Re: [Qemu-devel] [Xen-devel] [v2][PATCH] libxl: add one machine property to support IGD GFX passthrough

["Chen, Tiejun" <tiejun.chen@intel.com>]

On 2015/2/9 19:05, Ian Campbell wrote:
> On Mon, 2015-02-09 at 14:28 +0800, Chen, Tiejun wrote:
>
>> What about this?
>
> I've not read the code in detail,since I'm travelling but from a quick
> glance it looks to be implementing the sort of thing I meant, thanks.

Thanks for your time.

>
> A couple of higher level comments:
>
> I'd suggest to put the code for reading the vid/did into a helper
> function so it can be reused.

Looks good.

>
> You might like to optionally consider add a forcing option somehow so
> that people with new devices not in the list can control things without
> the need to recompile (e.g. gfx_passthru_kind_override?). Perhaps that
> isn't needed for a first cut though and it would be a libxl API so
> thought required.

What about 'gfx_passthru_force'? Because what we're doing is, we want to 
make sure if we have a such a IGD that needs to workaround by posting a 
parameter to qemu. So in case of non-listed devices we just need to 
provide a bool to force this regardless of that real device.

>
> I think it should probably log something at a lowish level when it has
> autodetected IGD.
>

So I tried to rebase that according to your all comments,

diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 98687bd..398d9da 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -361,6 +361,7 @@ int libxl__domain_build_info_setdefault(libxl__gc *gc,
          libxl_defbool_setdefault(&b_info->u.hvm.nographic, false);

          libxl_defbool_setdefault(&b_info->u.hvm.gfx_passthru, false);
+        libxl_defbool_setdefault(&b_info->u.hvm.gfx_passthru_force, false);

          break;
      case LIBXL_DOMAIN_TYPE_PV:
diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index 8599a6a..507034f 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -710,9 +710,6 @@ static char ** 
libxl__build_device_model_args_new(libxl__gc *gc,
              flexarray_append(dm_args, "-net");
              flexarray_append(dm_args, "none");
          }
-        if (libxl_defbool_val(b_info->u.hvm.gfx_passthru)) {
-            flexarray_append(dm_args, "-gfx_passthru");
-        }
      } else {
          if (!sdl && !vnc) {
              flexarray_append(dm_args, "-nographic");
@@ -757,6 +754,11 @@ static char ** 
libxl__build_device_model_args_new(libxl__gc *gc,
                                              machinearg, max_ram_below_4g);
              }
          }
+
+        if (libxl__is_igd_vga_passthru(gc, guest_config)) {
+            machinearg = GCSPRINTF("%s,igd-passthru=on", machinearg);
+        }
+
          flexarray_append(dm_args, machinearg);
          for (i = 0; b_info->extra_hvm && b_info->extra_hvm[i] != NULL; 
i++)
              flexarray_append(dm_args, b_info->extra_hvm[i]);
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 934465a..35ec5fc 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -1177,6 +1177,9 @@ _hidden int libxl__create_pci_backend(libxl__gc 
*gc, uint32_t domid,
                                        libxl_device_pci *pcidev, int num);
  _hidden int libxl__device_pci_destroy_all(libxl__gc *gc, uint32_t domid);

+_hidden int libxl__is_igd_vga_passthru(libxl__gc *gc,
+                                       const libxl_domain_config 
*d_config);
+
  /*----- xswait: wait for a xenstore node to be suitable -----*/

  typedef struct libxl__xswait_state libxl__xswait_state;
diff --git a/tools/libxl/libxl_pci.c b/tools/libxl/libxl_pci.c
index f3ae132..07b9e22 100644
--- a/tools/libxl/libxl_pci.c
+++ b/tools/libxl/libxl_pci.c
@@ -491,6 +491,130 @@ static int sysfs_dev_unbind(libxl__gc *gc, 
libxl_device_pci *pcidev,
      return 0;
  }

