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-rw-r--r--arch/arm64/kvm/Makefile2
-rw-r--r--arch/mips/kvm/Makefile2
-rw-r--r--arch/powerpc/kvm/Makefile2
-rw-r--r--arch/s390/kvm/Makefile3
-rw-r--r--arch/x86/kvm/Makefile2
-rw-r--r--include/linux/kvm_host.h82
-rw-r--r--include/linux/kvm_types.h2
-rw-r--r--include/uapi/linux/kvm.h73
-rw-r--r--virt/kvm/binary_stats.c146
9 files changed, 307 insertions, 7 deletions
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index 589921392cb1..989bb5dad2c8 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -11,7 +11,7 @@ obj-$(CONFIG_KVM) += kvm.o
obj-$(CONFIG_KVM) += hyp/
kvm-y := $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o \
- $(KVM)/vfio.o $(KVM)/irqchip.o \
+ $(KVM)/vfio.o $(KVM)/irqchip.o $(KVM)/binary_stats.o \
arm.o mmu.o mmio.o psci.o perf.o hypercalls.o pvtime.o \
inject_fault.o va_layout.o handle_exit.o \
guest.o debug.o reset.o sys_regs.o \
diff --git a/arch/mips/kvm/Makefile b/arch/mips/kvm/Makefile
index 30cc060857c7..c67250a956b8 100644
--- a/arch/mips/kvm/Makefile
+++ b/arch/mips/kvm/Makefile
@@ -2,7 +2,7 @@
# Makefile for KVM support for MIPS
#
-common-objs-y = $(addprefix ../../../virt/kvm/, kvm_main.o coalesced_mmio.o eventfd.o)
+common-objs-y = $(addprefix ../../../virt/kvm/, kvm_main.o coalesced_mmio.o eventfd.o binary_stats.o)
EXTRA_CFLAGS += -Ivirt/kvm -Iarch/mips/kvm
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index ab241317481c..583c14ef596e 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -6,7 +6,7 @@
ccflags-y := -Ivirt/kvm -Iarch/powerpc/kvm
KVM := ../../../virt/kvm
-common-objs-y = $(KVM)/kvm_main.o $(KVM)/eventfd.o
+common-objs-y = $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/binary_stats.o
common-objs-$(CONFIG_KVM_VFIO) += $(KVM)/vfio.o
common-objs-$(CONFIG_KVM_MMIO) += $(KVM)/coalesced_mmio.o
diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
index 12decca22e7c..b3aaadc60ead 100644
--- a/arch/s390/kvm/Makefile
+++ b/arch/s390/kvm/Makefile
@@ -4,7 +4,8 @@
# Copyright IBM Corp. 2008
KVM := ../../../virt/kvm
-common-objs = $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/async_pf.o $(KVM)/irqchip.o $(KVM)/vfio.o
+common-objs = $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/async_pf.o \
+ $(KVM)/irqchip.o $(KVM)/vfio.o $(KVM)/binary_stats.o
ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index 83331376b779..75dfd27b6e8a 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -11,7 +11,7 @@ KVM := ../../../virt/kvm
kvm-y += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o \
$(KVM)/eventfd.o $(KVM)/irqchip.o $(KVM)/vfio.o \
- $(KVM)/dirty_ring.o
+ $(KVM)/dirty_ring.o $(KVM)/binary_stats.o
kvm-$(CONFIG_KVM_ASYNC_PF) += $(KVM)/async_pf.o
kvm-y += x86.o emulate.o i8259.o irq.o lapic.o \
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 37cbb56ccd09..9ee7f350473b 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1272,16 +1272,94 @@ struct kvm_stats_debugfs_item {
int mode;
};
+struct _kvm_stats_desc {
+ struct kvm_stats_desc desc;
+ char name[KVM_STATS_NAME_SIZE];
+};
+
#define KVM_DBGFS_GET_MODE(dbgfs_item) \
((dbgfs_item)->mode ? (dbgfs_item)->mode : 0644)
-#define VM_STAT(n, x, ...) \
+#define VM_STAT(n, x, ...) \
{ n, offsetof(struct kvm, stat.x), KVM_STAT_VM, ## __VA_ARGS__ }
-#define VCPU_STAT(n, x, ...) \
+#define VCPU_STAT(n, x, ...) \
{ n, offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU, ## __VA_ARGS__ }
+#define STATS_DESC_COMMON(type, unit, base, exp) \
+ .flags = type | unit | base | \
+ BUILD_BUG_ON_ZERO(type & ~KVM_STATS_TYPE_MASK) | \
+ BUILD_BUG_ON_ZERO(unit & ~KVM_STATS_UNIT_MASK) | \
+ BUILD_BUG_ON_ZERO(base & ~KVM_STATS_BASE_MASK), \
