[PATCH 2/3] KVM: arm64: Don't pass a TLBI level hint when zapping table entries
Oliver Upton
oliver.upton at linux.dev
Tue Mar 26 01:37:43 PDT 2024
On Mon, Mar 25, 2024 at 06:51:57PM +0000, Will Deacon wrote:
> The TLBI level hints are for leaf entries only, so take care not to pass
> them incorrectly after clearing a table entry.
>
> Cc: Gavin Shan <gshan at redhat.com>
> Cc: Marc Zyngier <maz at kernel.org>
> Cc: Quentin Perret <qperret at google.com>
> Fixes: 82bb02445de5 ("KVM: arm64: Implement kvm_pgtable_hyp_unmap() at EL2")
> Fixes: 6d9d2115c480 ("KVM: arm64: Add support for stage-2 map()/unmap() in generic page-table")
> Signed-off-by: Will Deacon <will at kernel.org>
> ---
> arch/arm64/kvm/hyp/pgtable.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
> index de0b667ba296..a40dafc43bb6 100644
> --- a/arch/arm64/kvm/hyp/pgtable.c
> +++ b/arch/arm64/kvm/hyp/pgtable.c
> @@ -528,7 +528,7 @@ static int hyp_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx,
>
> kvm_clear_pte(ctx->ptep);
> dsb(ishst);
> - __tlbi_level(vae2is, __TLBI_VADDR(ctx->addr, 0), ctx->level);
> + __tlbi_level(vae2is, __TLBI_VADDR(ctx->addr, 0), TLBI_TTL_UNKNOWN);
> } else {
> if (ctx->end - ctx->addr < granule)
> return -EINVAL;
> @@ -896,10 +896,12 @@ static void stage2_unmap_put_pte(const struct kvm_pgtable_visit_ctx *ctx,
> if (kvm_pte_valid(ctx->old)) {
> kvm_clear_pte(ctx->ptep);
>
> - if (!stage2_unmap_defer_tlb_flush(pgt) ||
> - kvm_pte_table(ctx->old, ctx->level)) {
> - kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu,
> - ctx->addr, ctx->level);
> + if (kvm_pte_table(ctx->old, ctx->level)) {
> + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, ctx->addr,
> + TLBI_TTL_UNKNOWN);
Ah, here it is! Can you add this invalidation to patch #1? Otherwise the
fix will intermediately introduce another bug, AFAICT.
Rest of the diff looks good.
--
Thanks,
Oliver
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