Re: [PATCH v15 4/7] drm/i915/gvt: Add opregion support

From: Du, Changbin
Date: Wed Oct 11 2017 - 00:36:22 EST

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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@xxxxxxxxx>
> Signed-off-by: Tina Zhang <tina.zhang@xxxxxxxxx>
> ---
> 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@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev

--
Thanks,
Changbin Du

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In reply to: Tina Zhang: "[PATCH v15 4/7] drm/i915/gvt: Add opregion support"
Next in thread: Tina Zhang: "[PATCH v15 5/7] vfio: ABI for mdev display dma-buf operation"
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