Commit cb953129 authored by David Matlack's avatar David Matlack Committed by Paolo Bonzini
Browse files

kvm: add halt-polling cpu usage stats 



Two new stats for exposing halt-polling cpu usage:
halt_poll_success_ns
halt_poll_fail_ns

Thus sum of these 2 stats is the total cpu time spent polling. "success"
means the VCPU polled until a virtual interrupt was delivered. "fail"
means the VCPU had to schedule out (either because the maximum poll time
was reached or it needed to yield the CPU).

To avoid touching every arch's kvm_vcpu_stat struct, only update and
export halt-polling cpu usage stats if we're on x86.

Exporting cpu usage as a u64 and in nanoseconds means we will overflow at
~500 years, which seems reasonably large.

Signed-off-by: default avatarDavid Matlack <dmatlack@google.com>
Signed-off-by: default avatarJon Cargille <jcargill@google.com>
Reviewed-by: default avatarJim Mattson <jmattson@google.com>

Message-Id: <20200508182240.68440-1-jcargill@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 93dff2fe

arch/arm64/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -415,6 +415,8 @@ struct kvm_vm_stat { 
struct kvm_vcpu_stat {

	u64 halt_successful_poll;

	u64 halt_attempted_poll;

	u64 halt_poll_success_ns;

	u64 halt_poll_fail_ns;

	u64 halt_poll_invalid;

	u64 halt_wakeup;

	u64 hvc_exit_stat;

arch/arm64/kvm/guest.c

+2 −0
Original line number Diff line number Diff line
@@ -40,6 +40,8 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { 
	VCPU_STAT("mmio_exit_user", mmio_exit_user),

	VCPU_STAT("mmio_exit_kernel", mmio_exit_kernel),

	VCPU_STAT("exits", exits),

	VCPU_STAT("halt_poll_success_ns", halt_poll_success_ns),

	VCPU_STAT("halt_poll_fail_ns", halt_poll_fail_ns),

	{ NULL }

};

arch/mips/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -174,6 +174,8 @@ struct kvm_vcpu_stat { 
#endif

	u64 halt_successful_poll;

	u64 halt_attempted_poll;

	u64 halt_poll_success_ns;

	u64 halt_poll_fail_ns;

	u64 halt_poll_invalid;

	u64 halt_wakeup;

};

arch/mips/kvm/mips.c

+2 −0
Original line number Diff line number Diff line
@@ -72,6 +72,8 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { 
	VCPU_STAT("halt_attempted_poll", halt_attempted_poll),

	VCPU_STAT("halt_poll_invalid", halt_poll_invalid),

	VCPU_STAT("halt_wakeup", halt_wakeup),

	VCPU_STAT("halt_poll_success_ns", halt_poll_success_ns),

	VCPU_STAT("halt_poll_fail_ns", halt_poll_fail_ns),

	{NULL}

};

arch/powerpc/kvm/booke.c

+2 −0
Original line number Diff line number Diff line
@@ -54,6 +54,8 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { 
	VCPU_STAT("halt_wakeup", halt_wakeup),

	VCPU_STAT("doorbell", dbell_exits),

	VCPU_STAT("guest doorbell", gdbell_exits),

	VCPU_STAT("halt_poll_success_ns", halt_poll_success_ns),

	VCPU_STAT("halt_poll_fail_ns", halt_poll_fail_ns),

	VM_STAT("remote_tlb_flush", remote_tlb_flush),

	{ NULL }

};

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