riscv_isa_ext_keys[] is an array of static keys used in the unified
ISA extension framework. The keys added to this array may be used
anywhere, including in modules. Ensure the keys remain writable by
placing them in the data section.
The need to change riscv_isa_ext_keys[]'s section was found when the
kvm module started failing to load. Commit 8eb060e10185 ("arch/riscv:
add Zihintpause support") adds a static branch check for a newly
added isa-ext key to cpu_relax(), which kvm uses.
Fixes: c360cbec3511 ("riscv: introduce unified static key mechanism for ISA extensions")
Signed-off-by: Andrew Jones <[email protected]>
---
arch/riscv/kernel/cpufeature.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 553d755483ed..3b5583db9d80 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -28,7 +28,7 @@ unsigned long elf_hwcap __read_mostly;
/* Host ISA bitmap */
static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
-__ro_after_init DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
+DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
EXPORT_SYMBOL(riscv_isa_ext_keys);
/**
--
2.37.1
On 16/08/2022 17:30, Andrew Jones wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> riscv_isa_ext_keys[] is an array of static keys used in the unified
> ISA extension framework. The keys added to this array may be used
> anywhere, including in modules. Ensure the keys remain writable by
> placing them in the data section.
>
> The need to change riscv_isa_ext_keys[]'s section was found when the
> kvm module started failing to load. Commit 8eb060e10185 ("arch/riscv:
> add Zihintpause support") adds a static branch check for a newly
> added isa-ext key to cpu_relax(), which kvm uses.
>
> Fixes: c360cbec3511 ("riscv: introduce unified static key mechanism for ISA extensions")
> Signed-off-by: Andrew Jones <[email protected]>
Tested-by: Conor Dooley <[email protected]>
Thanks for the fix!
Still got issues booting mainline on my D1, but this is
no longer one of them :)
> ---
> arch/riscv/kernel/cpufeature.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 553d755483ed..3b5583db9d80 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -28,7 +28,7 @@ unsigned long elf_hwcap __read_mostly;
> /* Host ISA bitmap */
> static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
>
> -__ro_after_init DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> +DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> EXPORT_SYMBOL(riscv_isa_ext_keys);
>
> /**
> --
> 2.37.1
>
On 8/16/22 9:30 AM, Andrew Jones wrote:
> riscv_isa_ext_keys[] is an array of static keys used in the unified
> ISA extension framework. The keys added to this array may be used
> anywhere, including in modules. Ensure the keys remain writable by
> placing them in the data section.
>
> The need to change riscv_isa_ext_keys[]'s section was found when the
> kvm module started failing to load. Commit 8eb060e10185 ("arch/riscv:
> add Zihintpause support") adds a static branch check for a newly
> added isa-ext key to cpu_relax(), which kvm uses.
>
> Fixes: c360cbec3511 ("riscv: introduce unified static key mechanism for ISA extensions")
> Signed-off-by: Andrew Jones <[email protected]>
> ---
> arch/riscv/kernel/cpufeature.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 553d755483ed..3b5583db9d80 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -28,7 +28,7 @@ unsigned long elf_hwcap __read_mostly;
> /* Host ISA bitmap */
> static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
>
> -__ro_after_init DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> +DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> EXPORT_SYMBOL(riscv_isa_ext_keys);
>
> /**
Works good on HiFive Unmatched.
Tested-by: Ron Economos <[email protected]>
On Tue, Aug 16, 2022 at 9:31 AM Andrew Jones <[email protected]> wrote:
>
> riscv_isa_ext_keys[] is an array of static keys used in the unified
> ISA extension framework. The keys added to this array may be used
> anywhere, including in modules. Ensure the keys remain writable by
> placing them in the data section.
>
> The need to change riscv_isa_ext_keys[]'s section was found when the
> kvm module started failing to load. Commit 8eb060e10185 ("arch/riscv:
> add Zihintpause support") adds a static branch check for a newly
> added isa-ext key to cpu_relax(), which kvm uses.
