[PATCH v2 5/5] kvm_main: replace debugfs with stats_fs

From: Emanuele Giuseppe Esposito
Date: Mon May 04 2020 - 07:04:25 EST

Use stats_fs API instead of debugfs to create sources and add values.

This also requires to change all architecture files to replace the old
debugfs_entries with stats_fs_vcpu_entries and statsfs_vm_entries.

The files/folders name and organization is kept unchanged, and a symlink
in sys/kernel/debugfs/kvm is left for backward compatibility.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@xxxxxxxxxx>
---
arch/arm64/kvm/Kconfig | 1 +
arch/arm64/kvm/guest.c | 2 +-
arch/mips/kvm/Kconfig | 1 +
arch/mips/kvm/mips.c | 2 +-
arch/powerpc/kvm/Kconfig | 1 +
arch/powerpc/kvm/book3s.c | 6 +-
arch/powerpc/kvm/booke.c | 8 +-
arch/s390/kvm/Kconfig | 1 +
arch/s390/kvm/kvm-s390.c | 16 +-
arch/x86/include/asm/kvm_host.h | 2 +-
arch/x86/kvm/Kconfig | 1 +
arch/x86/kvm/Makefile | 2 +-
arch/x86/kvm/debugfs.c | 64 -------
arch/x86/kvm/stats_fs.c | 56 ++++++
arch/x86/kvm/x86.c | 6 +-
include/linux/kvm_host.h | 39 +---
virt/kvm/arm/arm.c | 2 +-
virt/kvm/kvm_main.c | 314 ++++----------------------------
18 files changed, 142 insertions(+), 382 deletions(-)
delete mode 100644 arch/x86/kvm/debugfs.c
create mode 100644 arch/x86/kvm/stats_fs.c

diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 449386d76441..8c125387b673 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -23,6 +23,7 @@ config KVM
depends on OF
# for TASKSTATS/TASK_DELAY_ACCT:
depends on NET && MULTIUSER
+ imply STATS_FS
select MMU_NOTIFIER
select PREEMPT_NOTIFIERS
select HAVE_KVM_CPU_RELAX_INTERCEPT
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 8417b200bec9..235ed44e4353 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -29,7 +29,7 @@

#include "trace.h"

-struct kvm_stats_debugfs_item debugfs_entries[] = {
+struct stats_fs_value stats_fs_vcpu_entries[] = {
VCPU_STAT("halt_successful_poll", halt_successful_poll),
VCPU_STAT("halt_attempted_poll", halt_attempted_poll),
VCPU_STAT("halt_poll_invalid", halt_poll_invalid),
diff --git a/arch/mips/kvm/Kconfig b/arch/mips/kvm/Kconfig
index b91d145aa2d5..19d14e979e5f 100644
--- a/arch/mips/kvm/Kconfig
+++ b/arch/mips/kvm/Kconfig
@@ -19,6 +19,7 @@ config KVM
tristate "Kernel-based Virtual Machine (KVM) support"
depends on HAVE_KVM
depends on MIPS_FP_SUPPORT
+ imply STATS_FS
select EXPORT_UASM
select PREEMPT_NOTIFIERS
select KVM_GENERIC_DIRTYLOG_READ_PROTECT
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index fdf1c14d9205..a47d21f35444 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -39,7 +39,7 @@
#define VECTORSPACING 0x100 /* for EI/VI mode */
#endif

-struct kvm_stats_debugfs_item debugfs_entries[] = {
+struct stats_fs_value stats_fs_vcpu_entries[] = {
VCPU_STAT("wait", wait_exits),
VCPU_STAT("cache", cache_exits),
VCPU_STAT("signal", signal_exits),
diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
index 12885eda324e..feb5e110ebb0 100644
--- a/arch/powerpc/kvm/Kconfig
+++ b/arch/powerpc/kvm/Kconfig
@@ -19,6 +19,7 @@ if VIRTUALIZATION

config KVM
bool
+ imply STATS_FS
select PREEMPT_NOTIFIERS
select HAVE_KVM_EVENTFD
select HAVE_KVM_VCPU_ASYNC_IOCTL
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 37508a356f28..76222ab148da 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -38,7 +38,7 @@