+static unsigned long sysfs_dev_get_vendor(libxl__gc *gc,
+                                          libxl_device_pci *pcidev)
+{
+    char *pci_device_vendor_path =
+            libxl__sprintf(gc, SYSFS_PCI_DEV"/"PCI_BDF"/vendor",
+                           pcidev->domain, pcidev->bus, pcidev->dev,
+                           pcidev->func);
+    int read_items;
+    unsigned long pci_device_vendor;
+
+    FILE *f = fopen(pci_device_vendor_path, "r");
+    if (!f) {
+        LOGE(ERROR,
+             "pci device "PCI_BDF" does not have vendor attribute",
+             pcidev->domain, pcidev->bus, pcidev->dev, pcidev->func);
+        return 0xffff;
+    }
+    read_items = fscanf(f, "0x%lx\n", &pci_device_vendor);
+    fclose(f);
+    if (read_items != 1) {
+        LOGE(ERROR,
+             "cannot read vendor of pci device "PCI_BDF,
+             pcidev->domain, pcidev->bus, pcidev->dev, pcidev->func);
+        return 0xffff;
+    }
+
+    return pci_device_vendor;
+}
+
+static unsigned long sysfs_dev_get_device(libxl__gc *gc,
+                                          libxl_device_pci *pcidev)
+{
+    char *pci_device_device_path =
+            libxl__sprintf(gc, SYSFS_PCI_DEV"/"PCI_BDF"/device",
+                           pcidev->domain, pcidev->bus, pcidev->dev,
+                           pcidev->func);
+    int read_items;
+    unsigned long pci_device_device;
+
+    FILE *f = fopen(pci_device_device_path, "r");
+    if (!f) {
+        LOGE(ERROR,
+             "pci device "PCI_BDF" does not have device attribute",
+             pcidev->domain, pcidev->bus, pcidev->dev, pcidev->func);
+        return 0xffff;
+    }
+    read_items = fscanf(f, "0x%lx\n", &pci_device_device);
+    fclose(f);
+    if (read_items != 1) {
+        LOGE(ERROR,
+             "cannot read device of pci device "PCI_BDF,
+             pcidev->domain, pcidev->bus, pcidev->dev, pcidev->func);
+        return 0xffff;
+    }
+
+    return pci_device_device;
+}
+
+static const uint16_t igd_ids[] = {
+    /* HSW Classic */
+    0x0402, /* HSWGT1D, HSWD_w7 */
+    0x0406,  /* HSWGT1M, HSWM_w7 */
+    0x0412,  /* HSWGT2D, HSWD_w7 */
+    0x0416,  /* HSWGT2M, HSWM_w7 */
+    0x041E,  /* HSWGT15D, HSWD_w7 */
+    /* HSW ULT */
+    0x0A06,  /* HSWGT1UT, HSWM_w7 */
+    0x0A16,  /* HSWGT2UT, HSWM_w7 */
+    0x0A26,  /* HSWGT3UT, HSWM_w7 */
+    0x0A2E,  /* HSWGT3UT28W, HSWM_w7 */
+    0x0A1E,  /* HSWGT2UX, HSWM_w7 */
+    0x0A0E,  /* HSWGT1ULX, HSWM_w7 */
+    /* HSW CRW */
+    0x0D26,  /* HSWGT3CW, HSWM_w7 */
+    0x0D22,  /* HSWGT3CWDT, HSWD_w7 */
+    /* HSW Sever */
+    0x041A,  /* HSWSVGT2, HSWD_w7 */
+    /* HSW SRVR */
+    0x040A,  /* HSWSVGT1, HSWD_w7 */
+    /* BSW */
+    0x1606,  /* BDWULTGT1, BDWM_w7 */
+    0x1616,  /* BDWULTGT2, BDWM_w7 */
+    0x1626,  /* BDWULTGT3, BDWM_w7 */
+    0x160E,  /* BDWULXGT1, BDWM_w7 */
+    0x161E,  /* BDWULXGT2, BDWM_w7 */
+    0x1602,  /* BDWHALOGT1, BDWM_w7 */
+    0x1612,  /* BDWHALOGT2, BDWM_w7 */
+    0x1622,  /* BDWHALOGT3, BDWM_w7 */
+    0x162B,  /* BDWHALO28W, BDWM_w7 */
+    0x162A,  /* BDWGT3WRKS, BDWM_w7 */
+    0x162D,  /* BDWGT3SRVR, BDWM_w7 */
+};
+
+int libxl__is_igd_vga_passthru(libxl__gc *gc,
+                               const libxl_domain_config *d_config)
+{
+    unsigned int i, j, num = ARRAY_SIZE(igd_ids);
+    libxl_ctx *ctx = libxl__gc_owner(gc);
+
+    if (!libxl_defbool_val(d_config->b_info.u.hvm.gfx_passthru))
+        return 0;
+
+    if (libxl_defbool_val(d_config->b_info.u.hvm.gfx_passthru_force)) {
+        LIBXL__LOG(ctx, LIBXL__LOG_WARNING, "Force to workaround IGD.");
+        return 1;
+    }
+
+    for (i = 0 ; i < d_config->num_pcidevs ; i++) {
+        libxl_device_pci *pcidev = &d_config->pcidevs[i];
+
+        if (sysfs_dev_get_vendor(gc, pcidev) != 0x8086) /* Intel class */
+            continue;
+
+        for (j = 0 ; j < num ; j++) {
+            if (sysfs_dev_get_device(gc, pcidev) == igd_ids[j]) { /* IGD */
+                LIBXL__LOG(ctx, LIBXL__LOG_INFO, "Detected supported 
IGD.");
+                return 1;
+            }
+        }
+    }
+
+    return 0;
+}
+
  /*
   * A brief comment about slots.  I don't know what slots are for; however,
   * I have by experimentation determined:
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index 02be466..d3015bc 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -430,6 +430,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
                                         ("spice", 
libxl_spice_info),

                                         ("gfx_passthru", 
libxl_defbool),
+                                       ("gfx_passthru_force", 
libxl_defbool),

                                         ("serial",           string),
                                         ("boot",             string),

Thanks
Tiejun