+ .exponent = exp, \
+ .size = 1
+
+#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
+ { \
+ { \
+ STATS_DESC_COMMON(type, unit, base, exp), \
+ .offset = offsetof(struct kvm_vm_stat, generic.stat) \
+ }, \
+ .name = #stat, \
+ }
+#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp) \
+ { \
+ { \
+ STATS_DESC_COMMON(type, unit, base, exp), \
+ .offset = offsetof(struct kvm_vcpu_stat, generic.stat) \
+ }, \
+ .name = #stat, \
+ }
+#define VM_STATS_DESC(stat, type, unit, base, exp) \
+ { \
+ { \
+ STATS_DESC_COMMON(type, unit, base, exp), \
+ .offset = offsetof(struct kvm_vm_stat, stat) \
+ }, \
+ .name = #stat, \
+ }
+#define VCPU_STATS_DESC(stat, type, unit, base, exp) \
+ { \
+ { \
+ STATS_DESC_COMMON(type, unit, base, exp), \
+ .offset = offsetof(struct kvm_vcpu_stat, stat) \
+ }, \
+ .name = #stat, \
+ }
+/* SCOPE: VM, VM_GENERIC, VCPU, VCPU_GENERIC */
+#define STATS_DESC(SCOPE, stat, type, unit, base, exp) \
+ SCOPE##_STATS_DESC(stat, type, unit, base, exp)
+
+#define STATS_DESC_CUMULATIVE(SCOPE, name, unit, base, exponent) \
+ STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, unit, base, exponent)
+#define STATS_DESC_INSTANT(SCOPE, name, unit, base, exponent) \
+ STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, unit, base, exponent)
+#define STATS_DESC_PEAK(SCOPE, name, unit, base, exponent) \
+ STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, unit, base, exponent)
+
+/* Cumulative counter, read/write */
+#define STATS_DESC_COUNTER(SCOPE, name) \
+ STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_NONE, \
+ KVM_STATS_BASE_POW10, 0)
+/* Instantaneous counter, read only */
+#define STATS_DESC_ICOUNTER(SCOPE, name) \
+ STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_NONE, \
+ KVM_STATS_BASE_POW10, 0)
+/* Peak counter, read/write */
+#define STATS_DESC_PCOUNTER(SCOPE, name) \
+ STATS_DESC_PEAK(SCOPE, name, KVM_STATS_UNIT_NONE, \
+ KVM_STATS_BASE_POW10, 0)
+
+/* Cumulative time in nanosecond */
+#define STATS_DESC_TIME_NSEC(SCOPE, name) \
+ STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
+ KVM_STATS_BASE_POW10, -9)
+
extern struct kvm_stats_debugfs_item debugfs_entries[];
extern struct dentry *kvm_debugfs_dir;
+ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
+ const struct _kvm_stats_desc *desc,
+ void *stats, size_t size_stats,
+ char __user *user_buffer, size_t size, loff_t *offset);
#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
static inline int mmu_notifier_retry(struct kvm *kvm, unsigned long mmu_seq)
diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
index 48db778291b7..ed6a985c5680 100644
--- a/include/linux/kvm_types.h
+++ b/include/linux/kvm_types.h
@@ -89,4 +89,6 @@ struct kvm_vcpu_stat_generic {
u64 halt_poll_fail_ns;
};
+#define KVM_STATS_NAME_SIZE 48
+
#endif /* __KVM_TYPES_H__ */
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 330835f1005b..f1ba602260f6 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1087,6 +1087,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_SREGS2 200
#define KVM_CAP_EXIT_HYPERCALL 201
#define KVM_CAP_PPC_RPT_INVALIDATE 202
+#define KVM_CAP_BINARY_STATS_FD 203
#ifdef KVM_CAP_IRQ_ROUTING
@@ -1906,4 +1907,76 @@ struct kvm_dirty_gfn {
#define KVM_BUS_LOCK_DETECTION_OFF (1 << 0)
#define KVM_BUS_LOCK_DETECTION_EXIT (1 << 1)
+/**
+ * struct kvm_stats_header - Header of per vm/vcpu binary statistics data.
+ * @flags: Some extra information for header, always 0 for now.
+ * @name_size: The size in bytes of the memory which contains statistics
+ * name string including trailing '\0'. The memory is allocated
+ * at the send of statistics descriptor.
