On Thu, 27 Jul 2023 13:47:06 +0100,
Marc Zyngier <maz@xxxxxxxxxx> wrote:
>
> On Sat, 22 Jul 2023 03:22:47 +0100,
> Raghavendra Rao Ananta <rananta@xxxxxxxxxx> wrote:
> >
> > Implement the helper kvm_tlb_flush_vmid_range() that acts
> > as a wrapper for range-based TLB invalidations. For the
> > given VMID, use the range-based TLBI instructions to do
> > the job or fallback to invalidating all the TLB entries.
> >
> > Signed-off-by: Raghavendra Rao Ananta <rananta@xxxxxxxxxx>
> > Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
> > Reviewed-by: Shaoqin Huang <shahuang@xxxxxxxxxx>
> > ---
> > arch/arm64/include/asm/kvm_pgtable.h | 10 ++++++++++
> > arch/arm64/kvm/hyp/pgtable.c | 20 ++++++++++++++++++++
> > 2 files changed, 30 insertions(+)
> >
> > diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
> > index 8294a9a7e566..5e8b1ff07854 100644
> > --- a/arch/arm64/include/asm/kvm_pgtable.h
> > +++ b/arch/arm64/include/asm/kvm_pgtable.h
> > @@ -754,4 +754,14 @@ enum kvm_pgtable_prot kvm_pgtable_stage2_pte_prot(kvm_pte_t pte);
> > * kvm_pgtable_prot format.
> > */
> > enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte);
> > +
> > +/**
> > + * kvm_tlb_flush_vmid_range() - Invalidate/flush a range of TLB entries
> > + *
> > + * @mmu: Stage-2 KVM MMU struct
> > + * @addr: The base Intermediate physical address from which to invalidate
> > + * @size: Size of the range from the base to invalidate
> > + */
> > +void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> > + phys_addr_t addr, size_t size);
> > #endif /* __ARM64_KVM_PGTABLE_H__ */
> > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
> > index aa740a974e02..5d14d5d5819a 100644
> > --- a/arch/arm64/kvm/hyp/pgtable.c
> > +++ b/arch/arm64/kvm/hyp/pgtable.c
> > @@ -670,6 +670,26 @@ static bool stage2_has_fwb(struct kvm_pgtable *pgt)
> > return !(pgt->flags & KVM_PGTABLE_S2_NOFWB);
> > }
> >
> > +void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> > + phys_addr_t addr, size_t size)
> > +{
> > + unsigned long pages, inval_pages;
> > +
> > + if (!system_supports_tlb_range()) {
> > + kvm_call_hyp(__kvm_tlb_flush_vmid, mmu);
> > + return;
> > + }
> > +
> > + pages = size >> PAGE_SHIFT;
> > + while (pages > 0) {
> > + inval_pages = min(pages, MAX_TLBI_RANGE_PAGES);
> > + kvm_call_hyp(__kvm_tlb_flush_vmid_range, mmu, addr, inval_pages);
> > +
> > + addr += inval_pages << PAGE_SHIFT;
> > + pages -= inval_pages;
> > + }
> > +}
> > +
>
> This really shouldn't live in pgtable.c. This code gets linked into
> the EL2 object. What do you think happens if, for some reason, this
> gets called *from EL2*?
Ah, actually, nothing too bad would happen, as we convert the
kvm_call_hyp() into a function call.
But still, we don't need two copies of this stuff, and it can live in
mmu.c.
M.
--
Without deviation from the norm, progress is not possible.
