>>> On 16.02.17 at 13:27, <andrew.coop...@citrix.com> wrote: > On 16/02/17 11:15, Jan Beulich wrote: >> When __context_switch() is being bypassed during original context >> switch handling, the vCPU "owning" the VMCS partially loses control of >> it: It will appear non-running to remote CPUs, and hence their attempt >> to pause the owning vCPU will have no effect on it (as it already >> looks to be paused). At the same time the "owning" CPU will re-enable >> interrupts eventually (the lastest when entering the idle loop) and >> hence becomes subject to IPIs from other CPUs requesting access to the >> VMCS. As a result, when __context_switch() finally gets run, the CPU >> may no longer have the VMCS loaded, and hence any accesses to it would >> fail. Hence we may need to re-load the VMCS in vmx_ctxt_switch_from(). >> >> Similarly, when __context_switch() is being bypassed also on the second >> (switch-in) path, VMCS ownership may have been lost and hence needs >> re-establishing. Since there's no existing hook to put this in, add a >> new one. >> >> Reported-by: Kevin Mayer <kevin.ma...@gdata.de> >> Reported-by: Anshul Makkar <anshul.mak...@citrix.com> >> Signed-off-by: Jan Beulich <jbeul...@suse.com> > > Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com> > > Although I would certainly prefer if we can get another round of testing > on this series for confidence.
Sure, I'd certainly like to stick a Tested-by on it. Plus VMX maintainer feedback will need waiting for anyway. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
