drm/i915/gvt: vGPU MMIO virtualization

This patch introduces the generic vGPU MMIO emulation intercept
framework.  The MPT modules will request GVT-g core logic to
emulate MMIO read/write through IO emulation operations
callback when hypervisor trapped a guest GTTMMIO read/write.

Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

1 files changed, 305 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gvt/mmio.c b/drivers/gpu/drm/i915/gvt/mmio.c
new file mode 100644
index 000000000000..ce3af95d049f
--- /dev/null
+++ b/drivers/gpu/drm/i915/gvt/mmio.c
@@ -0,0 +1,305 @@
+/*
+ * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Authors:
+ *    Ke Yu
+ *    Kevin Tian <kevin.tian@intel.com>
+ *    Dexuan Cui
+ *
+ * Contributors:
+ *    Tina Zhang <tina.zhang@intel.com>
+ *    Min He <min.he@intel.com>
+ *    Niu Bing <bing.niu@intel.com>
+ *    Zhi Wang <zhi.a.wang@intel.com>
+ *
+ */
+
+#include "i915_drv.h"
+
+/**
+ * intel_vgpu_gpa_to_mmio_offset - translate a GPA to MMIO offset
+ * @vgpu: a vGPU
+ *
+ * Returns:
+ * Zero on success, negative error code if failed
+ */
+int intel_vgpu_gpa_to_mmio_offset(struct intel_vgpu *vgpu, u64 gpa)
+{
+	u64 gttmmio_gpa = *(u64 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_0) &
+			  ~GENMASK(3, 0);
+	return gpa - gttmmio_gpa;
+}
+
+#define reg_is_mmio(gvt, reg)  \
+	(reg >= 0 && reg < gvt->device_info.mmio_size)
+
+#define reg_is_gtt(gvt, reg)   \
+	(reg >= gvt->device_info.gtt_start_offset \
+	 && reg < gvt->device_info.gtt_start_offset + gvt_ggtt_sz(gvt))
+
+/**
+ * intel_vgpu_emulate_mmio_read - emulate MMIO read
+ * @vgpu: a vGPU
+ * @pa: guest physical address
+ * @p_data: data return buffer
+ * @bytes: access data length
+ *
+ * Returns:
+ * Zero on success, negative error code if failed
+ */
+int intel_vgpu_emulate_mmio_read(void *__vgpu, uint64_t pa,
+		void *p_data, unsigned int bytes)
+{
+	struct intel_vgpu *vgpu = __vgpu;
+	struct intel_gvt *gvt = vgpu->gvt;
+	struct intel_gvt_mmio_info *mmio;
+	unsigned int offset = 0;
+	int ret = -EINVAL;
+
+	mutex_lock(&gvt->lock);
+
+	if (atomic_read(&vgpu->gtt.n_write_protected_guest_page)) {
+		struct intel_vgpu_guest_page *gp;
+
+		gp = intel_vgpu_find_guest_page(vgpu, pa >> PAGE_SHIFT);
+		if (gp) {
+			ret = intel_gvt_hypervisor_read_gpa(vgpu, pa,
+					p_data, bytes);
+			if (ret) {
+				gvt_err("vgpu%d: guest page read error %d, "
+					"gfn 0x%lx, pa 0x%llx, var 0x%x, len %d\n",
+					vgpu->id, ret,
+					gp->gfn, pa, *(u32 *)p_data, bytes);
+			}
+			mutex_unlock(&gvt->lock);
+			return ret;
+		}
+	}
+
+	offset = intel_vgpu_gpa_to_mmio_offset(vgpu, pa);
+
+	if (WARN_ON(bytes > 8))
+		goto err;
+
+	if (reg_is_gtt(gvt, offset)) {
