On Wed, Mar 29, 2023 at 5:53 PM Oliver Upton <oliver.upton@xxxxxxxxx> wrote: > > On Mon, Feb 06, 2023 at 05:23:37PM +0000, Raghavendra Rao Ananta wrote: > > Implement kvm_arch_flush_remote_tlbs_range() for arm64, > > such that it can utilize the TLBI range based instructions > > if supported. > > > > Signed-off-by: Raghavendra Rao Ananta <rananta@xxxxxxxxxx> > > --- > > arch/arm64/include/asm/kvm_host.h | 3 +++ > > arch/arm64/kvm/mmu.c | 15 +++++++++++++++ > > 2 files changed, 18 insertions(+) > > > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > > index dee530d75b957..211fab0c1de74 100644 > > --- a/arch/arm64/include/asm/kvm_host.h > > +++ b/arch/arm64/include/asm/kvm_host.h > > @@ -1002,6 +1002,9 @@ struct kvm *kvm_arch_alloc_vm(void); > > #define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS > > int kvm_arch_flush_remote_tlbs(struct kvm *kvm); > > > > +#define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS_RANGE > > +int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, u64 pages); > > + > > static inline bool kvm_vm_is_protected(struct kvm *kvm) > > { > > return false; > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > > index e98910a8d0af6..409cb187f4911 100644 > > --- a/arch/arm64/kvm/mmu.c > > +++ b/arch/arm64/kvm/mmu.c > > @@ -91,6 +91,21 @@ int kvm_arch_flush_remote_tlbs(struct kvm *kvm) > > return 0; > > } > > > > +int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn, u64 pages) > > +{ > > + phys_addr_t start, end; > > + > > + if (!system_supports_tlb_range()) > > + return -EOPNOTSUPP; > > There's multiple layers of fallback throughout this series, as it would > appear that deep in __kvm_tlb_flush_range() you're blasting the whole > VMID if either the range is too large or the feature isn't supported. > > Is it possible to just normalize on a single spot to gate the use of > range-based invalidations? I have a slight preference for doing it deep > in the handler, as it keeps the upper layers of code a bit more > readable. > I was a little skeptical on this part, since the kvm_arch_flush_remote_tlbs_range() expects to return -EOPNOTSUPP if indeed there's no support. But I see your point. The if-else in kvm_pgtable_stage2_flush_range() seems redundant and I can simply manage this conditions inside __kvm_tlb_flush_range_vmid_ipa() itself, but I'll leave the kvm_arch_flush_remote_tlbs_range()'s implementation as is. Thoughts? Thank you. Raghavendra > > + start = start_gfn << PAGE_SHIFT; > > + end = (start_gfn + pages) << PAGE_SHIFT; > > + > > + kvm_call_hyp(__kvm_tlb_flush_range_vmid_ipa, &kvm->arch.mmu, > > + start, end, KVM_PGTABLE_MAX_LEVELS - 1, 0); > > + return 0; > > +} > > + > > static bool kvm_is_device_pfn(unsigned long pfn) > > { > > return !pfn_is_map_memory(pfn); > > -- > > 2.39.1.519.gcb327c4b5f-goog > > > > > > -- > Thanks, > Oliver