+ * @num_desc: The number of statistics the vm or vcpu has.
+ * @id_offset: The offset of the vm/vcpu stats' id string in the file pointed
+ * by vm/vcpu stats fd.
+ * @desc_offset: The offset of the vm/vcpu stats' descriptor block in the file
+ * pointd by vm/vcpu stats fd.
+ * @data_offset: The offset of the vm/vcpu stats' data block in the file
+ * pointed by vm/vcpu stats fd.
+ *
+ * This is the header userspace needs to read from stats fd before any other
+ * readings. It is used by userspace to discover all the information about the
+ * vm/vcpu's binary statistics.
+ * Userspace reads this header from the start of the vm/vcpu's stats fd.
+ */
+struct kvm_stats_header {
+ __u32 flags;
+ __u32 name_size;
+ __u32 num_desc;
+ __u32 id_offset;
+ __u32 desc_offset;
+ __u32 data_offset;
+};
+
+#define KVM_STATS_TYPE_SHIFT 0
+#define KVM_STATS_TYPE_MASK (0xF << KVM_STATS_TYPE_SHIFT)
+#define KVM_STATS_TYPE_CUMULATIVE (0x0 << KVM_STATS_TYPE_SHIFT)
+#define KVM_STATS_TYPE_INSTANT (0x1 << KVM_STATS_TYPE_SHIFT)
+#define KVM_STATS_TYPE_PEAK (0x2 << KVM_STATS_TYPE_SHIFT)
+#define KVM_STATS_TYPE_MAX KVM_STATS_TYPE_PEAK
+
+#define KVM_STATS_UNIT_SHIFT 4
+#define KVM_STATS_UNIT_MASK (0xF << KVM_STATS_UNIT_SHIFT)
+#define KVM_STATS_UNIT_NONE (0x0 << KVM_STATS_UNIT_SHIFT)
+#define KVM_STATS_UNIT_BYTES (0x1 << KVM_STATS_UNIT_SHIFT)
+#define KVM_STATS_UNIT_SECONDS (0x2 << KVM_STATS_UNIT_SHIFT)
+#define KVM_STATS_UNIT_CYCLES (0x3 << KVM_STATS_UNIT_SHIFT)
+#define KVM_STATS_UNIT_MAX KVM_STATS_UNIT_CYCLES
+
+#define KVM_STATS_BASE_SHIFT 8
+#define KVM_STATS_BASE_MASK (0xF << KVM_STATS_BASE_SHIFT)
+#define KVM_STATS_BASE_POW10 (0x0 << KVM_STATS_BASE_SHIFT)
+#define KVM_STATS_BASE_POW2 (0x1 << KVM_STATS_BASE_SHIFT)
+#define KVM_STATS_BASE_MAX KVM_STATS_BASE_POW2
+
+/**
+ * struct kvm_stats_desc - Descriptor of a KVM statistics.
+ * @flags: Annotations of the stats, like type, unit, etc.
+ * @exponent: Used together with @flags to determine the unit.
+ * @size: The number of data items for this stats.
+ * Every data item is of type __u64.
+ * @offset: The offset of the stats to the start of stat structure in
+ * struture kvm or kvm_vcpu.
+ * @unused: Unused field for future usage. Always 0 for now.
+ * @name: The name string for the stats. Its size is indicated by the
+ * &kvm_stats_header->name_size.
+ */
+struct kvm_stats_desc {
+ __u32 flags;
+ __s16 exponent;
+ __u16 size;
+ __u32 offset;
+ __u32 unused;
+ char name[];
+};
+
+#define KVM_GET_STATS_FD _IO(KVMIO, 0xce)
+
#endif /* __LINUX_KVM_H */
diff --git a/virt/kvm/binary_stats.c b/virt/kvm/binary_stats.c
new file mode 100644
index 000000000000..e609d428811a
--- /dev/null
+++ b/virt/kvm/binary_stats.c
@@ -0,0 +1,146 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * KVM binary statistics interface implementation
+ *
+ * Copyright 2021 Google LLC
+ */
+
+#include <linux/kvm_host.h>
+#include <linux/kvm.h>
+#include <linux/errno.h>
+#include <linux/uaccess.h>
+
+/**
+ * kvm_stats_read() - Common function to read from the binary statistics
+ * file descriptor.
