[v1] target/arm: align exposed ID registers with Linux

[PATCH] target/arm: align exposed ID registers with Linux

Posted by Zhuojia Shen 1 year, 5 months ago

In CPUID registers exposed to userspace, some registers were missing
and some fields were not exposed.  This patch aligns exposed ID
registers and their fields with what Linux exposes currently.

Specifically, the following new ID registers/fields are exposed to
userspace:

ID_AA64PFR1_EL1.BT:       bits 3-0
ID_AA64PFR1_EL1.MTE:      bits 11-8
ID_AA64PFR1_EL1.SME:      bits 27-24

ID_AA64ZFR0_EL1.SVEver:   bits 3-0
ID_AA64ZFR0_EL1.AES:      bits 7-4
ID_AA64ZFR0_EL1.BitPerm:  bits 19-16
ID_AA64ZFR0_EL1.BF16:     bits 23-20
ID_AA64ZFR0_EL1.SHA3:     bits 35-32
ID_AA64ZFR0_EL1.SM4:      bits 43-40
ID_AA64ZFR0_EL1.I8MM:     bits 47-44
ID_AA64ZFR0_EL1.F32MM:    bits 55-52
ID_AA64ZFR0_EL1.F64MM:    bits 59-56

ID_AA64SMFR0_EL1.F32F32:  bit 32
ID_AA64SMFR0_EL1.B16F32:  bit 34
ID_AA64SMFR0_EL1.F16F32:  bit 35
ID_AA64SMFR0_EL1.I8I32:   bits 39-36
ID_AA64SMFR0_EL1.F64F64:  bit 48
ID_AA64SMFR0_EL1.I16I64:  bits 55-52
ID_AA64SMFR0_EL1.FA64:    bit 63

ID_AA64MMFR0_EL1.ECV:     bits 63-60

ID_AA64MMFR1_EL1.AFP:     bits 47-44

ID_AA64MMFR2_EL1.AT:      bits 35-32

ID_AA64ISAR0_EL1.RNDR:    bits 63-60

ID_AA64ISAR1_EL1.FRINTTS: bits 35-32
ID_AA64ISAR1_EL1.BF16:    bits 47-44
ID_AA64ISAR1_EL1.DGH:     bits 51-48
ID_AA64ISAR1_EL1.I8MM:    bits 55-52

ID_AA64ISAR2_EL1.WFxT:    bits 3-0
ID_AA64ISAR2_EL1.RPRES:   bits 7-4
ID_AA64ISAR2_EL1.GPA3:    bits 11-8
ID_AA64ISAR2_EL1.APA3:    bits 15-12

Signed-off-by: Zhuojia Shen <chaosdefinition@hotmail.com>
---
 target/arm/helper.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index d8c8223ec3..ce6fd7a96d 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -7826,13 +7826,20 @@ void register_cp_regs_for_features(ARMCPU *cpu)
               .exported_bits = 0x000f000f00ff0000,
               .fixed_bits    = 0x0000000000000011 },
             { .name = "ID_AA64PFR1_EL1",
-              .exported_bits = 0x00000000000000f0 },
+              .exported_bits = 0x000000000f000fff },
             { .name = "ID_AA64PFR*_EL1_RESERVED",
               .is_glob = true                     },
-            { .name = "ID_AA64ZFR0_EL1"           },
+            { .name = "ID_AA64ZFR0_EL1",
+              .exported_bits = 0x0ff0ff0f00ff00ff },
+            { .name = "ID_AA64SMFR0_EL1",
+              .exported_bits = 0x80f100fd00000000 },
             { .name = "ID_AA64MMFR0_EL1",
+              .exported_bits = 0xf000000000000000,
               .fixed_bits    = 0x00000000ff000000 },
-            { .name = "ID_AA64MMFR1_EL1"          },
+            { .name = "ID_AA64MMFR1_EL1",
+              .exported_bits = 0x0000f00000000000 },
+            { .name = "ID_AA64MMFR2_EL1",
+              .exported_bits = 0x0000000f00000000 },
             { .name = "ID_AA64MMFR*_EL1_RESERVED",
               .is_glob = true                     },
             { .name = "ID_AA64DFR0_EL1",
@@ -7843,9 +7850,11 @@ void register_cp_regs_for_features(ARMCPU *cpu)
             { .name = "ID_AA64AFR*",
               .is_glob = true                     },
             { .name = "ID_AA64ISAR0_EL1",
-              .exported_bits = 0x00fffffff0fffff0 },
+              .exported_bits = 0xf0fffffff0fffff0 },
             { .name = "ID_AA64ISAR1_EL1",
-              .exported_bits = 0x000000f0ffffffff },
+              .exported_bits = 0x00fff0ffffffffff },
+            { .name = "ID_AA64ISAR2_EL1",
+              .exported_bits = 0x000000000000ffff },
             { .name = "ID_AA64ISAR*_EL1_RESERVED",
               .is_glob = true                     },
         };
-- 
2.38.1