/* #define EXIT_DEBUG */

-struct kvm_stats_debugfs_item debugfs_entries[] = {
+struct stats_fs_value stats_fs_vcpu_entries[] = {
VCPU_STAT("exits", sum_exits),
VCPU_STAT("mmio", mmio_exits),
VCPU_STAT("sig", signal_exits),
@@ -66,6 +66,10 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
VCPU_STAT("pthru_all", pthru_all),
VCPU_STAT("pthru_host", pthru_host),
VCPU_STAT("pthru_bad_aff", pthru_bad_aff),
+ { NULL }
+};
+
+struct stats_fs_value stats_fs_vm_entries[] = {
VM_STAT("largepages_2M", num_2M_pages, .mode = 0444),
VM_STAT("largepages_1G", num_1G_pages, .mode = 0444),
{ NULL }
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index c2984cb6dfa7..b14c07786cc8 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -35,7 +35,12 @@

unsigned long kvmppc_booke_handlers;

-struct kvm_stats_debugfs_item debugfs_entries[] = {
+struct stats_fs_value stats_fs_vm_entries[] = {
+ VM_STAT("remote_tlb_flush", remote_tlb_flush),
+ { NULL }
+};
+
+struct stats_fs_value stats_fs_vcpu_entries[] = {
VCPU_STAT("mmio", mmio_exits),
VCPU_STAT("sig", signal_exits),
VCPU_STAT("itlb_r", itlb_real_miss_exits),
@@ -54,7 +59,6 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
VCPU_STAT("halt_wakeup", halt_wakeup),
VCPU_STAT("doorbell", dbell_exits),
VCPU_STAT("guest doorbell", gdbell_exits),
- VM_STAT("remote_tlb_flush", remote_tlb_flush),
{ NULL }
};

diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
index def3b60f1fe8..4e912ffcde78 100644
--- a/arch/s390/kvm/Kconfig
+++ b/arch/s390/kvm/Kconfig
@@ -20,6 +20,7 @@ config KVM
def_tristate y
prompt "Kernel-based Virtual Machine (KVM) support"
depends on HAVE_KVM
+ imply STATS_FS
select PREEMPT_NOTIFIERS
select HAVE_KVM_CPU_RELAX_INTERCEPT
select HAVE_KVM_VCPU_ASYNC_IOCTL
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index dbeb7da07f18..f2f090b78529 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -57,7 +57,16 @@
#define VCPU_IRQS_MAX_BUF (sizeof(struct kvm_s390_irq) * \
(KVM_MAX_VCPUS + LOCAL_IRQS))

-struct kvm_stats_debugfs_item debugfs_entries[] = {
+struct stats_fs_value stats_fs_vm_entries[] = {
+ VM_STAT("inject_float_mchk", inject_float_mchk),
+ VM_STAT("inject_io", inject_io),
+ VM_STAT("inject_pfault_done", inject_pfault_done),
+ VM_STAT("inject_service_signal", inject_service_signal),
+ VM_STAT("inject_virtio", inject_virtio),
+ { NULL }
+};
+
+struct stats_fs_value stats_fs_vcpu_entries[] = {
VCPU_STAT("userspace_handled", exit_userspace),
VCPU_STAT("exit_null", exit_null),
VCPU_STAT("exit_validity", exit_validity),
@@ -95,18 +104,13 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
VCPU_STAT("inject_ckc", inject_ckc),
VCPU_STAT("inject_cputm", inject_cputm),
VCPU_STAT("inject_external_call", inject_external_call),
- VM_STAT("inject_float_mchk", inject_float_mchk),
VCPU_STAT("inject_emergency_signal", inject_emergency_signal),
- VM_STAT("inject_io", inject_io),
VCPU_STAT("inject_mchk", inject_mchk),
- VM_STAT("inject_pfault_done", inject_pfault_done),
VCPU_STAT("inject_program", inject_program),
VCPU_STAT("inject_restart", inject_restart),
- VM_STAT("inject_service_signal", inject_service_signal),
VCPU_STAT("inject_set_prefix", inject_set_prefix),
VCPU_STAT("inject_stop_signal", inject_stop_signal),
VCPU_STAT("inject_pfault_init", inject_pfault_init),
- VM_STAT("inject_virtio", inject_virtio),
VCPU_STAT("instruction_epsw", instruction_epsw),
VCPU_STAT("instruction_gs", instruction_gs),
VCPU_STAT("instruction_io_other", instruction_io_other),
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 42a2d0d3984a..6a04f590963f 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -35,7 +35,7 @@
#include <asm/kvm_vcpu_regs.h>
#include <asm/hyperv-tlfs.h>

