arm: Allow the user to specify the GIC version

A platform may have a GIC compatible with previous version of the
device.

This is allow to virtualize an unmodified OS on new hardware if the GIC
is compatible with older version.

When a guest is created, the vGIC will emulate same version as the
hardware. Although, the user can specify in the configuration file the
preferred version (currently only GICv2 and GICv3 are supported).

Signed-off-by: Julien Grall <julien.grall@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5
index 38c977c184d62ff03a53d71d50aba1d9be5474fe..382f30b5d4c4cdf54c495c950f2e6818c51b7388 100644 (file)
--- a/docs/man/xl.cfg.pod.5
+++ b/docs/man/xl.cfg.pod.5
@@ -1680,6 +1680,40 @@ The default is B<en-us>.
 
 See L<qemu(1)> for more information.
 
+=head2 Architecture Specific options
+
+=head3 ARM
+
+=over 4
+
+=item B<gic_version="vN">
+
+Version of the GIC emulated for the guest. Currently, the following
+versions are supported:
+
+=over 4
+
+=item B<v2>
+
+Emulate a GICv2
+
+=item B<v3>
+
+Emulate a GICv3. Note that the emulated GIC does not support the
+GICv2 compatibility mode.
+
+=item B<default>
+
+Emulate the same version as the native GIC hardware used by host where
+the domain was created.
+
+=back
+
+This requires hardware compatibility with the requested version. Either
+natively or via hardware backwards compatibility support.
+
+=back
+
 =head1 SEE ALSO
 
 =over 4

diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index 942cbf147dd46db1d7d55ddb699e1aac1b6d560e..e9d63c9a5bf31bb99b5f7d9fa5212db5a1266bfd 100644 (file)
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -199,6 +199,11 @@
  */
 #define LIBXL_HAVE_DEVICETREE_PASSTHROUGH 1
 
+/*
+ * libxl_domain_build_info has the arm.gic_version field.
+ */
+#define LIBXL_HAVE_BUILDINFO_ARM_GIC_VERSION 1
+
 /*
  * libxl ABI compatibility
  *

diff --git a/tools/libxl/libxl_arch.h b/tools/libxl/libxl_arch.h
index d04871c55d35a034f8d6a409c1485b2c4cabac68..9a80d436e279ad937745bc3ccdefdba07cb957dd 100644 (file)
--- a/tools/libxl/libxl_arch.h
+++ b/tools/libxl/libxl_arch.h
@@ -21,6 +21,12 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc,
                                       libxl_domain_config *d_config,
                                       xc_domain_configuration_t *xc_config);
 
+/* save the arch specific configuration for the domain */
+_hidden
+int libxl__arch_domain_save_config(libxl__gc *gc,
+                                   libxl_domain_config *d_config,
+                                   const xc_domain_configuration_t *xc_config);
+
 /* arch specific internal domain creation function */
 _hidden
 int libxl__arch_domain_create(libxl__gc *gc, libxl_domain_config *d_config,

diff --git a/tools/libxl/libxl_arm.c b/tools/libxl/libxl_arm.c
index 03a92053bd5d7290bc5e2bf91ac75207a7630822..d30690548a3f7501a36c56a8cc22431664c74360 100644 (file)
--- a/tools/libxl/libxl_arm.c
+++ b/tools/libxl/libxl_arm.c
@@ -61,7 +61,40 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc,
     xc_config->nr_spis = nr_spis;
     LOG(DEBUG, " - Allocate %u SPIs", nr_spis);
 
