[PATCH 11/27] KVM: arm64: Correctly handle ACCDATA_EL1 traps

[Eric Auger]

Hi Marc,
On 7/12/23 16:57, Marc Zyngier wrote:
> As we blindly reset some HFGxTR_EL2 bits to 0, we also randomly trap
> unsuspecting sysregs that have their trap bits with a negative
> polarity.
>
> ACCDATA_EL1 is one such register that can be accessed by the guest,
> causing a splat on the host as we don't have a proper handler for
> it.
>
> Adding such handler addresses the issue, though there are a number
> of other registers missing as the current architecture documentation
> doesn't describe them yet.
>
> Signed-off-by: Marc Zyngier <maz at kernel.org>
> ---
>  arch/arm64/include/asm/sysreg.h | 2 ++
>  arch/arm64/kvm/sys_regs.c       | 2 ++
>  2 files changed, 4 insertions(+)
>
> diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
> index 6d3d16fac227..d528a79417a0 100644
> --- a/arch/arm64/include/asm/sysreg.h
> +++ b/arch/arm64/include/asm/sysreg.h
> @@ -389,6 +389,8 @@
>  #define SYS_ICC_IGRPEN0_EL1		sys_reg(3, 0, 12, 12, 6)
>  #define SYS_ICC_IGRPEN1_EL1		sys_reg(3, 0, 12, 12, 7)
>  
> +#define SYS_ACCDATA_EL1			sys_reg(3, 0, 13, 0, 5)
> +
>  #define SYS_CNTKCTL_EL1			sys_reg(3, 0, 14, 1, 0)
>  
>  #define SYS_AIDR_EL1			sys_reg(3, 1, 0, 0, 7)
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index bd3431823ec5..3a6f678ca67d 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -2151,6 +2151,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
>  	{ SYS_DESC(SYS_CONTEXTIDR_EL1), access_vm_reg, reset_val, CONTEXTIDR_EL1, 0 },
>  	{ SYS_DESC(SYS_TPIDR_EL1), NULL, reset_unknown, TPIDR_EL1 },
>  
> +	{ SYS_DESC(SYS_ACCDATA_EL1), undef_access },
> +
>  	{ SYS_DESC(SYS_SCXTNUM_EL1), undef_access },
>  
>  	{ SYS_DESC(SYS_CNTKCTL_EL1), NULL, reset_val, CNTKCTL_EL1, 0},
Reviewed-by: Eric Auger <eric.auger at redhat.com>

Eric