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Re: [Qemu-arm] [PATCH v5 2/2] arm_gicv3_kvm: kvm_dist_get/put: skip the
From: |
Peter Maydell |
Subject: |
Re: [Qemu-arm] [PATCH v5 2/2] arm_gicv3_kvm: kvm_dist_get/put: skip the registers banked by GICR |
Date: |
Thu, 31 May 2018 14:50:32 +0100 |
On 31 May 2018 at 04:15, Shannon Zhao <address@hidden> wrote:
> While we skip the GIC_INTERNAL irqs, we don't change the register offset
> accordingly. This will overlap the GICR registers value and leave the
> last GIC_INTERNAL irq's registers out of update.
>
> Fix this by skipping the registers banked by GICR.
>
> Also for migration compatibility if the migration source (old version
> qemu) doesn't send gicd_no_migration_shift_bug = 1 to destination, then
> we shift the data of PPI to get the right data for SPI.
>
> Fixes: 367b9f527becdd20ddf116e17a3c0c2bbc486920
> Cc: address@hidden
> Signed-off-by: Shannon Zhao <address@hidden>
> + /*
> + * While this new version QEMU doesn't have this kind of bug as we fix
> it,
> + * so it's need to set the flag to true to indicate that and it's
> neccessary
> + * for next migration to work from this new version QEMU.
> + */
> + cs->gicd_no_migration_shift_bug = true;
Nice catch; I would have forgotten that we needed to do this...
>
> + /* For the KVM GICv3, affinity routing is always enabled, and the
> + * GICD_IGROUPR0/GICD_IGRPMODR0/GICD_ISENABLER0/GICD_ISPENDR0/
> + * GICD_ISACTIVER0 registers are always RAZ/WI. The corresponding
> + * functionality is replaced by the GICR registers. It doesn't need to
> sync
> + * them. So it should increase the offset to skip GIC_INTERNAL irqs.
> + * This matches the for_each_dist_irq_reg() macro which also skips the
> + * first GIC_INTERNAL irqs.
> + */
> + offset += (GIC_INTERNAL * 1) / 8;
> + if (clroffset != 0) {
> + clroffset += (1 * sizeof(uint32_t));
> + }
> +
Shouldn't we be adding the same thing to clroffset that we add to offset ?
Otherwise
Reviewed-by: Peter Maydell <address@hidden>
thanks
-- PMM