From 4a4c29c96dde0eefd69054fd9e6b4255d4717799 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Wed, 14 Jun 2017 17:12:45 +0200 Subject: 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 Reviewed-by: Boris Ostrovsky Signed-off-by: Juergen Gross --- Documentation/ABI/testing/sysfs-hypervisor-pmu | 23 ----------------- Documentation/ABI/testing/sysfs-hypervisor-xen | 34 ++++++++++++++++++++++++++ MAINTAINERS | 2 +- drivers/xen/sys-hypervisor.c | 34 ++++++++++++++++++++++++++ 4 files changed, 69 insertions(+), 24 deletions(-) delete mode 100644 Documentation/ABI/testing/sysfs-hypervisor-pmu create mode 100644 Documentation/ABI/testing/sysfs-hypervisor-xen diff --git a/Documentation/ABI/testing/sysfs-hypervisor-pmu b/Documentation/ABI/testing/sysfs-hypervisor-pmu deleted file mode 100644 index 224faa105e18..000000000000 --- a/Documentation/ABI/testing/sysfs-hypervisor-pmu +++ /dev/null @@ -1,23 +0,0 @@ -What: /sys/hypervisor/pmu/pmu_mode -Date: August 2015 -KernelVersion: 4.3 -Contact: Boris Ostrovsky -Description: - Describes mode that Xen's performance-monitoring unit (PMU) - uses. Accepted values are - "off" -- PMU is disabled - "self" -- The guest can profile itself - "hv" -- The guest can profile itself and, if it is - privileged (e.g. dom0), the hypervisor - "all" -- The guest can profile itself, the hypervisor - and all other guests. Only available to - privileged guests. - -What: /sys/hypervisor/pmu/pmu_features -Date: August 2015 -KernelVersion: 4.3 -Contact: Boris Ostrovsky -Description: - 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/Documentation/ABI/testing/sysfs-hypervisor-xen b/Documentation/ABI/testing/sysfs-hypervisor-xen new file mode 100644 index 000000000000..c0edb3fdd6eb --- /dev/null +++ b/Documentation/ABI/testing/sysfs-hypervisor-xen @@ -0,0 +1,34 @@ +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 +Description: If running under Xen: + Describes mode that Xen's performance-monitoring unit (PMU) + uses. Accepted values are + "off" -- PMU is disabled + "self" -- The guest can profile itself + "hv" -- The guest can profile itself and, if it is + privileged (e.g. dom0), the hypervisor + "all" -- The guest can profile itself, the hypervisor + and all other guests. Only available to + privileged guests. + +What: /sys/hypervisor/pmu/pmu_features +Date: August 2015 +KernelVersion: 4.3 +Contact: Boris Ostrovsky +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 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; -- cgit v1.2.1