qemu-kvm/kvm-vfio-iommufd-Add-support-for-iova_ranges-and-pgsizes.patch

From 49435d4d592bc890f56b69c2290f890c87b5a103 Mon Sep 17 00:00:00 2001
From: Zhenzhong Duan <zhenzhong.duan@intel.com>
Date: Tue, 21 Nov 2023 16:44:05 +0800
Subject: [PATCH 026/101] vfio/iommufd: Add support for iova_ranges and pgsizes
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: 211: IOMMUFD backend backport
RH-Jira: RHEL-19302 RHEL-21057
RH-Acked-by: Cédric Le Goater <clg@redhat.com>
RH-Acked-by: Sebastian Ott <sebott@redhat.com>
RH-Commit: [25/67] 578af0547d97276ccd4936b574c12118fc70d468 (eauger1/centos-qemu-kvm)

Some vIOMMU such as virtio-iommu use IOVA ranges from host side to
setup reserved ranges for passthrough device, so that guest will not
use an IOVA range beyond host support.

Use an uAPI of IOMMUFD to get IOVA ranges of host side and pass to
vIOMMU just like the legacy backend, if this fails, fallback to
64bit IOVA range.

Also use out_iova_alignment returned from uAPI as pgsizes instead of
qemu_real_host_page_size() as a fallback.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
(cherry picked from commit 714e9affa8ae1d84007c8afde7bb10fef9cb883d)
Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 hw/vfio/iommufd.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 55 insertions(+), 1 deletion(-)

diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index 6d31aeac7b..01b448e840 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -261,6 +261,53 @@ static int iommufd_cdev_ram_block_discard_disable(bool state)
     return ram_block_uncoordinated_discard_disable(state);
 }
 
+static int iommufd_cdev_get_info_iova_range(VFIOIOMMUFDContainer *container,
+                                            uint32_t ioas_id, Error **errp)
+{
+    VFIOContainerBase *bcontainer = &container->bcontainer;
+    struct iommu_ioas_iova_ranges *info;
+    struct iommu_iova_range *iova_ranges;
+    int ret, sz, fd = container->be->fd;
+
+    info = g_malloc0(sizeof(*info));
+    info->size = sizeof(*info);
+    info->ioas_id = ioas_id;
+
+    ret = ioctl(fd, IOMMU_IOAS_IOVA_RANGES, info);
+    if (ret && errno != EMSGSIZE) {
+        goto error;
+    }
+
+    sz = info->num_iovas * sizeof(struct iommu_iova_range);
+    info = g_realloc(info, sizeof(*info) + sz);
+    info->allowed_iovas = (uintptr_t)(info + 1);
+
+    ret = ioctl(fd, IOMMU_IOAS_IOVA_RANGES, info);
+    if (ret) {
+        goto error;
+    }
+
+    iova_ranges = (struct iommu_iova_range *)(uintptr_t)info->allowed_iovas;
+
+    for (int i = 0; i < info->num_iovas; i++) {
+        Range *range = g_new(Range, 1);
+
+        range_set_bounds(range, iova_ranges[i].start, iova_ranges[i].last);
+        bcontainer->iova_ranges =
+            range_list_insert(bcontainer->iova_ranges, range);
+    }
+    bcontainer->pgsizes = info->out_iova_alignment;
+
+    g_free(info);
+    return 0;
+
+error:
+    ret = -errno;
+    g_free(info);
+    error_setg_errno(errp, errno, "Cannot get IOVA ranges");
+    return ret;
+}
+
 static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
                                AddressSpace *as, Error **errp)
 {
@@ -335,7 +382,14 @@ static int iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
         goto err_discard_disable;
     }
 
-    bcontainer->pgsizes = qemu_real_host_page_size();
+    ret = iommufd_cdev_get_info_iova_range(container, ioas_id, &err);
+    if (ret) {
+        error_append_hint(&err,
+                   "Fallback to default 64bit IOVA range and 4K page size\n");
+        warn_report_err(err);
+        err = NULL;
+        bcontainer->pgsizes = qemu_real_host_page_size();
+    }
 
     bcontainer->listener = vfio_memory_listener;
     memory_listener_register(&bcontainer->listener, bcontainer->space->as);
-- 
2.39.3