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authorJuergen Gross <jgross@suse.com>2017-06-14 17:12:45 +0200
committerJuergen Gross <jgross@suse.com>2017-06-15 08:50:32 +0200
commit4a4c29c96dde0eefd69054fd9e6b4255d4717799 (patch)
treed13f72b7468d13b163ec0102014d718c32ea66d3
parentdb985220778e200a935c6d8afddb2b1e32554375 (diff)
downloadlinux-4a4c29c96dde0eefd69054fd9e6b4255d4717799.tar.bz2
xen: add sysfs node for guest type
Currently there is no reliable user interface inside a Xen guest to determine its type (e.g. HVM, PV or PVH). Instead of letting user mode try to determine this by various rather hacky mechanisms (parsing of boot messages before they are gone, trying to make use of known subtle differences in behavior of some instructions), add a sysfs node /sys/hypervisor/guest_type to explicitly deliver this information as it is known to the kernel. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
-rw-r--r--Documentation/ABI/testing/sysfs-hypervisor-xen (renamed from Documentation/ABI/testing/sysfs-hypervisor-pmu)15
-rw-r--r--MAINTAINERS2
-rw-r--r--drivers/xen/sys-hypervisor.c34
3 files changed, 48 insertions, 3 deletions
diff --git a/Documentation/ABI/testing/sysfs-hypervisor-pmu b/Documentation/ABI/testing/sysfs-hypervisor-xen
index 224faa105e18..c0edb3fdd6eb 100644
--- a/Documentation/ABI/testing/sysfs-hypervisor-pmu
+++ b/Documentation/ABI/testing/sysfs-hypervisor-xen
@@ -1,8 +1,19 @@
+What: /sys/hypervisor/guest_type
+Date: May 2017
+KernelVersion: 4.13
+Contact: xen-devel@lists.xenproject.org
+Description: If running under Xen:
+ Type of guest:
+ "Xen": standard guest type on arm
+ "HVM": fully virtualized guest (x86)
+ "PV": paravirtualized guest (x86)
+ "PVH": fully virtualized guest without legacy emulation (x86)
+
What: /sys/hypervisor/pmu/pmu_mode
Date: August 2015
KernelVersion: 4.3
Contact: Boris Ostrovsky <boris.ostrovsky@oracle.com>
-Description:
+Description: If running under Xen:
Describes mode that Xen's performance-monitoring unit (PMU)
uses. Accepted values are
"off" -- PMU is disabled
@@ -17,7 +28,7 @@ What: /sys/hypervisor/pmu/pmu_features
Date: August 2015
KernelVersion: 4.3
Contact: Boris Ostrovsky <boris.ostrovsky@oracle.com>
-Description:
+Description: If running under Xen:
Describes Xen PMU features (as an integer). A set bit indicates
that the corresponding feature is enabled. See
include/xen/interface/xenpmu.h for available features
diff --git a/MAINTAINERS b/MAINTAINERS
index 730245ac2c18..c3ce334414e9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13984,7 +13984,7 @@ F: arch/x86/include/asm/xen/
F: include/xen/
F: include/uapi/xen/
F: Documentation/ABI/stable/sysfs-hypervisor-xen
-F: Documentation/ABI/testing/sysfs-hypervisor-pmu
+F: Documentation/ABI/testing/sysfs-hypervisor-xen
XEN HYPERVISOR ARM
M: Stefano Stabellini <sstabellini@kernel.org>
diff --git a/drivers/xen/sys-hypervisor.c b/drivers/xen/sys-hypervisor.c
index 84106f9c456c..2f78f84a31e9 100644
--- a/drivers/xen/sys-hypervisor.c
+++ b/drivers/xen/sys-hypervisor.c
@@ -50,6 +50,35 @@ static int __init xen_sysfs_type_init(void)
return sysfs_create_file(hypervisor_kobj, &type_attr.attr);
}
+static ssize_t guest_type_show(struct hyp_sysfs_attr *attr, char *buffer)
+{
+ const char *type;
+
+ switch (xen_domain_type) {
+ case XEN_NATIVE:
+ /* ARM only. */
+ type = "Xen";
+ break;
+ case XEN_PV_DOMAIN:
+ type = "PV";
+ break;
+ case XEN_HVM_DOMAIN:
+ type = xen_pvh_domain() ? "PVH" : "HVM";
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return sprintf(buffer, "%s\n", type);
+}
+
+HYPERVISOR_ATTR_RO(guest_type);
+
+static int __init xen_sysfs_guest_type_init(void)
+{
+ return sysfs_create_file(hypervisor_kobj, &guest_type_attr.attr);
+}
+
/* xen version attributes */
static ssize_t major_show(struct hyp_sysfs_attr *attr, char *buffer)
{
@@ -471,6 +500,9 @@ static int __init hyper_sysfs_init(void)
ret = xen_sysfs_type_init();
if (ret)
goto out;
+ ret = xen_sysfs_guest_type_init();
+ if (ret)
+ goto guest_type_out;
ret = xen_sysfs_version_init();
if (ret)
goto version_out;
@@ -502,6 +534,8 @@ uuid_out:
comp_out:
sysfs_remove_group(hypervisor_kobj, &version_group);
version_out:
+ sysfs_remove_file(hypervisor_kobj, &guest_type_attr.attr);
+guest_type_out:
sysfs_remove_file(hypervisor_kobj, &type_attr.attr);
out:
return ret;