[PATCH v2] KVM: arm64: Add endian casting to kvm_swap_s[12]_desc()

[PATCH v2] KVM: arm64: Add endian casting to kvm_swap_s[12]_desc()

[Marc Zyngier]

Keep sparse quiet by explicitly casting endianness conversion
when swapping S1 and S2 descriptors.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202511260246.JQDGsQKa-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202511260344.9XehvH5Q-lkp@intel.com/
Fixes: c59ca4b5b0c3f ("KVM: arm64: Implement HW access flag management in stage-1 SW PTW")
Fixes: 39db933ba67f8 ("KVM: arm64: nv: Implement HW access flag management in stage-2 SW PTW")
Signed-off-by: Marc Zyngier <maz@kernel.org>
---

Notes:
    Missed the S2 issue the first time, and only caught up with
    the robot's email.

 arch/arm64/kvm/at.c     | 8 ++++----
 arch/arm64/kvm/nested.c | 8 ++++----
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c
index f774a02d9393b..d25fef0f66e21 100644
--- a/arch/arm64/kvm/at.c
+++ b/arch/arm64/kvm/at.c
@@ -386,11 +386,11 @@ static int kvm_swap_s1_desc(struct kvm_vcpu *vcpu, u64 pa, u64 old, u64 new,
 			    struct s1_walk_info *wi)
 {
 	if (wi->be) {
-		old = cpu_to_be64(old);
-		new = cpu_to_be64(new);
+		old = (__force u64)cpu_to_be64(old);
+		new = (__force u64)cpu_to_be64(new);
 	} else {
-		old = cpu_to_le64(old);
-		new = cpu_to_le64(new);
+		old = (__force u64)cpu_to_le64(old);
+		new = (__force u64)cpu_to_le64(new);
 	}
 
 	return __kvm_at_swap_desc(vcpu->kvm, pa, old, new);
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index c3033d1fe718c..cdeeb8f09e722 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -224,11 +224,11 @@ static int swap_guest_s2_desc(struct kvm_vcpu *vcpu, phys_addr_t pa, u64 old, u6
 			      struct s2_walk_info *wi)
 {
 	if (wi->be) {
-		old = cpu_to_be64(old);
-		new = cpu_to_be64(new);
+		old = (__force u64)cpu_to_be64(old);
+		new = (__force u64)cpu_to_be64(new);
 	} else {
-		old = cpu_to_le64(old);
-		new = cpu_to_le64(new);
+		old = (__force u64)cpu_to_le64(old);
+		new = (__force u64)cpu_to_le64(new);
 	}
 
 	return __kvm_at_swap_desc(vcpu->kvm, pa, old, new);
-- 
2.47.3

Re: [PATCH v2] KVM: arm64: Add endian casting to kvm_swap_s[12]_desc()

[Oliver Upton]

On Tue, 25 Nov 2025 20:48:48 +0000, Marc Zyngier wrote:
> Keep sparse quiet by explicitly casting endianness conversion
> when swapping S1 and S2 descriptors.
> 
> 

Applied to next, thanks!

[1/1] KVM: arm64: Add endian casting to kvm_swap_s[12]_desc()
      https://git.kernel.org/kvmarm/kvmarm/c/1625e20fc198

--
Best,
Oliver