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* [PATCH 1/2] arm64: KVM: regmap: Mark expected switch fall-through
@ 2019-07-26 11:27 Anders Roxell
  2019-07-26 12:30 ` Marc Zyngier
  2019-07-26 14:17 ` Sasha Levin
  0 siblings, 2 replies; 4+ messages in thread
From: Anders Roxell @ 2019-07-26 11:27 UTC (permalink / raw)
  To: maz, catalin.marinas, will
  Cc: stable, Anders Roxell, kvmarm, linux-arm-kernel, linux-kernel

When fall-through warnings was enabled by default, commit d93512ef0f0e
("Makefile: Globally enable fall-through warning"), the following
warnings was starting to show up:

In file included from ../arch/arm64/include/asm/kvm_emulate.h:19,
                 from ../arch/arm64/kvm/regmap.c:13:
../arch/arm64/kvm/regmap.c: In function ‘vcpu_write_spsr32’:
../arch/arm64/include/asm/kvm_hyp.h:31:3: warning: this statement may fall
 through [-Wimplicit-fallthrough=]
   asm volatile(ALTERNATIVE(__msr_s(r##nvh, "%x0"), \
   ^~~
../arch/arm64/include/asm/kvm_hyp.h:46:31: note: in expansion of macro ‘write_sysreg_elx’
 #define write_sysreg_el1(v,r) write_sysreg_elx(v, r, _EL1, _EL12)
                               ^~~~~~~~~~~~~~~~
../arch/arm64/kvm/regmap.c:180:3: note: in expansion of macro ‘write_sysreg_el1’
   write_sysreg_el1(v, SYS_SPSR);
   ^~~~~~~~~~~~~~~~
../arch/arm64/kvm/regmap.c:181:2: note: here
  case KVM_SPSR_ABT:
  ^~~~
In file included from ../arch/arm64/include/asm/cputype.h:132,
                 from ../arch/arm64/include/asm/cache.h:8,
                 from ../include/linux/cache.h:6,
                 from ../include/linux/printk.h:9,
                 from ../include/linux/kernel.h:15,
                 from ../include/asm-generic/bug.h:18,
                 from ../arch/arm64/include/asm/bug.h:26,
                 from ../include/linux/bug.h:5,
                 from ../include/linux/mmdebug.h:5,
                 from ../include/linux/mm.h:9,
                 from ../arch/arm64/kvm/regmap.c:11:
../arch/arm64/include/asm/sysreg.h:837:2: warning: this statement may fall
 through [-Wimplicit-fallthrough=]
  asm volatile("msr " __stringify(r) ", %x0"  \
  ^~~
../arch/arm64/kvm/regmap.c:182:3: note: in expansion of macro ‘write_sysreg’
   write_sysreg(v, spsr_abt);
   ^~~~~~~~~~~~
../arch/arm64/kvm/regmap.c:183:2: note: here
  case KVM_SPSR_UND:
  ^~~~

Rework to add a 'break;' in the swich-case since it didn't have that.
That also made the compiler happy and didn't warn about fall-through.

Cc: stable@vger.kernel.org # v3.16+
Fixes: a892819560c4 ("KVM: arm64: Prepare to handle deferred save/restore of 32-bit registers")
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
---
 arch/arm64/kvm/regmap.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/kvm/regmap.c b/arch/arm64/kvm/regmap.c
index 0d60e4f0af66..a900181e3867 100644
--- a/arch/arm64/kvm/regmap.c
+++ b/arch/arm64/kvm/regmap.c
@@ -178,13 +178,18 @@ void vcpu_write_spsr32(struct kvm_vcpu *vcpu, unsigned long v)
 	switch (spsr_idx) {
 	case KVM_SPSR_SVC:
 		write_sysreg_el1(v, SYS_SPSR);
+		break;
 	case KVM_SPSR_ABT:
 		write_sysreg(v, spsr_abt);
+		break;
 	case KVM_SPSR_UND:
 		write_sysreg(v, spsr_und);
+		break;
 	case KVM_SPSR_IRQ:
 		write_sysreg(v, spsr_irq);
+		break;
 	case KVM_SPSR_FIQ:
 		write_sysreg(v, spsr_fiq);
+		break;
 	}
 }
-- 
2.20.1

