[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-devel] [PATCH v2 14/15] 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 on GICv2 and GICv3 are supported).

Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Wei Liu <wei.liu2@xxxxxxxxxx>

---
    The hypervisor will check if the GIC is able to virtualize the
    version specified by the user (via the DOMCTL createdomain).
    If it's not compatible an error will be send on the Xen console
    which will make the error not obvious for user.

    I left aside a user error reporting for a follow-up as I'm not
    sure how to notify the user which GIC versions are available. May be
    by a new mechanism similar to xen_get_caps?

    Changes in v2:
        - Introduce arch_arm in libxl_domain_build_info to store ARM
        specific field
        - Add docs
        - Remove code that is not necessary with the new version
---
 docs/man/xl.cfg.pod.5        | 27 ++++++++++++++++++++++++++
 tools/libxl/libxl.h          |  5 +++++
 tools/libxl/libxl_arm.c      | 16 +++++++++++++++-
 tools/libxl/libxl_types.idl  | 11 +++++++++++
 tools/libxl/xl_cmdimpl.c     | 12 ++++++++++++
 xen/arch/arm/domain.c        | 45 ++++++++++++++++++++++++++------------------
 xen/arch/arm/vgic.c          |  2 +-
 xen/include/asm-arm/domain.h |  2 ++
 8 files changed, 100 insertions(+), 20 deletions(-)

diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5
index a3e0e2e..663eb2d 100644
--- a/docs/man/xl.cfg.pod.5
+++ b/docs/man/xl.cfg.pod.5
@@ -1688,6 +1688,33 @@ 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 hardware
+
+=item B<v3>
+
+Emulate a GICv3 hardware. Note that the GICv2 compatibility is not supported.
+
+=back
+
+Although, all the versions may not be supported on the host.
+
+=back
+
 =head1 SEE ALSO
 
 =over 4
diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index 0a7913b..68bc954 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -200,6 +200,11 @@
 #define LIBXL_HAVE_DEVICETREE_PASSTHROUGH 1
 
 /*
+ * libxl_domain_build_info has the gic_version field.
+ */
+#define LIBXL_HAVE_BUILDINFO_GIC_VERSION 1
+
+/*
  * libxl ABI compatibility
  *
  * The only guarantee which libxl makes regarding ABI compatibility
diff --git a/tools/libxl/libxl_arm.c b/tools/libxl/libxl_arm.c
index f09c860..5b637e9 100644
--- a/tools/libxl/libxl_arm.c
+++ b/tools/libxl/libxl_arm.c
@@ -61,7 +61,21 @@ 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_DEFAULT;
+    switch (d_config->b_info.arch_arm.gic_version) {
+    case LIBXL_GIC_VERSION_DEFAULT:
+        xc_config->gic_version = XEN_DOMCTL_CONFIG_GIC_DEFAULT;
+        break;
+    case LIBXL_GIC_VERSION_2:
+        xc_config->gic_version = XEN_DOMCTL_CONFIG_GIC_V2;
+        break;
+    case LIBXL_GIC_VERSION_3:
+        xc_config->gic_version = XEN_DOMCTL_CONFIG_GIC_V3;
+        break;
+    default:
+        LOG(ERROR, "Unkwnon GIC version %s\n",
+            
libxl_gic_version_to_string(d_config->b_info.arch_arm.gic_version));
+        break;
+    }
 
     return 0;
 }
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index 23f27d4..30f69ea 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -366,6 +366,12 @@ libxl_vnode_info = Struct("vnode_info", [
     ("vcpus", libxl_bitmap), # vcpus in this node
     ])
 
+libxl_gic_version = Enumeration("gic_version", [
+    (0, "DEFAULT"),
+    (1, "2"),
+    (2, "3")
+    ], init_val = "LIBXL_GIC_VERSION_DEFAULT")
+
 libxl_domain_build_info = Struct("domain_build_info",[
     ("max_vcpus",       integer),
     ("avail_vcpus",     libxl_bitmap),
@@ -477,6 +483,11 @@ 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/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index c858068..dcf1963 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -2242,6 +2242,18 @@ skip_vfb:
         }
     }
 
+    if (!xlu_cfg_get_string (config, "gic_version", &buf, 1)) {
+        if (!strcmp(buf, "v2"))
+            b_info->arch_arm.gic_version = LIBXL_GIC_VERSION_2;
+        else if (!strcmp(buf, "v3"))
+            b_info->arch_arm.gic_version = LIBXL_GIC_VERSION_3;
+        else {
+            fprintf(stderr,
+                    "Uknown gic_version \"%s\" specified\n", buf);
+            exit(1);
+         }
+     }
+
     xlu_cfg_destroy(config);
 }
 
diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index 21a03df..107d58f 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -535,7 +535,6 @@ 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;
 
@@ -564,28 +563,38 @@ 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_DEFAULT
-     * is allowed. The DOMCTL will return the actual version of the
-     * GIC.
-     */
-    rc = -EOPNOTSUPP;
-    if ( config->gic_version != XEN_DOMCTL_CONFIG_GIC_DEFAULT )
-        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_DEFAULT:
+        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 08c5e45..f237914 100644
--- 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:
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index ecfdc10..cde1069 100644
--- 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;
         /*
-- 
2.4.3


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.