Manawyrm <openbsd.l...@tbspace.de> wrote: > (Hetzner engineer here, but speaking as a private individual) > > Hetzner Cloud is using regular mainline QEMU on Linux as the hypervisor, > so while I'd agree that faulting when the MSR is set isn't ideal, this > behaviour will probably also occur on a lot of other machines/setups. > > Another solution might be preferrable. Linux has started to do a very > similar thing and I haven't yet checked if it runs into a similar > situation/fault. > > At least on Hetzner Cloud, there is a lot of indications that the > machine is running as a virtual machine (ACPI/SMBIOS, etc.). If > possible, maybe skip setting the flag when running virtualized?
Indeed. We now check the cpuid ecx HV flag before performing this specific wrmsr. This kind of thing seems to keep coming up. In our codebase, we have a way to handle a faulting rdmsr. We don't have a maching way to handle a faulting wrmsr. We sort of don't want the latter..