Re: [PATCH] target/arm: align exposed ID registers with Linux

Posted by Peter Maydell 1 year, 5 months ago

On Tue, 22 Nov 2022 at 03:05, Zhuojia Shen <chaosdefinition@hotmail.com> wrote:
>
> In CPUID registers exposed to userspace, some registers were missing
> and some fields were not exposed.  This patch aligns exposed ID
> registers and their fields with what Linux exposes currently.
>
> Specifically, the following new ID registers/fields are exposed to
> userspace:

These changes don't quite seem to line up with what the kernel
documents that it exposes:
https://www.kernel.org/doc/Documentation/arm64/cpu-feature-registers.rst

> ID_AA64PFR1_EL1.BT:       bits 3-0
> ID_AA64PFR1_EL1.MTE:      bits 11-8
> ID_AA64PFR1_EL1.SME:      bits 27-24

.SME not listed as exposed.

> ID_AA64SMFR0_EL1.F32F32:  bit 32
> ID_AA64SMFR0_EL1.B16F32:  bit 34
> ID_AA64SMFR0_EL1.F16F32:  bit 35
> ID_AA64SMFR0_EL1.I8I32:   bits 39-36
> ID_AA64SMFR0_EL1.F64F64:  bit 48
> ID_AA64SMFR0_EL1.I16I64:  bits 55-52
> ID_AA64SMFR0_EL1.FA64:    bit 63

This register not listed as exposed.

> ID_AA64ISAR2_EL1.WFxT:    bits 3-0
> ID_AA64ISAR2_EL1.RPRES:   bits 7-4
> ID_AA64ISAR2_EL1.GPA3:    bits 11-8
> ID_AA64ISAR2_EL1.APA3:    bits 15-12

GPA3 and APA3 not listed as exposed.

thanks
-- PMM

Re: [PATCH] target/arm: align exposed ID registers with Linux

Posted by Zhuojia Shen 1 year, 5 months ago

On 11/22/2022 06:26 PM +0000, Peter Maydell wrote:
> On Tue, 22 Nov 2022 at 03:05, Zhuojia Shen <chaosdefinition@hotmail.com> wrote:
> >
> > In CPUID registers exposed to userspace, some registers were missing
> > and some fields were not exposed.  This patch aligns exposed ID
> > registers and their fields with what Linux exposes currently.
> >
> > Specifically, the following new ID registers/fields are exposed to
> > userspace:
> 
> These changes don't quite seem to line up with what the kernel
> documents that it exposes:
> https://www.kernel.org/doc/Documentation/arm64/cpu-feature-registers.rst

This kernel document seems not quite up-to-date.  The patch is based on
the upstream code:
https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/cpufeature.c

> 
> > ID_AA64PFR1_EL1.BT:       bits 3-0
> > ID_AA64PFR1_EL1.MTE:      bits 11-8
> > ID_AA64PFR1_EL1.SME:      bits 27-24
> 
> .SME not listed as exposed.
> 
> > ID_AA64SMFR0_EL1.F32F32:  bit 32
> > ID_AA64SMFR0_EL1.B16F32:  bit 34
> > ID_AA64SMFR0_EL1.F16F32:  bit 35
> > ID_AA64SMFR0_EL1.I8I32:   bits 39-36
> > ID_AA64SMFR0_EL1.F64F64:  bit 48
> > ID_AA64SMFR0_EL1.I16I64:  bits 55-52
> > ID_AA64SMFR0_EL1.FA64:    bit 63
> 
> This register not listed as exposed.

This register and ID_AA64PFR1_EL1.SME are exposed since v5.19.

