qemu-kvm/kvm-backends-iommufd-Add-get_pasid_info-callback.patch

From e614aef2ad181cc80c1688ebbf568d5eed193e37 Mon Sep 17 00:00:00 2001
From: Shameer Kolothum <skolothumtho@nvidia.com>
Date: Thu, 29 Jan 2026 13:32:05 +0000
Subject: [PATCH 041/111] backends/iommufd: Add get_pasid_info() callback
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

RH-Author: Eric Auger <eric.auger@redhat.com>
RH-MergeRequest: 505: SMMU Rebase for accelerated SMMU and CMDQV support
RH-Jira: RHEL-142465 RHEL-160190 RHEL-163596 RHEL-73794 RHEL-73796 RHEL-73798
RH-Acked-by: Cédric Le Goater <clg@redhat.com>
RH-Acked-by: Gavin Shan <gshan@redhat.com>
RH-Commit: [41/111] 3c436702f4ac6d8819ba999b7503a98efb770fec (eauger1/centos-qemu-kvm)

JIRA: https://redhat.atlassian.net/browse/RHEL-73794

The get_pasid_info callback retrieves PASID capability information
when the HostIOMMUDevice backend supports it. Currently, only the
Linux IOMMUFD backend provides this information.

This will be used by a subsequent patch to synthesize a PASID
capability for vfio-pci devices behind a vIOMMU that supports PASID.

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Message-id: 20260126104342.253965-34-skolothumtho@nvidia.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
(cherry picked from commit 22afd9d865cb05d93c92c8fca7a23e1eb879e889)
Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 backends/iommufd.c                 | 17 +++++++++++++++++
 include/system/host_iommu_device.h | 17 +++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/backends/iommufd.c b/backends/iommufd.c
index 6381f9664b..f1707eadc6 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -538,11 +538,28 @@ static int hiod_iommufd_get_cap(HostIOMMUDevice *hiod, int cap, Error **errp)
     }
 }
 
+static bool hiod_iommufd_get_pasid_info(HostIOMMUDevice *hiod,
+                                        PasidInfo *pasid_info)
+{
+    HostIOMMUDeviceCaps *caps = &hiod->caps;
+
+    if (!caps->max_pasid_log2) {
+        return false;
+    }
+
+    g_assert(pasid_info);
+    pasid_info->exec_perm = (caps->hw_caps & IOMMU_HW_CAP_PCI_PASID_EXEC);
+    pasid_info->priv_mod = (caps->hw_caps & IOMMU_HW_CAP_PCI_PASID_PRIV);
+    pasid_info->max_pasid_log2 = caps->max_pasid_log2;
+    return true;
+}
+
 static void hiod_iommufd_class_init(ObjectClass *oc, const void *data)
 {
     HostIOMMUDeviceClass *hioc = HOST_IOMMU_DEVICE_CLASS(oc);
 
     hioc->get_cap = hiod_iommufd_get_cap;
+    hioc->get_pasid_info = hiod_iommufd_get_pasid_info;
 };
 
 static const TypeInfo types[] = {
diff --git a/include/system/host_iommu_device.h b/include/system/host_iommu_device.h
index bfb2b60478..f000301583 100644
--- a/include/system/host_iommu_device.h
+++ b/include/system/host_iommu_device.h
@@ -59,6 +59,12 @@ struct HostIOMMUDevice {
 #endif
 };
 
+typedef struct PasidInfo {
+    bool exec_perm;
+    bool priv_mod;
+    uint8_t max_pasid_log2;
+} PasidInfo;
+
 /**
  * struct HostIOMMUDeviceClass - The base class for all host IOMMU devices.
  *
@@ -116,6 +122,17 @@ struct HostIOMMUDeviceClass {
      * @hiod: handle to the host IOMMU device
      */
     uint64_t (*get_page_size_mask)(HostIOMMUDevice *hiod);
+    /**
+     * @get_pasid_info: Return the PASID information associated with the
+     * @hiod Host IOMMU device.
+     *
+     * @hiod: handle to the host IOMMU device
+     *
+     * @pasid_info: If success, returns the PASID related information.
+     *
+     * Returns: true on success, false on failure.
+     */
+    bool (*get_pasid_info)(HostIOMMUDevice *hiod, PasidInfo *pasid_info);
 };
 
 /*
-- 
2.52.0