linux/arch/powerpc/kvm/trace_hv.h

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#if !defined(_TRACE_KVM_HV_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_KVM_HV_H
#include <linux/tracepoint.h>
#include "trace_book3s.h"
#include <asm/hvcall.h>
#include <asm/kvm_asm.h>
#undef TRACE_SYSTEM
#define TRACE_SYSTEM kvm_hv
#define TRACE_INCLUDE_PATH .
#define TRACE_INCLUDE_FILE trace_hv
#define kvm_trace_symbol_hcall \
{H_REMOVE, "H_REMOVE"}, \
{H_ENTER, "H_ENTER"}, \
{H_READ, "H_READ"}, \
{H_CLEAR_MOD, "H_CLEAR_MOD"}, \
{H_CLEAR_REF, "H_CLEAR_REF"}, \
{H_PROTECT, "H_PROTECT"}, \
{H_GET_TCE, "H_GET_TCE"}, \
{H_PUT_TCE, "H_PUT_TCE"}, \
{H_SET_SPRG0, "H_SET_SPRG0"}, \
{H_SET_DABR, "H_SET_DABR"}, \
{H_PAGE_INIT, "H_PAGE_INIT"}, \
{H_SET_ASR, "H_SET_ASR"}, \
{H_ASR_ON, "H_ASR_ON"}, \
{H_ASR_OFF, "H_ASR_OFF"}, \
{H_LOGICAL_CI_LOAD, "H_LOGICAL_CI_LOAD"}, \
{H_LOGICAL_CI_STORE, "H_LOGICAL_CI_STORE"}, \
{H_LOGICAL_CACHE_LOAD, "H_LOGICAL_CACHE_LOAD"}, \
{H_LOGICAL_CACHE_STORE, "H_LOGICAL_CACHE_STORE"}, \
{H_LOGICAL_ICBI, "H_LOGICAL_ICBI"}, \
{H_LOGICAL_DCBF, "H_LOGICAL_DCBF"}, \
{H_GET_TERM_CHAR, "H_GET_TERM_CHAR"}, \
{H_PUT_TERM_CHAR, "H_PUT_TERM_CHAR"}, \
{H_REAL_TO_LOGICAL, "H_REAL_TO_LOGICAL"}, \
{H_HYPERVISOR_DATA, "H_HYPERVISOR_DATA"}, \
{H_EOI, "H_EOI"}, \
{H_CPPR, "H_CPPR"}, \
{H_IPI, "H_IPI"}, \
{H_IPOLL, "H_IPOLL"}, \
{H_XIRR, "H_XIRR"}, \
{H_PERFMON, "H_PERFMON"}, \
{H_MIGRATE_DMA, "H_MIGRATE_DMA"}, \
{H_REGISTER_VPA, "H_REGISTER_VPA"}, \
{H_CEDE, "H_CEDE"}, \
{H_CONFER, "H_CONFER"}, \
{H_PROD, "H_PROD"}, \
{H_GET_PPP, "H_GET_PPP"}, \
{H_SET_PPP, "H_SET_PPP"}, \
{H_PURR, "H_PURR"}, \
{H_PIC, "H_PIC"}, \
{H_REG_CRQ, "H_REG_CRQ"}, \
{H_FREE_CRQ, "H_FREE_CRQ"}, \
{H_VIO_SIGNAL, "H_VIO_SIGNAL"}, \
{H_SEND_CRQ, "H_SEND_CRQ"}, \
{H_COPY_RDMA, "H_COPY_RDMA"}, \
{H_REGISTER_LOGICAL_LAN, "H_REGISTER_LOGICAL_LAN"}, \
{H_FREE_LOGICAL_LAN, "H_FREE_LOGICAL_LAN"}, \
{H_ADD_LOGICAL_LAN_BUFFER, "H_ADD_LOGICAL_LAN_BUFFER"}, \
{H_SEND_LOGICAL_LAN, "H_SEND_LOGICAL_LAN"}, \
{H_BULK_REMOVE, "H_BULK_REMOVE"}, \
{H_MULTICAST_CTRL, "H_MULTICAST_CTRL"}, \
{H_SET_XDABR, "H_SET_XDABR"}, \
{H_STUFF_TCE, "H_STUFF_TCE"}, \
{H_PUT_TCE_INDIRECT, "H_PUT_TCE_INDIRECT"}, \
{H_CHANGE_LOGICAL_LAN_MAC, "H_CHANGE_LOGICAL_LAN_MAC"}, \
{H_VTERM_PARTNER_INFO, "H_VTERM_PARTNER_INFO"}, \
{H_REGISTER_VTERM, "H_REGISTER_VTERM"}, \
{H_FREE_VTERM, "H_FREE_VTERM"}, \
{H_RESET_EVENTS, "H_RESET_EVENTS"}, \
{H_ALLOC_RESOURCE, "H_ALLOC_RESOURCE"}, \
{H_FREE_RESOURCE, "H_FREE_RESOURCE"}, \
{H_MODIFY_QP, "H_MODIFY_QP"}, \
