linux/include/trace/events/kvm.h
Christian Borntraeger 3491caf275 KVM: halt_polling: provide a way to qualify wakeups during poll
Some wakeups should not be considered a sucessful poll. For example on
s390 I/O interrupts are usually floating, which means that _ALL_ CPUs
would be considered runnable - letting all vCPUs poll all the time for
transactional like workload, even if one vCPU would be enough.
This can result in huge CPU usage for large guests.
This patch lets architectures provide a way to qualify wakeups if they
should be considered a good/bad wakeups in regard to polls.

For s390 the implementation will fence of halt polling for anything but
known good, single vCPU events. The s390 implementation for floating
interrupts does a wakeup for one vCPU, but the interrupt will be delivered
by whatever CPU checks first for a pending interrupt. We prefer the
woken up CPU by marking the poll of this CPU as "good" poll.
This code will also mark several other wakeup reasons like IPI or
expired timers as "good". This will of course also mark some events as
not sucessful. As  KVM on z runs always as a 2nd level hypervisor,
we prefer to not poll, unless we are really sure, though.

This patch successfully limits the CPU usage for cases like uperf 1byte
transactional ping pong workload or wakeup heavy workload like OLTP
while still providing a proper speedup.

This also introduced a new vcpu stat "halt_poll_no_tuning" that marks
wakeups that are considered not good for polling.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Radim Krčmář <rkrcmar@redhat.com> (for an earlier version)
Cc: David Matlack <dmatlack@google.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
[Rename config symbol. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-13 17:29:23 +02:00

