Re: [Qemu-devel] [PATCH v3 16/20] intc/arm_gic: Implement gic_update_virt() function

[Peter Maydell]

On 29 June 2018 at 14:29, Luc Michel <address@hidden> wrote:
> Add the gic_update_virt() function to update the vCPU interface states
> and raise vIRQ and vFIQ as needed. This commit renames gic_update() to
> gic_update_internal() and generalizes it to handle both cases, with a
> `virt' parameter to track whether we are updating the CPU or vCPU
> interfaces.
>
> The main difference between CPU and vCPU is the way we select the best
> IRQ. This part has been split into the gic_get_best_(v)irq functions.
> For the virt case, the LRs are iterated to find the best candidate.
>
> Signed-off-by: Luc Michel <address@hidden>
> ---
>  hw/intc/arm_gic.c | 170 +++++++++++++++++++++++++++++++++++-----------
>  1 file changed, 130 insertions(+), 40 deletions(-)


> +
> +/* Return true if IRQ signaling is enabled:
> + *   - !virt -> from the distributor to the CPU interfaces,
> + *              for the given group mask,
> + *   -  virt -> from the given virtual interface to the CPU virtual 
> interface.
> + */
> +static inline bool gic_irq_signaling_enabled(GICState *s, int cpu, bool virt,
> +                                    int group_mask)
> +{
> +    return (virt && (s->h_hcr[cpu] & R_GICH_HCR_EN_MASK))
> +        || (!virt && (s->ctlr & group_mask));
> +}

For a real CPU interface we test the GICC_CTLR EnableGrp0/1 bits here.
For a virt CPU interface shouldn't we test the GICV_CTLR bits ?

(This doesn't actually cause any wrong behaviour because this check
is just an efficiency check: "if interrupts are entirely disabled
then we don't need to do the expensive look-at-all-irqs checks".)


Otherwise looks OK.

thanks
-- PMM