[PATCH v6 31/33] Extend get_cap() callback to support PASID

[Shameer Kolothum <skolothumtho@nvidia.com>]

Modify get_cap() callback so that it can return cap via an output
uint64_t param. And add support for generic iommu hw capability
info and max_pasid_log2(pasid width).

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
---
 backends/iommufd.c                 | 23 ++++++++++++++++++-----
 hw/i386/intel_iommu.c              |  8 +++++---
 hw/vfio/container-legacy.c         |  8 ++++++--
 include/system/host_iommu_device.h | 18 ++++++++++++------
 4 files changed, 41 insertions(+), 16 deletions(-)

diff --git a/backends/iommufd.c b/backends/iommufd.c
index 6381f9664b..718d63f5cf 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -523,19 +523,32 @@ bool host_iommu_device_iommufd_detach_hwpt(HostIOMMUDeviceIOMMUFD *idev,
     return idevc->detach_hwpt(idev, errp);
 }
 
-static int hiod_iommufd_get_cap(HostIOMMUDevice *hiod, int cap, Error **errp)
+static int hiod_iommufd_get_cap(HostIOMMUDevice *hiod, int cap_id,
+                                uint64_t *out_cap, Error **errp)
 {
     HostIOMMUDeviceCaps *caps = &hiod->caps;
 
-    switch (cap) {
+    g_assert(out_cap);
+
+    switch (cap_id) {
     case HOST_IOMMU_DEVICE_CAP_IOMMU_TYPE:
-        return caps->type;
+        *out_cap = caps->type;
+        break;
     case HOST_IOMMU_DEVICE_CAP_AW_BITS:
-        return vfio_device_get_aw_bits(hiod->agent);
+        *out_cap = vfio_device_get_aw_bits(hiod->agent);
+        break;
+    case HOST_IOMMU_DEVICE_CAP_GENERIC_HW:
+        *out_cap = caps->hw_caps;
+        break;
+    case HOST_IOMMU_DEVICE_CAP_MAX_PASID_LOG2:
+        *out_cap = caps->max_pasid_log2;
+        break;
     default:
-        error_setg(errp, "%s: unsupported capability %x", hiod->name, cap);
+        *out_cap = 0;
+        error_setg(errp, "%s: unsupported capability %x", hiod->name, cap_id);
         return -EINVAL;
     }
+    return 0;
 }
 
 static void hiod_iommufd_class_init(ObjectClass *oc, const void *data)
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 78b142ccea..d5c131a814 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -4605,6 +4605,7 @@ static bool vtd_check_hiod(IntelIOMMUState *s, HostIOMMUDevice *hiod,
                            Error **errp)
 {
     HostIOMMUDeviceClass *hiodc = HOST_IOMMU_DEVICE_GET_CLASS(hiod);
+    uint64_t out_cap;
     int ret;
 
     if (!hiodc->get_cap) {
@@ -4613,12 +4614,13 @@ static bool vtd_check_hiod(IntelIOMMUState *s, HostIOMMUDevice *hiod,
     }
 
     /* Common checks */
-    ret = hiodc->get_cap(hiod, HOST_IOMMU_DEVICE_CAP_AW_BITS, errp);
+    ret = hiodc->get_cap(hiod, HOST_IOMMU_DEVICE_CAP_AW_BITS, &out_cap, errp);
     if (ret < 0) {
         return false;
     }
-    if (s->aw_bits > ret) {
-        error_setg(errp, "aw-bits %d > host aw-bits %d", s->aw_bits, ret);
+    if (s->aw_bits > out_cap) {
+        error_setg(errp, "aw-bits %d > host aw-bits 0x%" PRIx64, s->aw_bits,
+                   out_cap);
         return false;
     }
 
diff --git a/hw/vfio/container-legacy.c b/hw/vfio/container-legacy.c
index 32c260b345..1acf063762 100644
--- a/hw/vfio/container-legacy.c
+++ b/hw/vfio/container-legacy.c
@@ -1203,15 +1203,19 @@ static bool hiod_legacy_vfio_realize(HostIOMMUDevice *hiod, void *opaque,
 }
 
 static int hiod_legacy_vfio_get_cap(HostIOMMUDevice *hiod, int cap,
-                                    Error **errp)
+                                    uint64_t *out_cap, Error **errp)
 {
+    g_assert(out_cap);
+
     switch (cap) {
     case HOST_IOMMU_DEVICE_CAP_AW_BITS:
-        return vfio_device_get_aw_bits(hiod->agent);
+        *out_cap = vfio_device_get_aw_bits(hiod->agent);
+        break;
     default:
         error_setg(errp, "%s: unsupported capability %x", hiod->name, cap);
         return -EINVAL;
     }
+    return 0;
 }
 
 static GList *
diff --git a/include/system/host_iommu_device.h b/include/system/host_iommu_device.h
index bfb2b60478..4e891e5225 100644
--- a/include/system/host_iommu_device.h
+++ b/include/system/host_iommu_device.h
@@ -88,19 +88,21 @@ struct HostIOMMUDeviceClass {
      * @get_cap: check if a host IOMMU device capability is supported.
      *
      * Optional callback, if not implemented, hint not supporting query
-     * of @cap.
+     * of @cap_id.
      *
      * @hiod: pointer to a host IOMMU device instance.
      *
-     * @cap: capability to check.
+     * @cap_id: capability to check.
+     *
+     * @out_cap: 0 if a @cap_id is unsupported or else the capability
+     * value for @cap_id.
      *
      * @errp: pass an Error out when fails to query capability.
      *
-     * Returns: <0 on failure, 0 if a @cap is unsupported, or else
-     * 1 or some positive value for some special @cap,
-     * i.e., HOST_IOMMU_DEVICE_CAP_AW_BITS.
+     * Returns: <0 if @cap_id is not supported, 0 on success.
      */
-    int (*get_cap)(HostIOMMUDevice *hiod, int cap, Error **errp);
+    int (*get_cap)(HostIOMMUDevice *hiod, int cap_id, uint64_t *out_cap,
+                   Error **errp);
     /**
      * @get_iova_ranges: Return the list of usable iova_ranges along with
      * @hiod Host IOMMU device
@@ -123,6 +125,10 @@ struct HostIOMMUDeviceClass {
  */
 #define HOST_IOMMU_DEVICE_CAP_IOMMU_TYPE        0
 #define HOST_IOMMU_DEVICE_CAP_AW_BITS           1
+/* Generic IOMMU HW capability info */
+#define HOST_IOMMU_DEVICE_CAP_GENERIC_HW        2
+/* PASID width */
+#define HOST_IOMMU_DEVICE_CAP_MAX_PASID_LOG2    3
 
 #define HOST_IOMMU_DEVICE_CAP_AW_BITS_MAX       64
 #endif
-- 
2.43.0