drivers/vfio/pci/Kconfig
+++ b/drivers/vfio/pci/Kconfig
@@ -26,3 +26,7 @@ config VFIO_PCI_MMAP
 config VFIO_PCI_INTX
        depends on VFIO_PCI
        def_bool y if !S390
+
+config VFIO_PCI_IGD
+       depends on VFIO_PCI
+       def_bool y if X86

diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile
index 1310792..76d8ec0 100644 (file)
--- a/drivers/vfio/pci/Makefile
+++ b/drivers/vfio/pci/Makefile
@@ -1,4 +1,5 @@
 
 vfio-pci-y := vfio_pci.o vfio_pci_intrs.o vfio_pci_rdwr.o vfio_pci_config.o
+vfio-pci-$(CONFIG_VFIO_PCI_IGD) += vfio_pci_igd.o
 
 obj-$(CONFIG_VFIO_PCI) += vfio-pci.o

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 813a2e6..cb2624d 100644 (file)
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -169,6 +169,13 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev)
        if (!vfio_vga_disabled() && vfio_pci_is_vga(pdev))
                vdev->has_vga = true;
 
+
+       if (vfio_pci_is_vga(pdev) && pdev->vendor == PCI_VENDOR_ID_INTEL) {
+               if (vfio_pci_igd_opregion_init(vdev) == 0)
+                       dev_info(&pdev->dev,
+                                "Intel IGD OpRegion support enabled\n");
+       }
+
        return 0;
 }
 

diff --git a/drivers/vfio/pci/vfio_pci_igd.c b/drivers/vfio/pci/vfio_pci_igd.c
new file mode 100644 (file)
index 0000000..3b6a6f7
--- /dev/null
+++ b/drivers/vfio/pci/vfio_pci_igd.c
@@ -0,0 +1,111 @@
+/*
+ * VFIO PCI Intel Graphics support
+ *
+ * Copyright (C) 2016 Red Hat, Inc.  All rights reserved.
+ *     Author: Alex Williamson <alex.williamson@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Register a device specific region through which to provide read-only
+ * access to the Intel IGD opregion.  The register defining the opregion
+ * address is also virtualized to prevent user modification.
+ */
+
+#include <linux/io.h>
+#include <linux/pci.h>
+#include <linux/uaccess.h>
+#include <linux/vfio.h>
+
+#include "vfio_pci_private.h"
+
+#define OPREGION_SIGNATURE     "IntelGraphicsMem"
+#define OPREGION_SIZE          (8 * 1024)
+#define OPREGION_PCI_ADDR      0xfc
+
+static size_t vfio_pci_igd_rw(struct vfio_pci_device *vdev, char __user *buf,
+                             size_t count, loff_t *ppos, bool iswrite)
+{
+       unsigned int i = VFIO_PCI_OFFSET_TO_INDEX(*ppos) - VFIO_PCI_NUM_REGIONS;
+       void *base = vdev->region[i].data;
+       loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
+
+       if (pos >= vdev->region[i].size || iswrite)
+               return -EINVAL;
+
+       count = min(count, (size_t)(vdev->region[i].size - pos));
+
+       if (copy_to_user(buf, base + pos, count))
+               return -EFAULT;
+
+       *ppos += count;
+
+       return count;
+}
+
+static void vfio_pci_igd_release(struct vfio_pci_device *vdev,
+                                struct vfio_pci_region *region)
+{
+       memunmap(region->data);
+}
+
+static const struct vfio_pci_regops vfio_pci_igd_regops = {
+       .rw             = vfio_pci_igd_rw,
+       .release        = vfio_pci_igd_release,
+};
+
+int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev)
+{
+       __le32 *dwordp = (__le32 *)(vdev->vconfig + OPREGION_PCI_ADDR);
+       u32 addr, size;
+       void *base;
+       int ret;
+
+       ret = pci_read_config_dword(vdev->pdev, OPREGION_PCI_ADDR, &addr);
+       if (ret)
+               return ret;
+
+       if (!addr || !(~addr))
+               return -ENODEV;
+
+       base = memremap(addr, OPREGION_SIZE, MEMREMAP_WB);
+       if (!base)
+               return -ENOMEM;
+
+       if (memcmp(base, OPREGION_SIGNATURE, 16)) {
+               memunmap(base);
+               return -EINVAL;
+       }
+
+       size = le32_to_cpu(*(__le32 *)(base + 16));
+       if (!size) {
+               memunmap(base);
+               return -EINVAL;
+       }
+
+       size *= 1024; /* In KB */
+
+       if (size != OPREGION_SIZE) {
+               memunmap(base);
+               base = memremap(addr, size, MEMREMAP_WB);
+               if (!base)
+                       return -ENOMEM;
+       }
+
+       ret = vfio_pci_register_dev_region(vdev,
+               PCI_VENDOR_ID_INTEL | VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
+               VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION,
+               &vfio_pci_igd_regops, size, VFIO_REGION_INFO_FLAG_READ, base);
+       if (ret) {
+               memunmap(base);
+               return ret;
+       }
+
+       /* Fill vconfig with the hw value and virtualize register */
+       *dwordp = cpu_to_le32(addr);
+       memset(vdev->pci_config_map + OPREGION_PCI_ADDR,
+              PCI_CAP_ID_INVALID_VIRT, 4);
+
+       return ret;
+}

diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h
index b1e4032..19f7699 100644 (file)
--- a/drivers/vfio/pci/vfio_pci_private.h
+++ b/drivers/vfio/pci/vfio_pci_private.h
@@ -122,4 +122,12 @@ extern int vfio_pci_register_dev_region(struct vfio_pci_device *vdev,
                                        unsigned int type, unsigned int subtype,
                                        const struct vfio_pci_regops *ops,
                                        size_t size, u32 flags, void *data);
+#ifdef CONFIG_VFIO_PCI_IGD
+extern int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev);
+#else
+static inline int vfio_pci_igd_opregion_init(struct vfio_pci_device *vdev)
+{
+       return -ENODEV;
+}
+#endif
 #endif /* VFIO_PCI_PRIVATE_H */

diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 1c37a0e..e622982 100644 (file)
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -280,6 +280,11 @@ struct vfio_region_info_cap_type {
        __u32 subtype;  /* type specific */
 };
 
+#define VFIO_REGION_TYPE_PCI_VENDOR_TYPE       (1 << 31)
+#define VFIO_REGION_TYPE_PCI_VENDOR_MASK       (0xffff)
+
+#define VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION (1)
+
 /**
  * VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9,
  *                                 struct vfio_irq_info)