qemu/intel_iommu-Check-compatibility-with-host-IOMMU-capa.patch

From 4ef1b086272552378c09356b0e9fd2548a27a621 Mon Sep 17 00:00:00 2001
From: Zhenzhong Duan <zhenzhong.duan@intel.com>
Date: Wed, 5 Jun 2024 16:30:43 +0800
Subject: [PATCH] intel_iommu: Check compatibility with host IOMMU capabilities

If check fails, host device (either VFIO or VDPA device) is not
compatible with current vIOMMU config and should not be passed to
guest.

Only aw_bits is checked for now, we don't care about other caps
before scalable modern mode is introduced.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/i386/intel_iommu.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index bdc14f8438..60d86e0cb6 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -3838,6 +3838,30 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus,
     return vtd_dev_as;
 }
 
+static bool vtd_check_hiod(IntelIOMMUState *s, HostIOMMUDevice *hiod,
+                           Error **errp)
+{
+    HostIOMMUDeviceClass *hiodc = HOST_IOMMU_DEVICE_GET_CLASS(hiod);
+    int ret;
+
+    if (!hiodc->get_cap) {
+        error_setg(errp, ".get_cap() not implemented");
+        return false;
+    }
+
+    /* Common checks */
+    ret = hiodc->get_cap(hiod, HOST_IOMMU_DEVICE_CAP_AW_BITS, 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);
+        return false;
+    }
+
+    return true;
+}
+
 static bool vtd_dev_set_iommu_device(PCIBus *bus, void *opaque, int devfn,
                                      HostIOMMUDevice *hiod, Error **errp)
 {
@@ -3858,6 +3882,11 @@ static bool vtd_dev_set_iommu_device(PCIBus *bus, void *opaque, int devfn,
         return false;
     }
 
+    if (!vtd_check_hiod(s, hiod, errp)) {
+        vtd_iommu_unlock(s);
+        return false;
+    }
+
     new_key = g_malloc(sizeof(*new_key));
     new_key->bus = bus;
     new_key->devfn = devfn;
-- 
2.41.0.windows.1