-    xc_config->gic_version = XEN_DOMCTL_CONFIG_GIC_NATIVE;
+    switch (d_config->b_info.arch_arm.gic_version) {
+    case LIBXL_GIC_VERSION_DEFAULT:
+        xc_config->gic_version = XEN_DOMCTL_CONFIG_GIC_NATIVE;
+        break;
+    case LIBXL_GIC_VERSION_V2:
+        xc_config->gic_version = XEN_DOMCTL_CONFIG_GIC_V2;
+        break;
+    case LIBXL_GIC_VERSION_V3:
+        xc_config->gic_version = XEN_DOMCTL_CONFIG_GIC_V3;
+        break;
+    default:
+        LOG(ERROR, "Unknown GIC version %d\n",
+            d_config->b_info.arch_arm.gic_version);
+        return ERROR_FAIL;
+    }
+
+    return 0;
+}
+
+int libxl__arch_domain_save_config(libxl__gc *gc,
+                                   libxl_domain_config *d_config,
+                                   const xc_domain_configuration_t *xc_config)
+{
+    switch (xc_config->gic_version) {
+    case XEN_DOMCTL_CONFIG_GIC_V2:
+        d_config->b_info.arch_arm.gic_version = LIBXL_GIC_VERSION_V2;
+        break;
+    case XEN_DOMCTL_CONFIG_GIC_V3:
+        d_config->b_info.arch_arm.gic_version = LIBXL_GIC_VERSION_V3;
+        break;
+    default:
+        LOG(ERROR, "Unexpected gic version %u\n", xc_config->gic_version);
+        return ERROR_FAIL;
+    }
 
     return 0;
 }

diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 69bfa335fd637d5fc8702e31a2b6490757fcf186..b785ddd7a110478a500082b67561f1687330ce55 100644 (file)
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -527,6 +527,10 @@ int libxl__domain_make(libxl__gc *gc, libxl_domain_config *d_config,
         goto out;
     }
 
+    rc = libxl__arch_domain_save_config(gc, d_config, xc_config);
+    if (rc < 0)
+        goto out;
+
     ret = xc_cpupool_movedomain(ctx->xch, info->poolid, *domid);
     if (ret < 0) {
         LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "domain move fail");

diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index ec4cee5cf17f17cf841fce9c672c2203f40f8894..8dacf8d006d2a3106a2cfac9202324c2346eaea3 100644 (file)
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -380,6 +380,12 @@ libxl_vnode_info = Struct("vnode_info", [
     ("vcpus", libxl_bitmap), # vcpus in this node
     ])
 
+libxl_gic_version = Enumeration("gic_version", [
+    (0, "DEFAULT"),
+    (0x20, "v2"),
+    (0x30, "v3")
+    ], init_val = "LIBXL_GIC_VERSION_DEFAULT")
+
 libxl_domain_build_info = Struct("domain_build_info",[
     ("max_vcpus",       integer),
     ("avail_vcpus",     libxl_bitmap),
@@ -492,6 +498,11 @@ libxl_domain_build_info = Struct("domain_build_info",[
                                       ])),
                  ("invalid", None),
                  ], keyvar_init_val = "LIBXL_DOMAIN_TYPE_INVALID")),
+
+
+    ("arch_arm", Struct(None, [("gic_version", libxl_gic_version),
+                              ])),
+
     ], dir=DIR_IN
 )
 

diff --git a/tools/libxl/libxl_x86.c b/tools/libxl/libxl_x86.c
index ed2bd388cbf82829e525445e88281b999779602d..8cd15ca6986017f36a74d47c220707dcae11f788 100644 (file)
--- a/tools/libxl/libxl_x86.c
+++ b/tools/libxl/libxl_x86.c
@@ -10,6 +10,13 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc,
     return 0;
 }
 
+int libxl__arch_domain_save_config(libxl__gc *gc,
+                                   libxl_domain_config *d_config,
+                                   const xc_domain_configuration_t *xc_config)
+{
+    return 0;
+}
+
 static const char *e820_names(int type)
 {
     switch (type) {

diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index 14527c577f1d55d6e90df269b75138b5af9121b3..609cf04af94f93ee2dd091c7f25cdb8af9d9aa45 100644 (file)
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -2257,6 +2257,15 @@ skip_vfb:
         }
     }
 