{H_QUERY_QP, "H_QUERY_QP"}, \
{H_REREGISTER_PMR, "H_REREGISTER_PMR"}, \
{H_REGISTER_SMR, "H_REGISTER_SMR"}, \
{H_QUERY_MR, "H_QUERY_MR"}, \
{H_QUERY_MW, "H_QUERY_MW"}, \
{H_QUERY_HCA, "H_QUERY_HCA"}, \
{H_QUERY_PORT, "H_QUERY_PORT"}, \
{H_MODIFY_PORT, "H_MODIFY_PORT"}, \
{H_DEFINE_AQP1, "H_DEFINE_AQP1"}, \
{H_GET_TRACE_BUFFER, "H_GET_TRACE_BUFFER"}, \
{H_DEFINE_AQP0, "H_DEFINE_AQP0"}, \
{H_RESIZE_MR, "H_RESIZE_MR"}, \
{H_ATTACH_MCQP, "H_ATTACH_MCQP"}, \
{H_DETACH_MCQP, "H_DETACH_MCQP"}, \
{H_CREATE_RPT, "H_CREATE_RPT"}, \
{H_REMOVE_RPT, "H_REMOVE_RPT"}, \
{H_REGISTER_RPAGES, "H_REGISTER_RPAGES"}, \
{H_DISABLE_AND_GETC, "H_DISABLE_AND_GETC"}, \
{H_ERROR_DATA, "H_ERROR_DATA"}, \
{H_GET_HCA_INFO, "H_GET_HCA_INFO"}, \
{H_GET_PERF_COUNT, "H_GET_PERF_COUNT"}, \
{H_MANAGE_TRACE, "H_MANAGE_TRACE"}, \
{H_FREE_LOGICAL_LAN_BUFFER, "H_FREE_LOGICAL_LAN_BUFFER"}, \
{H_QUERY_INT_STATE, "H_QUERY_INT_STATE"}, \
{H_POLL_PENDING, "H_POLL_PENDING"}, \
{H_ILLAN_ATTRIBUTES, "H_ILLAN_ATTRIBUTES"}, \
{H_MODIFY_HEA_QP, "H_MODIFY_HEA_QP"}, \
{H_QUERY_HEA_QP, "H_QUERY_HEA_QP"}, \
{H_QUERY_HEA, "H_QUERY_HEA"}, \
{H_QUERY_HEA_PORT, "H_QUERY_HEA_PORT"}, \
{H_MODIFY_HEA_PORT, "H_MODIFY_HEA_PORT"}, \
{H_REG_BCMC, "H_REG_BCMC"}, \
{H_DEREG_BCMC, "H_DEREG_BCMC"}, \
{H_REGISTER_HEA_RPAGES, "H_REGISTER_HEA_RPAGES"}, \
{H_DISABLE_AND_GET_HEA, "H_DISABLE_AND_GET_HEA"}, \
{H_GET_HEA_INFO, "H_GET_HEA_INFO"}, \
{H_ALLOC_HEA_RESOURCE, "H_ALLOC_HEA_RESOURCE"}, \
{H_ADD_CONN, "H_ADD_CONN"}, \
{H_DEL_CONN, "H_DEL_CONN"}, \
{H_JOIN, "H_JOIN"}, \
{H_VASI_STATE, "H_VASI_STATE"}, \
{H_ENABLE_CRQ, "H_ENABLE_CRQ"}, \
{H_GET_EM_PARMS, "H_GET_EM_PARMS"}, \
{H_SET_MPP, "H_SET_MPP"}, \
{H_GET_MPP, "H_GET_MPP"}, \
{H_HOME_NODE_ASSOCIATIVITY, "H_HOME_NODE_ASSOCIATIVITY"}, \
{H_BEST_ENERGY, "H_BEST_ENERGY"}, \
{H_XIRR_X, "H_XIRR_X"}, \
{H_RANDOM, "H_RANDOM"}, \
{H_COP, "H_COP"}, \
{H_GET_MPP_X, "H_GET_MPP_X"}, \
{H_SET_MODE, "H_SET_MODE"}, \
{H_RTAS, "H_RTAS"}
#define kvm_trace_symbol_kvmret \
{RESUME_GUEST, "RESUME_GUEST"}, \
{RESUME_GUEST_NV, "RESUME_GUEST_NV"}, \
{RESUME_HOST, "RESUME_HOST"}, \
{RESUME_HOST_NV, "RESUME_HOST_NV"}
#define kvm_trace_symbol_hcall_rc \
{H_SUCCESS, "H_SUCCESS"}, \
{H_BUSY, "H_BUSY"}, \
{H_CLOSED, "H_CLOSED"}, \
{H_NOT_AVAILABLE, "H_NOT_AVAILABLE"}, \
{H_CONSTRAINED, "H_CONSTRAINED"}, \
{H_PARTIAL, "H_PARTIAL"}, \
{H_IN_PROGRESS, "H_IN_PROGRESS"}, \
{H_PAGE_REGISTERED, "H_PAGE_REGISTERED"}, \
{H_PARTIAL_STORE, "H_PARTIAL_STORE"}, \
{H_PENDING, "H_PENDING"}, \
{H_CONTINUE, "H_CONTINUE"}, \
