Re: [PATCH] x86/mm: Drop TS_COMPAT on 64-bit exec() syscall

[Dmitry Safonov <0x7f454c46@gmail.com>]

2018-05-19 0:10 GMT+01:00 Dmitry Safonov <0x7f454c46@gmail.com>:
> Sure.
> I'm on Intel actually:
> cpu family    : 6
> model        : 142
> model name    : Intel(R) Core(TM) i7-7600U CPU @ 2.80GHz
>
> But I usually test kernels in VM. So, I use virt-manager as it's
> easier to manage
> multiple VMs. The thing is that I've chosen "Copy host CPU configuration"
> and for some reason, I don't quite follow virt-manager makes model "Opteron_G4".
> I'm on Fedora 27, virt-manager 1.4.3, qemu 2.9.1(qemu-2.9.1-2.fc26).

Hmm, the reason it chooses AMD emulation looks like a bug in virt-manager:
When I try IvyBridge CPU, it gives the following error:
> Error starting domain: the CPU is incompatible with host CPU: Host CPU does not
> provide required features: vme, x2apic, tsc-deadline, avx, f16c, rdrand

Which to my naive mind is by the reason that "tsc-deadline" is not written with
a dash in cpuinfo:
flags        : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe
syscall nx pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs bts
rep_good nopl xtopology nonstop_tsc cpuid aperfmperf tsc_known_freq
pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 sdbg fma
cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt
tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch
cpuid_fault epb invpcid_single pti tpr_shadow vnmi flexpriority ept
vpid fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 erms invpcid rtm mpx
rdseed adx smap clflushopt intel_pt xsaveopt xsavec xgetbv1 xsaves
ibpb ibrs stibp dtherm ida arat pln pts hwp hwp_notify hwp_act_window
hwp_epp

But that just my naive suppose.

Thanks,
             Dmitry