From 02d578e5edd980eac3fbed15db4d9e5665f22089 Mon Sep 17 00:00:00 2001
From: Changbin Du <changbin.du@intel.com>
Date: Wed, 23 Aug 2017 14:08:10 +0800
Subject: [PATCH] drm/i915/gvt: Add support for PCIe extended configuration space
Git-commit: 02d578e5edd980eac3fbed15db4d9e5665f22089
Patch-mainline: v4.15-rc1
References: FATE#322643 bsc#1055900

IGD is PCIe device and has extended configuration space. Checking
the binary dump, we can see we have Caps located out of PCI compatible
Configuration Space range.

0x000: 86 80 12 19 17 04 10 00 06 00 00 03 00 00 00 00
0x010: 04 00 00 10 08 00 00 00 0c 00 00 00 08 00 00 00
0x020: 00 00 00 00 00 00 00 00 00 00 00 00 28 10 b9 06
0x030: 00 f8 ff ff 40 00 00 00 00 00 00 00 0b 01 00 00
0x040: 09 70 0c 01 71 26 01 62 c8 00 04 84 00 00 00 00
0x050: c1 00 00 00 39 00 00 00 00 00 00 00 01 00 00 a2
0x060: 00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00
0x070: 10 ac 92 00 00 80 00 10 00 00 00 00 00 00 00 00
0x080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0a0: 00 00 00 00 00 00 00 00 00 00 00 00 05 d0 01 00
0x0b0: 18 00 e0 fe 00 00 00 00 00 00 00 00 00 00 00 00
0x0c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0d0: 01 00 22 00 00 80 00 00 00 00 00 00 00 00 00 00
0x0e0: 00 00 00 00 00 00 00 00 00 80 00 00 00 00 00 00
0x0f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x100: 1b 00 01 20 02 14 00 00 00 00 00 00 00 00 00 00
...

Currently, we only emulate the PCI compatible Configuration Space.
This is okay if we attach vGPU to PCI bus. But when we attach to
a PCI Express bus (when Qemu emulates a Intel Q35 chipset which has
PCIe slot), it will not work. Extended Configuration Space is required
for a PCIe device.

This patch extended the virtual configuration space from 256 bytes
to 4KB bytes. So we are to be a *real* PCIe device. And for the
Extended CapList we keep same to physical GPU.

Cc: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/gvt/cfg_space.c |    4 ++--
 drivers/gpu/drm/i915/gvt/gvt.c       |    2 +-
 drivers/gpu/drm/i915/gvt/gvt.h       |    3 +--
 drivers/gpu/drm/i915/gvt/kvmgt.c     |    2 +-
 4 files changed, 5 insertions(+), 6 deletions(-)

--- a/drivers/gpu/drm/i915/gvt/cfg_space.c
+++ b/drivers/gpu/drm/i915/gvt/cfg_space.c
@@ -101,7 +101,7 @@ int intel_vgpu_emulate_cfg_read(struct i
 	if (WARN_ON(bytes > 4))
 		return -EINVAL;
 
-	if (WARN_ON(offset + bytes > INTEL_GVT_MAX_CFG_SPACE_SZ))
+	if (WARN_ON(offset + bytes > vgpu->gvt->device_info.cfg_space_size))
 		return -EINVAL;
 
 	memcpy(p_data, vgpu_cfg_space(vgpu) + offset, bytes);
@@ -289,7 +289,7 @@ int intel_vgpu_emulate_cfg_write(struct
 	if (WARN_ON(bytes > 4))
 		return -EINVAL;
 
-	if (WARN_ON(offset + bytes > INTEL_GVT_MAX_CFG_SPACE_SZ))
+	if (WARN_ON(offset + bytes > vgpu->gvt->device_info.cfg_space_size))
 		return -EINVAL;
 
 	/* First check if it's PCI_COMMAND */
--- a/drivers/gpu/drm/i915/gvt/gvt.c
+++ b/drivers/gpu/drm/i915/gvt/gvt.c
@@ -111,7 +111,7 @@ static void init_device_info(struct inte
 	if (IS_BROADWELL(gvt->dev_priv) || IS_SKYLAKE(gvt->dev_priv)
 		|| IS_KABYLAKE(gvt->dev_priv)) {
 		info->max_support_vgpus = 8;
-		info->cfg_space_size = 256;
+		info->cfg_space_size = PCI_CFG_SPACE_EXP_SIZE;
 		info->mmio_size = 2 * 1024 * 1024;
 		info->mmio_bar = 0;
 		info->gtt_start_offset = 8 * 1024 * 1024;
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -100,7 +100,6 @@ struct intel_vgpu_mmio {
 	bool disable_warn_untrack;
 };
 
-#define INTEL_GVT_MAX_CFG_SPACE_SZ 256
 #define INTEL_GVT_MAX_BAR_NUM 4
 
 struct intel_vgpu_pci_bar {
@@ -109,7 +108,7 @@ struct intel_vgpu_pci_bar {
 };
 
 struct intel_vgpu_cfg_space {
-	unsigned char virtual_cfg_space[INTEL_GVT_MAX_CFG_SPACE_SZ];
+	unsigned char virtual_cfg_space[PCI_CFG_SPACE_EXP_SIZE];
 	struct intel_vgpu_pci_bar bar[INTEL_GVT_MAX_BAR_NUM];
 };
 
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -978,7 +978,7 @@ static long intel_vgpu_ioctl(struct mdev
 		switch (info.index) {
 		case VFIO_PCI_CONFIG_REGION_INDEX:
 			info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
-			info.size = INTEL_GVT_MAX_CFG_SPACE_SZ;
+			info.size = vgpu->gvt->device_info.cfg_space_size;
 			info.flags = VFIO_REGION_INFO_FLAG_READ |
 				     VFIO_REGION_INFO_FLAG_WRITE;
 			break;