From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hollis Blanchard Date: Mon, 13 Dec 2010 17:17:25 +0000 Subject: Re: re-writing on powerpc Message-Id: <4D065525.5010105@mentor.com> List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: kvm-ppc@vger.kernel.org On 12/13/2010 12:35 AM, Avi Kivity wrote: > On 12/13/2010 06:45 AM, Yoder Stuart-B08248 wrote: >> Avi/Hollis, >> >> Exchanged some emails with Alex on the topic of rewriting on >> powerpc KVM-- the current approach taken by Alex's PV patch is >> to have a guest Linux paravirt itself, by re-writing certain >> instructions. >> >> The downside to this approach (guest side patching) is that every OS >> to be run on KVM has to be modified or dynamically patched. >> >> What were the reasons for not going down the path of doing the >> re-writing in the hypervisor? (Alex couldn't remember the >> specifics). What about doing it from Qemu? >> > > Rewriting is dangerous if the guest is unaware of it. As soon as it > is made aware of it, it might as well actually do it in the best way > that suits it. Can you list some examples of dangerous scenarios? Hollis Blanchard Mentor Graphics, Embedded Systems Division