expose FEAT_LSUI to guest.

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
---
 arch/arm64/kvm/sys_regs.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index b29f72478a50..abdf19ae250e 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1757,7 +1757,8 @@ static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu,
 			val &= ~ID_AA64ISAR2_EL1_WFxT;
 		break;
 	case SYS_ID_AA64ISAR3_EL1:
-		val &= ID_AA64ISAR3_EL1_FPRCVT | ID_AA64ISAR3_EL1_FAMINMAX;
+		val &= ID_AA64ISAR3_EL1_FPRCVT | ID_AA64ISAR3_EL1_FAMINMAX |
+		       ID_AA64ISAR3_EL1_LSUI;
 		break;
 	case SYS_ID_AA64MMFR2_EL1:
 		val &= ~ID_AA64MMFR2_EL1_CCIDX_MASK;
@@ -3141,7 +3142,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 					ID_AA64ISAR2_EL1_APA3 |
 					ID_AA64ISAR2_EL1_GPA3)),
 	ID_WRITABLE(ID_AA64ISAR3_EL1, (ID_AA64ISAR3_EL1_FPRCVT |
-				       ID_AA64ISAR3_EL1_FAMINMAX)),
+				       ID_AA64ISAR3_EL1_FAMINMAX | ID_AA64ISAR3_EL1_LSUI)),
 	ID_UNALLOCATED(6,4),
 	ID_UNALLOCATED(6,5),
 	ID_UNALLOCATED(6,6),
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

On Mon, Sep 22, 2025 at 11:22:41AM +0100, Yeoreum Yun wrote:

>  	case SYS_ID_AA64ISAR3_EL1:
> -		val &= ID_AA64ISAR3_EL1_FPRCVT | ID_AA64ISAR3_EL1_FAMINMAX;
> +		val &= ID_AA64ISAR3_EL1_FPRCVT | ID_AA64ISAR3_EL1_FAMINMAX |
> +		       ID_AA64ISAR3_EL1_LSUI;

This should be added to set_id_regs, but ID_AA64ISAR3_EL1 isn't covered
by that yet.  I posted a series for that the other day:

   https://lore.kernel.org/r/20250920-kvm-arm64-id-aa64isar3-el1-v1-0-1764c1c1c96d@kernel.org

Hi Mark,

[...]
> >  	case SYS_ID_AA64ISAR3_EL1:
> > -		val &= ID_AA64ISAR3_EL1_FPRCVT | ID_AA64ISAR3_EL1_FAMINMAX;
> > +		val &= ID_AA64ISAR3_EL1_FPRCVT | ID_AA64ISAR3_EL1_FAMINMAX |
> > +		       ID_AA64ISAR3_EL1_LSUI;
>
> This should be added to set_id_regs, but ID_AA64ISAR3_EL1 isn't covered
> by that yet.  I posted a series for that the other day:
>
>    https://lore.kernel.org/r/20250920-kvm-arm64-id-aa64isar3-el1-v1-0-1764c1c1c96d@kernel.org

Thank to let me know missing to add kselftest feature for this.
I'll add it :)


--
Sincerely,
Yeoreum Yun

> [...]
> > >  	case SYS_ID_AA64ISAR3_EL1:
> > > -		val &= ID_AA64ISAR3_EL1_FPRCVT | ID_AA64ISAR3_EL1_FAMINMAX;
> > > +		val &= ID_AA64ISAR3_EL1_FPRCVT | ID_AA64ISAR3_EL1_FAMINMAX |
> > > +		       ID_AA64ISAR3_EL1_LSUI;
> >
> > This should be added to set_id_regs, but ID_AA64ISAR3_EL1 isn't covered
> > by that yet.  I posted a series for that the other day:
> >
> >    https://lore.kernel.org/r/20250920-kvm-arm64-id-aa64isar3-el1-v1-0-1764c1c1c96d@kernel.org
>
> Thank to let me know missing to add kselftest feature for this.
> I'll add it :)

I mean after merging your patch series.

Thanks.

--
Sincerely,
Yeoreum Yun