On 16/11/2023 4:15 pm, James Dingwall wrote: > Hi, > > Per the msr_relaxed documentation: > > "If using this option is necessary to fix an issue, please report a bug." > > After recently upgrading an environment from Xen 4.14.5 to Xen 4.15.5 we > started experiencing a BSOD at boot with one of our Windows guests. We found > that enabling `msr_relaxed = 1` in the guest configuration has resolved the > problem. With a debug build of Xen and `hvm_debug=2048` on the command line > the following messages were caught as the BSOD happened: > > (XEN) [HVM:11.0] <vmx_msr_read_intercept> ecx=0x1a2 > (XEN) vmx.c:3298:d11v0 RDMSR 0x000001a2 unimplemented > (XEN) d11v0 VIRIDIAN CRASH: 1e ffffffffc0000096 fffff80b8de81eb5 0 0 > > I found that MSR 0x1a2 is MSR_TEMPERATURE_TARGET and from that this patch > series from last month: > > https://patchwork.kernel.org/project/xen-devel/list/?series=796550 > > Picking out just a small part of that fixes the problem for us. Although the > the patch is against 4.15.5 I think it would be relevant to more recent > releases too.
Which version of Windows, and what hardware? The Viridian Crash isn't about the RDMSR itself - it's presumably collateral damage shortly thereafter. Does filling in 0 for that MSR also resolve the issue? It's model specific and we absolutely cannot pass it through from real hardware like that. Thanks, ~Andrew