-#define __KVM_HAVE_ARCH_VCPU_DEBUGFS
+#define __KVM_HAVE_ARCH_VCPU_STATS_FS

#define KVM_MAX_VCPUS 288
#define KVM_SOFT_MAX_VCPUS 240
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index d8154e0684b6..834b8f4790a7 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -25,6 +25,7 @@ config KVM
# for TASKSTATS/TASK_DELAY_ACCT:
depends on NET && MULTIUSER
depends on X86_LOCAL_APIC
+ imply STATS_FS
select PREEMPT_NOTIFIERS
select MMU_NOTIFIER
select HAVE_KVM_IRQCHIP
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index a789759b7261..18285a382eba 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -11,7 +11,7 @@ kvm-$(CONFIG_KVM_ASYNC_PF) += $(KVM)/async_pf.o

kvm-y += x86.o emulate.o i8259.o irq.o lapic.o \
i8254.o ioapic.o irq_comm.o cpuid.o pmu.o mtrr.o \
- hyperv.o debugfs.o mmu/mmu.o mmu/page_track.o
+ hyperv.o stats_fs.o mmu/mmu.o mmu/page_track.o

kvm-intel-y += vmx/vmx.o vmx/vmenter.o vmx/pmu_intel.o vmx/vmcs12.o vmx/evmcs.o vmx/nested.o
kvm-amd-y += svm/svm.o svm/vmenter.o svm/pmu.o svm/nested.o svm/avic.o svm/sev.o
diff --git a/arch/x86/kvm/debugfs.c b/arch/x86/kvm/debugfs.c
deleted file mode 100644
index 018aebce33ff..000000000000
--- a/arch/x86/kvm/debugfs.c
+++ /dev/null
@@ -1,64 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Kernel-based Virtual Machine driver for Linux
- *
- * Copyright 2016 Red Hat, Inc. and/or its affiliates.
- */
-#include <linux/kvm_host.h>
-#include <linux/debugfs.h>
-#include "lapic.h"
-
-static int vcpu_get_timer_advance_ns(void *data, u64 *val)
-{
- struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
- *val = vcpu->arch.apic->lapic_timer.timer_advance_ns;
- return 0;
-}
-
-DEFINE_SIMPLE_ATTRIBUTE(vcpu_timer_advance_ns_fops, vcpu_get_timer_advance_ns, NULL, "%llu\n");
-
-static int vcpu_get_tsc_offset(void *data, u64 *val)
-{
- struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
- *val = vcpu->arch.tsc_offset;
- return 0;
-}
-
-DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_offset_fops, vcpu_get_tsc_offset, NULL, "%lld\n");
-
-static int vcpu_get_tsc_scaling_ratio(void *data, u64 *val)
-{
- struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
- *val = vcpu->arch.tsc_scaling_ratio;
- return 0;
-}
-
-DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_scaling_fops, vcpu_get_tsc_scaling_ratio, NULL, "%llu\n");
-
-static int vcpu_get_tsc_scaling_frac_bits(void *data, u64 *val)
-{
- *val = kvm_tsc_scaling_ratio_frac_bits;
- return 0;
-}
-
-DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_scaling_frac_fops, vcpu_get_tsc_scaling_frac_bits, NULL, "%llu\n");
-
-void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
-{
- debugfs_create_file("tsc-offset", 0444, vcpu->debugfs_dentry, vcpu,
- &vcpu_tsc_offset_fops);
-
- if (lapic_in_kernel(vcpu))
- debugfs_create_file("lapic_timer_advance_ns", 0444,
- vcpu->debugfs_dentry, vcpu,
- &vcpu_timer_advance_ns_fops);
-
- if (kvm_has_tsc_control) {
- debugfs_create_file("tsc-scaling-ratio", 0444,
- vcpu->debugfs_dentry, vcpu,
- &vcpu_tsc_scaling_fops);
- debugfs_create_file("tsc-scaling-ratio-frac-bits", 0444,
- vcpu->debugfs_dentry, vcpu,
- &vcpu_tsc_scaling_frac_fops);
- }
-}
diff --git a/arch/x86/kvm/stats_fs.c b/arch/x86/kvm/stats_fs.c
new file mode 100644
index 000000000000..f2ac6ed8b01b
--- /dev/null
+++ b/arch/x86/kvm/stats_fs.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Kernel-based Virtual Machine driver for Linux
+ *
+ * Copyright 2016 Red Hat, Inc. and/or its affiliates.
+ */
+#include <linux/kvm_host.h>
+#include <linux/stats_fs.h>
+#include "lapic.h"
+
+#define VCPU_ARCH_STATS_FS(n, s, x, ...) \
+ { n, offsetof(struct s, x), .aggr_kind = STATS_FS_SUM, \
+ ##__VA_ARGS__ }
+
+struct stats_fs_value stats_fs_vcpu_tsc_offset[] = {
+ VCPU_ARCH_STATS_FS("tsc-offset", kvm_vcpu_arch, tsc_offset,
+ .type = STATS_FS_S64, .mode = 0444),
+ { NULL }
+};
+
+struct stats_fs_value stats_fs_vcpu_arch_lapic_timer[] = {
+ VCPU_ARCH_STATS_FS("lapic_timer_advance_ns", kvm_timer, timer_advance_ns,
+ .type = STATS_FS_U64, .mode = 0444),
+ { NULL }
+};
+
+struct stats_fs_value stats_fs_vcpu_arch_tsc_ratio[] = {
+ VCPU_ARCH_STATS_FS("tsc-scaling-ratio", kvm_vcpu_arch, tsc_scaling_ratio,
+ .type = STATS_FS_U64, .mode = 0444),
+ { NULL }
+};
+
+struct stats_fs_value stats_fs_vcpu_arch_tsc_frac[] = {
+ { "tsc-scaling-ratio-frac-bits", 0, .type = STATS_FS_U64, .mode = 0444 },
+ { NULL } /* base is &kvm_tsc_scaling_ratio_frac_bits */
+};
+
+void kvm_arch_create_vcpu_stats_fs(struct kvm_vcpu *vcpu)
+{
+ stats_fs_source_add_values(vcpu->stats_fs_src, stats_fs_vcpu_tsc_offset,
+ &vcpu->arch);
+
+ if (lapic_in_kernel(vcpu))
+ stats_fs_source_add_values(vcpu->stats_fs_src,
+ stats_fs_vcpu_arch_lapic_timer,
+ &vcpu->arch.apic->lapic_timer);
+
+ if (kvm_has_tsc_control) {
+ stats_fs_source_add_values(vcpu->stats_fs_src,
+ stats_fs_vcpu_arch_tsc_ratio,
+ &vcpu->arch);
+ stats_fs_source_add_values(vcpu->stats_fs_src,
+ stats_fs_vcpu_arch_tsc_frac,
+ &kvm_tsc_scaling_ratio_frac_bits);
+ }
+}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 35723dafedeb..01fed7ac2e49 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -190,7 +190,7 @@ static u64 __read_mostly host_xss;
u64 __read_mostly supported_xss;
EXPORT_SYMBOL_GPL(supported_xss);

