KVM: arm64: pkvm: Use the mm_ops indirection for cache maintenance

BugLink: https://bugs.launchpad.net/bugs/1959879
[ Upstream commit 094d00f8ca58c5d29b25e23b4daaed1ff1f13b41 ]

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.

Fixes: 25aa28691bb9 ("KVM: arm64: Move guest CMOs to the fault handlers")
Reviewed-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220114125038.1336965-1-maz@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index f8ceebe4982eb130b884800bfea771cd1353d4db..4c77ff556f0ae90cb44adbf918c899ddb6e6f912 100644 (file)
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -921,13 +921,9 @@ 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);
@@ -1089,15 +1085,13 @@ 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;
 }