Re: [Xen-devel] [PATCH v2 09/17] arm64: vgic-v3: Add ICV_HPPIR1_EL1 handler

[Marc Zyngier <marc.zyngier@xxxxxxx>]

On 27/03/18 10:07, Manish Jaggi wrote:
> This patch is ported from linux to xen
> commit: 2724c11a1df4b22ee966c04809ea0e808f66b04e
> (KVM: arm64: vgic-v3: Add ICV_HPPIR1_EL1 handler)
> 
> Add a handler for reading the guest's view of the ICV_HPPIR1_EL1
> register. This is a simple parsing of the available LRs, extracting the
> highest available interrupt.
> 
> Signed-off-by: Manish Jaggi <manish.jaggi@xxxxxxxxxx>
> ---
>  xen/arch/arm/arm64/vgic-v3-sr.c     | 31 +++++++++++++++++++++++++++++++
>  xen/include/asm-arm/arm64/sysregs.h |  1 +
>  2 files changed, 32 insertions(+)
> 
> diff --git a/xen/arch/arm/arm64/vgic-v3-sr.c b/xen/arch/arm/arm64/vgic-v3-sr.c
> index c67e7c6ada..f11c7646da 100644
> --- a/xen/arch/arm/arm64/vgic-v3-sr.c
> +++ b/xen/arch/arm/arm64/vgic-v3-sr.c
> @@ -674,6 +674,33 @@ static void vreg_emulate_apxr3(struct cpu_user_regs 
> *regs,
>          vgic_v3_write_apxrn(regs, hsr, 3);
>  }
>  
> +static void vgic_v3_read_hppir1(struct cpu_user_regs *regs,
> +                                const union hsr hsr)
> +{
> +    uint64_t lr_val;
> +    int lr, lr_grp, grp;
> +    uint32_t vmcr = READ_SYSREG32(ICH_VMCR_EL2);
> +
> +    grp = vgic_v3_get_group(hsr);
> +    lr = vgic_v3_highest_priority_lr(regs, vmcr, &lr_val);
> +
> +    if ( lr == -1 )
> +        goto spurious;
> +
> +    lr_grp = !!(lr_val & ICH_LR_GROUP);
> +    if ( lr_grp != grp )
> +        lr_val = ICC_IAR1_EL1_SPURIOUS;
> +
> +spurious:
> +    set_user_reg(regs, hsr.sysreg.reg, lr_val & ICH_LR_VIRTUAL_ID_MASK);
> +}
> +
> +static void vreg_emulate_hppir1(struct cpu_user_regs *regs,
> +                                const union hsr hsr)
> +{
> +    vgic_v3_read_hppir1(regs, hsr);
> +}

See why I said that this "emulate" function idea didn't hold much water?

        M.
-- 
Jazz is not dead. It just smells funny...

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