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From: Christoffer Dall <christoffer.dall@linaro.org>
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Subject: Re: [Qemu-devel] [RFC PATCH 7/7] target-arm: Hacky implementation
 of kvm_arch_reset_vcpu() for KVM ARM64
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To: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>, Anup Patel <anup.patel@linaro.org>, patches@apm.com, qemu-devel <qemu-devel@nongnu.org>, Alexander Graf <agraf@suse.de>, "kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>

On Thu, Feb 27, 2014 at 04:05:04PM +0530, Pranavkumar Sawargaonkar wrote:
> Hi Peter,
> 
> On 27 February 2014 15:23, Peter Maydell <peter.maydell@linaro.org> wrote:
> > On 27 February 2014 06:51, Pranavkumar Sawargaonkar
> > <pranavkumar@linaro.org> wrote:
> >> We need to "Feed the kernel back its initial register state" using KVM
> >> ioctls for KVM ARM64 (just like KVM ARM). This means we need to save
> >> the "initial register state" in kvm_arch_init_vcpu() which is not the
> >> case for KVM ARM64 right now. In simpler work, we are depended upon
> >> VCPU register init/save/restore for implementing kvm_arch_reset_vcpu().
> >>
> >> This patch adds a hacky implementation of kvm_arch_reset_vcpu() which
> >> only works for "mach-virt". As-per this hacky implemenation, we re-init
> >> the VCPU using kvm_arch_init_vcpu() so that all registers of VCPU are
> >> set to their reset values by in-kernel KVM code.
> >
> > Re-initing the VCPU is actually the right way to do this -- it is feeding
> > all the register state back to KVM that is the hack. (One day I may
> > fix 32 bit ARM to re-init the VCPU).
> >
> 
Didn't I promise a patch to the KVM Documentation some time to clarify
this?  Hmmm.

-Christoffer