399 lines
8.8 KiB
C

#if !defined(_TRACE_KVM_MAIN_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_KVM_MAIN_H
#include <linux/tracepoint.h>
#undef TRACE_SYSTEM
#define TRACE_SYSTEM kvm
#define ERSN(x) { KVM_EXIT_##x, "KVM_EXIT_" #x }
#define kvm_trace_exit_reason \
ERSN(UNKNOWN), ERSN(EXCEPTION), ERSN(IO), ERSN(HYPERCALL), \
ERSN(DEBUG), ERSN(HLT), ERSN(MMIO), ERSN(IRQ_WINDOW_OPEN), \
ERSN(SHUTDOWN), ERSN(FAIL_ENTRY), ERSN(INTR), ERSN(SET_TPR), \
ERSN(TPR_ACCESS), ERSN(S390_SIEIC), ERSN(S390_RESET), ERSN(DCR),\
ERSN(NMI), ERSN(INTERNAL_ERROR), ERSN(OSI), ERSN(PAPR_HCALL), \
ERSN(S390_UCONTROL), ERSN(WATCHDOG), ERSN(S390_TSCH)
TRACE_EVENT(kvm_userspace_exit,
TP_PROTO(__u32 reason, int errno),
TP_ARGS(reason, errno),
TP_STRUCT__entry(
__field( __u32, reason )
__field( int, errno )
),
TP_fast_assign(
__entry->reason = reason;
__entry->errno = errno;
),
TP_printk("reason %s (%d)",
__entry->errno < 0 ?
(__entry->errno == -EINTR ? "restart" : "error") :
__print_symbolic(__entry->reason, kvm_trace_exit_reason),
__entry->errno < 0 ? -__entry->errno : __entry->reason)
);
TRACE_EVENT(kvm_vcpu_wakeup,
TP_PROTO(__u64 ns, bool waited, bool valid),
TP_ARGS(ns, waited, valid),
TP_STRUCT__entry(
__field( __u64, ns )
__field( bool, waited )
__field( bool, valid )
),
TP_fast_assign(
__entry->ns = ns;
__entry->waited = waited;
__entry->valid = valid;
),
TP_printk("%s time %lld ns, polling %s",
__entry->waited ? "wait" : "poll",
__entry->ns,
__entry->valid ? "valid" : "invalid")
);
#if defined(CONFIG_HAVE_KVM_IRQFD)
TRACE_EVENT(kvm_set_irq,
TP_PROTO(unsigned int gsi, int level, int irq_source_id),
TP_ARGS(gsi, level, irq_source_id),
TP_STRUCT__entry(
__field( unsigned int, gsi )
__field( int, level )
__field( int, irq_source_id )
),
TP_fast_assign(
__entry->gsi = gsi;
__entry->level = level;
__entry->irq_source_id = irq_source_id;
),
TP_printk("gsi %u level %d source %d",
__entry->gsi, __entry->level, __entry->irq_source_id)
);
#endif /* defined(CONFIG_HAVE_KVM_IRQFD) */
#if defined(__KVM_HAVE_IOAPIC)
#define kvm_deliver_mode \
{0x0, "Fixed"}, \
{0x1, "LowPrio"}, \
{0x2, "SMI"}, \
{0x3, "Res3"}, \
{0x4, "NMI"}, \
{0x5, "INIT"}, \
{0x6, "SIPI"}, \
{0x7, "ExtINT"}
TRACE_EVENT(kvm_ioapic_set_irq,
TP_PROTO(__u64 e, int pin, bool coalesced),
TP_ARGS(e, pin, coalesced),
TP_STRUCT__entry(
__field( __u64, e )
__field( int, pin )
__field( bool, coalesced )
),
TP_fast_assign(
__entry->e = e;
__entry->pin = pin;
__entry->coalesced = coalesced;
),
TP_printk("pin %u dst %x vec=%u (%s|%s|%s%s)%s",
__entry->pin, (u8)(__entry->e >> 56), (u8)__entry->e,
__print_symbolic((__entry->e >> 8 & 0x7), kvm_deliver_mode),
(__entry->e & (1<<11)) ? "logical" : "physical",
(__entry->e & (1<<15)) ? "level" : "edge",
(__entry->e & (1<<16)) ? "|masked" : "",
__entry->coalesced ? " (coalesced)" : "")
);
TRACE_EVENT(kvm_ioapic_delayed_eoi_inj,
TP_PROTO(__u64 e),
TP_ARGS(e),
TP_STRUCT__entry(
__field( __u64, e )
),
TP_fast_assign(
__entry->e = e;
),
TP_printk("dst %x vec=%u (%s|%s|%s%s)",
(u8)(__entry->e >> 56), (u8)__entry->e,
__print_symbolic((__entry->e >> 8 & 0x7), kvm_deliver_mode),
(__entry->e & (1<<11)) ? "logical" : "physical",
(__entry->e & (1<<15)) ? "level" : "edge",
(__entry->e & (1<<16)) ? "|masked" : "")
);
TRACE_EVENT(kvm_msi_set_irq,
TP_PROTO(__u64 address, __u64 data),
TP_ARGS(address, data),
TP_STRUCT__entry(
__field( __u64, address )
__field( __u64, data )
),
TP_fast_assign(
__entry->address = address;
__entry->data = data;
),
TP_printk("dst %u vec %x (%s|%s|%s%s)",
(u8)(__entry->address >> 12), (u8)__entry->data,
__print_symbolic((__entry->data >> 8 & 0x7), kvm_deliver_mode),
(__entry->address & (1<<2)) ? "logical" : "physical",
(__entry->data & (1<<15)) ? "level" : "edge",
(__entry->address & (1<<3)) ? "|rh" : "")
);
#define kvm_irqchips \
{KVM_IRQCHIP_PIC_MASTER, "PIC master"}, \
{KVM_IRQCHIP_PIC_SLAVE, "PIC slave"}, \
{KVM_IRQCHIP_IOAPIC, "IOAPIC"}
#endif /* defined(__KVM_HAVE_IOAPIC) */
#if defined(CONFIG_HAVE_KVM_IRQFD)
#ifdef kvm_irqchips
#define kvm_ack_irq_string "irqchip %s pin %u"
#define kvm_ack_irq_parm __print_symbolic(__entry->irqchip, kvm_irqchips), __entry->pin
#else
#define kvm_ack_irq_string "irqchip %d pin %u"
