From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eduardo Habkost Subject: Re: [PATCH -v2] target-i386: Reenable RDTSCP support on Opteron_G[345] CPU models CPU models Date: Thu, 20 Dec 2018 10:10:18 -0200 Message-ID: <20181220121018.GM19442@habkost.net> References: <20181210190600.GK4669@habkost.net> <20181210194258.GD5482@zn.tnic> <20181210200843.GN4669@habkost.net> <20181211103839.GC921@redhat.com> <20181211115546.GQ4669@habkost.net> <20181211153017.GN921@redhat.com> <20181211161440.GG27375@zn.tnic> <20181212195235.GX7141@habkost.net> <20181212200803.GG6653@zn.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , Paolo Bonzini , =?iso-8859-1?Q?J=F6rg_R=F6del?= , Andre Przywara , kvm ML , lkml , Tom Lendacky , Eric Blake , qemu-devel@nongnu.org To: Borislav Petkov Return-path: Content-Disposition: inline In-Reply-To: <20181212200803.GG6653@zn.tnic> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Wed, Dec 12, 2018 at 09:08:03PM +0100, Borislav Petkov wrote: > On Wed, Dec 12, 2018 at 05:52:35PM -0200, Eduardo Habkost wrote: > > Why did you remove this entry from PC_COMPAT_2_4? > > > > We must keep compatibility with old behavior of Opteron_G2 on > > pc-2.4, even if the old behavior was incorrect. > > Ok, hunk reverted. v2 below. > > Thx. > > --- > From: Borislav Petkov > > The missing functionality was added ~3 years ago with the Linux commit > > 46896c73c1a4 ("KVM: svm: add support for RDTSCP") > > so reenable RDTSCP support on those CPU models. > > Opteron_G2 - being family 15, model 6, doesn't have RDTSCP support > (the real hardware doesn't have it. K8 got RDTSCP support with the NPT > models, i.e., models >= 0x40). > > Document the host's minimum required kernel version, while at it. > > Signed-off-by: Borislav Petkov Queued, thanks. -- Eduardo