On 07/11/2022 17:58, Punit Agrawal wrote:
Usama Arif <usama.arif@xxxxxxxxxxxxx> writes:
Add a new SMCCC compatible hypercalls for PV lock features:
ARM_SMCCC_KVM_FUNC_PV_LOCK: 0xC6000002
Also add the header file which defines the ABI for the paravirtualized
lock features we're about to add.
Signed-off-by: Zengruan Ye <yezengruan@xxxxxxxxxx>
Signed-off-by: Usama Arif <usama.arif@xxxxxxxxxxxxx>
---
arch/arm64/include/asm/pvlock-abi.h | 17 +++++++++++++++++
include/linux/arm-smccc.h | 8 ++++++++
tools/include/linux/arm-smccc.h | 8 ++++++++
3 files changed, 33 insertions(+)
create mode 100644 arch/arm64/include/asm/pvlock-abi.h
diff --git a/arch/arm64/include/asm/pvlock-abi.h b/arch/arm64/include/asm/pvlock-abi.h
new file mode 100644
index 000000000000..3f4574071679
--- /dev/null
+++ b/arch/arm64/include/asm/pvlock-abi.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright(c) 2019 Huawei Technologies Co., Ltd
+ * Author: Zengruan Ye <yezengruan@xxxxxxxxxx>
+ * Usama Arif <usama.arif@xxxxxxxxxxxxx>
+ */
+
+#ifndef __ASM_PVLOCK_ABI_H
+#define __ASM_PVLOCK_ABI_H
+
+struct pvlock_vcpu_state {
+ __le64 preempted;
+ /* Structure must be 64 byte aligned, pad to that size */
+ u8 padding[56];
+} __packed;
For structure alignment, I'd have expected to see the use of "aligned"
attribute. Is there any benefit in using padding to achieve alignment?
Just made it consistent with pvclock-abi.h. If its more appropriate, can
change to aligned in next patchset:
diff --git a/arch/arm64/include/asm/pvlock-abi.h
b/arch/arm64/include/asm/pvlock-abi.h
index 3f4574071679..bacec4cb927a 100644
--- a/arch/arm64/include/asm/pvlock-abi.h
+++ b/arch/arm64/include/asm/pvlock-abi.h
@@ -11,7 +11,6 @@
struct pvlock_vcpu_state {
__le64 preempted;
/* Structure must be 64 byte aligned, pad to that size */
- u8 padding[56];
-} __packed;
+} __attribute__((aligned(64)));
[...]