#define kvm_ack_irq_parm __entry->irqchip, __entry->pin
#endif
TRACE_EVENT(kvm_ack_irq,
TP_PROTO(unsigned int irqchip, unsigned int pin),
TP_ARGS(irqchip, pin),
TP_STRUCT__entry(
__field( unsigned int, irqchip )
__field( unsigned int, pin )
),
TP_fast_assign(
__entry->irqchip = irqchip;
__entry->pin = pin;
),
TP_printk(kvm_ack_irq_string, kvm_ack_irq_parm)
);
#endif /* defined(CONFIG_HAVE_KVM_IRQFD) */
#define KVM_TRACE_MMIO_READ_UNSATISFIED 0
#define KVM_TRACE_MMIO_READ 1
#define KVM_TRACE_MMIO_WRITE 2
#define kvm_trace_symbol_mmio \
{ KVM_TRACE_MMIO_READ_UNSATISFIED, "unsatisfied-read" }, \
{ KVM_TRACE_MMIO_READ, "read" }, \
{ KVM_TRACE_MMIO_WRITE, "write" }
TRACE_EVENT(kvm_mmio,
TP_PROTO(int type, int len, u64 gpa, u64 val),
TP_ARGS(type, len, gpa, val),
TP_STRUCT__entry(
__field( u32, type )
__field( u32, len )
__field( u64, gpa )
__field( u64, val )
),
TP_fast_assign(
__entry->type = type;
__entry->len = len;
__entry->gpa = gpa;
__entry->val = val;
),
TP_printk("mmio %s len %u gpa 0x%llx val 0x%llx",
__print_symbolic(__entry->type, kvm_trace_symbol_mmio),
__entry->len, __entry->gpa, __entry->val)
);
#define kvm_fpu_load_symbol \
{0, "unload"}, \
{1, "load"}
TRACE_EVENT(kvm_fpu,
TP_PROTO(int load),
TP_ARGS(load),
TP_STRUCT__entry(
__field( u32, load )
),
TP_fast_assign(
__entry->load = load;
),
TP_printk("%s", __print_symbolic(__entry->load, kvm_fpu_load_symbol))
);
TRACE_EVENT(kvm_age_page,
TP_PROTO(ulong gfn, int level, struct kvm_memory_slot *slot, int ref),
TP_ARGS(gfn, level, slot, ref),
TP_STRUCT__entry(
__field( u64, hva )
__field( u64, gfn )
__field( u8, level )
__field( u8, referenced )
),
TP_fast_assign(
__entry->gfn = gfn;
__entry->level = level;
__entry->hva = ((gfn - slot->base_gfn) <<
PAGE_SHIFT) + slot->userspace_addr;
__entry->referenced = ref;
),
TP_printk("hva %llx gfn %llx level %u %s",
__entry->hva, __entry->gfn, __entry->level,
__entry->referenced ? "YOUNG" : "OLD")
);
#ifdef CONFIG_KVM_ASYNC_PF
DECLARE_EVENT_CLASS(kvm_async_get_page_class,
TP_PROTO(u64 gva, u64 gfn),
TP_ARGS(gva, gfn),
TP_STRUCT__entry(
__field(__u64, gva)
__field(u64, gfn)
),
TP_fast_assign(
__entry->gva = gva;
__entry->gfn = gfn;
),
TP_printk("gva = %#llx, gfn = %#llx", __entry->gva, __entry->gfn)
);
DEFINE_EVENT(kvm_async_get_page_class, kvm_try_async_get_page,
TP_PROTO(u64 gva, u64 gfn),
TP_ARGS(gva, gfn)
);
DEFINE_EVENT(kvm_async_get_page_class, kvm_async_pf_doublefault,
TP_PROTO(u64 gva, u64 gfn),
TP_ARGS(gva, gfn)
);
DECLARE_EVENT_CLASS(kvm_async_pf_nopresent_ready,
TP_PROTO(u64 token, u64 gva),
TP_ARGS(token, gva),
TP_STRUCT__entry(
__field(__u64, token)
__field(__u64, gva)
),
TP_fast_assign(
__entry->token = token;
__entry->gva = gva;
),
TP_printk("token %#llx gva %#llx", __entry->token, __entry->gva)
);
DEFINE_EVENT(kvm_async_pf_nopresent_ready, kvm_async_pf_not_present,
TP_PROTO(u64 token, u64 gva),
TP_ARGS(token, gva)
);
DEFINE_EVENT(kvm_async_pf_nopresent_ready, kvm_async_pf_ready,
TP_PROTO(u64 token, u64 gva),
TP_ARGS(token, gva)
);
TRACE_EVENT(
kvm_async_pf_completed,
TP_PROTO(unsigned long address, u64 gva),
TP_ARGS(address, gva),
TP_STRUCT__entry(
__field(unsigned long, address)
__field(u64, gva)
),
TP_fast_assign(
__entry->address = address;
__entry->gva = gva;
),
TP_printk("gva %#llx address %#lx", __entry->gva,
__entry->address)
);
#endif
TRACE_EVENT(kvm_halt_poll_ns,
TP_PROTO(bool grow, unsigned int vcpu_id, unsigned int new,
unsigned int old),
TP_ARGS(grow, vcpu_id, new, old),
TP_STRUCT__entry(
__field(bool, grow)
__field(unsigned int, vcpu_id)
__field(unsigned int, new)
__field(unsigned int, old)
),
TP_fast_assign(
__entry->grow = grow;
__entry->vcpu_id = vcpu_id;
__entry->new = new;
__entry->old = old;
),
TP_printk("vcpu %u: halt_poll_ns %u (%s %u)",
__entry->vcpu_id,
__entry->new,
__entry->grow ? "grow" : "shrink",
__entry->old)
);
#define trace_kvm_halt_poll_ns_grow(vcpu_id, new, old) \
trace_kvm_halt_poll_ns(true, vcpu_id, new, old)
#define trace_kvm_halt_poll_ns_shrink(vcpu_id, new, old) \
trace_kvm_halt_poll_ns(false, vcpu_id, new, old)
#endif /* _TRACE_KVM_MAIN_H */
/* This part must be outside protection */
#include <trace/define_trace.h>