> 
> > ID_AA64ISAR2_EL1.WFxT:    bits 3-0
> > ID_AA64ISAR2_EL1.RPRES:   bits 7-4
> > ID_AA64ISAR2_EL1.GPA3:    bits 11-8
> > ID_AA64ISAR2_EL1.APA3:    bits 15-12
> 
> GPA3 and APA3 not listed as exposed.

These two are exposed since v5.18.

> 
> thanks
> -- PMM

Re: [PATCH] target/arm: align exposed ID registers with Linux

Posted by Richard Henderson 1 year, 5 months ago

On 11/21/22 18:48, Zhuojia Shen wrote:
> In CPUID registers exposed to userspace, some registers were missing
> and some fields were not exposed.  This patch aligns exposed ID
> registers and their fields with what Linux exposes currently.
> 
> Specifically, the following new ID registers/fields are exposed to
> userspace:
> 
> ID_AA64PFR1_EL1.BT:       bits 3-0
> ID_AA64PFR1_EL1.MTE:      bits 11-8
> ID_AA64PFR1_EL1.SME:      bits 27-24
> 
> ID_AA64ZFR0_EL1.SVEver:   bits 3-0
> ID_AA64ZFR0_EL1.AES:      bits 7-4
> ID_AA64ZFR0_EL1.BitPerm:  bits 19-16
> ID_AA64ZFR0_EL1.BF16:     bits 23-20
> ID_AA64ZFR0_EL1.SHA3:     bits 35-32
> ID_AA64ZFR0_EL1.SM4:      bits 43-40
> ID_AA64ZFR0_EL1.I8MM:     bits 47-44
> ID_AA64ZFR0_EL1.F32MM:    bits 55-52
> ID_AA64ZFR0_EL1.F64MM:    bits 59-56
> 
> ID_AA64SMFR0_EL1.F32F32:  bit 32
> ID_AA64SMFR0_EL1.B16F32:  bit 34
> ID_AA64SMFR0_EL1.F16F32:  bit 35
> ID_AA64SMFR0_EL1.I8I32:   bits 39-36
> ID_AA64SMFR0_EL1.F64F64:  bit 48
> ID_AA64SMFR0_EL1.I16I64:  bits 55-52
> ID_AA64SMFR0_EL1.FA64:    bit 63
> 
> ID_AA64MMFR0_EL1.ECV:     bits 63-60
> 
> ID_AA64MMFR1_EL1.AFP:     bits 47-44
> 
> ID_AA64MMFR2_EL1.AT:      bits 35-32
> 
> ID_AA64ISAR0_EL1.RNDR:    bits 63-60
> 
> ID_AA64ISAR1_EL1.FRINTTS: bits 35-32
> ID_AA64ISAR1_EL1.BF16:    bits 47-44
> ID_AA64ISAR1_EL1.DGH:     bits 51-48
> ID_AA64ISAR1_EL1.I8MM:    bits 55-52
> 
> ID_AA64ISAR2_EL1.WFxT:    bits 3-0
> ID_AA64ISAR2_EL1.RPRES:   bits 7-4
> ID_AA64ISAR2_EL1.GPA3:    bits 11-8
> ID_AA64ISAR2_EL1.APA3:    bits 15-12
> 
> Signed-off-by: Zhuojia Shen <chaosdefinition@hotmail.com>
> ---
>   target/arm/helper.c | 19 ++++++++++++++-----
>   1 file changed, 14 insertions(+), 5 deletions(-)
> 
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index d8c8223ec3..ce6fd7a96d 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -7826,13 +7826,20 @@ void register_cp_regs_for_features(ARMCPU *cpu)
>                 .exported_bits = 0x000f000f00ff0000,
>                 .fixed_bits    = 0x0000000000000011 },
>               { .name = "ID_AA64PFR1_EL1",
> -              .exported_bits = 0x00000000000000f0 },
> +              .exported_bits = 0x000000000f000fff },

Existing, but I think it would be nicer to do this symbolically.  e.g.

