drm/i915/gvt: vGPU interrupt virtualization.

This patch introduces vGPU interrupt emulation framework.

The vGPU intrerrupt emulation framework is an event-based interrupt
emulation framework. It's responsible for emulating GEN hardware interrupts
during emulating other HW behaviour.

It consists several components:

- Descriptions of interrupt register bit
- Upper level <-> lower level interrupt mapping
- GEN HW IER/IMR/IIR register emulation routines
- Event-based interrupt propagation interface

When a GVT-g component wants to inject an interrupt to a VM during a
emulation, first it should specify the event needs to be emulated and the
framework will deal with the rest of emulation:

- Generating related virtual IIR bit according to virtual IER and IMRs,
- Generate related virtual upper level virtual IIR bit accodring to the
per-platform interrupt mapping
- Injecting a MSI to VM
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/gvt/Makefile

 GVT_DIR := gvt
-GVT_SOURCE := gvt.o aperture_gm.o handlers.o vgpu.o trace_points.o firmware.o
+GVT_SOURCE := gvt.o aperture_gm.o handlers.o vgpu.o trace_points.o firmware.o \
+	interrupt.o
 
 ccflags-y                      += -I$(src) -I$(src)/$(GVT_DIR) -Wall
 i915-y			       += $(addprefix $(GVT_DIR)/, $(GVT_SOURCE))

drivers/gpu/drm/i915/gvt/debug.h

@@ -30,8 +30,7 @@
 #define gvt_dbg_core(fmt, args...) \
 	DRM_DEBUG_DRIVER("gvt: core: "fmt, ##args)
 
-/*
- * Other GVT debug stuff will be introduced in the GVT device model patches.
- */
+#define gvt_dbg_irq(fmt, args...) \
+	DRM_DEBUG_DRIVER("gvt: irq: "fmt, ##args)
 
 #endif

drivers/gpu/drm/i915/gvt/gvt.c

@@ -97,9 +97,10 @@ static void init_device_info(struct intel_gvt *gvt)
 
 	if (IS_BROADWELL(gvt->dev_priv) || IS_SKYLAKE(gvt->dev_priv)) {
 		info->max_support_vgpus = 8;
-		info->mmio_size = 2 * 1024 * 1024;
 		info->cfg_space_size = 256;
+		info->mmio_size = 2 * 1024 * 1024;
 		info->mmio_bar = 0;
+		info->msi_cap_offset = IS_SKYLAKE(gvt->dev_priv) ? 0xac : 0x90;
 	}
 }
 
@@ -118,6 +119,7 @@ void intel_gvt_clean_device(struct drm_i915_private *dev_priv)
 	if (WARN_ON(!gvt->initialized))
 		return;
 
+	intel_gvt_clean_irq(gvt);
 	intel_gvt_clean_mmio_info(gvt);
 	intel_gvt_free_firmware(gvt);
 
@@ -165,10 +167,16 @@ int intel_gvt_init_device(struct drm_i915_private *dev_priv)
 	if (ret)
 		goto out_clean_mmio_info;
 
+	ret = intel_gvt_init_irq(gvt);
+	if (ret)
+		goto out_free_firmware;
+
 	gvt_dbg_core("gvt device creation is done\n");
 	gvt->initialized = true;
 	return 0;
 
+out_free_firmware:
+	intel_gvt_free_firmware(gvt);
 out_clean_mmio_info:
 	intel_gvt_clean_mmio_info(gvt);
 	return ret;

drivers/gpu/drm/i915/gvt/gvt.h

@@ -37,6 +37,7 @@
 #include "hypercall.h"
 #include "mmio.h"
 #include "reg.h"
+#include "interrupt.h"
 
 #define GVT_MAX_VGPU 8
 
@@ -56,9 +57,10 @@ extern struct intel_gvt_host intel_gvt_host;
 /* Describe per-platform limitations. */
 struct intel_gvt_device_info {
 	u32 max_support_vgpus;
-	u32 mmio_size;
 	u32 cfg_space_size;
+	u32 mmio_size;
 	u32 mmio_bar;
+	unsigned long msi_cap_offset;
 };
 
 /* GM resources owned by a vGPU */
@@ -98,6 +100,10 @@ struct intel_vgpu_cfg_space {
 
