On Wed, Aug 31, 2011 at 6:00 PM, Dhaval Giani <dhaval.gi...@gmail.com> wrote: > On Wed, Aug 31, 2011 at 10:58 AM, Blue Swirl <blauwir...@gmail.com> wrote: >> On Wed, Aug 31, 2011 at 8:38 AM, Avi Kivity <a...@redhat.com> wrote: >>> On 08/26/2011 10:06 PM, Blue Swirl wrote: >>>> >>>> Let guests inject tracepoint data via fw_cfg device. >>>> >>>> >>> >>> At least on x86, fw_cfg is pretty slow, involving multiple exits. IMO, for >>> kvm, even one exit per tracepoint is too high. We need to use a shared >>> memory transport with a way to order guest/host events later on (by using a >>> clock). >> >> This could be an easy way, if the guest always had access to an >> accurate clock, but that may not be the case. >> > > From what I understand, kvmclock should be good enoguh for this > purpose. That is what I am using.
It's only available for KVM on x86, that is most certainly not enough.