On 4/9/23 2:29 PM, Ricardo Koller wrote:
Add two flags to kvm_pgtable_visit_ctx, KVM_PGTABLE_WALK_SKIP_BBM and
KVM_PGTABLE_WALK_SKIP_CMO, to indicate that the walk should not
perform break-before-make (BBM) nor cache maintenance operations
(CMO). This will be used by a future commit to create unlinked tables
not accessible to the HW page-table walker.
Signed-off-by: Ricardo Koller <ricarkol@xxxxxxxxxx>
Reviewed-by: Shaoqin Huang <shahuang@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_pgtable.h | 8 ++++++
arch/arm64/kvm/hyp/pgtable.c | 37 +++++++++++++++++++---------
2 files changed, 34 insertions(+), 11 deletions(-)
Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index 26a4293726c14..3f2d43ba2b628 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h
@@ -195,6 +195,12 @@ typedef bool (*kvm_pgtable_force_pte_cb_t)(u64 addr, u64 end,
* with other software walkers.
* @KVM_PGTABLE_WALK_HANDLE_FAULT: Indicates the page-table walk was
* invoked from a fault handler.
+ * @KVM_PGTABLE_WALK_SKIP_BBM_TLBI: Visit and update table entries
+ * without Break-before-make's
+ * TLB invalidation.
+ * @KVM_PGTABLE_WALK_SKIP_CMO: Visit and update table entries
+ * without Cache maintenance
+ * operations required.
*/
enum kvm_pgtable_walk_flags {
KVM_PGTABLE_WALK_LEAF = BIT(0),
@@ -202,6 +208,8 @@ enum kvm_pgtable_walk_flags {
KVM_PGTABLE_WALK_TABLE_POST = BIT(2),
KVM_PGTABLE_WALK_SHARED = BIT(3),
KVM_PGTABLE_WALK_HANDLE_FAULT = BIT(4),
+ KVM_PGTABLE_WALK_SKIP_BBM_TLBI = BIT(5),
+ KVM_PGTABLE_WALK_SKIP_CMO = BIT(6),
};
struct kvm_pgtable_visit_ctx {
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index a3246d6cddec7..633679ee3c49a 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -62,6 +62,16 @@ struct kvm_pgtable_walk_data {
u64 end;
};
+static bool kvm_pgtable_walk_skip_bbm_tlbi(const struct kvm_pgtable_visit_ctx *ctx)
+{
+ return unlikely(ctx->flags & KVM_PGTABLE_WALK_SKIP_BBM_TLBI);
+}
+
+static bool kvm_pgtable_walk_skip_cmo(const struct kvm_pgtable_visit_ctx *ctx)
+{
+ return unlikely(ctx->flags & KVM_PGTABLE_WALK_SKIP_CMO);
+}
+
static bool kvm_phys_is_valid(u64 phys)
{
return phys < BIT(id_aa64mmfr0_parange_to_phys_shift(ID_AA64MMFR0_EL1_PARANGE_MAX));
@@ -741,14 +751,17 @@ static bool stage2_try_break_pte(const struct kvm_pgtable_visit_ctx *ctx,
if (!stage2_try_set_pte(ctx, KVM_INVALID_PTE_LOCKED))
return false;
- /*
- * Perform the appropriate TLB invalidation based on the evicted pte
- * value (if any).
- */
- if (kvm_pte_table(ctx->old, ctx->level))
- kvm_call_hyp(__kvm_tlb_flush_vmid, mmu);
- else if (kvm_pte_valid(ctx->old))
- kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, ctx->addr, ctx->level);
+ if (!kvm_pgtable_walk_skip_bbm_tlbi(ctx)) {
+ /*
+ * Perform the appropriate TLB invalidation based on the
+ * evicted pte value (if any).
+ */
+ if (kvm_pte_table(ctx->old, ctx->level))
+ kvm_call_hyp(__kvm_tlb_flush_vmid, mmu);
+ else if (kvm_pte_valid(ctx->old))
+ kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu,
+ ctx->addr, ctx->level);
+ }
if (stage2_pte_is_counted(ctx->old))
mm_ops->put_page(ctx->ptep);
@@ -832,11 +845,13 @@ static int stage2_map_walker_try_leaf(const struct kvm_pgtable_visit_ctx *ctx,
return -EAGAIN;
/* Perform CMOs before installation of the guest stage-2 PTE */
- if (mm_ops->dcache_clean_inval_poc && stage2_pte_cacheable(pgt, new))
+ if (!kvm_pgtable_walk_skip_cmo(ctx) && mm_ops->dcache_clean_inval_poc &&
+ stage2_pte_cacheable(pgt, new))
mm_ops->dcache_clean_inval_poc(kvm_pte_follow(new, mm_ops),
- granule);
+ granule);
- if (mm_ops->icache_inval_pou && stage2_pte_executable(new))
+ if (!kvm_pgtable_walk_skip_cmo(ctx) && mm_ops->icache_inval_pou &&
+ stage2_pte_executable(new))
mm_ops->icache_inval_pou(kvm_pte_follow(new, mm_ops), granule);
stage2_make_pte(ctx, new);