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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH 1/2] arm64: KVM: regmap: Mark expected switch fall-through
  2019-07-26 11:27 [PATCH 1/2] arm64: KVM: regmap: Mark expected switch fall-through Anders Roxell
@ 2019-07-26 12:30 ` Marc Zyngier
  2019-07-26 14:05   ` Anders Roxell
  2019-07-26 14:17 ` Sasha Levin
  1 sibling, 1 reply; 4+ messages in thread
From: Marc Zyngier @ 2019-07-26 12:30 UTC (permalink / raw)
  To: Anders Roxell
  Cc: catalin.marinas, linux-kernel, stable, will, kvmarm, linux-arm-kernel

Hi Anders,

On Fri, 26 Jul 2019 12:27:05 +0100,
Anders Roxell <anders.roxell@linaro.org> wrote:
> 
> When fall-through warnings was enabled by default, commit d93512ef0f0e
> ("Makefile: Globally enable fall-through warning"), the following
> warnings was starting to show up:
> 
> In file included from ../arch/arm64/include/asm/kvm_emulate.h:19,
>                  from ../arch/arm64/kvm/regmap.c:13:
> ../arch/arm64/kvm/regmap.c: In function ‘vcpu_write_spsr32’:
> ../arch/arm64/include/asm/kvm_hyp.h:31:3: warning: this statement may fall
>  through [-Wimplicit-fallthrough=]
>    asm volatile(ALTERNATIVE(__msr_s(r##nvh, "%x0"), \
>    ^~~
> ../arch/arm64/include/asm/kvm_hyp.h:46:31: note: in expansion of macro ‘write_sysreg_elx’
>  #define write_sysreg_el1(v,r) write_sysreg_elx(v, r, _EL1, _EL12)
>                                ^~~~~~~~~~~~~~~~
> ../arch/arm64/kvm/regmap.c:180:3: note: in expansion of macro ‘write_sysreg_el1’
>    write_sysreg_el1(v, SYS_SPSR);
>    ^~~~~~~~~~~~~~~~
> ../arch/arm64/kvm/regmap.c:181:2: note: here
>   case KVM_SPSR_ABT:
>   ^~~~
> In file included from ../arch/arm64/include/asm/cputype.h:132,
>                  from ../arch/arm64/include/asm/cache.h:8,
>                  from ../include/linux/cache.h:6,
>                  from ../include/linux/printk.h:9,
>                  from ../include/linux/kernel.h:15,
>                  from ../include/asm-generic/bug.h:18,
>                  from ../arch/arm64/include/asm/bug.h:26,
>                  from ../include/linux/bug.h:5,
>                  from ../include/linux/mmdebug.h:5,
>                  from ../include/linux/mm.h:9,
>                  from ../arch/arm64/kvm/regmap.c:11:
> ../arch/arm64/include/asm/sysreg.h:837:2: warning: this statement may fall
>  through [-Wimplicit-fallthrough=]
>   asm volatile("msr " __stringify(r) ", %x0"  \
>   ^~~
> ../arch/arm64/kvm/regmap.c:182:3: note: in expansion of macro ‘write_sysreg’
>    write_sysreg(v, spsr_abt);
>    ^~~~~~~~~~~~
> ../arch/arm64/kvm/regmap.c:183:2: note: here
>   case KVM_SPSR_UND:
>   ^~~~
> 
> Rework to add a 'break;' in the swich-case since it didn't have that.
> That also made the compiler happy and didn't warn about fall-through.
> 
> Cc: stable@vger.kernel.org # v3.16+

Erm... Are you sure about that? Here's what I have:

$ git describe --contains  a892819560c4
kvm-arm-for-v4.17~44
$ git describe --contains --match='v*' a892819560c4
v4.17-rc1~72^2~36^2~44


> Fixes: a892819560c4 ("KVM: arm64: Prepare to handle deferred save/restore of 32-bit registers")
> Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
> ---
>  arch/arm64/kvm/regmap.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/arm64/kvm/regmap.c b/arch/arm64/kvm/regmap.c
> index 0d60e4f0af66..a900181e3867 100644
> --- a/arch/arm64/kvm/regmap.c
> +++ b/arch/arm64/kvm/regmap.c
> @@ -178,13 +178,18 @@ void vcpu_write_spsr32(struct kvm_vcpu *vcpu, unsigned long v)
>  	switch (spsr_idx) {
>  	case KVM_SPSR_SVC:
>  		write_sysreg_el1(v, SYS_SPSR);
> +		break;
>  	case KVM_SPSR_ABT:
>  		write_sysreg(v, spsr_abt);
> +		break;
>  	case KVM_SPSR_UND:
>  		write_sysreg(v, spsr_und);
> +		break;
>  	case KVM_SPSR_IRQ:
>  		write_sysreg(v, spsr_irq);
> +		break;
>  	case KVM_SPSR_FIQ:
>  		write_sysreg(v, spsr_fiq);
> +		break;
>  	}
>  }

Otherwise looks like the right fix to me. Let me know what you think
about the Fixes: tag (no need to resend for that).