{H_LONG_BUSY_START_RANGE, "H_LONG_BUSY_START_RANGE"}, \
{H_LONG_BUSY_ORDER_1_MSEC, "H_LONG_BUSY_ORDER_1_MSEC"}, \
{H_LONG_BUSY_ORDER_10_MSEC, "H_LONG_BUSY_ORDER_10_MSEC"}, \
{H_LONG_BUSY_ORDER_100_MSEC, "H_LONG_BUSY_ORDER_100_MSEC"}, \
{H_LONG_BUSY_ORDER_1_SEC, "H_LONG_BUSY_ORDER_1_SEC"}, \
{H_LONG_BUSY_ORDER_10_SEC, "H_LONG_BUSY_ORDER_10_SEC"}, \
{H_LONG_BUSY_ORDER_100_SEC, "H_LONG_BUSY_ORDER_100_SEC"}, \
{H_LONG_BUSY_END_RANGE, "H_LONG_BUSY_END_RANGE"}, \
{H_TOO_HARD, "H_TOO_HARD"}, \
{H_HARDWARE, "H_HARDWARE"}, \
{H_FUNCTION, "H_FUNCTION"}, \
{H_PRIVILEGE, "H_PRIVILEGE"}, \
{H_PARAMETER, "H_PARAMETER"}, \
{H_BAD_MODE, "H_BAD_MODE"}, \
{H_PTEG_FULL, "H_PTEG_FULL"}, \
{H_NOT_FOUND, "H_NOT_FOUND"}, \
{H_RESERVED_DABR, "H_RESERVED_DABR"}, \
{H_NO_MEM, "H_NO_MEM"}, \
{H_AUTHORITY, "H_AUTHORITY"}, \
{H_PERMISSION, "H_PERMISSION"}, \
{H_DROPPED, "H_DROPPED"}, \
{H_SOURCE_PARM, "H_SOURCE_PARM"}, \
{H_DEST_PARM, "H_DEST_PARM"}, \
{H_REMOTE_PARM, "H_REMOTE_PARM"}, \
{H_RESOURCE, "H_RESOURCE"}, \
{H_ADAPTER_PARM, "H_ADAPTER_PARM"}, \
{H_RH_PARM, "H_RH_PARM"}, \
{H_RCQ_PARM, "H_RCQ_PARM"}, \
{H_SCQ_PARM, "H_SCQ_PARM"}, \
{H_EQ_PARM, "H_EQ_PARM"}, \
{H_RT_PARM, "H_RT_PARM"}, \
{H_ST_PARM, "H_ST_PARM"}, \
{H_SIGT_PARM, "H_SIGT_PARM"}, \
{H_TOKEN_PARM, "H_TOKEN_PARM"}, \
{H_MLENGTH_PARM, "H_MLENGTH_PARM"}, \
{H_MEM_PARM, "H_MEM_PARM"}, \
{H_MEM_ACCESS_PARM, "H_MEM_ACCESS_PARM"}, \
{H_ATTR_PARM, "H_ATTR_PARM"}, \
{H_PORT_PARM, "H_PORT_PARM"}, \
{H_MCG_PARM, "H_MCG_PARM"}, \
{H_VL_PARM, "H_VL_PARM"}, \
{H_TSIZE_PARM, "H_TSIZE_PARM"}, \
{H_TRACE_PARM, "H_TRACE_PARM"}, \
{H_MASK_PARM, "H_MASK_PARM"}, \
{H_MCG_FULL, "H_MCG_FULL"}, \
{H_ALIAS_EXIST, "H_ALIAS_EXIST"}, \
{H_P_COUNTER, "H_P_COUNTER"}, \
{H_TABLE_FULL, "H_TABLE_FULL"}, \
{H_ALT_TABLE, "H_ALT_TABLE"}, \
{H_MR_CONDITION, "H_MR_CONDITION"}, \
{H_NOT_ENOUGH_RESOURCES, "H_NOT_ENOUGH_RESOURCES"}, \
{H_R_STATE, "H_R_STATE"}, \
{H_RESCINDED, "H_RESCINDED"}, \
{H_P2, "H_P2"}, \
{H_P3, "H_P3"}, \
{H_P4, "H_P4"}, \
{H_P5, "H_P5"}, \
{H_P6, "H_P6"}, \
{H_P7, "H_P7"}, \
{H_P8, "H_P8"}, \
{H_P9, "H_P9"}, \
{H_TOO_BIG, "H_TOO_BIG"}, \
{H_OVERLAP, "H_OVERLAP"}, \
{H_INTERRUPT, "H_INTERRUPT"}, \
{H_BAD_DATA, "H_BAD_DATA"}, \
{H_NOT_ACTIVE, "H_NOT_ACTIVE"}, \
{H_SG_LIST, "H_SG_LIST"}, \
{H_OP_MODE, "H_OP_MODE"}, \
{H_COP_HW, "H_COP_HW"}, \
{H_UNSUPPORTED_FLAG_START, "H_UNSUPPORTED_FLAG_START"}, \
{H_UNSUPPORTED_FLAG_END, "H_UNSUPPORTED_FLAG_END"}, \
{H_MULTI_THREADS_ACTIVE, "H_MULTI_THREADS_ACTIVE"}, \
{H_OUTSTANDING_COP_OPS, "H_OUTSTANDING_COP_OPS"}
TRACE_EVENT(kvm_guest_enter,
