Unverified Commit e21659e4 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!13822 v4 arm64: Add xcall/xint support 

Merge Pull Request from: @ci-robot 
 
PR sync from: Jinjie Ruan <ruanjinjie@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/XC73EQZ6YI2QHOAREFB3U4OKHP4KYZBD/ 
Add xcall/xint support for arm64.

Changes in v4:
- Fix the missing Comma about check_xint_pre_kernel_entry.
- When CONFIG_SECURITY_FEATURE_BYPASS not set, ret_to_user/kernel
  instead of "kernel_exit \el" for xcall/xint.

Changes in v3:
- Fix few typos in entry.S.

Changes in v2:
- Avoid enable xint without GICv3 enabled.
- Fix cpucap KABI break.
- Fix missing openeuler_defconfig update.
- Correct the marco control for SECURITY_FEATURE_BYPASS in entry.S.

Jinjie Ruan (2):
  arm64: Introduce Xint software solution
  arm64: Add debugfs dir for xint

Yipeng Zou (2):
  arm64: Introduce xcall a faster svc exception handling
  arm64: Faster SVC exception handler with xcall


-- 
2.34.1
 
https://gitee.com/openeuler/release-management/issues/IB6JLE 
 
Link:https://gitee.com/openeuler/kernel/pulls/13822

 

Reviewed-by: default avatarXie XiuQi <xiexiuqi@huawei.com>
Reviewed-by: default avatarZhang Jianhua <chris.zjh@huawei.com>
Reviewed-by: default avatarLiu Chao <liuchao173@huawei.com>
Signed-off-by: default avatarZhang Peng <zhangpeng362@huawei.com>
parents 4a0359af 63f9ef21

arch/Kconfig

+64 −0
Original line number Diff line number Diff line
@@ -1530,4 +1530,68 @@ config FUNCTION_ALIGNMENT 
	default 4 if FUNCTION_ALIGNMENT_4B

	default 0



config ARCH_SUPPORTS_FAST_SYSCALL

	bool



config FAST_SYSCALL

	bool "Fast Syscall support"

	depends on ARCH_SUPPORTS_FAST_SYSCALL

	default n

	help

	  This enable support Fast syscall feature.

	  The svc exception handling process, which includes auxiliary

	  functions for debug/trace and core functions like

	  KPTI, has been identified as overly "lengthy".

	  This inefficiency is particularly noticeable in short syscalls

	  such as lseek() and getpid(), where the syscall function itself

	  comprises a small percentage of the total instructions executed.

	  To address this, we introduce the concept of fast syscall, a fast svc

	  exception handling path that only considers necessary features

	  such as security, context saving, and recovery.



config ARCH_SUPPORTS_FAST_IRQ

	bool



config FAST_IRQ

	bool "Fast irq support"

	depends on ARCH_SUPPORTS_FAST_IRQ

	default n

	help

	  The irq handling process, which includes auxiliary

	  functions for debug/trace and core functions like

	  KPTI, interrupt time record, interrupt processing as

	  a random number source, interrupt affinity

	  modification and interrupt processing race, as well as

	  spurious and unhandled interrupt debugging, has been

	  identified as overly "lengthy".

	  To address this, we introduce the concept of fast irq,

	  a fast interrupt handling path that only considers

	  necessary features such as security, context saving

	  and recovery, which adds an lightweight interrupt processing

	  framework for latency-sensitive interrupts.



config DEBUG_FEATURE_BYPASS

	bool "Bypass debug feature in fast syscall"

	depends on FAST_SYSCALL || FAST_IRQ

	default y

	help

	  This to bypass debug feature in fast syscall.

	  The svc exception handling process, which includes auxiliary

	  functions for debug/trace and core functions like

	  KPTI, has been identified as overly "lengthy".

	  In fast syscall we only considers necessary features.

	  Disable this config to keep debug feature in fast syscall.



config SECURITY_FEATURE_BYPASS

	bool "Bypass security feature in fast syscall"

	depends on FAST_SYSCALL || FAST_IRQ

	default y

	help

	  This to bypass security feature in fast syscall.