Thanks,

	M.

-- 
Jazz is not dead, it just smells funny.
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH 1/2] arm64: KVM: regmap: Mark expected switch fall-through
  2019-07-26 12:30 ` Marc Zyngier
@ 2019-07-26 14:05   ` Anders Roxell
  0 siblings, 0 replies; 4+ messages in thread
From: Anders Roxell @ 2019-07-26 14:05 UTC (permalink / raw)
  To: Marc Zyngier
  Cc: Catalin Marinas, Linux Kernel Mailing List, stable, will, kvmarm,
	Linux ARM

On Fri, 26 Jul 2019 at 14:30, Marc Zyngier <marc.zyngier@arm.com> wrote:
>
> Hi Anders,
>
> On Fri, 26 Jul 2019 12:27:05 +0100,
> Anders Roxell <anders.roxell@linaro.org> wrote:
> >
> > When fall-through warnings was enabled by default, commit d93512ef0f0e
> > ("Makefile: Globally enable fall-through warning"), the following
> > warnings was starting to show up:
> >
> > In file included from ../arch/arm64/include/asm/kvm_emulate.h:19,
> >                  from ../arch/arm64/kvm/regmap.c:13:
> > ../arch/arm64/kvm/regmap.c: In function ‘vcpu_write_spsr32’:
> > ../arch/arm64/include/asm/kvm_hyp.h:31:3: warning: this statement may fall
> >  through [-Wimplicit-fallthrough=]
> >    asm volatile(ALTERNATIVE(__msr_s(r##nvh, "%x0"), \
> >    ^~~
> > ../arch/arm64/include/asm/kvm_hyp.h:46:31: note: in expansion of macro ‘write_sysreg_elx’
> >  #define write_sysreg_el1(v,r) write_sysreg_elx(v, r, _EL1, _EL12)
> >                                ^~~~~~~~~~~~~~~~
> > ../arch/arm64/kvm/regmap.c:180:3: note: in expansion of macro ‘write_sysreg_el1’
> >    write_sysreg_el1(v, SYS_SPSR);
> >    ^~~~~~~~~~~~~~~~
> > ../arch/arm64/kvm/regmap.c:181:2: note: here
> >   case KVM_SPSR_ABT:
> >   ^~~~
> > In file included from ../arch/arm64/include/asm/cputype.h:132,
> >                  from ../arch/arm64/include/asm/cache.h:8,
> >                  from ../include/linux/cache.h:6,
> >                  from ../include/linux/printk.h:9,
> >                  from ../include/linux/kernel.h:15,
> >                  from ../include/asm-generic/bug.h:18,
> >                  from ../arch/arm64/include/asm/bug.h:26,
> >                  from ../include/linux/bug.h:5,
> >                  from ../include/linux/mmdebug.h:5,
> >                  from ../include/linux/mm.h:9,
> >                  from ../arch/arm64/kvm/regmap.c:11:
> > ../arch/arm64/include/asm/sysreg.h:837:2: warning: this statement may fall
> >  through [-Wimplicit-fallthrough=]
> >   asm volatile("msr " __stringify(r) ", %x0"  \
> >   ^~~
> > ../arch/arm64/kvm/regmap.c:182:3: note: in expansion of macro ‘write_sysreg’
> >    write_sysreg(v, spsr_abt);
> >    ^~~~~~~~~~~~
> > ../arch/arm64/kvm/regmap.c:183:2: note: here
> >   case KVM_SPSR_UND:
> >   ^~~~
> >
> > Rework to add a 'break;' in the swich-case since it didn't have that.
> > That also made the compiler happy and didn't warn about fall-through.
> >
> > Cc: stable@vger.kernel.org # v3.16+
>
> Erm... Are you sure about that?

