On Mon, Dec 10, 2018 at 08:42:58PM +0100, Borislav Petkov wrote: > On Mon, Dec 10, 2018 at 05:06:00PM -0200, Eduardo Habkost wrote: > > I mean documenting it. We already have code that will print > > warnings if a feature isn't available. > > > > See my previous attempt to document the minimum kernel version > > at <https://www.mail-archive.com/qemu-devel@xxxxxxxxxx/msg486559.html>. > > Something like this? > > I still have no clue how to add RDTSCP on pc-*-4.0 and newer. qemu.git master have no PC_COMPAT_3_1 and pc-*-4.0 machine-types yet. I've sent another reply with additional pointers. > > Thx. > > --- > diff --git a/qemu-doc.texi b/qemu-doc.texi > index f7ad1dfe4b69..913b2ef68d54 100644 > --- a/qemu-doc.texi > +++ b/qemu-doc.texi > @@ -37,6 +37,7 @@ > * QEMU System emulator for non PC targets:: > * QEMU Guest Agent:: > * QEMU User space emulator:: > +* System requirements:: > * Implementation notes:: > * Deprecated features:: > * Supported build platforms:: > @@ -2813,6 +2814,13 @@ Act as if the host page size was 'pagesize' bytes > Run the emulation in single step mode. > @end table > > +@node System requirements > +@chapter System requirements > + > +@section KVM kernel module > + > +On x86_64 hosts, the default set of CPU features enabled by the KVM accelerator > +require the host to be running Linux v4.5 or newer. > Sounds good, but it would be nice to document what exactly makes Linux 4.5+ necessary. e.g.: | On x86_64 hosts, it is recommended to run Linux 4.5 or newer on | the host when using the KVM accelerator. | | The Opteron_G2, OpteronG3, Opteron_G4, and Opteron_G5 CPU | models require KVM support for RDTSCP, which was added on | Linux 4.5. I'm CCing some people who may help review English grammar and style. -- Eduardo
