This fixes a confusion in the help output. (Although, if you squint
long enough at the '-cpu help' output, you _do_ notice that
"Skylake-Client-noTSX-IBRS" is an alias of "Skylake-Client-v3";
similarly for Skylake-Server-v3.)
Without this patch:
$ qemu-system-x86 -cpu help
...
x86 Skylake-Client-v1 Intel Core Processor (Skylake)
x86 Skylake-Client-v2 Intel Core Processor (Skylake, IBRS)
x86 Skylake-Client-v3 Intel Core Processor (Skylake, IBRS)
...
x86 Skylake-Server-v1 Intel Xeon Processor (Skylake)
x86 Skylake-Server-v2 Intel Xeon Processor (Skylake, IBRS)
x86 Skylake-Server-v3 Intel Xeon Processor (Skylake, IBRS)
...
With this patch:
$ ./qemu-system-x86 -cpu help
...
x86 Skylake-Client-v1 Intel Core Processor (Skylake)
x86 Skylake-Client-v2 Intel Core Processor (Skylake, IBRS)
x86 Skylake-Client-v3 Intel Core Processor (Skylake, IBRS, no TSX)
...
x86 Skylake-Server-v1 Intel Xeon Processor (Skylake)
x86 Skylake-Server-v2 Intel Xeon Processor (Skylake, IBRS)
x86 Skylake-Server-v3 Intel Xeon Processor (Skylake, IBRS, no TSX)
Backports commit 673b0add9ea7f432f34c1c99eaa7c567012fc838 from qemu