On 3/18/26 7:49 PM, Nathan Chen wrote:
> From: Nathan Chen <[email protected]>
>
> Change accel SMMUv3 SSIDSIZE property from uint8_t to SsidSizeMode.
> The 'auto' value is not implemented, as this commit is meant to set the
> property to the correct type and avoid breaking JSON/QMP when the auto
> mode is introduced. A future patch will implement resolution of 'auto'
> value to match the host SMMUv3 SSIDSIZE value.
>
> Fixes: b8c6f8a69d27 ("hw/arm/smmuv3-accel: Make SubstreamID support
> configurable")
> Tested-by: Eric Auger <[email protected]>
> Signed-off-by: Nathan Chen <[email protected]>
Reviewed-by: Eric Auger <[email protected]>
Eric
> ---
> hw/arm/smmuv3-accel.c | 23 +++++++++++++++++++++--
> hw/arm/smmuv3.c | 19 ++++++++++---------
> include/hw/arm/smmuv3-common.h | 1 -
> include/hw/arm/smmuv3.h | 3 ++-
> 4 files changed, 33 insertions(+), 13 deletions(-)
>
> diff --git a/hw/arm/smmuv3-accel.c b/hw/arm/smmuv3-accel.c
> index c31b64295e..bc6cbfebc2 100644
> --- a/hw/arm/smmuv3-accel.c
> +++ b/hw/arm/smmuv3-accel.c
> @@ -802,7 +802,7 @@ static uint64_t smmuv3_accel_get_viommu_flags(void
> *opaque)
> SMMUState *bs = opaque;
> SMMUv3State *s = ARM_SMMUV3(bs);
>
> - if (s->ssidsize) {
> + if (s->ssidsize > SSID_SIZE_MODE_0) {
> flags |= VIOMMU_FLAG_PASID_SUPPORTED;
> }
> return flags;
> @@ -817,6 +817,22 @@ static const PCIIOMMUOps smmuv3_accel_ops = {
> .get_msi_direct_gpa = smmuv3_accel_get_msi_gpa,
> };
>
> +/*
> + * This returns the value of a SsidSizeMode value offset by 1 to
> + * account for the enum values offset by 1 from actual values.
> + *
> + * SSID_SIZE_MODE_0 = 1, SSID_SIZE_MODE_1 = 2, etc. so return 0
> + * if SSID_SIZE_MODE_0 is passed as input, return 1 if
> + * SSID_SIZE_MODE_1 is passed as input, etc.
> + */
> +static uint8_t ssidsize_mode_to_value(SsidSizeMode mode)
> +{
> + if (mode == SSID_SIZE_MODE_AUTO) {
> + return 0;
> + }
> + return mode - 1;
> +}
> +
> void smmuv3_accel_idr_override(SMMUv3State *s)
> {
> if (!s->accel) {
> @@ -842,7 +858,10 @@ void smmuv3_accel_idr_override(SMMUv3State *s)
> * By default QEMU SMMUv3 has no SubstreamID support. Update IDR1 if user
> * has enabled it.
> */
> - s->idr[1] = FIELD_DP32(s->idr[1], IDR1, SSIDSIZE, s->ssidsize);
> + if (s->ssidsize > SSID_SIZE_MODE_0) {
> + s->idr[1] = FIELD_DP32(s->idr[1], IDR1, SSIDSIZE,
> + ssidsize_mode_to_value(s->ssidsize));
> + }
> }
>
> /* Based on SMUUv3 GPBA.ABORT configuration, attach a corresponding HWPT */
> diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
> index ea285bdf64..79018f8d66 100644
> --- a/hw/arm/smmuv3.c
> +++ b/hw/arm/smmuv3.c
> @@ -20,6 +20,7 @@
> #include "qemu/bitops.h"
> #include "hw/core/irq.h"
> #include "hw/core/sysbus.h"
> +#include "hw/core/qdev-properties-system.h"
> #include "migration/blocker.h"
> #include "migration/vmstate.h"
> #include "hw/core/qdev-properties.h"
> @@ -625,7 +626,7 @@ static int decode_ste(SMMUv3State *s, SMMUTransCfg *cfg,
> }
>
> /* Multiple context descriptors require SubstreamID support */
> - if (!s->ssidsize && STE_S1CDMAX(ste) != 0) {