 #define vgpu_cfg_space(vgpu) ((vgpu)->cfg_space.virtual_cfg_space)
 
+struct intel_vgpu_irq {
+	bool irq_warn_once[INTEL_GVT_EVENT_MAX];
+};
+
 struct intel_vgpu {
 	struct intel_gvt *gvt;
 	int id;
@@ -109,6 +115,7 @@ struct intel_vgpu {
 	struct intel_vgpu_gm gm;
 	struct intel_vgpu_cfg_space cfg_space;
 	struct intel_vgpu_mmio mmio;
+	struct intel_vgpu_irq irq;
 };
 
 struct intel_gvt_gm {
@@ -145,6 +152,7 @@ struct intel_gvt {
 	struct intel_gvt_fence fence;
 	struct intel_gvt_mmio mmio;
 	struct intel_gvt_firmware firmware;
+	struct intel_gvt_irq irq;
 };
 
 void intel_gvt_free_firmware(struct intel_gvt *gvt);

drivers/gpu/drm/i915/gvt/hypercall.h

@@ -41,6 +41,7 @@ struct intel_gvt_mpt {
 	int (*detect_host)(void);
 	int (*attach_vgpu)(void *vgpu, unsigned long *handle);
 	void (*detach_vgpu)(unsigned long handle);
+	int (*inject_msi)(unsigned long handle, u32 addr, u16 data);
 };
 
 extern struct intel_gvt_mpt xengt_mpt;

