Messages in this thread Patch in this message | | | Date | Thu, 30 Mar 2023 01:19:06 +0000 | From | Oliver Upton <> | Subject | Re: [PATCH v2 2/7] KVM: arm64: Add FEAT_TLBIRANGE support |
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On Mon, Feb 06, 2023 at 05:23:35PM +0000, Raghavendra Rao Ananta wrote: > Define a generic function __kvm_tlb_flush_range() to > invalidate the TLBs over a range of addresses. The > implementation accepts 'op' as a generic TLBI operation. > Upcoming patches will use this to implement IPA based > TLB invalidations (ipas2e1is). > > If the system doesn't support FEAT_TLBIRANGE, the > implementation falls back to flushing the pages one by one > for the range supplied. > > Signed-off-by: Raghavendra Rao Ananta <rananta@google.com> > --- > arch/arm64/include/asm/kvm_asm.h | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h > index 43c3bc0f9544d..995ff048e8851 100644 > --- a/arch/arm64/include/asm/kvm_asm.h > +++ b/arch/arm64/include/asm/kvm_asm.h > @@ -221,6 +221,24 @@ DECLARE_KVM_NVHE_SYM(__per_cpu_end); > DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs); > #define __bp_harden_hyp_vecs CHOOSE_HYP_SYM(__bp_harden_hyp_vecs) > > +#define __kvm_tlb_flush_range(op, mmu, start, end, level, tlb_level) do { \ > + unsigned long pages, stride; \ > + \ > + stride = kvm_granule_size(level); \
Hmm... There's a rather subtle and annoying complication here that I don't believe is handled.
Similar to what I said in the last spin of the series, there is no guarantee that a range of IPAs is mapped at the exact same level throughout. Dirty logging and memslots that aren't hugepage aligned could lead to a mix of mapping levels being used within a range of the IPA space.
> + start = round_down(start, stride); \ > + end = round_up(end, stride); \ > + pages = (end - start) >> PAGE_SHIFT; \ > + \ > + if ((!system_supports_tlb_range() && \ > + (end - start) >= (MAX_TLBI_OPS * stride)) || \
Doesn't checking for TLBIRANGE above eliminate the need to test against MAX_TLBI_OPS?
> + pages >= MAX_TLBI_RANGE_PAGES) { \ > + __kvm_tlb_flush_vmid(mmu); \ > + break; \ > + } \ > + \ > + __flush_tlb_range_op(op, start, pages, stride, 0, tlb_level, false); \ > +} while (0) > + > extern void __kvm_flush_vm_context(void); > extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu); > extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa, > -- > 2.39.1.519.gcb327c4b5f-goog > >
-- Thanks, Oliver
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