| Message ID | 20221104062105.4119003-3-usama.arif@bytedance.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: implement vcpu_is_preempted check | expand |
Usama Arif <usama.arif@bytedance.com> 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@huawei.com> > Signed-off-by: Usama Arif <usama.arif@bytedance.com> > --- > 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@huawei.com> > + * Usama Arif <usama.arif@bytedance.com> > + */ > + > +#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? [...]
On 07/11/2022 17:58, Punit Agrawal wrote: > Usama Arif <usama.arif@bytedance.com> 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@huawei.com> >> Signed-off-by: Usama Arif <usama.arif@bytedance.com> >> --- >> 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@huawei.com> >> + * Usama Arif <usama.arif@bytedance.com> >> + */ >> + >> +#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))); > [...]
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@huawei.com> + * Usama Arif <usama.arif@bytedance.com> + */ + +#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; + +#endif diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h index 220c8c60e021..104c10035b10 100644 --- a/include/linux/arm-smccc.h +++ b/include/linux/arm-smccc.h @@ -112,6 +112,7 @@ /* KVM "vendor specific" services */ #define ARM_SMCCC_KVM_FUNC_FEATURES 0 #define ARM_SMCCC_KVM_FUNC_PTP 1 +#define ARM_SMCCC_KVM_FUNC_PV_LOCK 2 #define ARM_SMCCC_KVM_FUNC_FEATURES_2 127 #define ARM_SMCCC_KVM_NUM_FUNCS 128 @@ -151,6 +152,13 @@ ARM_SMCCC_OWNER_STANDARD_HYP, \ 0x21) +/* Paravirtualised lock calls */ +#define ARM_SMCCC_VENDOR_HYP_KVM_PV_LOCK_FUNC_ID \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_64, \ + ARM_SMCCC_OWNER_VENDOR_HYP, \ + ARM_SMCCC_KVM_FUNC_PV_LOCK) + /* TRNG entropy source calls (defined by ARM DEN0098) */ #define ARM_SMCCC_TRNG_VERSION \ ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ diff --git a/tools/include/linux/arm-smccc.h b/tools/include/linux/arm-smccc.h index 63ce9bebccd3..c21e539c0228 100644 --- a/tools/include/linux/arm-smccc.h +++ b/tools/include/linux/arm-smccc.h @@ -111,6 +111,7 @@ /* KVM "vendor specific" services */ #define ARM_SMCCC_KVM_FUNC_FEATURES 0 #define ARM_SMCCC_KVM_FUNC_PTP 1 +#define ARM_SMCCC_KVM_FUNC_PV_LOCK 2 #define ARM_SMCCC_KVM_FUNC_FEATURES_2 127 #define ARM_SMCCC_KVM_NUM_FUNCS 128 @@ -150,6 +151,13 @@ ARM_SMCCC_OWNER_STANDARD_HYP, \ 0x21) +/* Paravirtualised lock calls */ +#define ARM_SMCCC_VENDOR_HYP_KVM_PV_LOCK_FUNC_ID \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_64, \ + ARM_SMCCC_OWNER_VENDOR_HYP, \ + ARM_SMCCC_KVM_FUNC_PV_LOCK) + /* TRNG entropy source calls (defined by ARM DEN0098) */ #define ARM_SMCCC_TRNG_VERSION \ ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \