Re: [PATCH 29/36] cpuidle,xenpv: Make more PARAVIRT_XXL noinstr clean

["Srivatsa S. Bhat" <srivatsa@csail.mit.edu>]

com, Arnd Bergmann <arnd@arndb.de>, ulli.kroll@googlemail.com, vgupta@kernel.org, josh@joshtriplett.org, rostedt@goodmis.org, rcu@vger.kernel.org, bp@alien8.de, bcain@quicinc.com, tsbogend@alpha.franken.de, linux-parisc@vger.kernel.org, sudeep.holla@arm.com, shawnguo@kernel.org, davem@davemloft.net, dalias@libc.org, tony@atomide.com, amakhalov@vmware.com, bjorn.andersson@linaro.org, hpa@zytor.com, sparclinux@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-riscv@lists.infradead.org, anton.ivanov@cambridgegreys.com, jonas@southpole.se, yury.norov@gmail.com, richard@nod.at, x86@kernel.org, linux@armlinux.org.uk, mingo@redhat.com, aou@eecs.berkeley.edu, paulmck@kernel.org, hca@linux.ibm.com, stefan.kristiansson@saunalahti.fi, openrisc@lists.librecores.org, paul.walmsley@sifive.com, linux-tegra@vger.kernel.org, namhyung@kernel.org, andriy.shevchenko@linux.intel.com, jpoimboe@kernel.org, jgross@suse.com, monstr@monstr.eu, linux-mips@vger.kernel.org, palmer@dabbelt.com, anup@brainfaul
 t.org, ink@jurassic.park.msu.ru, johannes@sipsolutions.net, linuxppc-dev@lists.ozlabs.org
Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org
Sender: "Linuxppc-dev" <linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org>

On 6/8/22 4:27 PM, Peter Zijlstra wrote:
> vmlinux.o: warning: objtool: acpi_idle_enter_s2idle+0xde: call to wbinvd() leaves .noinstr.text section
> vmlinux.o: warning: objtool: default_idle+0x4: call to arch_safe_halt() leaves .noinstr.text section
> vmlinux.o: warning: objtool: xen_safe_halt+0xa: call to HYPERVISOR_sched_op.constprop.0() leaves .noinstr.text section
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Reviewed-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>