TP_PROTO(struct kvm_vcpu *vcpu),
TP_ARGS(vcpu),
TP_STRUCT__entry(
__field(int, vcpu_id)
__field(unsigned long, pc)
__field(unsigned long, pending_exceptions)
__field(u8, ceded)
),
TP_fast_assign(
__entry->vcpu_id = vcpu->vcpu_id;
__entry->pc = kvmppc_get_pc(vcpu);
__entry->ceded = vcpu->arch.ceded;
__entry->pending_exceptions = vcpu->arch.pending_exceptions;
),
TP_printk("VCPU %d: pc=0x%lx pexcp=0x%lx ceded=%d",
__entry->vcpu_id,
__entry->pc,
__entry->pending_exceptions, __entry->ceded)
);
TRACE_EVENT(kvm_guest_exit,
TP_PROTO(struct kvm_vcpu *vcpu),
TP_ARGS(vcpu),
TP_STRUCT__entry(
__field(int, vcpu_id)
__field(int, trap)
__field(unsigned long, pc)
__field(unsigned long, msr)
__field(u8, ceded)
),
TP_fast_assign(
__entry->vcpu_id = vcpu->vcpu_id;
__entry->trap = vcpu->arch.trap;
__entry->ceded = vcpu->arch.ceded;
__entry->pc = kvmppc_get_pc(vcpu);
__entry->msr = vcpu->arch.shregs.msr;
),
TP_printk("VCPU %d: trap=%s pc=0x%lx msr=0x%lx, ceded=%d",
__entry->vcpu_id,
__print_symbolic(__entry->trap, kvm_trace_symbol_exit),
__entry->pc, __entry->msr, __entry->ceded
)
);
TRACE_EVENT(kvm_page_fault_enter,
TP_PROTO(struct kvm_vcpu *vcpu, unsigned long *hptep,
struct kvm_memory_slot *memslot, unsigned long ea,
unsigned long dsisr),
TP_ARGS(vcpu, hptep, memslot, ea, dsisr),
TP_STRUCT__entry(
__field(int, vcpu_id)
__field(unsigned long, hpte_v)
__field(unsigned long, hpte_r)
__field(unsigned long, gpte_r)
__field(unsigned long, ea)
__field(u64, base_gfn)
__field(u32, slot_flags)
__field(u32, dsisr)
),
TP_fast_assign(
__entry->vcpu_id = vcpu->vcpu_id;
__entry->hpte_v = hptep[0];
__entry->hpte_r = hptep[1];
__entry->gpte_r = hptep[2];
__entry->ea = ea;
__entry->dsisr = dsisr;
__entry->base_gfn = memslot ? memslot->base_gfn : -1UL;
__entry->slot_flags = memslot ? memslot->flags : 0;
),
TP_printk("VCPU %d: hpte=0x%lx:0x%lx guest=0x%lx ea=0x%lx,%x slot=0x%llx,0x%x",
__entry->vcpu_id,
__entry->hpte_v, __entry->hpte_r, __entry->gpte_r,
__entry->ea, __entry->dsisr,
__entry->base_gfn, __entry->slot_flags)
);
TRACE_EVENT(kvm_page_fault_exit,
TP_PROTO(struct kvm_vcpu *vcpu, unsigned long *hptep, long ret),
TP_ARGS(vcpu, hptep, ret),
TP_STRUCT__entry(
__field(int, vcpu_id)
__field(unsigned long, hpte_v)
__field(unsigned long, hpte_r)
__field(long, ret)
),
TP_fast_assign(
__entry->vcpu_id = vcpu->vcpu_id;
__entry->hpte_v = hptep[0];
__entry->hpte_r = hptep[1];
__entry->ret = ret;
),
TP_printk("VCPU %d: hpte=0x%lx:0x%lx ret=0x%lx",
__entry->vcpu_id,
__entry->hpte_v, __entry->hpte_r, __entry->ret)
);
