KVM: stats: Support binary stats retrieval for a VM

Add a VM ioctl to get a statistics file descriptor by which a read
functionality is provided for userspace to read out VM stats header,
descriptors and data.
Define VM statistics descriptors and header for all architectures.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com> #arm64
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-4-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 988ead309cbe07e5e6bc5b553be60b5192d8912b..d7606a3c449b0c6ee8be04c6ba1a38a1715a1f29 100644 (file)
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -28,6 +28,21 @@
 
 #include "trace.h"
 
+const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
+       KVM_GENERIC_VM_STATS()
+};
+static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
+               sizeof(struct kvm_vm_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vm_stats_header = {
+       .name_size = KVM_STATS_NAME_SIZE,
+       .num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
+       .id_offset =  sizeof(struct kvm_stats_header),
+       .desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+       .data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+                      sizeof(kvm_vm_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
        VCPU_STAT("halt_successful_poll", generic.halt_successful_poll),
        VCPU_STAT("halt_attempted_poll", generic.halt_attempted_poll),

diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 2f2969aef60c60f15a30c0e4b62cb5da85b571bb..9f8b203737df2207361c973bb997b09f59a6fd7d 100644 (file)
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -38,6 +38,21 @@
 #define VECTORSPACING 0x100    /* for EI/VI mode */
 #endif
 
+const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
+       KVM_GENERIC_VM_STATS()
+};
+static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
+               sizeof(struct kvm_vm_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vm_stats_header = {
+       .name_size = KVM_STATS_NAME_SIZE,
+       .num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
+       .id_offset = sizeof(struct kvm_stats_header),
+       .desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+       .data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+                      sizeof(kvm_vm_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
        VCPU_STAT("wait", wait_exits),
        VCPU_STAT("cache", cache_exits),

diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index ae9f1b855ff9d2e3abfdb4c27471416f9df43526..1f004837f9c576ef9aa88e5a88461c953ed2d751 100644 (file)
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -38,6 +38,23 @@
 
 /* #define EXIT_DEBUG */
 
+const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
+       KVM_GENERIC_VM_STATS(),
+       STATS_DESC_ICOUNTER(VM, num_2M_pages),
+       STATS_DESC_ICOUNTER(VM, num_1G_pages)
+};
+static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
+               sizeof(struct kvm_vm_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vm_stats_header = {
+       .name_size = KVM_STATS_NAME_SIZE,
+       .num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
+       .id_offset = sizeof(struct kvm_stats_header),
+       .desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+       .data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+                      sizeof(kvm_vm_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
        VCPU_STAT("exits", sum_exits),
        VCPU_STAT("mmio", mmio_exits),

diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 7a75559ab51d544297195725f1a2526cdb866840..a49ea4dcf9638872898f6ad5edec5dd639484b0a 100644 (file)
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -36,6 +36,23 @@
 
 unsigned long kvmppc_booke_handlers;
 
+const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
+       KVM_GENERIC_VM_STATS(),
+       STATS_DESC_ICOUNTER(VM, num_2M_pages),
+       STATS_DESC_ICOUNTER(VM, num_1G_pages)
+};
+static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
+               sizeof(struct kvm_vm_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vm_stats_header = {
+       .name_size = KVM_STATS_NAME_SIZE,
+       .num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
+       .id_offset = sizeof(struct kvm_stats_header),
+       .desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+       .data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+                      sizeof(kvm_vm_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
        VCPU_STAT("mmio", mmio_exits),
        VCPU_STAT("sig", signal_exits),

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 75ad44c447176603722583136e72dd65d698d460..c7c7a28af41cb53d53225c9ff4b2a5bbf9c7dbda 100644 (file)
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -58,6 +58,26 @@
 #define VCPU_IRQS_MAX_BUF (sizeof(struct kvm_s390_irq) * \
                           (KVM_MAX_VCPUS + LOCAL_IRQS))
 
+const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
+       KVM_GENERIC_VM_STATS(),
+       STATS_DESC_COUNTER(VM, inject_io),
+       STATS_DESC_COUNTER(VM, inject_float_mchk),
+       STATS_DESC_COUNTER(VM, inject_pfault_done),
+       STATS_DESC_COUNTER(VM, inject_service_signal),
+       STATS_DESC_COUNTER(VM, inject_virtio)
+};
+static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
+               sizeof(struct kvm_vm_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vm_stats_header = {
+       .name_size = KVM_STATS_NAME_SIZE,
+       .num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
+       .id_offset = sizeof(struct kvm_stats_header),
+       .desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+       .data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+                      sizeof(kvm_vm_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
        VCPU_STAT("userspace_handled", exit_userspace),
        VCPU_STAT("exit_null", exit_null),

