RE: [PATCH v2 2/5] drm/i915/gvt: OpRegion support for GVT-g

[He, Min]

> -----Original Message-----
> From: Chen, Xiaoguang
> Sent: Thursday, May 18, 2017 7:20 PM
> To: He, Min <min.he@xxxxxxxxx>; alex.williamson@xxxxxxxxxx;
> kraxel@xxxxxxxxxx; intel-gfx@xxxxxxxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; zhenyuw@xxxxxxxxxxxxxxx; Lv, Zhiyuan
> <zhiyuan.lv@xxxxxxxxx>; intel-gvt-dev@xxxxxxxxxxxxxxxxxxxxx; Wang, Zhi A
> <zhi.a.wang@xxxxxxxxx>; Tian, Kevin <kevin.tian@xxxxxxxxx>
> Cc: Niu, Bing <bing.niu@xxxxxxxxx>
> Subject: RE: [PATCH v2 2/5] drm/i915/gvt: OpRegion support for GVT-g
> 
> Hi min,
> 
> >-----Original Message-----
> >From: He, Min
> >Sent: Thursday, May 18, 2017 11:44 PM
> >To: Chen, Xiaoguang <xiaoguang.chen@xxxxxxxxx>;
> >alex.williamson@xxxxxxxxxx; kraxel@xxxxxxxxxx; intel-
> >gfx@xxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> >zhenyuw@xxxxxxxxxxxxxxx; Lv, Zhiyuan <zhiyuan.lv@xxxxxxxxx>; intel-gvt-
> >dev@xxxxxxxxxxxxxxxxxxxxx; Wang, Zhi A <zhi.a.wang@xxxxxxxxx>; Tian, Kevin
> ><kevin.tian@xxxxxxxxx>
> >Cc: Niu, Bing <bing.niu@xxxxxxxxx>; Chen, Xiaoguang
> ><xiaoguang.chen@xxxxxxxxx>
> >Subject: RE: [PATCH v2 2/5] drm/i915/gvt: OpRegion support for GVT-g
> >
> >Xiaoguang,
> >I have some comments inline. Thanks.
> >
> >> -----Original Message-----
> >> From: intel-gvt-dev
> >> [mailto:intel-gvt-dev-bounces@xxxxxxxxxxxxxxxxxxxxx] On Behalf Of
> >> Xiaoguang Chen
> >> Sent: Thursday, May 18, 2017 2:50 AM
> >> To: alex.williamson@xxxxxxxxxx; kraxel@xxxxxxxxxx; intel-
> >> gfx@xxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> >> zhenyuw@xxxxxxxxxxxxxxx; Lv, Zhiyuan <zhiyuan.lv@xxxxxxxxx>;
> >> intel-gvt- dev@xxxxxxxxxxxxxxxxxxxxx; Wang, Zhi A
> >> <zhi.a.wang@xxxxxxxxx>; Tian, Kevin <kevin.tian@xxxxxxxxx>
> >> Cc: Niu, Bing <bing.niu@xxxxxxxxx>; Chen, Xiaoguang
> >> <xiaoguang.chen@xxxxxxxxx>
> >> Subject: [PATCH v2 2/5] drm/i915/gvt: OpRegion support for GVT-g
> >>
> >> 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/kvmgt.c    | 97
> >> +++++++++++++++++++++++++++++++++++++
> >>  drivers/gpu/drm/i915/gvt/opregion.c | 12 ++++-
> >>  2 files changed, 107 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c
> >> b/drivers/gpu/drm/i915/gvt/kvmgt.c
> >> index 3c6a02b..389f072 100644
> >> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
> >> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
> >> @@ -53,6 +53,8 @@
> >>  #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 +438,92
> >> @@ 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 intel_vgpu_reg_init_opregion(struct intel_vgpu *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);
> >In current GVT code, we already have a function init_vgpu_opregion, which will
> >copy the physical opregion into a per vgpu structure:
> >vgpu_opregion(vgpu)->va, why donât you reuse this function and set the
> >vgpu_opregion(vgpu)->va to the intel_vgpu_register_reg function?
> The reason is we do not the know the gpa of the OpRegion.
> For KVMGT the gpa of the OpRegion is allocated by seabios.

Maybe you can consolidate them into one function to remove duplicate code.