> + if (s->ssidsize == SSID_SIZE_MODE_0 && STE_S1CDMAX(ste) != 0) {
> qemu_log_mask(LOG_UNIMP,
> "SMMUv3: multiple S1 context descriptors require SubstreamID
> support. "
> "Configure ssidsize > 0 (requires accel=on)\n");
> @@ -1979,6 +1980,10 @@ static bool smmu_validate_property(SMMUv3State *s,
> Error **errp)
> error_setg(errp, "ril auto mode is not supported");
> return false;
> }
> + if (s->ssidsize == SSID_SIZE_MODE_AUTO) {
> + error_setg(errp, "ssidsize auto mode is not supported");
> + return false;
> + }
>
> if (!s->accel) {
> if (s->ril == ON_OFF_AUTO_OFF) {
> @@ -1993,7 +1998,7 @@ static bool smmu_validate_property(SMMUv3State *s,
> Error **errp)
> error_setg(errp, "OAS must be 44 bits when accel=off");
> return false;
> }
> - if (s->ssidsize) {
> + if (s->ssidsize > SSID_SIZE_MODE_0) {
> error_setg(errp, "ssidsize can only be set if accel=on");
> return false;
> }
> @@ -2011,11 +2016,6 @@ static bool smmu_validate_property(SMMUv3State *s,
> Error **errp)
> error_setg(errp, "OAS can only be set to 44 or 48 bits");
> return false;
> }
> - if (s->ssidsize > SMMU_SSID_MAX_BITS) {
> - error_setg(errp, "ssidsize must be in the range 0 to %d",
> - SMMU_SSID_MAX_BITS);
> - return false;
> - }
>
> return true;
> }
> @@ -2144,7 +2144,8 @@ static const Property smmuv3_properties[] = {
> DEFINE_PROP_ON_OFF_AUTO("ril", SMMUv3State, ril, ON_OFF_AUTO_ON),
> DEFINE_PROP_ON_OFF_AUTO("ats", SMMUv3State, ats, ON_OFF_AUTO_OFF),
> DEFINE_PROP_UINT8("oas", SMMUv3State, oas, 44),
> - DEFINE_PROP_UINT8("ssidsize", SMMUv3State, ssidsize, 0),
> + DEFINE_PROP_SSIDSIZE_MODE("ssidsize", SMMUv3State, ssidsize,
> + SSID_SIZE_MODE_0),
> };
>
> static void smmuv3_instance_init(Object *obj)
> @@ -2185,7 +2186,7 @@ static void smmuv3_class_init(ObjectClass *klass, const
> void *data)
> "A value of N allows SSIDs in the range [0 .. 2^N - 1]. "
> "Valid range is 0-20, where 0 disables SubstreamID support. "
> "Defaults to 0. A value greater than 0 is required to enable "
> - "PASID support.");
> + "PASID support. ssidsize=auto is not supported.");
> }
>
> static int smmuv3_notify_flag_changed(IOMMUMemoryRegion *iommu,
> diff --git a/include/hw/arm/smmuv3-common.h b/include/hw/arm/smmuv3-common.h
> index 9f78bbe89e..7f0f992dfd 100644
> --- a/include/hw/arm/smmuv3-common.h
> +++ b/include/hw/arm/smmuv3-common.h
> @@ -311,7 +311,6 @@ REG32(IDR1, 0x4)
> FIELD(IDR1, TABLES_PRESET, 30, 1)
> FIELD(IDR1, ECMDQ, 31, 1)
>
> -#define SMMU_SSID_MAX_BITS 20
> #define SMMU_IDR1_SIDSIZE 16
> #define SMMU_CMDQS 19
> #define SMMU_EVENTQS 19
> diff --git a/include/hw/arm/smmuv3.h b/include/hw/arm/smmuv3.h
> index c35e599bbc..ddf472493d 100644
> --- a/include/hw/arm/smmuv3.h
> +++ b/include/hw/arm/smmuv3.h
> @@ -21,6 +21,7 @@
>
> #include "hw/arm/smmu-common.h"
> #include "qom/object.h"
> +#include "qapi/qapi-types-misc-arm.h"
>
> #define TYPE_SMMUV3_IOMMU_MEMORY_REGION "smmuv3-iommu-memory-region"
>
> @@ -72,7 +73,7 @@ struct SMMUv3State {
> OnOffAuto ril;
> OnOffAuto ats;
> uint8_t oas;
> - uint8_t ssidsize;
> + SsidSizeMode ssidsize;
> };
>
> typedef enum {