TRACE_EVENT(kvm_hcall_enter,
TP_PROTO(struct kvm_vcpu *vcpu),
TP_ARGS(vcpu),
TP_STRUCT__entry(
__field(int, vcpu_id)
__field(unsigned long, req)
__field(unsigned long, gpr4)
__field(unsigned long, gpr5)
__field(unsigned long, gpr6)
__field(unsigned long, gpr7)
),
TP_fast_assign(
__entry->vcpu_id = vcpu->vcpu_id;
__entry->req = kvmppc_get_gpr(vcpu, 3);
__entry->gpr4 = kvmppc_get_gpr(vcpu, 4);
__entry->gpr5 = kvmppc_get_gpr(vcpu, 5);
__entry->gpr6 = kvmppc_get_gpr(vcpu, 6);
__entry->gpr7 = kvmppc_get_gpr(vcpu, 7);
),
TP_printk("VCPU %d: hcall=%s GPR4-7=0x%lx,0x%lx,0x%lx,0x%lx",
__entry->vcpu_id,
__print_symbolic(__entry->req, kvm_trace_symbol_hcall),
__entry->gpr4, __entry->gpr5, __entry->gpr6, __entry->gpr7)
);
TRACE_EVENT(kvm_hcall_exit,
TP_PROTO(struct kvm_vcpu *vcpu, int ret),
TP_ARGS(vcpu, ret),
TP_STRUCT__entry(
__field(int, vcpu_id)
__field(unsigned long, ret)
__field(unsigned long, hcall_rc)
),
TP_fast_assign(
__entry->vcpu_id = vcpu->vcpu_id;
__entry->ret = ret;
__entry->hcall_rc = kvmppc_get_gpr(vcpu, 3);
),
TP_printk("VCPU %d: ret=%s hcall_rc=%s",
__entry->vcpu_id,
__print_symbolic(__entry->ret, kvm_trace_symbol_kvmret),
__print_symbolic(__entry->ret & RESUME_FLAG_HOST ?
H_TOO_HARD : __entry->hcall_rc,
kvm_trace_symbol_hcall_rc))
);
TRACE_EVENT(kvmppc_run_core,
TP_PROTO(struct kvmppc_vcore *vc, int where),
TP_ARGS(vc, where),
TP_STRUCT__entry(
__field(int, n_runnable)
__field(int, runner_vcpu)
__field(int, where)
__field(pid_t, tgid)
),
TP_fast_assign(
__entry->runner_vcpu = vc->runner->vcpu_id;
__entry->n_runnable = vc->n_runnable;
__entry->where = where;
__entry->tgid = current->tgid;
),
TP_printk("%s runner_vcpu==%d runnable=%d tgid=%d",
__entry->where ? "Exit" : "Enter",
__entry->runner_vcpu, __entry->n_runnable, __entry->tgid)
);
TRACE_EVENT(kvmppc_vcore_blocked,
TP_PROTO(struct kvmppc_vcore *vc, int where),
TP_ARGS(vc, where),
TP_STRUCT__entry(
__field(int, n_runnable)
__field(int, runner_vcpu)
__field(int, where)
__field(pid_t, tgid)
),
TP_fast_assign(
__entry->runner_vcpu = vc->runner->vcpu_id;
__entry->n_runnable = vc->n_runnable;
__entry->where = where;
__entry->tgid = current->tgid;
),
TP_printk("%s runner_vcpu=%d runnable=%d tgid=%d",
__entry->where ? "Exit" : "Enter",
__entry->runner_vcpu, __entry->n_runnable, __entry->tgid)
);
