Platform
- Guest: Opensuse with Linux3.10
- Host: Linux3.10
- virtio enabled?: Yes
Boot VM
Boot A VM with virtio block
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| qemu-system-x86_64 -enable-kvm -rtc base=utc,clock=vm,driftfix=none -bios bios.bin \
-device piix3-usb-uhci -soundhw ac97,hda -m 1024 -serial tcp::1223,server,nowait \
-net nic,macaddr=00:20:18:11:01:23,model=rtl8139,vlan=0 \
-net tap,vlan=0,script=/data/images/qemu-image/qemu-ifup0.sh \
-drive file=/data/images/qemu-image/opensuse-50G.raw,if=virtio,boot=on \
-name 23 -cpu core2duo -monitor stdio -smp sockets=1,cores=1,threads=1 -vnc :23
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Count VMExit for block R/W
Create an empty file (1GB) and count how many VMExits happens.
On host Machine
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| perf kvm stat record -a ssh root@GuestIP "dd if=/dev/zero of=tempfile bs=1MB count=1024"
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Read report
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| perf kvm stat report --event=vmexit
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- You will get statistics about VMEXIT
- There are three event you can capture vmexit,mmio,ioport
Detailed report
- Boot the VM first
- On Host Machine
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| perf kvm record -a ssh root@GuestIP "dd if=/dev/zero of=tempfile bs=1MB count=1024"
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- After that, You will get a file named perf.data.guest
- Run report command to look at it
collect performance data from the host
Add --host between kvm and record
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| perf kvm --host record -a ssh root@GuestIP "dd if=/dev/zero of=tempfile bs=1MB count=1024"
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You will get a file namedd perf.data.kvm
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| perf kvm report --input perf.data.kvm
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