[PATCH v7 2/6] drm/i915/gvt: OpRegion support for GVT-g

From: Xiaoguang Chen
Date: Wed Jun 07 2017 - 03:46:57 EST


OpRegion is needed to support display related operation for
intel vgpu.

A vfio device region is added to intel vgpu to deliver the
host OpRegion information to user space so user space can
construct the OpRegion for vgpu.

Signed-off-by: Bing Niu <bing.niu@xxxxxxxxx>
Signed-off-by: Xiaoguang Chen <xiaoguang.chen@xxxxxxxxx>
---
drivers/gpu/drm/i915/gvt/hypercall.h | 1 +
drivers/gpu/drm/i915/gvt/kvmgt.c | 88 ++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/gvt/mpt.h | 15 ++++++
drivers/gpu/drm/i915/gvt/opregion.c | 26 ++++++++---
drivers/gpu/drm/i915/gvt/vgpu.c | 4 ++
5 files changed, 128 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/hypercall.h b/drivers/gpu/drm/i915/gvt/hypercall.h
index df7f33a..32c345c 100644
--- a/drivers/gpu/drm/i915/gvt/hypercall.h
+++ b/drivers/gpu/drm/i915/gvt/hypercall.h
@@ -55,6 +55,7 @@ struct intel_gvt_mpt {
unsigned long mfn, unsigned int nr, bool map);
int (*set_trap_area)(unsigned long handle, u64 start, u64 end,
bool map);
+ int (*set_opregion)(void *vgpu);
};

extern struct intel_gvt_mpt xengt_mpt;
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 3c6a02b..6b4652a 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -53,6 +53,8 @@ static const struct intel_gvt_ops *intel_gvt_ops;
#define VFIO_PCI_INDEX_TO_OFFSET(index) ((u64)(index) << VFIO_PCI_OFFSET_SHIFT)
#define VFIO_PCI_OFFSET_MASK (((u64)(1) << VFIO_PCI_OFFSET_SHIFT) - 1)

+#define OPREGION_SIGNATURE "IntelGraphicsMem"
+
struct vfio_region;
struct intel_vgpu_regops {
size_t (*rw)(struct intel_vgpu *vgpu, char *buf,
@@ -436,6 +438,91 @@ static void kvmgt_protect_table_del(struct kvmgt_guest_info *info,
}
}

+static size_t intel_vgpu_reg_rw_opregion(struct intel_vgpu *vgpu, char *buf,
+ size_t count, loff_t *ppos, bool iswrite)
+{
+ unsigned int i = VFIO_PCI_OFFSET_TO_INDEX(*ppos) -
+ VFIO_PCI_NUM_REGIONS;
+ void *base = vgpu->vdev.region[i].data;
+ loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK;
+
+ if (pos >= vgpu->vdev.region[i].size || iswrite) {
+ gvt_vgpu_err("invalid op or offset for Intel vgpu OpRegion\n");
+ return -EINVAL;
+ }
+ count = min(count, (size_t)(vgpu->vdev.region[i].size - pos));
+ memcpy(buf, base + pos, count);
+
+ return count;
+}
+
+static void intel_vgpu_reg_release_opregion(struct intel_vgpu *vgpu,
+ struct vfio_region *region)
+{
+ memunmap(region->data);
+}
+
+static const struct intel_vgpu_regops intel_vgpu_regops_opregion = {
+ .rw = intel_vgpu_reg_rw_opregion,
+ .release = intel_vgpu_reg_release_opregion,
+};
+
+static int intel_vgpu_register_reg(struct intel_vgpu *vgpu,
+ unsigned int type, unsigned int subtype,
+ const struct intel_vgpu_regops *ops,
+ size_t size, u32 flags, void *data)
+{
+ struct vfio_region *region;
+
+ region = krealloc(vgpu->vdev.region,
+ (vgpu->vdev.num_regions + 1) * sizeof(*region),
+ GFP_KERNEL);
+ if (!region)
+ return -ENOMEM;
+
+ vgpu->vdev.region = region;
+ vgpu->vdev.region[vgpu->vdev.num_regions].type = type;
+ vgpu->vdev.region[vgpu->vdev.num_regions].subtype = subtype;
+ vgpu->vdev.region[vgpu->vdev.num_regions].ops = ops;
+ vgpu->vdev.region[vgpu->vdev.num_regions].size = size;
+ vgpu->vdev.region[vgpu->vdev.num_regions].flags = flags;
+ vgpu->vdev.region[vgpu->vdev.num_regions].data = data;
+ vgpu->vdev.num_regions++;
+
+ return 0;
+}
+
+static int kvmgt_set_opregion(void *p_vgpu)
+{
+ struct intel_vgpu *vgpu = (struct intel_vgpu *)p_vgpu;
+ unsigned int addr;
+ void *base;
+ int ret;
+
+ addr = vgpu->gvt->opregion.opregion_pa;
+ 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;
+ }
+
+ ret = intel_vgpu_register_reg(vgpu,
+ PCI_VENDOR_ID_INTEL | VFIO_REGION_TYPE_PCI_VENDOR_TYPE,
+ VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION,
+ &intel_vgpu_regops_opregion, OPREGION_SIZE,
+ VFIO_REGION_INFO_FLAG_READ, base);
+ if (ret)
+ memunmap(base);
+
+ return ret;
+}
+
static int intel_vgpu_create(struct kobject *kobj, struct mdev_device *mdev)
{
struct intel_vgpu *vgpu = NULL;
@@ -1524,6 +1611,7 @@ struct intel_gvt_mpt kvmgt_mpt = {
.read_gpa = kvmgt_read_gpa,
.write_gpa = kvmgt_write_gpa,
.gfn_to_mfn = kvmgt_gfn_to_pfn,
+ .set_opregion = kvmgt_set_opregion,
};
EXPORT_SYMBOL_GPL(kvmgt_mpt);

