xen, gfx passthrough: add opregion mapping

The OpRegion shouldn't be mapped 1:1 because the address in the host
can't be used in the guest directly.

This patch traps read and write access to the opregion of the Intel
GPU config space (offset 0xfc).

The original patch is from Jean Guyader <jean.guyader@eu.citrix.com>

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

1 files changed, 49 insertions, 2 deletions

diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
index dd37be38a4..9fb36704f8 100644
--- a/hw/xen/xen_pt_config_init.c
+++ b/hw/xen/xen_pt_config_init.c
@@ -552,6 +552,22 @@ static int xen_pt_exp_rom_bar_reg_write(XenPCIPassthroughState *s,
     return 0;
 }
 
+static int xen_pt_intel_opregion_read(XenPCIPassthroughState *s,
+                                      XenPTReg *cfg_entry,
+                                      uint32_t *value, uint32_t valid_mask)
+{
+    *value = igd_read_opregion(s);
+    return 0;
+}
+
+static int xen_pt_intel_opregion_write(XenPCIPassthroughState *s,
+                                       XenPTReg *cfg_entry, uint32_t *value,
+                                       uint32_t dev_value, uint32_t valid_mask)
+{
+    igd_write_opregion(s, *value);
+    return 0;
+}
+
 /* Header Type0 reg static information table */
 static XenPTRegInfo xen_pt_emu_reg_header0[] = {
     /* Vendor ID reg */
@@ -1492,6 +1508,19 @@ static XenPTRegInfo xen_pt_emu_reg_msix[] = {
     },
 };
 
+static XenPTRegInfo xen_pt_emu_reg_igd_opregion[] = {
+    /* Intel IGFX OpRegion reg */
+    {
+        .offset     = 0x0,
+        .size       = 4,
+        .init_val   = 0,
+        .u.dw.read   = xen_pt_intel_opregion_read,
+        .u.dw.write  = xen_pt_intel_opregion_write,
+    },
+    {
+        .size = 0,
+    },
+};
 
 /****************************
  * Capabilities
@@ -1729,6 +1758,14 @@ static const XenPTRegGroupInfo xen_pt_emu_reg_grps[] = {
         .size_init   = xen_pt_msix_size_init,
         .emu_regs = xen_pt_emu_reg_msix,
     },
+    /* Intel IGD Opregion group */
+    {
+        .grp_id      = XEN_PCI_INTEL_OPREGION,
+        .grp_type    = XEN_PT_GRP_TYPE_EMU,
+        .grp_size    = 0x4,
+        .size_init   = xen_pt_reg_grp_size_init,
+        .emu_regs    = xen_pt_emu_reg_igd_opregion,
+    },
     {
         .grp_size = 0,
     },
@@ -1779,7 +1816,7 @@ out:
 static uint8_t find_cap_offset(XenPCIPassthroughState *s, uint8_t cap)
 {
     uint8_t id;
-    unsigned max_cap = PCI_CAP_MAX;
+    unsigned max_cap = XEN_PCI_CAP_MAX;
     uint8_t pos = PCI_CAPABILITY_LIST;
     uint8_t status = 0;
 
@@ -1858,7 +1895,8 @@ int xen_pt_config_init(XenPCIPassthroughState *s)
         uint32_t reg_grp_offset = 0;
         XenPTRegGroup *reg_grp_entry = NULL;
 
-        if (xen_pt_emu_reg_grps[i].grp_id != 0xFF) {
+        if (xen_pt_emu_reg_grps[i].grp_id != 0xFF
+            && xen_pt_emu_reg_grps[i].grp_id != XEN_PCI_INTEL_OPREGION) {
             if (xen_pt_hide_dev_cap(&s->real_device,
                                     xen_pt_emu_reg_grps[i].grp_id)) {
                 continue;
@@ -1871,6 +1909,15 @@ int xen_pt_config_init(XenPCIPassthroughState *s)
             }
         }
 
+        /*
+         * By default we will trap up to 0x40 in the cfg space.
+         * If an intel device is pass through we need to trap 0xfc,
+         * therefore the size should be 0xff.
+         */
+        if (xen_pt_emu_reg_grps[i].grp_id == XEN_PCI_INTEL_OPREGION) {
+            reg_grp_offset = XEN_PCI_INTEL_OPREGION;
+        }
+
         reg_grp_entry = g_new0(XenPTRegGroup, 1);
         QLIST_INIT(&reg_grp_entry->reg_tbl_list);
         QLIST_INSERT_HEAD(&s->reg_grps, reg_grp_entry, entries);