-struct kvm_stats_debugfs_item debugfs_entries[] = {
+struct stats_fs_value stats_fs_vcpu_entries[] = {
VCPU_STAT("pf_fixed", pf_fixed),
VCPU_STAT("pf_guest", pf_guest),
VCPU_STAT("tlb_flush", tlb_flush),
@@ -217,6 +217,10 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
VCPU_STAT("nmi_injections", nmi_injections),
VCPU_STAT("req_event", req_event),
VCPU_STAT("l1d_flush", l1d_flush),
+ { NULL }
+};
+
+struct stats_fs_value stats_fs_vm_entries[] = {
VM_STAT("mmu_shadow_zapped", mmu_shadow_zapped),
VM_STAT("mmu_pte_write", mmu_pte_write),
VM_STAT("mmu_pte_updated", mmu_pte_updated),
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 3845f857ef7b..1282799aa46e 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -27,6 +27,7 @@
#include <linux/refcount.h>
#include <linux/nospec.h>
#include <asm/signal.h>
+#include <linux/stats_fs.h>

#include <linux/kvm.h>
#include <linux/kvm_para.h>
@@ -318,7 +319,7 @@ struct kvm_vcpu {
bool preempted;
bool ready;
struct kvm_vcpu_arch arch;
- struct dentry *debugfs_dentry;
+ struct stats_fs_source *stats_fs_src;
};

static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
@@ -498,8 +499,7 @@ struct kvm {
long tlbs_dirty;
struct list_head devices;
u64 manual_dirty_log_protect;
- struct dentry *debugfs_dentry;
- struct kvm_stat_data **debugfs_stat_data;
+ struct stats_fs_source *stats_fs_src;
struct srcu_struct srcu;
struct srcu_struct irq_srcu;
pid_t userspace_pid;
@@ -880,8 +880,8 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu);

-#ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
-void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu);
+#ifdef __KVM_HAVE_ARCH_VCPU_STATS_FS
+void kvm_arch_create_vcpu_stats_fs(struct kvm_vcpu *vcpu);
#endif

int kvm_arch_hardware_enable(void);
@@ -1110,33 +1110,14 @@ static inline bool kvm_is_error_gpa(struct kvm *kvm, gpa_t gpa)
return kvm_is_error_hva(hva);
}