diff --git a/drivers/gpu/drm/i915/gvt/mpt.h b/drivers/gpu/drm/i915/gvt/mpt.h
index 4193536..ab71300 100644
--- a/drivers/gpu/drm/i915/gvt/mpt.h
+++ b/drivers/gpu/drm/i915/gvt/mpt.h
@@ -293,4 +293,19 @@ static inline int intel_gvt_hypervisor_set_trap_area(
return intel_gvt_host.mpt->set_trap_area(vgpu->handle, start, end, map);
}

+/**
+ * intel_gvt_hypervisor_set_opregion - Set opregion for guest
+ * @vgpu: a vGPU
+ *
+ * Returns:
+ * Zero on success, negative error code if failed.
+ */
+static inline int intel_gvt_hypervisor_set_opregion(struct intel_vgpu *vgpu)
+{
+ if (!intel_gvt_host.mpt->set_opregion)
+ return 0;
+
+ return intel_gvt_host.mpt->set_opregion(vgpu);
+}
+
#endif /* _GVT_MPT_H_ */
diff --git a/drivers/gpu/drm/i915/gvt/opregion.c b/drivers/gpu/drm/i915/gvt/opregion.c
index 3117991..04c0452 100644
--- a/drivers/gpu/drm/i915/gvt/opregion.c
+++ b/drivers/gpu/drm/i915/gvt/opregion.c
@@ -113,23 +113,37 @@ void intel_vgpu_clean_opregion(struct intel_vgpu *vgpu)
*/
int intel_vgpu_init_opregion(struct intel_vgpu *vgpu, u32 gpa)
{
- int ret;
+ int ret = 0;
+ unsigned long pfn;

gvt_dbg_core("vgpu%d: init vgpu opregion\n", vgpu->id);

- if (intel_gvt_host.hypervisor_type == INTEL_GVT_HYPERVISOR_XEN) {
+ switch (intel_gvt_host.hypervisor_type) {
+ case INTEL_GVT_HYPERVISOR_KVM:
+ pfn = intel_gvt_hypervisor_gfn_to_mfn(vgpu, gpa >> PAGE_SHIFT);
+ vgpu_opregion(vgpu)->va = memremap(pfn << PAGE_SHIFT,
+ INTEL_GVT_OPREGION_SIZE,
+ MEMREMAP_WB);
+ if (!vgpu_opregion(vgpu)->va) {
+ gvt_vgpu_err("failed to map guest opregion\n");
+ ret = -EFAULT;
+ }
+ break;
+ case INTEL_GVT_HYPERVISOR_XEN:
gvt_dbg_core("emulate opregion from kernel\n");

ret = init_vgpu_opregion(vgpu, gpa);
if (ret)
- return ret;
+ break;

ret = map_vgpu_opregion(vgpu, true);
- if (ret)
- return ret;
+ break;
+ default:
+ ret = -EINVAL;
+ gvt_vgpu_err("not supported hypervisor\n");
}

- return 0;
+ return ret;
}

/**
diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c
index 6e3cbd8..8e1d504 100644
--- a/drivers/gpu/drm/i915/gvt/vgpu.c
+++ b/drivers/gpu/drm/i915/gvt/vgpu.c
@@ -383,6 +383,10 @@ static struct intel_vgpu *__intel_gvt_create_vgpu(struct intel_gvt *gvt,
if (ret)
goto out_clean_shadow_ctx;

+ ret = intel_gvt_hypervisor_set_opregion(vgpu);
+ if (ret)
+ goto out_clean_shadow_ctx;
+
mutex_unlock(&gvt->lock);

return vgpu;
--
2.7.4