    .exported_bits = R_ID_AA64PFR1_BT_MASK |
                     R_ID_AA64PFR1_SBSS_MASK |
                     R_ID_AA64PFR1_MTE_MASK |
                     R_ID_AA64PFR1_SME_MASK,

etc.


r~

Re: [PATCH] target/arm: align exposed ID registers with Linux

Posted by Zhuojia Shen 1 year, 5 months ago

On 11/22/2022 10:12 AM -0800, Richard Henderson wrote:
> On 11/21/22 18:48, Zhuojia Shen wrote:
> > In CPUID registers exposed to userspace, some registers were missing
> > and some fields were not exposed.  This patch aligns exposed ID
> > registers and their fields with what Linux exposes currently.
> > 
> > Specifically, the following new ID registers/fields are exposed to
> > userspace:
> > 
> > ID_AA64PFR1_EL1.BT:       bits 3-0
> > ID_AA64PFR1_EL1.MTE:      bits 11-8
> > ID_AA64PFR1_EL1.SME:      bits 27-24
> > 
> > ID_AA64ZFR0_EL1.SVEver:   bits 3-0
> > ID_AA64ZFR0_EL1.AES:      bits 7-4
> > ID_AA64ZFR0_EL1.BitPerm:  bits 19-16
> > ID_AA64ZFR0_EL1.BF16:     bits 23-20
> > ID_AA64ZFR0_EL1.SHA3:     bits 35-32
> > ID_AA64ZFR0_EL1.SM4:      bits 43-40
> > ID_AA64ZFR0_EL1.I8MM:     bits 47-44
> > ID_AA64ZFR0_EL1.F32MM:    bits 55-52
> > ID_AA64ZFR0_EL1.F64MM:    bits 59-56
> > 
> > ID_AA64SMFR0_EL1.F32F32:  bit 32
> > ID_AA64SMFR0_EL1.B16F32:  bit 34
> > ID_AA64SMFR0_EL1.F16F32:  bit 35
> > ID_AA64SMFR0_EL1.I8I32:   bits 39-36
> > ID_AA64SMFR0_EL1.F64F64:  bit 48
> > ID_AA64SMFR0_EL1.I16I64:  bits 55-52
> > ID_AA64SMFR0_EL1.FA64:    bit 63
> > 
> > ID_AA64MMFR0_EL1.ECV:     bits 63-60
> > 
> > ID_AA64MMFR1_EL1.AFP:     bits 47-44
> > 
> > ID_AA64MMFR2_EL1.AT:      bits 35-32
> > 
> > ID_AA64ISAR0_EL1.RNDR:    bits 63-60
> > 
> > ID_AA64ISAR1_EL1.FRINTTS: bits 35-32
> > ID_AA64ISAR1_EL1.BF16:    bits 47-44
> > ID_AA64ISAR1_EL1.DGH:     bits 51-48
> > ID_AA64ISAR1_EL1.I8MM:    bits 55-52
> > 
> > ID_AA64ISAR2_EL1.WFxT:    bits 3-0
> > ID_AA64ISAR2_EL1.RPRES:   bits 7-4
> > ID_AA64ISAR2_EL1.GPA3:    bits 11-8
> > ID_AA64ISAR2_EL1.APA3:    bits 15-12
> > 
> > Signed-off-by: Zhuojia Shen <chaosdefinition@hotmail.com>
> > ---
> >   target/arm/helper.c | 19 ++++++++++++++-----
> >   1 file changed, 14 insertions(+), 5 deletions(-)
> > 
> > diff --git a/target/arm/helper.c b/target/arm/helper.c
> > index d8c8223ec3..ce6fd7a96d 100644
> > --- a/target/arm/helper.c
> > +++ b/target/arm/helper.c
> > @@ -7826,13 +7826,20 @@ void register_cp_regs_for_features(ARMCPU *cpu)
> >                 .exported_bits = 0x000f000f00ff0000,
> >                 .fixed_bits    = 0x0000000000000011 },
> >               { .name = "ID_AA64PFR1_EL1",
> > -              .exported_bits = 0x00000000000000f0 },
> > +              .exported_bits = 0x000000000f000fff },
> 
> Existing, but I think it would be nicer to do this symbolically.  e.g.
> 
>    .exported_bits = R_ID_AA64PFR1_BT_MASK |
>                     R_ID_AA64PFR1_SBSS_MASK |
>                     R_ID_AA64PFR1_MTE_MASK |
>                     R_ID_AA64PFR1_SME_MASK,
> 
> etc.

It would be more readable but longer.  I can try to refactor this way.

> 
> 
> r~