-enum kvm_stat_kind {
- KVM_STAT_VM,
- KVM_STAT_VCPU,
-};
-
-struct kvm_stat_data {
- struct kvm *kvm;
- struct kvm_stats_debugfs_item *dbgfs_item;
-};
-
-struct kvm_stats_debugfs_item {
- const char *name;
- int offset;
- enum kvm_stat_kind kind;
- int mode;
-};
-
-#define KVM_DBGFS_GET_MODE(dbgfs_item) \
- ((dbgfs_item)->mode ? (dbgfs_item)->mode : 0644)
-
#define VM_STAT(n, x, ...) \
- { n, offsetof(struct kvm, stat.x), KVM_STAT_VM, ## __VA_ARGS__ }
+ { n, offsetof(struct kvm, stat.x), STATS_FS_U64, STATS_FS_SUM, ## __VA_ARGS__ }
#define VCPU_STAT(n, x, ...) \
- { n, offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU, ## __VA_ARGS__ }
+ { n, offsetof(struct kvm_vcpu, stat.x), STATS_FS_U64, STATS_FS_SUM, ## __VA_ARGS__ }

-extern struct kvm_stats_debugfs_item debugfs_entries[];
-extern struct dentry *kvm_debugfs_dir;
+extern struct stats_fs_value stats_fs_vcpu_entries[];
+extern struct stats_fs_value stats_fs_vm_entries[];
+extern struct stats_fs_source *kvm_stats_fs_dir;

#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/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 48d0ec44ad77..4171f92fa473 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -140,7 +140,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
return ret;
}

-int kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
+int kvm_arch_create_vcpu_stats_fs(struct kvm_vcpu *vcpu)
{
return 0;
}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 74bdb7bf3295..093150125bc2 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -25,6 +25,7 @@
#include <linux/vmalloc.h>
#include <linux/reboot.h>
#include <linux/debugfs.h>
+#include <linux/stats_fs.h>
#include <linux/highmem.h>
#include <linux/file.h>
#include <linux/syscore_ops.h>
@@ -109,11 +110,8 @@ static struct kmem_cache *kvm_vcpu_cache;
static __read_mostly struct preempt_ops kvm_preempt_ops;
static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_running_vcpu);

-struct dentry *kvm_debugfs_dir;
-EXPORT_SYMBOL_GPL(kvm_debugfs_dir);
-
-static int kvm_debugfs_num_entries;
-static const struct file_operations stat_fops_per_vm;
+struct stats_fs_source *kvm_stats_fs_dir;
+EXPORT_SYMBOL_GPL(kvm_stats_fs_dir);

static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
unsigned long arg);
@@ -356,6 +354,8 @@ static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)

void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
{
+ stats_fs_source_revoke(vcpu->stats_fs_src);
+ stats_fs_source_put(vcpu->stats_fs_src);
kvm_arch_vcpu_destroy(vcpu);

/*
@@ -601,52 +601,27 @@ static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots)
kvfree(slots);
}

-static void kvm_destroy_vm_debugfs(struct kvm *kvm)
+static void kvm_destroy_vm_stats_fs(struct kvm *kvm)
{
- int i;
-
- if (!kvm->debugfs_dentry)
- return;
-
- debugfs_remove_recursive(kvm->debugfs_dentry);
-
- if (kvm->debugfs_stat_data) {
- for (i = 0; i < kvm_debugfs_num_entries; i++)
- kfree(kvm->debugfs_stat_data[i]);
- kfree(kvm->debugfs_stat_data);
- }
+ stats_fs_source_remove_subordinate(kvm_stats_fs_dir, kvm->stats_fs_src);
+ stats_fs_source_revoke(kvm->stats_fs_src);
+ stats_fs_source_put(kvm->stats_fs_src);
}

-static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
+static int kvm_create_vm_stats_fs(struct kvm *kvm, int fd)
{
char dir_name[ITOA_MAX_LEN * 2];
- struct kvm_stat_data *stat_data;
- struct kvm_stats_debugfs_item *p;

- if (!debugfs_initialized())
+ if (!stats_fs_initialized())
return 0;

snprintf(dir_name, sizeof(dir_name), "%d-%d", task_pid_nr(current), fd);
- kvm->debugfs_dentry = debugfs_create_dir(dir_name, kvm_debugfs_dir);
+ kvm->stats_fs_src = stats_fs_source_create(dir_name);
+ stats_fs_source_add_subordinate(kvm_stats_fs_dir, kvm->stats_fs_src);