+		if (WARN_ON(!IS_ALIGNED(offset, 4) && !IS_ALIGNED(offset, 8)))
+			goto err;
+		if (WARN_ON(bytes != 4 && bytes != 8))
+			goto err;
+		if (WARN_ON(!reg_is_gtt(gvt, offset + bytes - 1)))
+			goto err;
+
+		ret = intel_vgpu_emulate_gtt_mmio_read(vgpu, offset,
+				p_data, bytes);
+		if (ret)
+			goto err;
+		mutex_unlock(&gvt->lock);
+		return ret;
+	}
+
+	if (WARN_ON_ONCE(!reg_is_mmio(gvt, offset))) {
+		ret = intel_gvt_hypervisor_read_gpa(vgpu, pa, p_data, bytes);
+		mutex_unlock(&gvt->lock);
+		return ret;
+	}
+
+	if (WARN_ON(!reg_is_mmio(gvt, offset + bytes - 1)))
+		goto err;
+
+	mmio = intel_gvt_find_mmio_info(gvt, rounddown(offset, 4));
+	if (!mmio && !vgpu->mmio.disable_warn_untrack) {
+		gvt_err("vgpu%d: read untracked MMIO %x len %d val %x\n",
+				vgpu->id, offset, bytes, *(u32 *)p_data);
+
+		if (offset == 0x206c) {
+			gvt_err("------------------------------------------\n");
+			gvt_err("vgpu%d: likely triggers a gfx reset\n",
+			vgpu->id);
+			gvt_err("------------------------------------------\n");
+			vgpu->mmio.disable_warn_untrack = true;
+		}
+	}
+
+	if (!intel_gvt_mmio_is_unalign(gvt, offset)) {
+		if (WARN_ON(!IS_ALIGNED(offset, bytes)))
+			goto err;
+	}
+
+	if (mmio) {
+		if (!intel_gvt_mmio_is_unalign(gvt, mmio->offset)) {
+			if (WARN_ON(offset + bytes > mmio->offset + mmio->size))
+				goto err;
+			if (WARN_ON(mmio->offset != offset))
+				goto err;
+		}
+		ret = mmio->read(vgpu, offset, p_data, bytes);
+	} else
+		ret = intel_vgpu_default_mmio_read(vgpu, offset, p_data, bytes);
+
+	if (ret)
+		goto err;
+
+	intel_gvt_mmio_set_accessed(gvt, offset);
+	mutex_unlock(&gvt->lock);
+	return 0;
+err:
+	gvt_err("vgpu%d: fail to emulate MMIO read %08x len %d\n",
+			vgpu->id, offset, bytes);
+	mutex_unlock(&gvt->lock);
+	return ret;
+}
+
+/**
+ * intel_vgpu_emulate_mmio_write - emulate MMIO write
+ * @vgpu: a vGPU
+ * @pa: guest physical address
+ * @p_data: write data buffer
+ * @bytes: access data length
+ *
+ * Returns:
+ * Zero on success, negative error code if failed
+ */
+int intel_vgpu_emulate_mmio_write(void *__vgpu, uint64_t pa,
+		void *p_data, unsigned int bytes)
+{
+	struct intel_vgpu *vgpu = __vgpu;
+	struct intel_gvt *gvt = vgpu->gvt;
+	struct intel_gvt_mmio_info *mmio;
+	unsigned int offset = 0;
+	u32 old_vreg = 0, old_sreg = 0;
+	int ret = -EINVAL;
+
+	mutex_lock(&gvt->lock);
+
+	if (atomic_read(&vgpu->gtt.n_write_protected_guest_page)) {
+		struct intel_vgpu_guest_page *gp;
+
+		gp = intel_vgpu_find_guest_page(vgpu, pa >> PAGE_SHIFT);
+		if (gp) {
+			ret = gp->handler(gp, pa, p_data, bytes);
+			if (ret) {
+				gvt_err("vgpu%d: guest page write error %d, "
+					"gfn 0x%lx, pa 0x%llx, var 0x%x, len %d\n",
+					vgpu->id, ret,
