Convert stage2_map_walker_try_leaf() to use the new break-before-make
helpers, thereby making the handler parallel-aware. As before, avoid the
break-before-make if recreating the existing mapping. Additionally,
retry execution if another vCPU thread is modifying the same PTE.
Signed-off-by: Oliver Upton <oliver.up...@linux.dev>
---
arch/arm64/kvm/hyp/pgtable.c | 26 ++++++++++++--------------
1 file changed, 12 insertions(+), 14 deletions(-)
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 71ae96608752..de1d352657d0 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -829,18 +829,17 @@ static int stage2_map_walker_try_leaf(u64 addr, u64 end,
u32 level,
else
new = kvm_init_invalid_leaf_owner(data->owner_id);
- if (stage2_pte_is_counted(old)) {
- /*
- * Skip updating the PTE if we are trying to recreate the exact
- * same mapping or only change the access permissions. Instead,
- * the vCPU will exit one more time from guest if still needed
- * and then go through the path of relaxing permissions.
- */
- if (!stage2_pte_needs_update(old, new))
- return -EAGAIN;
+ /*
+ * Skip updating the PTE if we are trying to recreate the exact
+ * same mapping or only change the access permissions. Instead,
+ * the vCPU will exit one more time from guest if still needed
+ * and then go through the path of relaxing permissions.
+ */
+ if (!stage2_pte_needs_update(old, new))
+ return -EAGAIN;
- stage2_put_pte(ptep, data->mmu, addr, level, mm_ops);
- }
+ if (!stage2_try_break_pte(ptep, old, addr, level, data))
+ return -EAGAIN;
/* Perform CMOs before installation of the guest stage-2 PTE */
if (mm_ops->dcache_clean_inval_poc && stage2_pte_cacheable(pgt, new))
@@ -850,9 +849,8 @@ static int stage2_map_walker_try_leaf(u64 addr, u64 end,
u32 level,
if (mm_ops->icache_inval_pou && stage2_pte_executable(new))
mm_ops->icache_inval_pou(kvm_pte_follow(new, mm_ops), granule);
- smp_store_release(ptep, new);
- if (stage2_pte_is_counted(new))
- mm_ops->get_page(ptep);
+ stage2_make_pte(ptep, old, new, data);
+
if (kvm_phys_is_valid(phys))
data->phys += granule;
return 0;
--
2.37.2.672.g94769d06f0-goog
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