- kvm->debugfs_stat_data = kcalloc(kvm_debugfs_num_entries,
- sizeof(*kvm->debugfs_stat_data),
- GFP_KERNEL_ACCOUNT);
- if (!kvm->debugfs_stat_data)
- return -ENOMEM;
+ stats_fs_source_add_values(kvm->stats_fs_src, stats_fs_vm_entries, kvm);

- for (p = debugfs_entries; p->name; p++) {
- stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT);
- if (!stat_data)
- return -ENOMEM;
-
- stat_data->kvm = kvm;
- stat_data->dbgfs_item = p;
- kvm->debugfs_stat_data[p - debugfs_entries] = stat_data;
- debugfs_create_file(p->name, KVM_DBGFS_GET_MODE(p),
- kvm->debugfs_dentry, stat_data,
- &stat_fops_per_vm);
- }
+ stats_fs_source_add_values(kvm->stats_fs_src, stats_fs_vcpu_entries, NULL);
return 0;
}

@@ -783,7 +758,7 @@ static void kvm_destroy_vm(struct kvm *kvm)
struct mm_struct *mm = kvm->mm;

kvm_uevent_notify_change(KVM_EVENT_DESTROY_VM, kvm);
- kvm_destroy_vm_debugfs(kvm);
+ kvm_destroy_vm_stats_fs(kvm);
kvm_arch_sync_events(kvm);
mutex_lock(&kvm_lock);
list_del(&kvm->vm_list);
@@ -2946,7 +2921,6 @@ static int kvm_vcpu_release(struct inode *inode, struct file *filp)
{
struct kvm_vcpu *vcpu = filp->private_data;

- debugfs_remove_recursive(vcpu->debugfs_dentry);
kvm_put_kvm(vcpu->kvm);
return 0;
}
@@ -2970,19 +2944,22 @@ static int create_vcpu_fd(struct kvm_vcpu *vcpu)
return anon_inode_getfd(name, &kvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC);
}

-static void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
+static void kvm_create_vcpu_stats_fs(struct kvm_vcpu *vcpu)
{
-#ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
char dir_name[ITOA_MAX_LEN * 2];

- if (!debugfs_initialized())
+ if (!stats_fs_initialized())
return;

snprintf(dir_name, sizeof(dir_name), "vcpu%d", vcpu->vcpu_id);
- vcpu->debugfs_dentry = debugfs_create_dir(dir_name,
- vcpu->kvm->debugfs_dentry);

- kvm_arch_create_vcpu_debugfs(vcpu);
+ vcpu->stats_fs_src = stats_fs_source_create(dir_name);
+ stats_fs_source_add_subordinate(vcpu->kvm->stats_fs_src, vcpu->stats_fs_src);
+
+ stats_fs_source_add_values(vcpu->stats_fs_src, stats_fs_vcpu_entries, vcpu);
+
+#ifdef __KVM_HAVE_ARCH_VCPU_STATS_FS
+ kvm_arch_create_vcpu_stats_fs(vcpu);
#endif
}

@@ -3031,8 +3008,6 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
if (r)
goto vcpu_free_run_page;

- kvm_create_vcpu_debugfs(vcpu);
-
mutex_lock(&kvm->lock);
if (kvm_get_vcpu_by_id(kvm, id)) {
r = -EEXIST;
@@ -3061,11 +3036,11 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)

mutex_unlock(&kvm->lock);
kvm_arch_vcpu_postcreate(vcpu);
+ kvm_create_vcpu_stats_fs(vcpu);
return r;

unlock_vcpu_destroy:
mutex_unlock(&kvm->lock);
- debugfs_remove_recursive(vcpu->debugfs_dentry);
kvm_arch_vcpu_destroy(vcpu);
vcpu_free_run_page:
free_page((unsigned long)vcpu->run);
@@ -3839,7 +3814,7 @@ static int kvm_dev_ioctl_create_vm(unsigned long type)
* cases it will be called by the final fput(file) and will take
* care of doing kvm_put_kvm(kvm).
*/
- if (kvm_create_vm_debugfs(kvm, r) < 0) {
+ if (kvm_create_vm_stats_fs(kvm, r) < 0) {
put_unused_fd(r);
fput(file);
return -ENOMEM;
@@ -4295,214 +4270,6 @@ struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,
}
EXPORT_SYMBOL_GPL(kvm_io_bus_get_dev);