+ *
+ * @id: identification string of the stats
+ * @header: stats header for a vm or a vcpu
+ * @desc: start address of an array of stats descriptors for a vm or a vcpu
+ * @stats: start address of stats data block for a vm or a vcpu
+ * @size_stats: the size of stats data block pointed by @stats
+ * @user_buffer: start address of userspace buffer
+ * @size: requested read size from userspace
+ * @offset: the start position from which the content will be read for the
+ * corresponding vm or vcp file descriptor
+ *
+ * The file content of a vm/vcpu file descriptor is now defined as below:
+ * +-------------+
+ * | Header |
+ * +-------------+
+ * | id string |
+ * +-------------+
+ * | Descriptors |
+ * +-------------+
+ * | Stats Data |
+ * +-------------+
+ * Although this function allows userspace to read any amount of data (as long
+ * as in the limit) from any position, the typical usage would follow below
+ * steps:
+ * 1. Read header from offset 0. Get the offset of descriptors and stats data
+ * and some other necessary information. This is a one-time work for the
+ * lifecycle of the corresponding vm/vcpu stats fd.
+ * 2. Read id string from its offset. This is a one-time work for the lifecycle
+ * of the corresponding vm/vcpu stats fd.
+ * 3. Read descriptors from its offset and discover all the stats by parsing
+ * descriptors. This is a one-time work for the lifecycle of the
+ * corresponding vm/vcpu stats fd.
+ * 4. Periodically read stats data from its offset using pread.
+ *
+ * Return: the number of bytes that has been successfully read
+ */
+ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
+ const struct _kvm_stats_desc *desc,
+ void *stats, size_t size_stats,
+ char __user *user_buffer, size_t size, loff_t *offset)
+{
+ ssize_t len;
+ ssize_t copylen;
+ ssize_t remain = size;
+ size_t size_desc;
+ size_t size_header;
+ void *src;
+ loff_t pos = *offset;
+ char __user *dest = user_buffer;
+
+ size_header = sizeof(*header);
+ size_desc = header->num_desc * sizeof(*desc);
+
+ len = KVM_STATS_NAME_SIZE + size_header + size_desc + size_stats - pos;
+ len = min(len, remain);
+ if (len <= 0)
+ return 0;
+ remain = len;
+
+ /*
+ * Copy kvm stats header.
+ * The header is the first block of content userspace usually read out.
+ * The pos is 0 and the copylen and remain would be the size of header.
+ * The copy of the header would be skipped if offset is larger than the
+ * size of header. That usually happens when userspace reads stats
+ * descriptors and stats data.
+ */
+ copylen = size_header - pos;
+ copylen = min(copylen, remain);
+ if (copylen > 0) {
+ src = (void *)header + pos;
+ if (copy_to_user(dest, src, copylen))
+ return -EFAULT;
+ remain -= copylen;
+ pos += copylen;
+ dest += copylen;
+ }
+
+ /*
+ * Copy kvm stats header id string.
+ * The id string is unique for every vm/vcpu, which is stored in kvm
+ * and kvm_vcpu structure.
+ * The id string is part of the stat header from the perspective of
+ * userspace, it is usually read out together with previous constant
+ * header part and could be skipped for later descriptors and stats
+ * data readings.
+ */
+ copylen = header->id_offset + KVM_STATS_NAME_SIZE - pos;
+ copylen = min(copylen, remain);
+ if (copylen > 0) {
+ src = id + pos - header->id_offset;
+ if (copy_to_user(dest, src, copylen))
+ return -EFAULT;
+ remain -= copylen;
+ pos += copylen;
+ dest += copylen;
+ }
+
+ /*
+ * Copy kvm stats descriptors.
+ * The descriptors copy would be skipped in the typical case that
+ * userspace periodically read stats data, since the pos would be
+ * greater than the end address of descriptors
+ * (header->header.desc_offset + size_desc) causing copylen <= 0.
+ */
+ copylen = header->desc_offset + size_desc - pos;
+ copylen = min(copylen, remain);
+ if (copylen > 0) {
+ src = (void *)desc + pos - header->desc_offset;
+ if (copy_to_user(dest, src, copylen))
+ return -EFAULT;
+ remain -= copylen;
+ pos += copylen;
+ dest += copylen;
+ }
+
+ /* Copy kvm stats values */
+ copylen = header->data_offset + size_stats - pos;
+ copylen = min(copylen, remain);
+ if (copylen > 0) {
+ src = stats + pos - header->data_offset;
+ if (copy_to_user(dest, src, copylen))
+ return -EFAULT;
+ remain -= copylen;
+ pos += copylen;
+ dest += copylen;
+ }
+
+ *offset = pos;
+ return len;
+}
generated by cgit v1.2.3 (git 2.39.0) at 2024-06-11 17:43:48 +0300