Patch "KVM: arm64: pkvm: Use the mm_ops indirection for cache maintenance" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

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

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     kvm-arm64-pkvm-use-the-mm_ops-indirection-for-cache-.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 41765f8db2c68d1a74aa3fb495b8411b596046ab
Author: Marc Zyngier <maz@xxxxxxxxxx>
Date:   Fri Jan 14 08:57:58 2022 +0000

    KVM: arm64: pkvm: Use the mm_ops indirection for cache maintenance
    
    [ 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@xxxxxxxxxx>
    Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20220114125038.1336965-1-maz@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index f8ceebe4982eb..4c77ff556f0ae 100644
--- 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;
 }