-static int kvm_debugfs_open(struct inode *inode, struct file *file,
- int (*get)(void *, u64 *), int (*set)(void *, u64),
- const char *fmt)
-{
- struct kvm_stat_data *stat_data = (struct kvm_stat_data *)
- inode->i_private;
-
- /* The debugfs files are a reference to the kvm struct which
- * is still valid when kvm_destroy_vm is called.
- * To avoid the race between open and the removal of the debugfs
- * directory we test against the users count.
- */
- if (!refcount_inc_not_zero(&stat_data->kvm->users_count))
- return -ENOENT;
-
- if (simple_attr_open(inode, file, get,
- KVM_DBGFS_GET_MODE(stat_data->dbgfs_item) & 0222
- ? set : NULL,
- fmt)) {
- kvm_put_kvm(stat_data->kvm);
- return -ENOMEM;
- }
-
- return 0;
-}
-
-static int kvm_debugfs_release(struct inode *inode, struct file *file)
-{
- struct kvm_stat_data *stat_data = (struct kvm_stat_data *)
- inode->i_private;
-
- simple_attr_release(inode, file);
- kvm_put_kvm(stat_data->kvm);
-
- return 0;
-}
-
-static int kvm_get_stat_per_vm(struct kvm *kvm, size_t offset, u64 *val)
-{
- *val = *(ulong *)((void *)kvm + offset);
-
- return 0;
-}
-
-static int kvm_clear_stat_per_vm(struct kvm *kvm, size_t offset)
-{
- *(ulong *)((void *)kvm + offset) = 0;
-
- return 0;
-}
-
-static int kvm_get_stat_per_vcpu(struct kvm *kvm, size_t offset, u64 *val)
-{
- int i;
- struct kvm_vcpu *vcpu;
-
- *val = 0;
-
- kvm_for_each_vcpu(i, vcpu, kvm)
- *val += *(u64 *)((void *)vcpu + offset);
-
- return 0;
-}
-
-static int kvm_clear_stat_per_vcpu(struct kvm *kvm, size_t offset)
-{
- int i;
- struct kvm_vcpu *vcpu;
-
- kvm_for_each_vcpu(i, vcpu, kvm)
- *(u64 *)((void *)vcpu + offset) = 0;
-
- return 0;
-}
-
-static int kvm_stat_data_get(void *data, u64 *val)
-{
- int r = -EFAULT;
- struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data;
-
- switch (stat_data->dbgfs_item->kind) {
- case KVM_STAT_VM:
- r = kvm_get_stat_per_vm(stat_data->kvm,
- stat_data->dbgfs_item->offset, val);
- break;
- case KVM_STAT_VCPU:
- r = kvm_get_stat_per_vcpu(stat_data->kvm,
- stat_data->dbgfs_item->offset, val);
- break;
- }
-
- return r;
-}
-
-static int kvm_stat_data_clear(void *data, u64 val)
-{
- int r = -EFAULT;
- struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data;
-
- if (val)
- return -EINVAL;
-
- switch (stat_data->dbgfs_item->kind) {
- case KVM_STAT_VM:
- r = kvm_clear_stat_per_vm(stat_data->kvm,
- stat_data->dbgfs_item->offset);
- break;
- case KVM_STAT_VCPU:
- r = kvm_clear_stat_per_vcpu(stat_data->kvm,
- stat_data->dbgfs_item->offset);
- break;
- }
-
- return r;
-}
-
-static int kvm_stat_data_open(struct inode *inode, struct file *file)
-{
- __simple_attr_check_format("%llu\n", 0ull);
- return kvm_debugfs_open(inode, file, kvm_stat_data_get,
- kvm_stat_data_clear, "%llu\n");
-}
-
-static const struct file_operations stat_fops_per_vm = {
- .owner = THIS_MODULE,
- .open = kvm_stat_data_open,
- .release = kvm_debugfs_release,
- .read = simple_attr_read,
- .write = simple_attr_write,
- .llseek = no_llseek,
-};
-
-static int vm_stat_get(void *_offset, u64 *val)
-{
- unsigned offset = (long)_offset;
- struct kvm *kvm;
- u64 tmp_val;
-
- *val = 0;
- mutex_lock(&kvm_lock);
- list_for_each_entry(kvm, &vm_list, vm_list) {
- kvm_get_stat_per_vm(kvm, offset, &tmp_val);
- *val += tmp_val;
- }
- mutex_unlock(&kvm_lock);
- return 0;
-}
-
-static int vm_stat_clear(void *_offset, u64 val)
-{
- unsigned offset = (long)_offset;
- struct kvm *kvm;
-
- if (val)
- return -EINVAL;
-
- mutex_lock(&kvm_lock);
- list_for_each_entry(kvm, &vm_list, vm_list) {
- kvm_clear_stat_per_vm(kvm, offset);
- }
- mutex_unlock(&kvm_lock);
-
- return 0;
-}
-
-DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, vm_stat_clear, "%llu\n");
-
-static int vcpu_stat_get(void *_offset, u64 *val)
-{
- unsigned offset = (long)_offset;
- struct kvm *kvm;
- u64 tmp_val;
-
- *val = 0;
- mutex_lock(&kvm_lock);
- list_for_each_entry(kvm, &vm_list, vm_list) {
- kvm_get_stat_per_vcpu(kvm, offset, &tmp_val);
- *val += tmp_val;
- }
- mutex_unlock(&kvm_lock);
- return 0;
-}
-
-static int vcpu_stat_clear(void *_offset, u64 val)
-{
- unsigned offset = (long)_offset;
- struct kvm *kvm;
-
- if (val)
- return -EINVAL;
-
- mutex_lock(&kvm_lock);
- list_for_each_entry(kvm, &vm_list, vm_list) {
- kvm_clear_stat_per_vcpu(kvm, offset);
- }
- mutex_unlock(&kvm_lock);
-
- return 0;
-}
-
-DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, vcpu_stat_clear,
- "%llu\n");
-
-static const struct file_operations *stat_fops[] = {
- [KVM_STAT_VCPU] = &vcpu_stat_fops,
- [KVM_STAT_VM] = &vm_stat_fops,
-};
-
static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
{
struct kobj_uevent_env *env;
@@ -4537,34 +4304,32 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
}
add_uevent_var(env, "PID=%d", kvm->userspace_pid);

