From: Boris Ostrovsky Date: Mon, 10 Aug 2015 20:34:33 +0000 (-0400) Subject: xen/PMU: Sysfs interface for setting Xen PMU mode X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=5f141548824cebbff2e838ff401c34e667797467;p=linux-beck.git xen/PMU: Sysfs interface for setting Xen PMU mode Set Xen's PMU mode via /sys/hypervisor/pmu/pmu_mode. Add XENPMU hypercall. Signed-off-by: Boris Ostrovsky Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: David Vrabel --- diff --git a/Documentation/ABI/testing/sysfs-hypervisor-pmu b/Documentation/ABI/testing/sysfs-hypervisor-pmu new file mode 100644 index 000000000000..224faa105e18 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-hypervisor-pmu @@ -0,0 +1,23 @@ +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/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h index ca08a27b90b3..83aea8055119 100644 --- a/arch/x86/include/asm/xen/hypercall.h +++ b/arch/x86/include/asm/xen/hypercall.h @@ -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) { diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig index 7bcf21b865d1..a8ffdb85656f 100644 --- a/arch/x86/xen/Kconfig +++ b/arch/x86/xen/Kconfig @@ -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 diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index 936760455dd5..73708acce3ca 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -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 diff --git a/drivers/xen/sys-hypervisor.c b/drivers/xen/sys-hypervisor.c index 96453f8a85c5..b5a7342e0ba5 100644 --- a/drivers/xen/sys-hypervisor.c +++ b/drivers/xen/sys-hypervisor.c @@ -20,6 +20,9 @@ #include #include #include +#ifdef CONFIG_XEN_HAVE_VPMU +#include +#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 @@ out: 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(); diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h index 8194270edcf0..e9d4501d1f5e 100644 --- a/include/xen/interface/xen.h +++ b/include/xen/interface/xen.h @@ -80,6 +80,7 @@ #define __HYPERVISOR_kexec_op 37 #define __HYPERVISOR_tmem_op 38 #define __HYPERVISOR_xc_reserved_op 39 /* reserved for XenClient */ +#define __HYPERVISOR_xenpmu_op 40 /* Architecture-specific hypercall definitions. */ #define __HYPERVISOR_arch_0 48 diff --git a/include/xen/interface/xenpmu.h b/include/xen/interface/xenpmu.h new file mode 100644 index 000000000000..eac1b498b89f --- /dev/null +++ b/include/xen/interface/xenpmu.h @@ -0,0 +1,59 @@ +#ifndef __XEN_PUBLIC_XENPMU_H__ +#define __XEN_PUBLIC_XENPMU_H__ + +#include "xen.h" + +#define XENPMU_VER_MAJ 0 +#define XENPMU_VER_MIN 1 + +/* + * ` enum neg_errnoval + * ` HYPERVISOR_xenpmu_op(enum xenpmu_op cmd, struct xenpmu_params *args); + * + * @cmd == XENPMU_* (PMU operation) + * @args == struct xenpmu_params + */ +/* ` enum xenpmu_op { */ +#define XENPMU_mode_get 0 /* Also used for getting PMU version */ +#define XENPMU_mode_set 1 +#define XENPMU_feature_get 2 +#define XENPMU_feature_set 3 +#define XENPMU_init 4 +#define XENPMU_finish 5 + +/* ` } */ + +/* Parameters structure for HYPERVISOR_xenpmu_op call */ +struct xen_pmu_params { + /* IN/OUT parameters */ + struct { + uint32_t maj; + uint32_t min; + } version; + uint64_t val; + + /* IN parameters */ + uint32_t vcpu; + uint32_t pad; +}; + +/* PMU modes: + * - XENPMU_MODE_OFF: No PMU virtualization + * - XENPMU_MODE_SELF: Guests can profile themselves + * - XENPMU_MODE_HV: Guests can profile themselves, dom0 profiles + * itself and Xen + * - XENPMU_MODE_ALL: Only dom0 has access to VPMU and it profiles + * everyone: itself, the hypervisor and the guests. + */ +#define XENPMU_MODE_OFF 0 +#define XENPMU_MODE_SELF (1<<0) +#define XENPMU_MODE_HV (1<<1) +#define XENPMU_MODE_ALL (1<<2) + +/* + * PMU features: + * - XENPMU_FEATURE_INTEL_BTS: Intel BTS support (ignored on AMD) + */ +#define XENPMU_FEATURE_INTEL_BTS 1 + +#endif /* __XEN_PUBLIC_XENPMU_H__ */