drivers/gpu/drm/i915/gvt/interrupt.h

+/*
+ * 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:
+ *    Kevin Tian <kevin.tian@intel.com>
+ *    Zhi Wang <zhi.a.wang@intel.com>
+ *
+ * Contributors:
+ *    Min he <min.he@intel.com>
+ *
+ */
+
+#ifndef _GVT_INTERRUPT_H_
+#define _GVT_INTERRUPT_H_
+
+enum intel_gvt_event_type {
+	RCS_MI_USER_INTERRUPT = 0,
+	RCS_DEBUG,
+	RCS_MMIO_SYNC_FLUSH,
+	RCS_CMD_STREAMER_ERR,
+	RCS_PIPE_CONTROL,
+	RCS_L3_PARITY_ERR,
+	RCS_WATCHDOG_EXCEEDED,
+	RCS_PAGE_DIRECTORY_FAULT,
+	RCS_AS_CONTEXT_SWITCH,
+	RCS_MONITOR_BUFF_HALF_FULL,
+
+	VCS_MI_USER_INTERRUPT,
+	VCS_MMIO_SYNC_FLUSH,
+	VCS_CMD_STREAMER_ERR,
+	VCS_MI_FLUSH_DW,
+	VCS_WATCHDOG_EXCEEDED,
+	VCS_PAGE_DIRECTORY_FAULT,
+	VCS_AS_CONTEXT_SWITCH,
+
+	VCS2_MI_USER_INTERRUPT,
+	VCS2_MI_FLUSH_DW,
+	VCS2_AS_CONTEXT_SWITCH,
+
+	BCS_MI_USER_INTERRUPT,
+	BCS_MMIO_SYNC_FLUSH,
+	BCS_CMD_STREAMER_ERR,
+	BCS_MI_FLUSH_DW,
+	BCS_PAGE_DIRECTORY_FAULT,
+	BCS_AS_CONTEXT_SWITCH,
+
+	VECS_MI_USER_INTERRUPT,
+	VECS_MI_FLUSH_DW,
+	VECS_AS_CONTEXT_SWITCH,
+
+	PIPE_A_FIFO_UNDERRUN,
+	PIPE_B_FIFO_UNDERRUN,
+	PIPE_A_CRC_ERR,
+	PIPE_B_CRC_ERR,
+	PIPE_A_CRC_DONE,
+	PIPE_B_CRC_DONE,
+	PIPE_A_ODD_FIELD,
+	PIPE_B_ODD_FIELD,
+	PIPE_A_EVEN_FIELD,
+	PIPE_B_EVEN_FIELD,
+	PIPE_A_LINE_COMPARE,
+	PIPE_B_LINE_COMPARE,
+	PIPE_C_LINE_COMPARE,
+	PIPE_A_VBLANK,
+	PIPE_B_VBLANK,
+	PIPE_C_VBLANK,
+	PIPE_A_VSYNC,
+	PIPE_B_VSYNC,
+	PIPE_C_VSYNC,
+	PRIMARY_A_FLIP_DONE,
+	PRIMARY_B_FLIP_DONE,
+	PRIMARY_C_FLIP_DONE,
+	SPRITE_A_FLIP_DONE,
+	SPRITE_B_FLIP_DONE,
+	SPRITE_C_FLIP_DONE,
+
+	PCU_THERMAL,
+	PCU_PCODE2DRIVER_MAILBOX,
+
+	DPST_PHASE_IN,
+	DPST_HISTOGRAM,
+	GSE,
+	DP_A_HOTPLUG,
+	AUX_CHANNEL_A,
+	PERF_COUNTER,
+	POISON,
+	GTT_FAULT,
+	ERROR_INTERRUPT_COMBINED,
+
+	FDI_RX_INTERRUPTS_TRANSCODER_A,
+	AUDIO_CP_CHANGE_TRANSCODER_A,
+	AUDIO_CP_REQUEST_TRANSCODER_A,
+	FDI_RX_INTERRUPTS_TRANSCODER_B,
+	AUDIO_CP_CHANGE_TRANSCODER_B,
+	AUDIO_CP_REQUEST_TRANSCODER_B,
+	FDI_RX_INTERRUPTS_TRANSCODER_C,
+	AUDIO_CP_CHANGE_TRANSCODER_C,
+	AUDIO_CP_REQUEST_TRANSCODER_C,
+	ERR_AND_DBG,
+	GMBUS,
+	SDVO_B_HOTPLUG,
+	CRT_HOTPLUG,
+	DP_B_HOTPLUG,
+	DP_C_HOTPLUG,
+	DP_D_HOTPLUG,
+	AUX_CHANNEL_B,
+	AUX_CHANNEL_C,
+	AUX_CHANNEL_D,
+	AUDIO_POWER_STATE_CHANGE_B,
+	AUDIO_POWER_STATE_CHANGE_C,
+	AUDIO_POWER_STATE_CHANGE_D,
+
+	INTEL_GVT_EVENT_RESERVED,
+	INTEL_GVT_EVENT_MAX,
+};
+
+struct intel_gvt_irq;
+struct intel_gvt;
+
+typedef void (*gvt_event_virt_handler_t)(struct intel_gvt_irq *irq,
+	enum intel_gvt_event_type event, struct intel_vgpu *vgpu);
+
+struct intel_gvt_irq_ops {
+	void (*init_irq)(struct intel_gvt_irq *irq);
+	void (*check_pending_irq)(struct intel_vgpu *vgpu);
+};
+
+/* the list of physical interrupt control register groups */
+enum intel_gvt_irq_type {
+	INTEL_GVT_IRQ_INFO_GT,
+	INTEL_GVT_IRQ_INFO_DPY,
+	INTEL_GVT_IRQ_INFO_PCH,
+	INTEL_GVT_IRQ_INFO_PM,
+
+	INTEL_GVT_IRQ_INFO_MASTER,
+	INTEL_GVT_IRQ_INFO_GT0,
+	INTEL_GVT_IRQ_INFO_GT1,
+	INTEL_GVT_IRQ_INFO_GT2,
+	INTEL_GVT_IRQ_INFO_GT3,
+	INTEL_GVT_IRQ_INFO_DE_PIPE_A,
+	INTEL_GVT_IRQ_INFO_DE_PIPE_B,
+	INTEL_GVT_IRQ_INFO_DE_PIPE_C,
+	INTEL_GVT_IRQ_INFO_DE_PORT,
+	INTEL_GVT_IRQ_INFO_DE_MISC,
+	INTEL_GVT_IRQ_INFO_AUD,
+	INTEL_GVT_IRQ_INFO_PCU,
+
+	INTEL_GVT_IRQ_INFO_MAX,
+};
+
+#define INTEL_GVT_IRQ_BITWIDTH	32
+
+/* device specific interrupt bit definitions */
+struct intel_gvt_irq_info {
+	char *name;
+	i915_reg_t reg_base;
+	enum intel_gvt_event_type bit_to_event[INTEL_GVT_IRQ_BITWIDTH];
+	unsigned long warned;
+	int group;
+	DECLARE_BITMAP(downstream_irq_bitmap, INTEL_GVT_IRQ_BITWIDTH);
+	bool has_upstream_irq;
+};
+
+/* per-event information */
+struct intel_gvt_event_info {
+	int bit;				/* map to register bit */
+	int policy;				/* forwarding policy */
+	struct intel_gvt_irq_info *info;	/* register info */
+	gvt_event_virt_handler_t v_handler;	/* for v_event */
+};
+
+struct intel_gvt_irq_map {
+	int up_irq_group;
+	int up_irq_bit;
+	int down_irq_group;
+	u32 down_irq_bitmask;
+};
+
+/* structure containing device specific IRQ state */
+struct intel_gvt_irq {
+	struct intel_gvt_irq_ops *ops;
+	struct intel_gvt_irq_info *info[INTEL_GVT_IRQ_INFO_MAX];
+	DECLARE_BITMAP(irq_info_bitmap, INTEL_GVT_IRQ_INFO_MAX);
+	struct intel_gvt_event_info events[INTEL_GVT_EVENT_MAX];
+	DECLARE_BITMAP(pending_events, INTEL_GVT_EVENT_MAX);
+	struct intel_gvt_irq_map *irq_map;
+};
+
+int intel_gvt_init_irq(struct intel_gvt *gvt);
+void intel_gvt_clean_irq(struct intel_gvt *gvt);
+
+void intel_vgpu_trigger_virtual_event(struct intel_vgpu *vgpu,
+	enum intel_gvt_event_type event);
+
+int intel_vgpu_reg_iir_handler(struct intel_vgpu *vgpu, unsigned int reg,
+	void *p_data, unsigned int bytes);
+int intel_vgpu_reg_ier_handler(struct intel_vgpu *vgpu,
+	unsigned int reg, void *p_data, unsigned int bytes);
+int intel_vgpu_reg_master_irq_handler(struct intel_vgpu *vgpu,
+	unsigned int reg, void *p_data, unsigned int bytes);
+int intel_vgpu_reg_imr_handler(struct intel_vgpu *vgpu,
+	unsigned int reg, void *p_data, unsigned int bytes);
+
+#endif /* _GVT_INTERRUPT_H_ */

