msix: Assert that specified vector is in range

There were several different ways to deal with the situation where the
vector specified for a msix function is out of bound:
- early return a function and keep progresssing
- propagate the error to the caller
- mark msix unusable
- assert it is in bound
- just ignore

An out-of-bound vector should not be specified if the device
implementation is correct so let msix functions always assert that the
specified vector is in range.

An exceptional case is virtio-pci, which allows the guest to configure
vectors. For virtio-pci, it is more appropriate to introduce its own
checks because it is sometimes too late to check the vector range in
msix functions.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-Id: <20220829083524.143640-1-akihiko.odaki@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Yuval Shaia <yuval.shaia.ml@gmail.com>
Signed-off-by: Akihiko Odaki &lt;<a href="mailto:akihiko.odaki@daynix.com" target="_blank">akihiko.odaki@daynix.com</a>&gt;<br>

1 files changed, 3 insertions, 12 deletions

diff --git a/hw/net/e1000e.c b/hw/net/e1000e.c
index ac96f7665a..7523e9f5d2 100644
--- a/hw/net/e1000e.c
+++ b/hw/net/e1000e.c
@@ -276,25 +276,18 @@ e1000e_unuse_msix_vectors(E1000EState *s, int num_vectors)
     }
 }
 
-static bool
+static void
 e1000e_use_msix_vectors(E1000EState *s, int num_vectors)
 {
     int i;
     for (i = 0; i < num_vectors; i++) {
-        int res = msix_vector_use(PCI_DEVICE(s), i);
-        if (res < 0) {
-            trace_e1000e_msix_use_vector_fail(i, res);
-            e1000e_unuse_msix_vectors(s, i);
-            return false;
-        }
+        msix_vector_use(PCI_DEVICE(s), i);
     }
-    return true;
 }
 
 static void
 e1000e_init_msix(E1000EState *s)
 {
-    PCIDevice *d = PCI_DEVICE(s);
     int res = msix_init(PCI_DEVICE(s), E1000E_MSIX_VEC_NUM,
                         &s->msix,
                         E1000E_MSIX_IDX, E1000E_MSIX_TABLE,
@@ -305,9 +298,7 @@ e1000e_init_msix(E1000EState *s)
     if (res < 0) {
         trace_e1000e_msix_init_fail(res);
     } else {
-        if (!e1000e_use_msix_vectors(s, E1000E_MSIX_VEC_NUM)) {
-            msix_uninit(d, &s->msix, &s->msix);
-        }
+        e1000e_use_msix_vectors(s, E1000E_MSIX_VEC_NUM);
     }
 }