From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mackerras Date: Fri, 31 May 2019 06:37:52 +0000 Subject: Re: [PATCH] KVM: PPC: Book3S HV: Restore SPRG3 in kvmhv_p9_guest_entry() Message-Id: <20190531063752.GH26651@blackberry> List-Id: References: <20190530021718.22584-1-sjitindarsingh@gmail.com> In-Reply-To: <20190530021718.22584-1-sjitindarsingh@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Suraj Jitindar Singh Cc: kvm-ppc@vger.kernel.org, kvm@vger.kernel.org On Thu, May 30, 2019 at 12:17:18PM +1000, Suraj Jitindar Singh wrote: > The sprgs are a set of 4 general purpose sprs provided for software use. > SPRG3 is special in that it can also be read from userspace. Thus it is > used on linux to store the cpu and numa id of the process to speed up > syscall access to this information. > > This register is overwritten with the guest value on kvm guest entry, > and so needs to be restored on exit again. Thus restore the value on > the guest exit path in kvmhv_p9_guest_entry(). > > Fixes: 95a6432ce9038 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests") > > Signed-off-by: Suraj Jitindar Singh Thanks, patch applied to my kvm-ppc-fixes branch. Paul.