- if (!IS_ERR_OR_NULL(kvm->debugfs_dentry)) {
+ if (!IS_ERR_OR_NULL(kvm->stats_fs_src->source_dentry)) {
char *tmp, *p = kmalloc(PATH_MAX, GFP_KERNEL_ACCOUNT);

if (p) {
- tmp = dentry_path_raw(kvm->debugfs_dentry, p, PATH_MAX);
+ tmp = dentry_path_raw(kvm->stats_fs_src->source_dentry, p, PATH_MAX);
if (!IS_ERR(tmp))
add_uevent_var(env, "STATS_PATH=%s", tmp);
kfree(p);
}
}
+
/* no need for checks, since we are adding at most only 5 keys */
env->envp[env->envp_idx++] = NULL;
kobject_uevent_env(&kvm_dev.this_device->kobj, KOBJ_CHANGE, env->envp);
kfree(env);
}

-static void kvm_init_debug(void)
+static void kvm_init_stats_fs(void)
{
- struct kvm_stats_debugfs_item *p;
+ kvm_stats_fs_dir = stats_fs_source_create("kvm");
+ /* symlink to debugfs */
+ debugfs_create_symlink("kvm", NULL, "/sys/kernel/stats_fs/kvm");
+ stats_fs_source_register(kvm_stats_fs_dir);

- kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
-
- kvm_debugfs_num_entries = 0;
- for (p = debugfs_entries; p->name; ++p, kvm_debugfs_num_entries++) {
- debugfs_create_file(p->name, KVM_DBGFS_GET_MODE(p),
- kvm_debugfs_dir, (void *)(long)p->offset,
- stat_fops[p->kind]);
- }
+ stats_fs_source_add_values(kvm_stats_fs_dir, stats_fs_vcpu_entries, NULL);
+ stats_fs_source_add_values(kvm_stats_fs_dir, stats_fs_vm_entries, NULL);
}

static int kvm_suspend(void)
@@ -4738,7 +4503,7 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
kvm_preempt_ops.sched_in = kvm_sched_in;
kvm_preempt_ops.sched_out = kvm_sched_out;

- kvm_init_debug();
+ kvm_init_stats_fs();

r = kvm_vfio_ops_init();
WARN_ON(r);
@@ -4767,7 +4532,8 @@ EXPORT_SYMBOL_GPL(kvm_init);

void kvm_exit(void)
{
- debugfs_remove_recursive(kvm_debugfs_dir);
+ stats_fs_source_revoke(kvm_stats_fs_dir);
+ stats_fs_source_put(kvm_stats_fs_dir);
misc_deregister(&kvm_dev);
kmem_cache_destroy(kvm_vcpu_cache);
kvm_async_pf_deinit();
--
2.25.2