[PATCH 1/3] tools/libxl: Grant VGA IO port permission for stubdom/target domain

[Grzegorz Uriasz <gorbak25@gmail.com>]

When qemu is running inside a linux based stubdomain, qemu does not
have the necessary permissions to map the ioports to the target domain.
Currently, libxl is granting permissions only for the VGA RAM memory region
and not passing the required ioports. This patch grants the required
permission for the necessary vga io ports.

Signed-off-by: Grzegorz Uriasz <gorbak25@gmail.com>
---
 tools/libxl/libxl_pci.c | 99 ++++++++++++++++++++++++++++++-----------
 1 file changed, 73 insertions(+), 26 deletions(-)

diff --git a/tools/libxl/libxl_pci.c b/tools/libxl/libxl_pci.c
index 957ff5c8e9..436190f790 100644
--- a/tools/libxl/libxl_pci.c
+++ b/tools/libxl/libxl_pci.c
@@ -2441,17 +2441,75 @@ void libxl__device_pci_destroy_all(libxl__egc *egc, uint32_t domid,
     }
 }
 
+static int libxl__grant_legacy_vga_permissions(libxl__gc *gc, const uint32_t domid) {
+    int ret, i;
+    uint64_t vga_iomem_start = 0xa0000 >> XC_PAGE_SHIFT;
+    uint64_t vga_iomem_npages = 0x20;
+    uint32_t stubdom_domid = libxl_get_stubdom_id(CTX, domid);
+    uint64_t vga_ioport_start[] = {0x3B0, 0x3C0};
+    uint64_t vga_ioport_size[] = {0xC, 0x20};
+
+    /* VGA RAM */
+    ret = xc_domain_iomem_permission(CTX->xch, stubdom_domid,
+                                     vga_iomem_start, vga_iomem_npages, 1);
+    if (ret < 0) {
+        LOGED(ERROR, domid,
+              "failed to give stubdom%d access to iomem range "
+              "%"PRIx64"-%"PRIx64" for VGA passthru",
+              stubdom_domid,
+              vga_iomem_start, (vga_iomem_start + (vga_iomem_npages << XC_PAGE_SHIFT) - 1));
+        return ret;
+    }
+    ret = xc_domain_iomem_permission(CTX->xch, domid,
+                                     vga_iomem_start, vga_iomem_npages, 1);
+    if (ret < 0) {
+        LOGED(ERROR, domid,
+              "failed to give dom%d access to iomem range "
+              "%"PRIx64"-%"PRIx64" for VGA passthru",
+              domid, vga_iomem_start, (vga_iomem_start + (vga_iomem_npages << XC_PAGE_SHIFT) - 1));
+        return ret;
+    }
+
+    /* VGA IOPORTS */
+    for (i = 0 ; i < 2 ; i++) {
+        ret = xc_domain_ioport_permission(CTX->xch, stubdom_domid,
+                                          vga_ioport_start[i], vga_ioport_size[i], 1);
+        if (ret < 0) {
+            LOGED(ERROR, domid,
+                  "failed to give stubdom%d access to ioport range "
+                  "%"PRIx64"-%"PRIx64" for VGA passthru",
+                  stubdom_domid,
+                  vga_ioport_start[i], (vga_ioport_start[i] + vga_ioport_size[i] - 1));
+            return ret;
+        }
+        ret = xc_domain_ioport_permission(CTX->xch, domid,
+                                          vga_ioport_start[i], vga_ioport_size[i], 1);
+        if (ret < 0) {
+            LOGED(ERROR, domid,
+                  "failed to give dom%d access to ioport range "
+                  "%"PRIx64"-%"PRIx64" for VGA passthru",
+                  domid, vga_ioport_start[i], (vga_ioport_start[i] + vga_ioport_size[i] - 1));
+            return ret;
+        }
+    }
+
+    return 0;
+}
+
+static int libxl__grant_igd_opregion_permission(libxl__gc *gc, const uint32_t domid) {
+    return 0;
+}
+
 int libxl__grant_vga_iomem_permission(libxl__gc *gc, const uint32_t domid,
                                       libxl_domain_config *const d_config)
 {
-    int i, ret;
+    int i, ret = 0;
+    bool vga_found = false, igd_found = false;
 
     if (!libxl_defbool_val(d_config->b_info.u.hvm.gfx_passthru))
         return 0;
 
-    for (i = 0 ; i < d_config->num_pcidevs ; i++) {
-        uint64_t vga_iomem_start = 0xa0000 >> XC_PAGE_SHIFT;
-        uint32_t stubdom_domid;
+    for (i = 0 ; i < d_config->num_pcidevs && !igd_found ; i++) {
         libxl_device_pci *pcidev = &d_config->pcidevs[i];
         unsigned long pci_device_class;
 
@@ -2460,30 +2518,19 @@ int libxl__grant_vga_iomem_permission(libxl__gc *gc, const uint32_t domid,
         if (pci_device_class != 0x030000) /* VGA class */
             continue;
 
-        stubdom_domid = libxl_get_stubdom_id(CTX, domid);
-        ret = xc_domain_iomem_permission(CTX->xch, stubdom_domid,
-                                         vga_iomem_start, 0x20, 1);
-        if (ret < 0) {
-            LOGED(ERROR, domid,
-                  "failed to give stubdom%d access to iomem range "
-                  "%"PRIx64"-%"PRIx64" for VGA passthru",
-                  stubdom_domid,
-                  vga_iomem_start, (vga_iomem_start + 0x20 - 1));
-            return ret;
-        }
-        ret = xc_domain_iomem_permission(CTX->xch, domid,
-                                         vga_iomem_start, 0x20, 1);
-        if (ret < 0) {
-            LOGED(ERROR, domid,
-                  "failed to give dom%d access to iomem range "
-                  "%"PRIx64"-%"PRIx64" for VGA passthru",
-                  domid, vga_iomem_start, (vga_iomem_start + 0x20 - 1));
-            return ret;
-        }
-        break;
+        vga_found = true;
+        if (pcidev->bus == 0 && pcidev->dev == 2 && pcidev->func == 0)
+            igd_found = true;
     }
 
-    return 0;
+    if (vga_found)
+        ret = libxl__grant_legacy_vga_permissions(gc, domid);
+    if (ret < 0)
+        return ret;
+    if (igd_found)
+        ret = libxl__grant_igd_opregion_permission(gc, domid);
+
+    return ret;
 }
 
 static int libxl_device_pci_compare(const libxl_device_pci *d1,
-- 
2.27.0