Re: [Qemu-devel] [PATCH v3 8/8] vmxnet3: remove unnecessary internal msix state flag

[Markus Armbruster <armbru@redhat.com>]

Cao jin <caoj.fnst@cn.fujitsu.com> writes:

> The corresponding msi flag is already dropped in commit 1070048e.

Repeating the rationale for the change wouldn't hurt:

    Internal flag msix_used is unnecessary, it has the same effect as
    msix_enabled().

    The corresponding msi flag is already dropped in commit 1070048e.

Can hopefully be touched up on commit.

>
> CC: Dmitry Fleytman <dmitry@daynix.com>
> CC: Jason Wang <jasowang@redhat.com>
> CC: Michael S. Tsirkin <mst@redhat.com>
> CC: Markus Armbruster <armbru@redhat.com>
> CC: Marcel Apfelbaum <marcel@redhat.com>
> Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
> ---
>  hw/net/vmxnet3.c | 38 ++++++++++++++------------------------
>  1 file changed, 14 insertions(+), 24 deletions(-)
>
> diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c
> index 7d44af1..1decb53 100644
> --- a/hw/net/vmxnet3.c
> +++ b/hw/net/vmxnet3.c
> @@ -281,8 +281,6 @@ typedef struct {
>          Vmxnet3RxqDescr rxq_descr[VMXNET3_DEVICE_MAX_RX_QUEUES];
>          Vmxnet3TxqDescr txq_descr[VMXNET3_DEVICE_MAX_TX_QUEUES];
>  
> -        /* Whether MSI-X support was installed successfully */
> -        bool msix_used;
>          hwaddr drv_shmem;
>          hwaddr temp_shared_guest_driver_memory;
>  
> @@ -359,7 +357,7 @@ static bool _vmxnet3_assert_interrupt_line(VMXNET3State *s, uint32_t int_idx)
>  {
>      PCIDevice *d = PCI_DEVICE(s);
>  
> -    if (s->msix_used && msix_enabled(d)) {
> +    if (msix_enabled(d)) {
>          VMW_IRPRN("Sending MSI-X notification for vector %u", int_idx);
>          msix_notify(d, int_idx);
>          return false;
> @@ -383,7 +381,7 @@ static void _vmxnet3_deassert_interrupt_line(VMXNET3State *s, int lidx)
>       * This function should never be called for MSI(X) interrupts
>       * because deassertion never required for message interrupts
>       */
> -    assert(!s->msix_used || !msix_enabled(d));
> +    assert(!msix_enabled(d));
>      /*
>       * This function should never be called for MSI(X) interrupts
>       * because deassertion never required for message interrupts
> @@ -421,7 +419,7 @@ static void vmxnet3_trigger_interrupt(VMXNET3State *s, int lidx)
>      s->interrupt_states[lidx].is_pending = true;
>      vmxnet3_update_interrupt_line_state(s, lidx);
>  
> -    if (s->msix_used && msix_enabled(d) && s->auto_int_masking) {
> +    if (msix_enabled(d) && s->auto_int_masking) {
>          goto do_automask;
>      }
>  
> @@ -1427,7 +1425,7 @@ static void vmxnet3_update_features(VMXNET3State *s)
>  
>  static bool vmxnet3_verify_intx(VMXNET3State *s, int intx)
>  {
> -    return s->msix_used || msi_enabled(PCI_DEVICE(s))
> +    return msix_enabled(PCI_DEVICE(s)) || msi_enabled(PCI_DEVICE(s))
>          || intx == pci_get_byte(s->parent_obj.config + PCI_INTERRUPT_PIN) - 1;
>  }
>  
> @@ -1444,18 +1442,18 @@ static void vmxnet3_validate_interrupts(VMXNET3State *s)
>      int i;
>  
>      VMW_CFPRN("Verifying event interrupt index (%d)", s->event_int_idx);
> -    vmxnet3_validate_interrupt_idx(s->msix_used, s->event_int_idx);
> +    vmxnet3_validate_interrupt_idx(msix_enabled(PCI_DEVICE(s)), s->event_int_idx);
>  
>      for (i = 0; i < s->txq_num; i++) {
>          int idx = s->txq_descr[i].intr_idx;
>          VMW_CFPRN("Verifying TX queue %d interrupt index (%d)", i, idx);
> -        vmxnet3_validate_interrupt_idx(s->msix_used, idx);
> +        vmxnet3_validate_interrupt_idx(msix_enabled(PCI_DEVICE(s)), idx);
>      }
>  
>      for (i = 0; i < s->rxq_num; i++) {
>          int idx = s->rxq_descr[i].intr_idx;
>          VMW_CFPRN("Verifying RX queue %d interrupt index (%d)", i, idx);
> -        vmxnet3_validate_interrupt_idx(s->msix_used, idx);
> +        vmxnet3_validate_interrupt_idx(msix_enabled(PCI_DEVICE(s)), idx);
>      }
>  }
>  
> @@ -2184,6 +2182,7 @@ vmxnet3_use_msix_vectors(VMXNET3State *s, int num_vectors)
>  static bool
>  vmxnet3_init_msix(VMXNET3State *s)
>  {
> +    bool msix;
>      PCIDevice *d = PCI_DEVICE(s);
>      int res = msix_init(d, VMXNET3_MAX_INTRS,
>                          &s->msix_bar,
> @@ -2198,17 +2197,18 @@ vmxnet3_init_msix(VMXNET3State *s)
>  
>      if (0 > res) {
>          VMW_WRPRN("Failed to initialize MSI-X, board's MSI support is broken");
> -        s->msix_used = false;
> +        msix = false;
>      } else {
>          if (!vmxnet3_use_msix_vectors(s, VMXNET3_MAX_INTRS)) {
>              VMW_WRPRN("Failed to use MSI-X vectors, error %d", res);
>              msix_uninit(d, &s->msix_bar, &s->msix_bar);
> -            s->msix_used = false;
> +            msix = false;
>          } else {
> -            s->msix_used = true;
> +            msix = true;
>          }
>      }
> -    return s->msix_used;
> +
> +    return msix;
>  }
>  
>  static void
> @@ -2216,7 +2216,7 @@ vmxnet3_cleanup_msix(VMXNET3State *s)
>  {
>      PCIDevice *d = PCI_DEVICE(s);
>  
> -    if (s->msix_used) {
> +    if (msix_enabled(d)) {
>          vmxnet3_unuse_msix_vectors(s, VMXNET3_MAX_INTRS);
>          msix_uninit(d, &s->msix_bar, &s->msix_bar);
>      }
> @@ -2551,21 +2551,11 @@ static void vmxnet3_put_rxq_descr(QEMUFile *f, void *pv, size_t size)
>  static int vmxnet3_post_load(void *opaque, int version_id)
>  {
>      VMXNET3State *s = opaque;
> -    PCIDevice *d = PCI_DEVICE(s);
>  
>      net_tx_pkt_init(&s->tx_pkt, PCI_DEVICE(s),
>                      s->max_tx_frags, s->peer_has_vhdr);
>      net_rx_pkt_init(&s->rx_pkt, s->peer_has_vhdr);
>  
> -    if (s->msix_used) {
> -        if  (!vmxnet3_use_msix_vectors(s, VMXNET3_MAX_INTRS)) {
> -            VMW_WRPRN("Failed to re-use MSI-X vectors");
> -            msix_uninit(d, &s->msix_bar, &s->msix_bar);
> -            s->msix_used = false;
> -            return -1;
> -        }
> -    }
> -
>      vmxnet3_validate_queues(s);
>      vmxnet3_validate_interrupts(s);

This hunk isn't obvious.  Can you explain the change?