| Message ID | 20240325185158.8565-3-will@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: TLBI fixes for the pgtable code | expand |
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@redhat.com> > Cc: Marc Zyngier <maz@kernel.org> > Cc: Quentin Perret <qperret@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@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.
On Tue, Mar 26, 2024 at 01:37:43AM -0700, Oliver Upton wrote: > 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@redhat.com> > > Cc: Marc Zyngier <maz@kernel.org> > > Cc: Quentin Perret <qperret@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@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. Heh, well I'd argue that bug already exists in the case that TLB invalidation isn't deferred, so that's why I kept them separate. But happy to fold in if you prefer. Main thing is to get it fixed! Will
On Tue, Mar 26, 2024 at 09:34:16AM +0000, Will Deacon wrote: > On Tue, Mar 26, 2024 at 01:37:43AM -0700, Oliver Upton wrote: > > 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@redhat.com> > > > Cc: Marc Zyngier <maz@kernel.org> > > > Cc: Quentin Perret <qperret@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@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. > > Heh, well I'd argue that bug already exists in the case that TLB > invalidation isn't deferred, so that's why I kept them separate. Ah, that's fine, when I was looking at this earlier I thought this patch was getting blamed on LPA2, although patch #1 needs to go a bit further back. I'm fine with this as is, but maybe add a blurb to the changelog hinting that the level hint is BS but will be fixed in a future change.
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); + } else if (!stage2_unmap_defer_tlb_flush(pgt)) { + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, ctx->addr, + ctx->level); } }
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@redhat.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@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@kernel.org> --- arch/arm64/kvm/hyp/pgtable.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)