On 07/02/20 23:35, Peter Xu wrote: > [This series is RFC because I don't have MIPS to compile and test] > > kvm_flush_remote_tlbs() can be arch-specific, by either: > > - Completely replace kvm_flush_remote_tlbs(), like ARM, who is the > only user of CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL so far > > - Doing something extra before kvm_flush_remote_tlbs(), like MIPS VZ > support, however still wants to have the common tlb flush to be part > of the process. Could refer to kvm_vz_flush_shadow_all(). Then in > MIPS it's awkward to flush remote TLBs: we'll need to call the mips > hooks. > > It's awkward to have different ways to specialize this procedure, > especially MIPS cannot use the genenal interface which is quite a > pity. It's good to make it a common interface. > > This patch series removes the 2nd MIPS usage above, and let it also > use the common kvm_flush_remote_tlbs() interface. It should be > suggested that we always keep kvm_flush_remote_tlbs() be a common > entrance for tlb flushing on all archs. > > This idea comes from the reading of Sean's patchset on dynamic memslot > allocation, where a new dirty log specific hook is added for flushing > TLBs only for the MIPS code [1]. With this patchset, logically the > new hook in that patch can be dropped so we can directly use > kvm_flush_remote_tlbs(). > > TODO: We can even extend another common interface for ranged TLB, but > let's see how we think about this series first. > > Any comment is welcomed, thanks. > > Peter Xu (4): > KVM: Provide kvm_flush_remote_tlbs_common() > KVM: MIPS: Drop flush_shadow_memslot() callback > KVM: MIPS: Replace all the kvm_flush_remote_tlbs() references > KVM: MIPS: Define arch-specific kvm_flush_remote_tlbs() > > arch/mips/include/asm/kvm_host.h | 7 ------- > arch/mips/kvm/Kconfig | 1 + > arch/mips/kvm/mips.c | 22 ++++++++++------------ > arch/mips/kvm/trap_emul.c | 15 +-------------- > arch/mips/kvm/vz.c | 14 ++------------ > include/linux/kvm_host.h | 1 + > virt/kvm/kvm_main.c | 10 ++++++++-- > 7 files changed, 23 insertions(+), 47 deletions(-) > Compile-tested and queued. MIPS folks, I see that arch/mips/kvm/mmu.c uses pud_index, so it's not clear to me if it's meant to only work if CONFIG_PGTABLE_LEVELS=4 or it's just bit rot. Should I add a "depends on PGTABLE_LEVEL=4" to arch/mips/Kconfig? Paolo