+					gp->gfn, pa, *(u32 *)p_data, bytes);
+			}
+			mutex_unlock(&gvt->lock);
+			return ret;
+		}
+	}
+
+	offset = intel_vgpu_gpa_to_mmio_offset(vgpu, pa);
+
+	if (WARN_ON(bytes > 8))
+		goto err;
+
+	if (reg_is_gtt(gvt, offset)) {
+		if (WARN_ON(!IS_ALIGNED(offset, 4) && !IS_ALIGNED(offset, 8)))
+			goto err;
+		if (WARN_ON(bytes != 4 && bytes != 8))
+			goto err;
+		if (WARN_ON(!reg_is_gtt(gvt, offset + bytes - 1)))
+			goto err;
+
+		ret = intel_vgpu_emulate_gtt_mmio_write(vgpu, offset,
+				p_data, bytes);
+		if (ret)
+			goto err;
+		mutex_unlock(&gvt->lock);
+		return ret;
+	}
+
+	if (WARN_ON_ONCE(!reg_is_mmio(gvt, offset))) {
+		ret = intel_gvt_hypervisor_write_gpa(vgpu, pa, p_data, bytes);
+		mutex_unlock(&gvt->lock);
+		return ret;
+	}
+
+	mmio = intel_gvt_find_mmio_info(gvt, rounddown(offset, 4));
+	if (!mmio && !vgpu->mmio.disable_warn_untrack)
+		gvt_err("vgpu%d: write untracked MMIO %x len %d val %x\n",
+				vgpu->id, offset, bytes, *(u32 *)p_data);
+
+	if (!intel_gvt_mmio_is_unalign(gvt, offset)) {
+		if (WARN_ON(!IS_ALIGNED(offset, bytes)))
+			goto err;
+	}
+
+	if (mmio) {
+		u64 ro_mask = mmio->ro_mask;
+
+		if (!intel_gvt_mmio_is_unalign(gvt, mmio->offset)) {
+			if (WARN_ON(offset + bytes > mmio->offset + mmio->size))
+				goto err;
+			if (WARN_ON(mmio->offset != offset))
+				goto err;
+		}
+
+		if (intel_gvt_mmio_has_mode_mask(gvt, mmio->offset)) {
+			old_vreg = vgpu_vreg(vgpu, offset);
+			old_sreg = vgpu_sreg(vgpu, offset);
+		}
+
+		if (!ro_mask) {
+			ret = mmio->write(vgpu, offset, p_data, bytes);
+		} else {
+			/* Protect RO bits like HW */
+			u64 data = 0;
+
+			/* all register bits are RO. */
+			if (ro_mask == ~(u64)0) {
+				gvt_err("vgpu%d: try to write RO reg %x\n",
+						vgpu->id, offset);
+				ret = 0;
+				goto out;
+			}
+			/* keep the RO bits in the virtual register */
+			memcpy(&data, p_data, bytes);
+			data &= ~mmio->ro_mask;
+			data |= vgpu_vreg(vgpu, offset) & mmio->ro_mask;
+			ret = mmio->write(vgpu, offset, &data, bytes);
+		}
+
+		/* higher 16bits of mode ctl regs are mask bits for change */
+		if (intel_gvt_mmio_has_mode_mask(gvt, mmio->offset)) {
+			u32 mask = vgpu_vreg(vgpu, offset) >> 16;
+
+			vgpu_vreg(vgpu, offset) = (old_vreg & ~mask)
+				| (vgpu_vreg(vgpu, offset) & mask);
+			vgpu_sreg(vgpu, offset) = (old_sreg & ~mask)
+				| (vgpu_sreg(vgpu, offset) & mask);
+		}
+	} else
+		ret = intel_vgpu_default_mmio_write(vgpu, offset, p_data,
+				bytes);
+	if (ret)
+		goto err;
+out:
+	intel_gvt_mmio_set_accessed(gvt, offset);
+	mutex_unlock(&gvt->lock);
+	return 0;
+err:
+	gvt_err("vgpu%d: fail to emulate MMIO write %08x len %d\n",
+			vgpu->id, offset, bytes);
+	mutex_unlock(&gvt->lock);
+	return ret;
+}