>
> Fixes: c360cbec3511 ("riscv: introduce unified static key mechanism for ISA extensions")
> Signed-off-by: Andrew Jones <[email protected]>
> ---
> arch/riscv/kernel/cpufeature.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 553d755483ed..3b5583db9d80 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -28,7 +28,7 @@ unsigned long elf_hwcap __read_mostly;
> /* Host ISA bitmap */
> static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
>
> -__ro_after_init DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> +DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> EXPORT_SYMBOL(riscv_isa_ext_keys);
>
> /**
> --
> 2.37.1
>
>
> --
> kvm-riscv mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/kvm-riscv
Thanks for the quick fix. Tested with kvm guests booting in Qemu.
Tested-by: Atish Patra <[email protected]>
--
Regards,
Atish
On Tue, 16 Aug 2022 16:41:46 PDT (-0700), [email protected] wrote:
> On Tue, Aug 16, 2022 at 9:31 AM Andrew Jones <[email protected]> wrote:
>>
>> riscv_isa_ext_keys[] is an array of static keys used in the unified
>> ISA extension framework. The keys added to this array may be used
>> anywhere, including in modules. Ensure the keys remain writable by
>> placing them in the data section.
>>
>> The need to change riscv_isa_ext_keys[]'s section was found when the
>> kvm module started failing to load. Commit 8eb060e10185 ("arch/riscv:
>> add Zihintpause support") adds a static branch check for a newly
>> added isa-ext key to cpu_relax(), which kvm uses.
>>
>> Fixes: c360cbec3511 ("riscv: introduce unified static key mechanism for ISA extensions")
>> Signed-off-by: Andrew Jones <[email protected]>
>> ---
>> arch/riscv/kernel/cpufeature.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
>> index 553d755483ed..3b5583db9d80 100644
>> --- a/arch/riscv/kernel/cpufeature.c
>> +++ b/arch/riscv/kernel/cpufeature.c
>> @@ -28,7 +28,7 @@ unsigned long elf_hwcap __read_mostly;
>> /* Host ISA bitmap */
>> static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
>>
>> -__ro_after_init DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
>> +DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
>> EXPORT_SYMBOL(riscv_isa_ext_keys);
>>
>> /**
>> --
>> 2.37.1
>>
>>
>> --
>> kvm-riscv mailing list
>> [email protected]
>> http://lists.infradead.org/mailman/listinfo/kvm-riscv
>
> Thanks for the quick fix. Tested with kvm guests booting in Qemu.
>
> Tested-by: Atish Patra <[email protected]>
Thanks, I hadn't realized how static keys work but looks like having them as
__ro_after_init was always bogus. Sorry to break stuff, looks like I should be
loading some module (probably KVM, as it's in the defconfig) during testing.
This is on fixes, I'm planning on sending it up later this week.
On Tue, Aug 16, 2022 at 09:29:36PM -0700, Palmer Dabbelt wrote:
> On Tue, 16 Aug 2022 16:41:46 PDT (-0700), [email protected] wrote:
> > On Tue, Aug 16, 2022 at 9:31 AM Andrew Jones <[email protected]> wrote:
> > >
> > > riscv_isa_ext_keys[] is an array of static keys used in the unified
> > > ISA extension framework. The keys added to this array may be used
> > > anywhere, including in modules. Ensure the keys remain writable by
> > > placing them in the data section.
> > >
> > > The need to change riscv_isa_ext_keys[]'s section was found when the
> > > kvm module started failing to load. Commit 8eb060e10185 ("arch/riscv:
> > > add Zihintpause support") adds a static branch check for a newly
> > > added isa-ext key to cpu_relax(), which kvm uses.