drivers/gpu/drm/i915/gvt/mpt.h

@@ -79,4 +79,42 @@ static inline void intel_gvt_hypervisor_detach_vgpu(struct intel_vgpu *vgpu)
 	intel_gvt_host.mpt->detach_vgpu(vgpu->handle);
 }
 
+#define MSI_CAP_CONTROL(offset) (offset + 2)
+#define MSI_CAP_ADDRESS(offset) (offset + 4)
+#define MSI_CAP_DATA(offset) (offset + 8)
+#define MSI_CAP_EN 0x1
+
+/**
+ * intel_gvt_hypervisor_inject_msi - inject a MSI interrupt into vGPU
+ *
+ * Returns:
+ * Zero on success, negative error code if failed.
+ */
+static inline int intel_gvt_hypervisor_inject_msi(struct intel_vgpu *vgpu)
+{
+	unsigned long offset = vgpu->gvt->device_info.msi_cap_offset;
+	u16 control, data;
+	u32 addr;
+	int ret;
+
+	control = *(u16 *)(vgpu_cfg_space(vgpu) + MSI_CAP_CONTROL(offset));
+	addr = *(u32 *)(vgpu_cfg_space(vgpu) + MSI_CAP_ADDRESS(offset));
+	data = *(u16 *)(vgpu_cfg_space(vgpu) + MSI_CAP_DATA(offset));
+
+	/* Do not generate MSI if MSIEN is disable */
+	if (!(control & MSI_CAP_EN))
+		return 0;
+
+	if (WARN(control & GENMASK(15, 1), "only support one MSI format\n"))
+		return -EINVAL;
+
+	gvt_dbg_irq("vgpu%d: inject msi address %x data%x\n", vgpu->id, addr,
+		    data);
+
+	ret = intel_gvt_host.mpt->inject_msi(vgpu->handle, addr, data);
+	if (ret)
+		return ret;
+	return 0;
+}
+
 #endif /* _GVT_MPT_H_ */