Regards,
Srivatsa
VMware Photon OS

> ---
>  arch/x86/include/asm/paravirt.h      |    6 ++++--
>  arch/x86/include/asm/special_insns.h |    4 ++--
>  arch/x86/include/asm/xen/hypercall.h |    2 +-
>  arch/x86/kernel/paravirt.c           |   14 ++++++++++++--
>  arch/x86/xen/enlighten_pv.c          |    2 +-
>  arch/x86/xen/irq.c                   |    2 +-
>  6 files changed, 21 insertions(+), 9 deletions(-)
> 
> --- a/arch/x86/include/asm/paravirt.h
> +++ b/arch/x86/include/asm/paravirt.h
> @@ -168,7 +168,7 @@ static inline void __write_cr4(unsigned
>  	PVOP_VCALL1(cpu.write_cr4, x);
>  }
>  
> -static inline void arch_safe_halt(void)
> +static __always_inline void arch_safe_halt(void)
>  {
>  	PVOP_VCALL0(irq.safe_halt);
>  }
> @@ -178,7 +178,9 @@ static inline void halt(void)
>  	PVOP_VCALL0(irq.halt);
>  }
>  
> -static inline void wbinvd(void)
> +extern noinstr void pv_native_wbinvd(void);
> +
> +static __always_inline void wbinvd(void)
>  {
>  	PVOP_ALT_VCALL0(cpu.wbinvd, "wbinvd", ALT_NOT(X86_FEATURE_XENPV));
>  }
> --- a/arch/x86/include/asm/special_insns.h
> +++ b/arch/x86/include/asm/special_insns.h
> @@ -115,7 +115,7 @@ static inline void wrpkru(u32 pkru)
>  }
>  #endif
>  
> -static inline void native_wbinvd(void)
> +static __always_inline void native_wbinvd(void)
>  {
>  	asm volatile("wbinvd": : :"memory");
>  }
> @@ -179,7 +179,7 @@ static inline void __write_cr4(unsigned
>  	native_write_cr4(x);
>  }
>  
> -static inline void wbinvd(void)
> +static __always_inline void wbinvd(void)
>  {
>  	native_wbinvd();
>  }
> --- a/arch/x86/include/asm/xen/hypercall.h
> +++ b/arch/x86/include/asm/xen/hypercall.h
> @@ -382,7 +382,7 @@ MULTI_stack_switch(struct multicall_entr
>  }
>  #endif
>  
> -static inline int
> +static __always_inline int
>  HYPERVISOR_sched_op(int cmd, void *arg)
>  {
>  	return _hypercall2(int, sched_op, cmd, arg);
> --- a/arch/x86/kernel/paravirt.c
> +++ b/arch/x86/kernel/paravirt.c
> @@ -233,6 +233,11 @@ static noinstr void pv_native_set_debugr
>  	native_set_debugreg(regno, val);
>  }
>  
> +noinstr void pv_native_wbinvd(void)
> +{
> +	native_wbinvd();
> +}
> +
>  static noinstr void pv_native_irq_enable(void)
>  {
>  	native_irq_enable();
> @@ -242,6 +247,11 @@ static noinstr void pv_native_irq_disabl
>  {
>  	native_irq_disable();
>  }
> +
> +static noinstr void pv_native_safe_halt(void)
> +{
> +	native_safe_halt();
> +}
>  #endif
>  
>  enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
> @@ -273,7 +283,7 @@ struct paravirt_patch_template pv_ops =
>  	.cpu.read_cr0		= native_read_cr0,
>  	.cpu.write_cr0		= native_write_cr0,
>  	.cpu.write_cr4		= native_write_cr4,
> -	.cpu.wbinvd		= native_wbinvd,
> +	.cpu.wbinvd		= pv_native_wbinvd,
>  	.cpu.read_msr		= native_read_msr,
>  	.cpu.write_msr		= native_write_msr,
>  	.cpu.read_msr_safe	= native_read_msr_safe,
> @@ -307,7 +317,7 @@ struct paravirt_patch_template pv_ops =
>  	.irq.save_fl		= __PV_IS_CALLEE_SAVE(native_save_fl),
>  	.irq.irq_disable	= __PV_IS_CALLEE_SAVE(pv_native_irq_disable),
>  	.irq.irq_enable		= __PV_IS_CALLEE_SAVE(pv_native_irq_enable),
> -	.irq.safe_halt		= native_safe_halt,
> +	.irq.safe_halt		= pv_native_safe_halt,
>  	.irq.halt		= native_halt,
>  #endif /* CONFIG_PARAVIRT_XXL */
>  
> --- a/arch/x86/xen/enlighten_pv.c
> +++ b/arch/x86/xen/enlighten_pv.c
> @@ -1019,7 +1019,7 @@ static const typeof(pv_ops) xen_cpu_ops
>  
>  		.write_cr4 = xen_write_cr4,
>  
> -		.wbinvd = native_wbinvd,
> +		.wbinvd = pv_native_wbinvd,
>  
>  		.read_msr = xen_read_msr,
>  		.write_msr = xen_write_msr,
> --- a/arch/x86/xen/irq.c
> +++ b/arch/x86/xen/irq.c
> @@ -24,7 +24,7 @@ noinstr void xen_force_evtchn_callback(v
>  	(void)HYPERVISOR_xen_version(0, NULL);
>  }
>  
> -static void xen_safe_halt(void)
> +static noinstr void xen_safe_halt(void)
>  {
>  	/* Blocking includes an implicit local_irq_enable(). */
>  	if (HYPERVISOR_sched_op(SCHEDOP_block, NULL) != 0)
> 
>