MFC 290948:

Only use a power of 2 for the number of receive and transmit queues.
Using other values causes VMXNET3_CMD_ENABLE to fail.  The Linux
driver also enforces this restriction.

1 files changed, 9 insertions, 2 deletions

diff --git a/sys/dev/vmware/vmxnet3/if_vmx.c b/sys/dev/vmware/vmxnet3/if_vmx.c
index 202bc8e..e92cc00 100644
--- a/sys/dev/vmware/vmxnet3/if_vmx.c
+++ b/sys/dev/vmware/vmxnet3/if_vmx.c
@@ -511,6 +511,13 @@ vmxnet3_check_version(struct vmxnet3_softc *sc)
 	return (0);
 }
 
+static int
+trunc_powerof2(int val)
+{
+
+	return (1U << (fls(val) - 1));
+}
+
 static void
 vmxnet3_initial_config(struct vmxnet3_softc *sc)
 {
@@ -521,14 +528,14 @@ vmxnet3_initial_config(struct vmxnet3_softc *sc)
 		nqueue = VMXNET3_DEF_TX_QUEUES;
 	if (nqueue > mp_ncpus)
 		nqueue = mp_ncpus;
-	sc->vmx_max_ntxqueues = nqueue;
+	sc->vmx_max_ntxqueues = trunc_powerof2(nqueue);
 
 	nqueue = vmxnet3_tunable_int(sc, "rxnqueue", vmxnet3_default_rxnqueue);
 	if (nqueue > VMXNET3_MAX_RX_QUEUES || nqueue < 1)
 		nqueue = VMXNET3_DEF_RX_QUEUES;
 	if (nqueue > mp_ncpus)
 		nqueue = mp_ncpus;
-	sc->vmx_max_nrxqueues = nqueue;
+	sc->vmx_max_nrxqueues = trunc_powerof2(nqueue);
 
 	if (vmxnet3_tunable_int(sc, "mq_disable", vmxnet3_mq_disable)) {
 		sc->vmx_max_nrxqueues = 1;