> On 6. Nov 2025, at 10:40, Gustavo Romero <gustavo.romero@linaro.org> wrote:
>
> Hi Mohamed and Phil,
>
> On 10/29/25 17:54, Mohamed Mediouni wrote:
>> Looks like in the prior Qemu ACPI table handling, GICv2 configurations
>> had vms->its=1...
>
> To me, ITS should not be present on machines that have GICv2, so we should not generate
> any ACPI table advertising ITS when GICv2 is used.
>
The problem is breaking migration/backwards compatibility… is it an ignorable concern or
should be the new behaviour be quirked to apply to only Qemu 11.0 onwards?
Thank you,
-Mohamed
> Cheers,
> Gustavo
>
>> Match that assumption to not make the test suite fail. Probably not merge-worthy...
>> And then maybe see what to do for older releases too?
>> Signed-off-by: Mohamed Mediouni <mohamed@unpredictable.fr>
>> ---
>> hw/arm/virt-acpi-build.c | 10 +++++-----
>> 1 file changed, 5 insertions(+), 5 deletions(-)
>> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
>> index a6a56455a9..39dd3d1020 100644
>> --- a/hw/arm/virt-acpi-build.c
>> +++ b/hw/arm/virt-acpi-build.c
>> @@ -472,7 +472,7 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>> nb_nodes = num_smmus + 1; /* RC and SMMUv3 */
>> rc_mapping_count = rc_smmu_idmaps_len;
>> - if (virt_is_its_enabled(vms)) {
>> + if (virt_is_its_enabled(vms) || vms->gic_version == 2) {
>> /*
>> * Knowing the ID ranges from the RC to the SMMU, it's possible to
>> * determine the ID ranges from RC that go directly to ITS.
>> @@ -483,7 +483,7 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>> rc_mapping_count += rc_its_idmaps->len;
>> }
>> } else {
>> - if (virt_is_its_enabled(vms)) {
>> + if (virt_is_its_enabled(vms) || vms->gic_version == 2) {
>> nb_nodes = 2; /* RC and ITS */
>> rc_mapping_count = 1; /* Direct map to ITS */
>> } else {
>> @@ -498,7 +498,7 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>> build_append_int_noprefix(table_data, IORT_NODE_OFFSET, 4);
>> build_append_int_noprefix(table_data, 0, 4); /* Reserved */
>> - if (virt_is_its_enabled(vms)) {
>> + if (virt_is_its_enabled(vms) || vms->gic_version == 2) {
>> /* Table 12 ITS Group Format */
>> build_append_int_noprefix(table_data, 0 /* ITS Group */, 1); /* Type */
>> node_size = 20 /* fixed header size */ + 4 /* 1 GIC ITS Identifier */;
>> @@ -517,7 +517,7 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>> int smmu_mapping_count, offset_to_id_array;
>> int irq = sdev->irq;
>> - if (virt_is_its_enabled(vms)) {
>> + if (virt_is_its_enabled(vms) || vms->gic_version == 2) {
>> smmu_mapping_count = 1; /* ITS Group node */
>> offset_to_id_array = SMMU_V3_ENTRY_SIZE; /* Just after the header */
>> } else {
>> @@ -610,7 +610,7 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>> }
>> }
>> - if (virt_is_its_enabled(vms)) {
>> + if (virt_is_its_enabled(vms) || vms->gic_version == 2) {
>> /*
>> * Map bypassed (don't go through the SMMU) RIDs (input) to
>> * ITS Group node directly: RC -> ITS.
>
>