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df13c0b477
This patch maps /domain/cpu/cache element into -cpu parameters: - <cache mode='passthrough'/> is translated to host-cache-info=on - <cache level='3' mode='emulate'/> is transformed into l3-cache=on - <cache mode='disable'/> is turned in host-cache-info=off,l3-cache=off Any other <cache> element is forbidden. The tricky part is detecting whether QEMU supports the CPU properties. The 'host-cache-info' property is introduced in v2.4.0-1389-ge265e3e480, earlier QEMU releases enabled host-cache-info by default and had no way to disable it. If the property is present, it defaults to 'off' for any QEMU until at least 2.9.0. The 'l3-cache' property was introduced later by v2.7.0-200-g14c985cffa. Earlier versions worked as if l3-cache=off was passed. For any QEMU until at least 2.9.0 l3-cache is 'off' by default. QEMU 2.9.0 was the first release which supports probing both properties by running device-list-properties with typename=host-x86_64-cpu. Older QEMU releases did not support device-list-properties command for CPU devices. Thus we can't really rely on probing them and we can just use query-cpu-model-expansion QMP command as a witness. Because the cache property probing is only reliable for QEMU >= 2.9.0 when both are already supported for quite a few releases, we let QEMU report an error if a specific cache mode is explicitly requested. The other mode (or both if a user requested CPU cache to be disabled) is explicitly turned off for QEMU >= 2.9.0 to avoid any surprises in case the QEMU defaults change. Any older QEMU already turns them off so not doing so explicitly does not make any harm. Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
22 lines
460 B
Plaintext
22 lines
460 B
Plaintext
LC_ALL=C \
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PATH=/bin \
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HOME=/home/test \
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USER=test \
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LOGNAME=test \
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QEMU_AUDIO_DRV=none \
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/usr/bin/qemu-system-x86_64 \
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-name foo \
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-S \
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-M pc \
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-cpu host,host-cache-info=off,l3-cache=off \
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-m 214 \
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-smp 1,sockets=1,cores=1,threads=1 \
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-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
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-nographic \
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-nodefaults \
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-monitor unix:/tmp/lib/domain--1-foo/monitor.sock,server,nowait \
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-no-acpi \
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-boot c \
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-usb \
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-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3
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