KVM: PPC: Book3S HV: Implement halt polling This patch introduces new halt polling functionality into the kvm_hv kernel module. When a vcore is idle it will poll for some period of time before scheduling itself out. When all of the runnable vcpus on a vcore have ceded (and thus the vcore is idle) we schedule ourselves out to allow something else to run. In the event that we need to wake up very quickly (for example an interrupt arrives), we are required to wait until we get scheduled again. Implement halt polling so that when a vcore is idle, and before scheduling ourselves, we poll for vcpus in the runnable_threads list which have pending exceptions or which leave the ceded state. If we poll successfully then we can get back into the guest very quickly without ever scheduling ourselves, otherwise we schedule ourselves out as before. There exists generic halt_polling code in virt/kvm_main.c, however on powerpc the polling conditions are different to the generic case. It would be nice if we could just implement an arch specific kvm_check_block() function, but there is still other arch specific things which need to be done for kvm_hv (for example manipulating vcore states) which means that a separate implementation is the best option. Testing of this patch with a TCP round robin test between two guests with virtio network interfaces has found a decrease in round trip time of ~15us on average. A performance gain is only seen when going out of and back into the guest often and quickly, otherwise there is no net benefit from the polling. The polling interval is adjusted such that when we are often scheduled out for long periods of time it is reduced, and when we often poll successfully it is increased. The rate at which the polling interval increases or decreases, and the maximum polling interval, can be set through module parameters. Based on the implementation in the generic kvm module by Wanpeng Li and Paolo Bonzini, and on direction from Paul Mackerras. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-08-02 12:03:21 +08:00
TRACE_EVENT(kvmppc_vcore_wakeup,
TP_PROTO(int do_sleep, __u64 ns),
TP_ARGS(do_sleep, ns),
TP_STRUCT__entry(
__field(__u64, ns)
__field(int, waited)
__field(pid_t, tgid)
),
TP_fast_assign(
__entry->ns = ns;
__entry->waited = do_sleep;
__entry->tgid = current->tgid;
),
TP_printk("%s time %llu ns, tgid=%d",
KVM: PPC: Book3S HV: Implement halt polling This patch introduces new halt polling functionality into the kvm_hv kernel module. When a vcore is idle it will poll for some period of time before scheduling itself out. When all of the runnable vcpus on a vcore have ceded (and thus the vcore is idle) we schedule ourselves out to allow something else to run. In the event that we need to wake up very