From b681247c29b59af40c86f8f0ae5709138ae9bf1a Mon Sep 17 00:00:00 2001
From: Zhenzhong Duan <zhenzhong.duan@intel.com>
Date: Thu, 23 Jun 2022 10:31:52 +0800
Subject: [PATCH 04/17] virtio-iommu: Fix the partial copy of probe request

RH-Author: Eric Auger <eric.auger@redhat.com>
RH-MergeRequest: 105: virtio-iommu: Fix bypass mode for assigned devices
RH-Commit: [4/5] c402164414a8e69bbb6df20af3c2b6d2589d6f3e (eauger1/centos-qemu-kvm)
RH-Bugzilla: 2100106
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Acked-by: Peter Xu <peterx@redhat.com>
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2100106

The structure of probe request doesn't include the tail, this leads
to a few field missed to be copied. Currently this isn't an issue as
those missed field belong to reserved field, just in case reserved
field will be used in the future.

Changed 4th parameter of virtio_iommu_iov_to_req() to receive size
of device-readable part.

Fixes: 1733eebb9e75b ("virtio-iommu: Implement RESV_MEM probe request")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Message-Id: <20220623023152.3473231-1-zhenzhong.duan@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
(cherry picked from commit 45461aace83d961e933b27519b81d17b4c690514)
Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 hw/virtio/virtio-iommu.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
index e970d4d5a6..44a041dec9 100644
--- a/hw/virtio/virtio-iommu.c
+++ b/hw/virtio/virtio-iommu.c
@@ -676,11 +676,10 @@ static int virtio_iommu_probe(VirtIOIOMMU *s,
 
 static int virtio_iommu_iov_to_req(struct iovec *iov,
                                    unsigned int iov_cnt,
-                                   void *req, size_t req_sz)
+                                   void *req, size_t payload_sz)
 {
-    size_t sz, payload_sz = req_sz - sizeof(struct virtio_iommu_req_tail);
+    size_t sz = iov_to_buf(iov, iov_cnt, 0, req, payload_sz);
 
-    sz = iov_to_buf(iov, iov_cnt, 0, req, payload_sz);
     if (unlikely(sz != payload_sz)) {
         return VIRTIO_IOMMU_S_INVAL;
     }
@@ -693,7 +692,8 @@ static int virtio_iommu_handle_ ## __req(VirtIOIOMMU *s,                \
                                          unsigned int iov_cnt)          \
 {                                                                       \
     struct virtio_iommu_req_ ## __req req;                              \
-    int ret = virtio_iommu_iov_to_req(iov, iov_cnt, &req, sizeof(req)); \
+    int ret = virtio_iommu_iov_to_req(iov, iov_cnt, &req,               \
+                    sizeof(req) - sizeof(struct virtio_iommu_req_tail));\
                                                                         \
     return ret ? ret : virtio_iommu_ ## __req(s, &req);                 \
 }
-- 
2.31.1