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

Srivatsa S. Bhat
2022-06-13T20:33:41Z

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)
>
>