xen/PMU: Sysfs interface for setting Xen PMU mode (5f141548) · Commits · e / devices / android_kernel_fairphone_FP3

Documentation/ABI/testing/sysfs-hypervisor-pmu

0 → 100644

+23 −0

Original line number	Diff line number	Diff line
		What: /sys/hypervisor/pmu/pmu_mode
		Date: August 2015
		KernelVersion: 4.3
		Contact: Boris Ostrovsky <boris.ostrovsky@oracle.com>
		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 <boris.ostrovsky@oracle.com>
		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

arch/x86/include/asm/xen/hypercall.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -465,6 +465,12 @@ HYPERVISOR_tmem_op(
		return _hypercall1(int, tmem_op, op);
		}

		static inline int
		HYPERVISOR_xenpmu_op(unsigned int op, void *arg)
		{
		return _hypercall2(int, xenpmu_op, op, arg);
		}

		static inline void
		MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
		{

arch/x86/xen/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -7,6 +7,7 @@ config XEN
		depends on PARAVIRT
		select PARAVIRT_CLOCK
		select XEN_HAVE_PVMMU
		select XEN_HAVE_VPMU
		depends on X86_64 \|\| (X86_32 && X86_PAE)
		depends on X86_TSC
		help

drivers/xen/Kconfig

+3 −0

Original line number	Diff line number	Diff line
		@@ -288,4 +288,7 @@ config XEN_SYMS
		Exports hypervisor symbols (along with their types and addresses) via
		/proc/xen/xensyms file, similar to /proc/kallsyms

		config XEN_HAVE_VPMU
		bool

		endmenu

drivers/xen/sys-hypervisor.c

+135 −1

Original line number	Diff line number	Diff line
		@@ -20,6 +20,9 @@
		#include <xen/xenbus.h>
		#include <xen/interface/xen.h>
		#include <xen/interface/version.h>
		#ifdef CONFIG_XEN_HAVE_VPMU
		#include <xen/interface/xenpmu.h>
		#endif

		#define HYPERVISOR_ATTR_RO(_name) \
		static struct hyp_sysfs_attr _name##_attr = __ATTR_RO(_name)
		@@ -368,6 +371,126 @@ static void xen_properties_destroy(void)
		sysfs_remove_group(hypervisor_kobj, &xen_properties_group);
		}

		#ifdef CONFIG_XEN_HAVE_VPMU
		struct pmu_mode {
		const char *name;
		uint32_t mode;
		};

		static struct pmu_mode pmu_modes[] = {
		{"off", XENPMU_MODE_OFF},
		{"self", XENPMU_MODE_SELF},
		{"hv", XENPMU_MODE_HV},
		{"all", XENPMU_MODE_ALL}
		};

		static ssize_t pmu_mode_store(struct hyp_sysfs_attr *attr,
		const char *buffer, size_t len)
		{
		int ret;
		struct xen_pmu_params xp;
		int i;

		for (i = 0; i < ARRAY_SIZE(pmu_modes); i++) {
		if (strncmp(buffer, pmu_modes[i].name, len - 1) == 0) {
		xp.val = pmu_modes[i].mode;
		break;
		}
		}

		if (i == ARRAY_SIZE(pmu_modes))
		return -EINVAL;

		xp.version.maj = XENPMU_VER_MAJ;
		xp.version.min = XENPMU_VER_MIN;
		ret = HYPERVISOR_xenpmu_op(XENPMU_mode_set, &xp);
		if (ret)
		return ret;

		return len;
		}

		static ssize_t pmu_mode_show(struct hyp_sysfs_attr attr, char buffer)
		{
		int ret;
		struct xen_pmu_params xp;
		int i;
		uint32_t mode;

		xp.version.maj = XENPMU_VER_MAJ;
		xp.version.min = XENPMU_VER_MIN;
		ret = HYPERVISOR_xenpmu_op(XENPMU_mode_get, &xp);
		if (ret)
		return ret;

		mode = (uint32_t)xp.val;
		for (i = 0; i < ARRAY_SIZE(pmu_modes); i++) {
		if (mode == pmu_modes[i].mode)
		return sprintf(buffer, "%s\n", pmu_modes[i].name);
		}

		return -EINVAL;
		}
		HYPERVISOR_ATTR_RW(pmu_mode);

		static ssize_t pmu_features_store(struct hyp_sysfs_attr *attr,
		const char *buffer, size_t len)
		{
		int ret;
		uint32_t features;
		struct xen_pmu_params xp;

		ret = kstrtou32(buffer, 0, &features);
		if (ret)
		return ret;

		xp.val = features;
		xp.version.maj = XENPMU_VER_MAJ;
		xp.version.min = XENPMU_VER_MIN;
		ret = HYPERVISOR_xenpmu_op(XENPMU_feature_set, &xp);
		if (ret)
		return ret;

		return len;
		}

		static ssize_t pmu_features_show(struct hyp_sysfs_attr attr, char buffer)
		{
		int ret;
		struct xen_pmu_params xp;

		xp.version.maj = XENPMU_VER_MAJ;
		xp.version.min = XENPMU_VER_MIN;
		ret = HYPERVISOR_xenpmu_op(XENPMU_feature_get, &xp);
		if (ret)
		return ret;

		return sprintf(buffer, "0x%x\n", (uint32_t)xp.val);
		}
		HYPERVISOR_ATTR_RW(pmu_features);

		static struct attribute *xen_pmu_attrs[] = {
		&pmu_mode_attr.attr,
		&pmu_features_attr.attr,
		NULL
		};

		static const struct attribute_group xen_pmu_group = {
		.name = "pmu",
		.attrs = xen_pmu_attrs,
		};

		static int __init xen_pmu_init(void)
		{
		return sysfs_create_group(hypervisor_kobj, &xen_pmu_group);
		}

		static void xen_pmu_destroy(void)
		{
		sysfs_remove_group(hypervisor_kobj, &xen_pmu_group);
		}
		#endif

		static int __init hyper_sysfs_init(void)
		{
		int ret;
		@@ -390,7 +513,15 @@ static int __init hyper_sysfs_init(void)
		ret = xen_properties_init();
		if (ret)
		goto prop_out;

		#ifdef CONFIG_XEN_HAVE_VPMU
		if (xen_initial_domain()) {
		ret = xen_pmu_init();
		if (ret) {
		xen_properties_destroy();
		goto prop_out;
		}
		}
		#endif
		goto out;

		prop_out:
		@@ -407,6 +538,9 @@ static int __init hyper_sysfs_init(void)

		static void __exit hyper_sysfs_exit(void)
		{
		#ifdef CONFIG_XEN_HAVE_VPMU
		xen_pmu_destroy();
		#endif
		xen_properties_destroy();
		xen_compilation_destroy();
		xen_sysfs_uuid_destroy();