Re: [PATCH 03/13] hw/arm/virt: Remove VirtMachineClass::disallow_affinity_adjustment

[Thomas Huth]

On 15/01/2025 18.09, Philippe Mathieu-Daudé wrote:
> The VirtMachineClass::disallow_affinity_adjustment
> field was only used by virt-2.6 machine, which got
> removed. Remove it along with the GIC*_TARGETLIST_BITS
> definitions, and simplify virt_cpu_mp_affinity().
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   include/hw/arm/virt.h              |  1 -
>   include/hw/intc/arm_gic.h          |  1 -
>   include/hw/intc/arm_gicv3_common.h |  3 ---
>   hw/arm/virt.c                      | 16 ----------------
>   4 files changed, 21 deletions(-)
>
> diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
> index 27c5bb585cb..5d3b25509ff 100644
> --- a/include/hw/arm/virt.h
> +++ b/include/hw/arm/virt.h
> @@ -117,7 +117,6 @@ typedef enum VirtGICType {
>   
>   struct VirtMachineClass {
>       MachineClass parent;
> -    bool disallow_affinity_adjustment;
>       bool no_its;
>       bool no_tcg_its;
>       bool claim_edge_triggered_timers;
> diff --git a/include/hw/intc/arm_gic.h b/include/hw/intc/arm_gic.h
> index 48f6a51a70a..f5e6e5e70b4 100644
> --- a/include/hw/intc/arm_gic.h
> +++ b/include/hw/intc/arm_gic.h
> @@ -68,7 +68,6 @@
>   #include "qom/object.h"
>   
>   /* Number of SGI target-list bits */
> -#define GIC_TARGETLIST_BITS 8
>   #define GIC_MAX_PRIORITY_BITS 8
>   #define GIC_MIN_PRIORITY_BITS 4
>   
> diff --git a/include/hw/intc/arm_gicv3_common.h b/include/hw/intc/arm_gicv3_common.h
> index a3d6a0e5077..fff5e55a97d 100644
> --- a/include/hw/intc/arm_gicv3_common.h
> +++ b/include/hw/intc/arm_gicv3_common.h
> @@ -45,9 +45,6 @@
>   #define GICV3_REDIST_SIZE 0x20000
>   #define GICV4_REDIST_SIZE 0x40000
>   
> -/* Number of SGI target-list bits */
> -#define GICV3_TARGETLIST_BITS 16
> -
>   /* Maximum number of list registers (architectural limit) */
>   #define GICV3_LR_MAX 16
>   
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 0080577e1a9..2a2a0bd9154 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -1760,23 +1760,7 @@ void virt_machine_done(Notifier *notifier, void *data)
>   static uint64_t virt_cpu_mp_affinity(VirtMachineState *vms, int idx)
>   {
>       uint8_t clustersz = ARM_DEFAULT_CPUS_PER_CLUSTER;
> -    VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);
>   
> -    if (!vmc->disallow_affinity_adjustment) {

I think this change is wrong - disallow_affinity_adjustment is false for 
newer machines, so you removed code here that is still in use on newer machines?

 Thomas

> -        /* Adjust MPIDR like 64-bit KVM hosts, which incorporate the
> -         * GIC's target-list limitations. 32-bit KVM hosts currently
> -         * always create clusters of 4 CPUs, but that is expected to
> -         * change when they gain support for gicv3. When KVM is enabled
> -         * it will override the changes we make here, therefore our
> -         * purposes are to make TCG consistent (with 64-bit KVM hosts)
> -         * and to improve SGI efficiency.
> -         */
> -        if (vms->gic_version == VIRT_GIC_VERSION_2) {
> -            clustersz = GIC_TARGETLIST_BITS;
> -        } else {
> -            clustersz = GICV3_TARGETLIST_BITS;
> -        }
> -    }
>       return arm_build_mp_affinity(idx, clustersz);
>   }
>