+    if (!xlu_cfg_get_string (config, "gic_version", &buf, 1)) {
+        e = libxl_gic_version_from_string(buf, &b_info->arch_arm.gic_version);
+        if (e) {
+            fprintf(stderr,
+                    "Unknown gic_version \"%s\" specified\n", buf);
+            exit(-ERROR_FAIL);
+        }
+     }
+
     xlu_cfg_destroy(config);
 }
 

diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index b97ab6ca003ed38655cb4c383bb672db0275e245..b2bfc7d293ada3cd1695873c014e71d809c8e69d 100644 (file)
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -531,7 +531,6 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
                        struct xen_arch_domainconfig *config)
 {
     int rc;
-    uint8_t gic_version;
 
     d->arch.relmem = RELMEM_not_started;
 
@@ -560,28 +559,38 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags,
     if ( (rc = p2m_alloc_table(d)) != 0 )
         goto fail;
 
-    /*
-     * Currently the vGIC is emulating the same version of the
-     * hardware GIC. Only the value XEN_DOMCTL_CONFIG_GIC_NATIVE
-     * is allowed. The DOMCTL will return the actual version of the
-     * GIC.
-     */
-    rc = -EOPNOTSUPP;
-    if ( config->gic_version != XEN_DOMCTL_CONFIG_GIC_NATIVE )
-        goto fail;
-
-    switch ( gic_hw_version() )
+    switch ( config->gic_version )
     {
-    case GIC_V3:
-        gic_version = XEN_DOMCTL_CONFIG_GIC_V3;
+    case XEN_DOMCTL_CONFIG_GIC_NATIVE:
+        switch ( gic_hw_version () )
+        {
+        case GIC_V2:
+            config->gic_version = XEN_DOMCTL_CONFIG_GIC_V2;
+            d->arch.vgic.version = GIC_V2;
+            break;
+
+        case GIC_V3:
+            config->gic_version = XEN_DOMCTL_CONFIG_GIC_V3;
+            d->arch.vgic.version = GIC_V3;
+            break;
+
+        default:
+            BUG();
+        }
+        break;
+
+    case XEN_DOMCTL_CONFIG_GIC_V2:
+        d->arch.vgic.version = GIC_V2;
         break;
-    case GIC_V2:
-        gic_version = XEN_DOMCTL_CONFIG_GIC_V2;
+
+    case XEN_DOMCTL_CONFIG_GIC_V3:
+        d->arch.vgic.version = GIC_V3;
         break;
+
     default:
-        BUG();
+        rc = -EOPNOTSUPP;
+        goto fail;
     }
-    config->gic_version = gic_version;
 
     if ( (rc = domain_vgic_init(d, config->nr_spis)) != 0 )
         goto fail;

diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index 01fc9d8722b1d30fb6a06993c67ca3f75e6ebaa7..a6835a806cd2a1b3a87313281cafc544b38f3b97 100644 (file)
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -81,7 +81,7 @@ int domain_vgic_init(struct domain *d, unsigned int nr_spis)
 
     d->arch.vgic.nr_spis = nr_spis;
 
-    switch ( gic_hw_version() )
+    switch ( d->arch.vgic.version )
     {
 #ifdef HAS_GICV3
     case GIC_V3:
@@ -95,7 +95,7 @@ int domain_vgic_init(struct domain *d, unsigned int nr_spis)
         break;
     default:
         printk(XENLOG_G_ERR "d%d: Unknown vGIC version %u\n",
-               d->domain_id, gic_hw_version());
+               d->domain_id, d->arch.vgic.version);
         return -ENODEV;
     }
 

diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index 8f5a6898afbc10ad8b75bb876ffd1ec4b7217525..56aa208995667ce2f5ccb81b7ac44f29e991a101 100644 (file)
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -77,6 +77,8 @@ struct arch_domain
     } virt_timer_base;
 
     struct {
+        /* Version of the vGIC */
+        enum gic_version version;
         /* GIC HW version specific vGIC driver handler */
         const struct vgic_ops *handler;
         /*