> >> > >
> > > Fixes: c360cbec3511 ("riscv: introduce unified static key mechanism for ISA extensions")
> > > Signed-off-by: Andrew Jones <[email protected]>
> > > > > ---
> > > arch/riscv/kernel/cpufeature.c | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> > > index 553d755483ed..3b5583db9d80 100644
> > > --- a/arch/riscv/kernel/cpufeature.c
> > > +++ b/arch/riscv/kernel/cpufeature.c
> > > @@ -28,7 +28,7 @@ unsigned long elf_hwcap __read_mostly;
> > > /* Host ISA bitmap */
> > > static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
> > >
> > > -__ro_after_init DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> > > +DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> > > EXPORT_SYMBOL(riscv_isa_ext_keys);
> > >
> > > /**
> > > --
> > > 2.37.1
> > >
> > >
> > > --
> > > kvm-riscv mailing list
> > > [email protected]
> > > http://lists.infradead.org/mailman/listinfo/kvm-riscv
> >
> > Thanks for the quick fix. Tested with kvm guests booting in Qemu.
> >
> > Tested-by: Atish Patra <[email protected]>
Reviewed-by: Jisheng Zhang <[email protected]>
Thanks for catching the bug in my code.
>
> Thanks, I hadn't realized how static keys work but looks like having them as
> __ro_after_init was always bogus. Sorry to break stuff, looks like I should be
Sorry for breaking the static isa extension key usage in modules.
It's a good idea to make them readonly, but need to cope with the usage
in module properly. This may be a good improvement item.
> loading some module (probably KVM, as it's in the defconfig) during testing.
>
> This is on fixes, I'm planning on sending it up later this week.
On Wed, Aug 17, 2022 at 10:30:07PM +0800, Jisheng Zhang wrote:
> On Tue, Aug 16, 2022 at 09:29:36PM -0700, Palmer Dabbelt wrote:
> > On Tue, 16 Aug 2022 16:41:46 PDT (-0700), [email protected] wrote:
> > > On Tue, Aug 16, 2022 at 9:31 AM Andrew Jones <[email protected]> wrote:
> > > >
> > > > riscv_isa_ext_keys[] is an array of static keys used in the unified
> > > > ISA extension framework. The keys added to this array may be used
> > > > anywhere, including in modules. Ensure the keys remain writable by
> > > > placing them in the data section.
> > > >
> > > > The need to change riscv_isa_ext_keys[]'s section was found when the
> > > > kvm module started failing to load. Commit 8eb060e10185 ("arch/riscv:
> > > > add Zihintpause support") adds a static branch check for a newly
> > > > added isa-ext key to cpu_relax(), which kvm uses.
> > >> > >
> > > > Fixes: c360cbec3511 ("riscv: introduce unified static key mechanism for ISA extensions")
> > > > Signed-off-by: Andrew Jones <[email protected]>
> > > > > > ---
> > > > arch/riscv/kernel/cpufeature.c | 2 +-
> > > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > > >
> > > > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> > > > index 553d755483ed..3b5583db9d80 100644
> > > > --- a/arch/riscv/kernel/cpufeature.c
> > > > +++ b/arch/riscv/kernel/cpufeature.c
> > > > @@ -28,7 +28,7 @@ unsigned long elf_hwcap __read_mostly;
> > > > /* Host ISA bitmap */
> > > > static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
> > > >
> > > > -__ro_after_init DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> > > > +DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> > > > EXPORT_SYMBOL(riscv_isa_ext_keys);
> > > >
> > > > /**
> > > > --
> > > > 2.37.1
> > > >
> > > >
> > > > --
> > > > kvm-riscv mailing list
> > > > [email protected]
> > > > http://lists.infradead.org/mailman/listinfo/kvm-riscv
> > >
> > > Thanks for the quick fix. Tested with kvm guests booting in Qemu.
> > >
> > > Tested-by: Atish Patra <[email protected]>
>
> Reviewed-by: Jisheng Zhang <[email protected]>
>
> Thanks for catching the bug in my code.
>
> >
> > Thanks, I hadn't realized how static keys work but looks like having them as
> > __ro_after_init was always bogus. Sorry to break stuff, looks like I should be
>
> Sorry for breaking the static isa extension key usage in modules.
> It's a good idea to make them readonly, but need to cope with the usage
> in module properly. This may be a good improvement item.
While some static keys do use __ro_after_init, they're almost all locally
defined (static __ro_after_init). I see a few instances of __read_mostly
global static key definitions, though. That may make sense for
riscv_isa_ext_keys[] as well.
Thanks,
drew