On Tue, Jan 16, 2018 at 12:46:10PM +0000, Wei Liu wrote: > On Fri, Jan 12, 2018 at 01:24:09PM +0000, Wei Liu wrote: > > Hi all, > > > > Two solutions are proposed to mitigate Meltdown. One is called Vixen and the > > other is called Comet. The long term goal is to merge the two > > implementations > > to one. > > > > Here I list the differences between the two implementations. > > > > Vixen Comet > > Boot mode HVM PVH + HVM > > Kconfig options XEN_GUEST XEN_GUEST + PVH_GUEST > > + SHIM_EXCLUSIVE > > Xen build system No change New build target for > > shim > > Guest console Output only Bi-directional > > Guest domid 1 or set via shim option 1 or retrieved via > > cpuid > > Guest type Hardware domain Normal domain > > Time source Emulated Xen PV clock > > Shutdown PV + HW PV > > SI mapping Reserved page Fixed map, PFN chosen > > at runtime > > VCPU id Handled by L1 Provide by L0 if > > available > > VCPU runstate Forwarded to L0 Handled by L1 > > Xen version L0 version L1 version > > CPUID faulting None Changes for Intel and > > AMD > > Grant table What is forwarded is more or less the same but > > differs in implementation > > Event channel setup 3 mechanisms 1 mechanism > > Event channel ECS_PROXY state Use ECS_RESERVED > > Differences in what gets forwarded > > Migration No Yes > > CPU hotplug No Yes > > Memory hotplug No Yes > > > > These are the things I can think of when comparing the two series side > > by side. Feel free to provide addition and / or correction. The list > > serves as a guidance on what areas need attention. > > We've come to agree on the following goals among stakeholders: > > 1. We will use Comet as base to develop Rudolph. > 2. We will start to commit patches into staging and develop there. > 3. We will maintain Vixen and Comet until Rudolph is ready. We will > be cherry-picking bug fixes to Vixen and Comet as we develop Rudolph. > > In order to make goal #3 easier, I suggest we commit Comet almost as-is > to minimise the difference between staging and backported Comet > branches. > > I will post a version of Comet suitable for committing to staging as > soon as possible. We will start porting over functionalities from Vixen > once Comet is committed.
I've pushed comet-for-unstable to my xenbits/xen.git. That branch is a forward port of 4.10.0-shim-comet branch to staging. https://xenbits.xen.org/gitweb/?p=people/liuw/xen.git;a=shortlog;h=refs/heads/comet-for-unstable There will be follow-up patches to fix some bugs, which have not been pushed to that branch yet: 1. Michael Young's -xen-attach patch 2. Roger's patch to move mapping vcpu_info earlier (Due to things go in parallel, they are probably not yet on list) Jan and Andrew, please check the branch and explicitly ack the action of committing that branch. Wei. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
