Lguest and Xen pv-guests are the only users of pv_mmu_ops (with the one exception of the .exit_mmap member, which is being used by Xen HVM-guests, too). As it is possible now to build a kernel without Xen pv-guest support while keeping PVH and PVHVM support, I thought about putting most pv_mmu_ops functions in #ifdef CONFIG_XEN_HAS_PVMMU sections. If there wouldn't be lguest... So my question: is anybody still using lguest or would like to keep it? If yes, I'd add CONFIG_PARAVIRT_MMU selected by CONFIG_XEN_PV and CONFIG_LGUEST_GUEST. If no, I'd remove lguest support and just use CONFIG_XEN_HAS_PVMMU, in case nobody would like me to use CONFIG_PARAVIRT_MMU even if lguest isn't there any more. Juergen
Juergen Gross <jgross at suse.com> writes:> Lguest and Xen pv-guests are the only users of pv_mmu_ops (with the > one exception of the .exit_mmap member, which is being used by Xen > HVM-guests, too). > > As it is possible now to build a kernel without Xen pv-guest support > while keeping PVH and PVHVM support, I thought about putting most > pv_mmu_ops functions in #ifdef CONFIG_XEN_HAS_PVMMU sections.There is an ongoing work to enable PV TLB flushing for Hyper-V guests: http://driverdev.linuxdriverproject.org/pipermail/driverdev-devel/2017-April/104411.html it utilizes .flush_tlb_others member in pv_mmu_ops. hopefully, this work will be merged in 4.13. -- Vitaly
On 15/05/17 16:22, Vitaly Kuznetsov wrote:> Juergen Gross <jgross at suse.com> writes: > >> Lguest and Xen pv-guests are the only users of pv_mmu_ops (with the >> one exception of the .exit_mmap member, which is being used by Xen >> HVM-guests, too). >> >> As it is possible now to build a kernel without Xen pv-guest support >> while keeping PVH and PVHVM support, I thought about putting most >> pv_mmu_ops functions in #ifdef CONFIG_XEN_HAS_PVMMU sections. > > There is an ongoing work to enable PV TLB flushing for Hyper-V guests: > http://driverdev.linuxdriverproject.org/pipermail/driverdev-devel/2017-April/104411.html > > it utilizes .flush_tlb_others member in pv_mmu_ops. > > hopefully, this work will be merged in 4.13.Thanks for the information. I'll keep .flush_tlb_others member outside the #ifdef section. Juergen