I made two mistakes.
1. saying 3.x instead of 4.x
2. I said the same kernel that 'git describe' showed and not the later one.

I did not know about '--match='.

> Here's what I have:
>
> $ git describe --contains  a892819560c4
> kvm-arm-for-v4.17~44
> $ git describe --contains --match='v*' a892819560c4
> v4.17-rc1~72^2~36^2~44

That's correct.

>
>
> > Fixes: a892819560c4 ("KVM: arm64: Prepare to handle deferred save/restore of 32-bit registers")
> > Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
> > ---
> >  arch/arm64/kvm/regmap.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> >
> > diff --git a/arch/arm64/kvm/regmap.c b/arch/arm64/kvm/regmap.c
> > index 0d60e4f0af66..a900181e3867 100644
> > --- a/arch/arm64/kvm/regmap.c
> > +++ b/arch/arm64/kvm/regmap.c
> > @@ -178,13 +178,18 @@ void vcpu_write_spsr32(struct kvm_vcpu *vcpu, unsigned long v)
> >       switch (spsr_idx) {
> >       case KVM_SPSR_SVC:
> >               write_sysreg_el1(v, SYS_SPSR);
> > +             break;
> >       case KVM_SPSR_ABT:
> >               write_sysreg(v, spsr_abt);
> > +             break;
> >       case KVM_SPSR_UND:
> >               write_sysreg(v, spsr_und);
> > +             break;
> >       case KVM_SPSR_IRQ:
> >               write_sysreg(v, spsr_irq);
> > +             break;
> >       case KVM_SPSR_FIQ:
> >               write_sysreg(v, spsr_fiq);
> > +             break;
> >       }
> >  }
>
> Otherwise looks like the right fix to me. Let me know what you think
> about the Fixes: tag (no need to resend for that).

It should be v4.17+.

Cheers,
Anders
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH 1/2] arm64: KVM: regmap: Mark expected switch fall-through
  2019-07-26 11:27 [PATCH 1/2] arm64: KVM: regmap: Mark expected switch fall-through Anders Roxell
  2019-07-26 12:30 ` Marc Zyngier
@ 2019-07-26 14:17 ` Sasha Levin
  1 sibling, 0 replies; 4+ messages in thread
From: Sasha Levin @ 2019-07-26 14:17 UTC (permalink / raw)
  To: Sasha Levin; +Cc: , stable, kvmarm, linux-arm-kernel

Hi,

[This is an automated email]

This commit has been processed because it contains a "Fixes:" tag,
fixing commit: a892819560c4 KVM: arm64: Prepare to handle deferred save/restore of 32-bit registers.

The bot has tested the following trees: v5.2.2, v5.1.19, v4.19.60.

v5.2.2: Failed to apply! Possible dependencies:
    fdec2a9ef853 ("KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s")

v5.1.19: Failed to apply! Possible dependencies:
    73433762fcae ("KVM: arm64/sve: System register context switch and access support")
    be604c616ca7 ("arm64: sysreg: Make mrs_s and msr_s macros work with Clang and LTO")
    fdec2a9ef853 ("KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s")

v4.19.60: Failed to apply! Possible dependencies:
    84135d3d18da ("KVM: arm/arm64: consolidate arch timer trap handlers")
    8a411b060f82 ("KVM: arm/arm64: Remove arch timer workqueue")
    9e01dc76be6a ("KVM: arm/arm64: arch_timer: Assign the phys timer on VHE systems")
    accb99bcd0ca ("KVM: arm/arm64: Simplify bg_timer programming")
    bd7d95cafb49 ("arm64: KVM: Consistently advance singlestep when emulating instructions")
    e604dd5d45c7 ("KVM: arm/arm64: timer: Rework data structures for multiple timers")
    fdec2a9ef853 ("KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s")


NOTE: The patch will not be queued to stable trees until it is upstream.

How should we proceed with this patch?

--
Thanks,
Sasha
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

^ permalink raw reply	[flat|nested] 4+ messages in thread

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-- links below jump to the message on this page --
2019-07-26 11:27 [PATCH 1/2] arm64: KVM: regmap: Mark expected switch fall-through Anders Roxell
2019-07-26 12:30 ` Marc Zyngier
2019-07-26 14:05   ` Anders Roxell
2019-07-26 14:17 ` Sasha Levin

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