On Friday 14 Jan 2022 at 12:50:38 (+0000), Marc Zyngier wrote:
> CMOs issued from EL2 cannot directly use the kernel helpers,
> as EL2 doesn't have a mapping of the guest pages. Oops.
>
> Instead, use the mm_ops indirection to use helpers that will
> perform a mapping at EL2 and allow the CMO to be effective.
Right, we were clearly lucky not to use those paths at EL2 _yet_, but
that's going to change soon and this is better for consistency, so:
Reviewed-by: Quentin Perret <qperret@xxxxxxxxxx>
> Fixes: 25aa28691bb9 ("KVM: arm64: Move guest CMOs to the fault handlers")
> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
> ---
> arch/arm64/kvm/hyp/pgtable.c | 18 ++++++------------
> 1 file changed, 6 insertions(+), 12 deletions(-)
>
> diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
> index 844a6f003fd5..2cb3867eb7c2 100644
> --- a/arch/arm64/kvm/hyp/pgtable.c
> +++ b/arch/arm64/kvm/hyp/pgtable.c
> @@ -983,13 +983,9 @@ static int stage2_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
> */
> stage2_put_pte(ptep, mmu, addr, level, mm_ops);
>
> - if (need_flush) {
> - kvm_pte_t *pte_follow = kvm_pte_follow(pte, mm_ops);
> -
> - dcache_clean_inval_poc((unsigned long)pte_follow,
> - (unsigned long)pte_follow +
> - kvm_granule_size(level));
> - }
> + if (need_flush && mm_ops->dcache_clean_inval_poc)
> + mm_ops->dcache_clean_inval_poc(kvm_pte_follow(pte, mm_ops),
> + kvm_granule_size(level));
>
> if (childp)
> mm_ops->put_page(childp);
> @@ -1151,15 +1147,13 @@ static int stage2_flush_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
> struct kvm_pgtable *pgt = arg;
> struct kvm_pgtable_mm_ops *mm_ops = pgt->mm_ops;
> kvm_pte_t pte = *ptep;
> - kvm_pte_t *pte_follow;
>
> if (!kvm_pte_valid(pte) || !stage2_pte_cacheable(pgt, pte))
> return 0;
>
> - pte_follow = kvm_pte_follow(pte, mm_ops);
> - dcache_clean_inval_poc((unsigned long)pte_follow,
> - (unsigned long)pte_follow +
> - kvm_granule_size(level));
> + if (mm_ops->dcache_clean_inval_poc)
> + mm_ops->dcache_clean_inval_poc(kvm_pte_follow(pte, mm_ops),
> + kvm_granule_size(level));
> return 0;
> }
>
> --
> 2.30.2
>
_______________________________________________
kvmarm mailing list
kvmarm@xxxxxxxxxxxxxxxxxxxxx
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