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 71202330848ad1eec22f56a314f498a2e1bbc058..570fd07048471141f58a7896c9a47f19410dcd33 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -223,6 +223,31 @@ EXPORT_SYMBOL_GPL(host_xss);
 u64 __read_mostly supported_xss;
 EXPORT_SYMBOL_GPL(supported_xss);
 
+const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
+       KVM_GENERIC_VM_STATS(),
+       STATS_DESC_COUNTER(VM, mmu_shadow_zapped),
+       STATS_DESC_COUNTER(VM, mmu_pte_write),
+       STATS_DESC_COUNTER(VM, mmu_pde_zapped),
+       STATS_DESC_COUNTER(VM, mmu_flooded),
+       STATS_DESC_COUNTER(VM, mmu_recycled),
+       STATS_DESC_COUNTER(VM, mmu_cache_miss),
+       STATS_DESC_ICOUNTER(VM, mmu_unsync),
+       STATS_DESC_ICOUNTER(VM, lpages),
+       STATS_DESC_ICOUNTER(VM, nx_lpage_splits),
+       STATS_DESC_ICOUNTER(VM, max_mmu_page_hash_collisions)
+};
+static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
+               sizeof(struct kvm_vm_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vm_stats_header = {
+       .name_size = KVM_STATS_NAME_SIZE,
+       .num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
+       .id_offset = sizeof(struct kvm_stats_header),
+       .desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+       .data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+                      sizeof(kvm_vm_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
        VCPU_STAT("pf_fixed", pf_fixed),
        VCPU_STAT("pf_guest", pf_guest),

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 9ee7f350473bfcd4eb885769c7eaf675d40bd0fd..e79ce64b9f6fef48dfea39dd294fab6c69710f00 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -599,6 +599,7 @@ struct kvm {
 #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
        struct notifier_block pm_notifier;
 #endif
+       char stats_id[KVM_STATS_NAME_SIZE];
 };
 
 #define kvm_err(fmt, ...) \
@@ -1354,12 +1355,17 @@ struct _kvm_stats_desc {
        STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS,             \
                KVM_STATS_BASE_POW10, -9)
 
+#define KVM_GENERIC_VM_STATS()                                                \
+       STATS_DESC_COUNTER(VM_GENERIC, remote_tlb_flush)
+
 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);
+extern const struct kvm_stats_header kvm_vm_stats_header;
+extern const struct _kvm_stats_desc kvm_vm_stats_desc[];
 
 #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/kvm_main.c b/virt/kvm/kvm_main.c
index cec986487b3085c95d3fad2f03455d9edd09141f..33ec43a87d0f862ca55b0d173d6890cc0c589f8a 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4055,6 +4055,42 @@ static int kvm_vm_ioctl_enable_cap_generic(struct kvm *kvm,
        }
 }
 
+static ssize_t kvm_vm_stats_read(struct file *file, char __user *user_buffer,
+                             size_t size, loff_t *offset)
+{
+       struct kvm *kvm = file->private_data;
+
+       return kvm_stats_read(kvm->stats_id, &kvm_vm_stats_header,
+                               &kvm_vm_stats_desc[0], &kvm->stat,
+                               sizeof(kvm->stat), user_buffer, size, offset);
+}
+
+static const struct file_operations kvm_vm_stats_fops = {
+       .read = kvm_vm_stats_read,
+       .llseek = noop_llseek,
+};
+
+static int kvm_vm_ioctl_get_stats_fd(struct kvm *kvm)
+{
+       int fd;
+       struct file *file;
+
+       fd = get_unused_fd_flags(O_CLOEXEC);
+       if (fd < 0)
+               return fd;
+
+       file = anon_inode_getfile("kvm-vm-stats",
+                       &kvm_vm_stats_fops, kvm, O_RDONLY);
+       if (IS_ERR(file)) {
+               put_unused_fd(fd);
+               return PTR_ERR(file);
+       }
+       file->f_mode |= FMODE_PREAD;
+       fd_install(fd, file);
+
+       return fd;
+}
+
 static long kvm_vm_ioctl(struct file *filp,
                           unsigned int ioctl, unsigned long arg)
 {
@@ -4237,6 +4273,9 @@ static long kvm_vm_ioctl(struct file *filp,
        case KVM_RESET_DIRTY_RINGS:
                r = kvm_vm_ioctl_reset_dirty_pages(kvm);
                break;
+       case KVM_GET_STATS_FD:
+               r = kvm_vm_ioctl_get_stats_fd(kvm);
+               break;
        default:
                r = kvm_arch_vm_ioctl(filp, ioctl, arg);
        }
@@ -4316,6 +4355,9 @@ static int kvm_dev_ioctl_create_vm(unsigned long type)
        if (r < 0)
                goto put_kvm;
 
+       snprintf(kvm->stats_id, sizeof(kvm->stats_id),
+                       "kvm-%d", task_pid_nr(current));
+
        file = anon_inode_getfile("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
        if (IS_ERR(file)) {
                put_unused_fd(r);