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-rw-r--r-- | documentation/dev-manual/dev-manual-qemu.xml | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/documentation/dev-manual/dev-manual-qemu.xml b/documentation/dev-manual/dev-manual-qemu.xml index f4719ebc3c..4e7b5de4e8 100644 --- a/documentation/dev-manual/dev-manual-qemu.xml +++ b/documentation/dev-manual/dev-manual-qemu.xml | |||
@@ -343,6 +343,40 @@ | |||
343 | </para> | 343 | </para> |
344 | </section> | 344 | </section> |
345 | 345 | ||
346 | <section id='qemu-kvm-cpu-compatibility'> | ||
347 | <title>QEMU CPU Compatibility Under KVM</title> | ||
348 | |||
349 | <para> | ||
350 | By default, the QEMU build compiles for and targets 64-bit and x86 | ||
351 | <trademark class='registered'>Intel</trademark> <trademark class='trademark'>Core</trademark>2 | ||
352 | Duo processors and 32-bit x86 | ||
353 | <trademark class='registered'>Intel</trademark> <trademark class='registered'>Pentium</trademark> | ||
354 | II processors. | ||
355 | QEMU builds for and targets these CPU types because they display | ||
356 | a broad range of CPU feature compatibility with many commonly | ||
357 | used CPUs. | ||
358 | </para> | ||
359 | |||
360 | <para> | ||
361 | Despite this broad range of compatibility, the CPUs could support | ||
362 | a feature that your host CPU does not support. | ||
363 | Although this situation is not a problem when QEMU uses software | ||
364 | emulation of the feature, it can be a problem when QEMU is | ||
365 | running with KVM enabled. | ||
366 | Specifically, software compiled with a certain CPU feature crashes | ||
367 | when run on a CPU under KVM that does not support that feature. | ||
368 | To work around this problem, you can override QEMU's runtime CPU | ||
369 | setting by changing the <filename>QB_CPU_KVM</filename> | ||
370 | variable in <filename>qemuboot.conf</filename> in the | ||
371 | <ulink url='&YOCTO_DOCS_REF_URL;#build-directory'>Build Directory's</ulink> | ||
372 | <filename>deploy/image</filename> directory. | ||
373 | This setting specifies a <filename>-cpu</filename> option | ||
374 | passed into QEMU in the <filename>runqemu</filename> script. | ||
375 | Running <filename>qemu -cpu help</filename> returns a list of | ||
376 | available supported CPU types. | ||
377 | </para> | ||
378 | </section> | ||
379 | |||
346 | <section id='qemu-dev-performance'> | 380 | <section id='qemu-dev-performance'> |
347 | <title>QEMU Performance</title> | 381 | <title>QEMU Performance</title> |
348 | 382 | ||