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Diffstat (limited to 'results/classifier/deepseek-r1:14b/output/hypervisor/1908489')
| -rw-r--r-- | results/classifier/deepseek-r1:14b/output/hypervisor/1908489 | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/results/classifier/deepseek-r1:14b/output/hypervisor/1908489 b/results/classifier/deepseek-r1:14b/output/hypervisor/1908489 new file mode 100644 index 00000000..71da3147 --- /dev/null +++ b/results/classifier/deepseek-r1:14b/output/hypervisor/1908489 @@ -0,0 +1,17 @@ + +qemu 4.2 bootloops with -cpu host and nested hypervisor + +I've noticed that after upgrading from Ubuntu 18.04 to 20.04 that nested virtualization isn't working anymore. + +I have a simple repro where I create a Windows 10 2004 guest and enable Hyper-V in it. This worked fine in 18.04 and specifically qemu <4.2 (I specifically tested Qemu 2.11-4.1 which work fine). + +The -cpu arg I'm passing is simply: + -cpu host,l3-cache=on,hv_relaxed,hv_spinlocks=0x1fff,hv_vapic,hv_time + +Using that Windows won't boot because the nested hypervisor (Hyper-V) is unable to be initialize and so it just boot loops. Using the exact same qemu command works fine with 4.1 and lower. + +Switching to a named CPU model like Skylake-Client-noTSX-IBRS instead of host lets the VM boot but causes some weird behaviour later trying to use nested VMs. + +If I had to guess I think it would probably be related to this change https://github.com/qemu/qemu/commit/20a78b02d31534ae478779c2f2816c273601e869 which would line up with 4.2 being the first bad version but unsure. + +For now I just have to keep an older build of QEMU to work around this. Let me know if there's anything else needed. I can also try out any patches. I already have at least a dozen copies of qemu lying around now. \ No newline at end of file |