Hi Shameer,
On 9/4/26 8:05 PM, Shameer Kolothum wrote:
> Add a subsection carrying idr[0] to idr[5], needed when accel=on. pre_load
I would explain what you try to achieve before the how.
> saves the locally resolved values and post_load fails the migration if the
> incoming ones differ. Accepting the source values would leave QEMU
> advertising features the destination host cannot provide.
>
> Signed-off-by: Shameer Kolothum <[email protected]>
> ---
> hw/arm/smmuv3-accel.h | 1 +
> include/hw/arm/smmuv3.h | 7 ++++-
> hw/arm/smmuv3-accel-stubs.c | 12 ++++++++
> hw/arm/smmuv3-accel.c | 58 +++++++++++++++++++++++++++++++++++++
> hw/arm/smmuv3.c | 1 +
> 5 files changed, 78 insertions(+), 1 deletion(-)
>
> diff --git a/hw/arm/smmuv3-accel.h b/hw/arm/smmuv3-accel.h
> index ea11d513cc..a91d188d61 100644
> --- a/hw/arm/smmuv3-accel.h
> +++ b/hw/arm/smmuv3-accel.h
> @@ -99,6 +99,7 @@ void smmuv3_accel_idr_override(SMMUv3State *s);
> bool smmuv3_accel_alloc_veventq(SMMUv3State *s, Error **errp);
> int smmuv3_accel_event_read_validate(IOMMUFDVeventq *veventq, uint32_t type,
> void *buf, size_t size, Error **errp);
> +extern const VMStateDescription vmstate_smmuv3_accel;
> void smmuv3_accel_reset(SMMUv3State *s);
> SMMUv3AccelCmdqvType smmuv3_accel_cmdqv_type(Object *obj);
>
> diff --git a/include/hw/arm/smmuv3.h b/include/hw/arm/smmuv3.h
> index d39fe8850b..9e0836b81a 100644
> --- a/include/hw/arm/smmuv3.h
> +++ b/include/hw/arm/smmuv3.h
> @@ -26,6 +26,9 @@
>
> #define TYPE_SMMUV3_IOMMU_MEMORY_REGION "smmuv3-iommu-memory-region"
>
> +/* Number of IDR registers, IDR0 to IDR5 */
> +#define SMMU_NUM_IDR 6
> +
> typedef struct SMMUQueue {
> uint64_t base; /* base register */
> uint32_t prod;
> @@ -41,7 +44,9 @@ struct SMMUv3State {
> uint8_t sid_size;
> uint8_t sid_split;
>
> - uint32_t idr[6];
> + uint32_t idr[SMMU_NUM_IDR];
> + /* Locally resolved IDRs, saved by pre_load for post_load to check */
> + uint32_t local_idr[SMMU_NUM_IDR];
> uint32_t iidr;
> uint32_t aidr;
> uint32_t cr[3];
> diff --git a/hw/arm/smmuv3-accel-stubs.c b/hw/arm/smmuv3-accel-stubs.c
> index b8dd7e7b89..b57b5c01e7 100644
> --- a/hw/arm/smmuv3-accel-stubs.c
> +++ b/hw/arm/smmuv3-accel-stubs.c
> @@ -8,6 +8,7 @@
> #include "qapi/error.h"
> #include "hw/arm/smmuv3.h"
> #include "hw/arm/smmuv3-accel.h"
> +#include "migration/vmstate.h"
>
> bool smmuv3_accel_init(SMMUv3State *s, Error **errp)
> {
> @@ -53,6 +54,17 @@ int smmuv3_accel_event_read_validate(IOMMUFDVeventq
> *veventq, uint32_t type,
> return 0;
> }
>
> +static bool smmuv3_accel_vmstate_needed(void *opaque)
> +{
> + return false;
> +}
> +
> +const VMStateDescription vmstate_smmuv3_accel = {
> + .name = "smmuv3/accel",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .needed = smmuv3_accel_vmstate_needed,
> +};
>
> void smmuv3_accel_reset(SMMUv3State *s)
> {
> diff --git a/hw/arm/smmuv3-accel.c b/hw/arm/smmuv3-accel.c
> index 73509dbd8d..287ea91fbe 100644
> --- a/hw/arm/smmuv3-accel.c
> +++ b/hw/arm/smmuv3-accel.c
> @@ -18,6 +18,7 @@
>
> #include "smmuv3-internal.h"
> #include "smmuv3-accel.h"
> +#include "migration/vmstate.h"
> #include "system/runstate.h"
> #include "system/system.h"
> #include "tegra241-cmdqv.h"
> @@ -1096,6 +1097,63 @@ bool smmuv3_accel_attach_gbpa_hwpt(SMMUv3State *s,
> Error **errp)
> return all_ok;
> }
>
> +static bool smmuv3_accel_vmstate_pre_load(void *opaque, Error **errp)
> +{
> + SMMUv3State *s = opaque;
> +
> + if (!s->s_accel) {
> + error_setg(errp, "Incoming stream carries SMMUv3 accelerator state "
> + "but this arm-smmuv3 has accel=off");
> + return false;
> + }
> +
> + /* Save the locally resolved IDRs before the stream overwrites them. */
> + memcpy(s->local_idr, s->idr, sizeof(s->idr));
> + return true;
> +}
> +
> +static bool smmuv3_accel_vmstate_post_load(void *opaque, int version_id,
> + Error **errp)
> +{
> + ERRP_GUARD();
> + SMMUv3State *s = opaque;
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(s->idr); i++) {
> + if (s->idr[i] == s->local_idr[i]) {
> + continue;
> + }
> + error_setg(errp, "SMMUv3 IDR%d mismatch: source 0x%08x, "
> + "destination 0x%08x", i, s->idr[i],
> + s->local_idr[i]);
> + error_append_hint(errp, "ril, ats, oas and ssidsize must resolve to "
> + "the same values on source and destination.\n");
don't you want to be more precise then and just check the corresponding
fields?
> + return false;
> + }
> +
> + return true;
> +}
> +
> +static bool smmuv3_accel_vmstate_needed(void *opaque)
> +{
> + SMMUv3State *s = opaque;
> +
> + return s->accel;
> +}
> +
> +const VMStateDescription vmstate_smmuv3_accel = {
> + .name = "smmuv3/accel",
> + .version_id = 1,
> + .minimum_version_id = 1,
> + .needed = smmuv3_accel_vmstate_needed,
> + .pre_load_errp = smmuv3_accel_vmstate_pre_load,
> + .post_load_errp = smmuv3_accel_vmstate_post_load,
> + .fields = (const VMStateField[]) {
> + VMSTATE_UINT32_ARRAY(idr, SMMUv3State, SMMU_NUM_IDR),
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +
> void smmuv3_accel_reset(SMMUv3State *s)
> {
> SMMUv3AccelState *accel = s->s_accel;
> diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
> index ed19536a4d..66d95e1076 100644
> --- a/hw/arm/smmuv3.c
> +++ b/hw/arm/smmuv3.c
> @@ -2137,6 +2137,7 @@ static const VMStateDescription vmstate_smmuv3 = {
> },
> .subsections = (const VMStateDescription * const []) {
> &vmstate_gbpa,
> + &vmstate_smmuv3_accel,
> NULL
> }
> };
Thanks
Eric