	  The svc exception handling process, which includes auxiliary

	  functions for debug/trace and core functions like

	  KPTI, has been identified as overly "lengthy".

	  In fast syscall we only considers necessary features.

	  Disable this config to keep security feature in fast syscall.



endmenu

arch/arm64/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -262,6 +262,8 @@ config ARM64 
	select TRACE_IRQFLAGS_SUPPORT

	select TRACE_IRQFLAGS_NMI_SUPPORT

	select HAVE_SOFTIRQ_ON_OWN_STACK

	select ARCH_SUPPORTS_FAST_SYSCALL if !ARM64_MTE && !KASAN_HW_TAGS

	select ARCH_SUPPORTS_FAST_IRQ if ARM_GIC_V3 && !ARM64_MTE && !KASAN_HW_TAGS

	help

	  ARM 64-bit (AArch64) Linux support.

arch/arm64/configs/openeuler_defconfig

+4 −0
Original line number Diff line number Diff line
@@ -891,6 +891,10 @@ CONFIG_HAVE_GCC_PLUGINS=y 
CONFIG_FUNCTION_ALIGNMENT_4B=y

CONFIG_FUNCTION_ALIGNMENT_8B=y

CONFIG_FUNCTION_ALIGNMENT=8

CONFIG_ARCH_SUPPORTS_FAST_SYSCALL=y

# CONFIG_FAST_SYSCALL is not set

CONFIG_ARCH_SUPPORTS_FAST_IRQ=y

# CONFIG_FAST_IRQ is not set

# end of General architecture-dependent options



CONFIG_RT_MUTEXES=y

arch/arm64/kernel/asm-offsets.c

+3 −0
Original line number Diff line number Diff line
@@ -28,6 +28,9 @@ 


int main(void)

{

#ifdef CONFIG_FAST_SYSCALL

	DEFINE(TSK_XCALL,		offsetof(struct task_struct, xcall_enable));

#endif

  DEFINE(TSK_ACTIVE_MM,		offsetof(struct task_struct, active_mm));

  BLANK();

  DEFINE(TSK_TI_CPU,		offsetof(struct task_struct, thread_info.cpu));

arch/arm64/kernel/cpufeature.c

+54 −0
Original line number Diff line number Diff line
@@ -2375,6 +2375,44 @@ static void mpam_extra_caps(void) 
		__enable_mpam_hcr();

}



#ifdef CONFIG_FAST_SYSCALL

static bool is_xcall_support;

static int __init xcall_setup(char *str)

{

	is_xcall_support = true;

	return 1;

}

__setup("xcall", xcall_setup);



bool fast_syscall_enabled(void)

{

	return is_xcall_support;

}



static bool has_xcall_support(const struct arm64_cpu_capabilities *entry, int __unused)

{

	return is_xcall_support;

}

#endif



#ifdef CONFIG_FAST_IRQ

bool is_xint_support;

static int __init xint_setup(char *str)

{

	if (!cpus_have_cap(ARM64_HAS_GIC_CPUIF_SYSREGS))

		return 1;



	is_xint_support = true;

	return 1;

}

__setup("xint", xint_setup);



static bool has_xint_support(const struct arm64_cpu_capabilities *entry, int __unused)

{

	return is_xint_support;

}

#endif



static const struct arm64_cpu_capabilities arm64_features[] = {

	{

		.capability = ARM64_ALWAYS_BOOT,
@@ -2891,6 +2929,22 @@ static const struct arm64_cpu_capabilities arm64_features[] = { 
		.matches = has_cpuid_feature,

		ARM64_CPUID_FIELDS(ID_AA64MMFR1_EL1, TWED, IMP)

	},

#endif

#ifdef CONFIG_FAST_SYSCALL

	{

		.desc = "Xcall Support",

		.capability = ARM64_HAS_XCALL,

		.type = ARM64_CPUCAP_SYSTEM_FEATURE,

		.matches = has_xcall_support,

	},

#endif

#ifdef CONFIG_FAST_IRQ

	{

		.desc = "Xint Support",

		.capability = ARM64_HAS_XINT,

		.type = ARM64_CPUCAP_SYSTEM_FEATURE,

		.matches = has_xint_support,

	},

#endif

	{},

};