quickly (for example an interrupt arrives), we are required to wait until we get scheduled again. Implement halt polling so that when a vcore is idle, and before scheduling ourselves, we poll for vcpus in the runnable_threads list which have pending exceptions or which leave the ceded state. If we poll successfully then we can get back into the guest very quickly without ever scheduling ourselves, otherwise we schedule ourselves out as before. There exists generic halt_polling code in virt/kvm_main.c, however on powerpc the polling conditions are different to the generic case. It would be nice if we could just implement an arch specific kvm_check_block() function, but there is still other arch specific things which need to be done for kvm_hv (for example manipulating vcore states) which means that a separate implementation is the best option. Testing of this patch with a TCP round robin test between two guests with virtio network interfaces has found a decrease in round trip time of ~15us on average. A performance gain is only seen when going out of and back into the guest often and quickly, otherwise there is no net benefit from the polling. The polling interval is adjusted such that when we are often scheduled out for long periods of time it is reduced, and when we often poll successfully it is increased. The rate at which the polling interval increases or decreases, and the maximum polling interval, can be set through module parameters. Based on the implementation in the generic kvm module by Wanpeng Li and Paolo Bonzini, and on direction from Paul Mackerras. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-08-02 12:03:21 +08:00
__entry->waited ? "wait" : "poll",
__entry->ns, __entry->tgid)
);
TRACE_EVENT(kvmppc_run_vcpu_enter,
TP_PROTO(struct kvm_vcpu *vcpu),
TP_ARGS(vcpu),
TP_STRUCT__entry(
__field(int, vcpu_id)
__field(pid_t, tgid)
),
TP_fast_assign(
__entry->vcpu_id = vcpu->vcpu_id;
__entry->tgid = current->tgid;
),
TP_printk("VCPU %d: tgid=%d", __entry->vcpu_id, __entry->tgid)
);
TRACE_EVENT(kvmppc_run_vcpu_exit,
TP_PROTO(struct kvm_vcpu *vcpu, struct kvm_run *run),
TP_ARGS(vcpu, run),
TP_STRUCT__entry(
__field(int, vcpu_id)
__field(int, exit)
__field(int, ret)
),
TP_fast_assign(
__entry->vcpu_id = vcpu->vcpu_id;
__entry->exit = run->exit_reason;
__entry->ret = vcpu->arch.ret;
),
TP_printk("VCPU %d: exit=%d, ret=%d",
__entry->vcpu_id, __entry->exit, __entry->ret)
);
#endif /* _TRACE_KVM_HV_H */
/* This part must be outside protection */
#include <trace/define_trace.h>