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Subject[PATCH v2] KVM: arm64: fix compile error because of shift overflow
Date
Using GENMASK() to generate the masks of device type and device id, it makes
code unambiguous, also it can fix the following fix compile error because of
shift overflow when using low verison gcc(mine version is 7.5):

In function ‘kvm_vm_ioctl_set_device_addr.isra.38’,
inlined from ‘kvm_arch_vm_ioctl’ at arch/arm64/kvm/arm.c:1454:10:
././include/linux/compiler_types.h:354:38: error: call to ‘__compiletime_assert_599’ \
declared with attribute error: FIELD_GET: mask is not constant
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)

Fixes: 9f968c9266aa ("KVM: arm64: vgic-v2: Add helper for legacy dist/cpuif base address setting")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
v2:
Using GENMASK() to generate the masks.
---
arch/arm64/include/uapi/asm/kvm.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 3bb134355874..5e7dfaf76ec1 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -75,9 +75,9 @@ struct kvm_regs {

/* KVM_ARM_SET_DEVICE_ADDR ioctl id encoding */
#define KVM_ARM_DEVICE_TYPE_SHIFT 0
-#define KVM_ARM_DEVICE_TYPE_MASK (0xffff << KVM_ARM_DEVICE_TYPE_SHIFT)
+#define KVM_ARM_DEVICE_TYPE_MASK GENMASK(15, KVM_ARM_DEVICE_TYPE_SHIFT)
#define KVM_ARM_DEVICE_ID_SHIFT 16
-#define KVM_ARM_DEVICE_ID_MASK (0xffff << KVM_ARM_DEVICE_ID_SHIFT)
+#define KVM_ARM_DEVICE_ID_MASK GENMASK(31, KVM_ARM_DEVICE_ID_SHIFT)

/* Supported device IDs */
#define KVM_ARM_DEVICE_VGIC_V2 0
--
2.25.1
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