Message-ID: <20171011042929.GA29216@intel.com>
Date:   Wed, 11 Oct 2017 12:29:29 +0800
From:   "Du, Changbin" <changbin.du@...el.com>
To:     Tina Zhang <tina.zhang@...el.com>
Cc:     alex.williamson@...hat.com, kraxel@...hat.com,
        chris@...is-wilson.co.uk, zhenyuw@...ux.intel.com,
        zhiyuan.lv@...el.com, zhi.a.wang@...el.com, kevin.tian@...el.com,
        daniel@...ll.ch, kwankhede@...dia.com,
        intel-gfx@...ts.freedesktop.org, Bing Niu <bing.niu@...el.com>,
        intel-gvt-dev@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        changbin.du@...el.com
Subject: Re: [PATCH v15 4/7] drm/i915/gvt: Add opregion support

On Tue, Oct 10, 2017 at 05:50:04PM +0800, Tina Zhang wrote:
> Windows guest driver needs vbt in opregion, to configure the setting
> for display. Without opregion support, the display registers won't
> be set and this blocks display model to get the correct information
> of the guest display plane.
> 
> This patch is to provide a virtual opregion for guest. Current
> implementation is to fill the virtual opregion with the content in
> host's opregion. The original author of this patch is Xiaoguang Chen.
> 
> Signed-off-by: Bing Niu <bing.niu@...el.com>
> Signed-off-by: Tina Zhang <tina.zhang@...el.com>
> ---
>  drivers/gpu/drm/i915/gvt/hypercall.h |   1 +
>  drivers/gpu/drm/i915/gvt/kvmgt.c     | 109 ++++++++++++++++++++++++++++++++++-
>  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, 146 insertions(+), 9 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);
Seems we try to hide struct intel_vgpu for kvmgt, but acctually kvmgt already
use it. So set type as struct intel_vgpu directly? I am not sure about xengt,
but the code shows that 'handle' is correct thing?

>  };
>  
>  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 fd0c85f..6b0a330 100644
> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
> @@ -53,11 +53,23 @@ 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,
> +			size_t count, loff_t *ppos, bool iswrite);
> +	void (*release)(struct intel_vgpu *vgpu,
> +			struct vfio_region *region);
> +};
> +
>  struct vfio_region {
>  	u32				type;
>  	u32				subtype;
>  	size_t				size;
>  	u32				flags;
> +	const struct intel_vgpu_regops	*ops;
> +	void				*data;
>  };
>  
>  struct kvmgt_pgfn {
> @@ -430,6 +442,91 @@ 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)
Personally I think intel_vgpu_rw_opregion() is better. :)

> +{
> +	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,
Maybe full name xx_register_region? coufusing between a register and region.

> +		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;
No need map again, i915 has mapped it (dev_priv->opregion->header).

> +
> +	if (memcmp(base, OPREGION_SIGNATURE, 16)) {
> +		memunmap(base);
> +		return -EINVAL;
> +	}
> +
Just check "opregion->header != NULL", since i915 already validates it.

> +	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;
> @@ -646,7 +743,7 @@ static ssize_t intel_vgpu_rw(struct mdev_device *mdev, char *buf,
>  	int ret = -EINVAL;
>  
>  
> -	if (index >= VFIO_PCI_NUM_REGIONS) {
> +	if (index >= VFIO_PCI_NUM_REGIONS + vgpu->vdev.num_regions) {
>  		gvt_vgpu_err("invalid index: %u\n", index);
>  		return -EINVAL;
>  	}
> @@ -680,8 +777,11 @@ static ssize_t intel_vgpu_rw(struct mdev_device *mdev, char *buf,
>  	case VFIO_PCI_BAR5_REGION_INDEX:
>  	case VFIO_PCI_VGA_REGION_INDEX:
>  	case VFIO_PCI_ROM_REGION_INDEX:
> +		break;
>  	default:
> -		gvt_vgpu_err("unsupported region: %u\n", index);
> +		index -= VFIO_PCI_NUM_REGIONS;
> +		return vgpu->vdev.region[index].ops->rw(vgpu, buf, count,
> +				ppos, is_write);
Make region ops gerneric is great. You can factor out MMIO and CFG region ops as
well. It is better not to mix generic and special handling.

>  	}
>  
>  	return ret == 0 ? count : ret;
> @@ -944,7 +1044,8 @@ static long intel_vgpu_ioctl(struct mdev_device *mdev, unsigned int cmd,
>  
>  		info.flags = VFIO_DEVICE_FLAGS_PCI;
>  		info.flags |= VFIO_DEVICE_FLAGS_RESET;
> -		info.num_regions = VFIO_PCI_NUM_REGIONS;
> +		info.num_regions = VFIO_PCI_NUM_REGIONS +
> +				vgpu->vdev.num_regions;
>  		info.num_irqs = VFIO_PCI_NUM_IRQS;
>  
>  		return copy_to_user((void __user *)arg, &info, minsz) ?
> @@ -1065,6 +1166,7 @@ static long intel_vgpu_ioctl(struct mdev_device *mdev, unsigned int cmd,
>  		}
>  
>  		if (caps.size) {
> +			info.flags |= VFIO_REGION_INFO_FLAG_CAPS;
>  			if (info.argsz < sizeof(info) + caps.size) {
>  				info.argsz = sizeof(info) + caps.size;
>  				info.cap_offset = 0;
> @@ -1513,6 +1615,7 @@ 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 f0e5487..9e73f2e 100644
> --- a/drivers/gpu/drm/i915/gvt/mpt.h
> +++ b/drivers/gpu/drm/i915/gvt/mpt.h
> @@ -292,4 +292,19 @@ 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;
> +		}
ditto.

> +		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 3deadcb..bcbf535 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
> 
> _______________________________________________
> intel-gvt-dev mailing list
> intel-gvt-dev@...ts.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev

-- 
Thanks,
Changbin Du

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