Date: Mon, 5 Nov 2018 12:19:36 +0100
From: Cornelia Huck <cohuck@redhat.com>
Message-ID: <20181105121936.243260a6.cohuck@redhat.com>
In-Reply-To: <20181105110313.29312-2-david@redhat.com>
References: <20181105110313.29312-1-david@redhat.com>
	<20181105110313.29312-2-david@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH v1 1/4] s390x/zpci: drop msix.available
To: David Hildenbrand <david@redhat.com>
Cc: qemu-devel@nongnu.org, "Michael S . Tsirkin" <mst@redhat.com>, Igor Mammedov <imammedo@redhat.com>, Alexander Graf <agraf@suse.de>, Christian Borntraeger <borntraeger@de.ibm.com>, qemu-s390x@nongnu.org, Richard Henderson <rth@twiddle.net>, =Collin Walling <walling@linux.ibm.com>, Thomas Huth <thuth@redhat.com>

On Mon,  5 Nov 2018 12:03:10 +0100
David Hildenbrand <david@redhat.com> wrote:

> I fail to see why this is useful as we require MSIX always and
> completely fail adding a device.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  hw/s390x/s390-pci-bus.c | 2 --
>  hw/s390x/s390-pci-bus.h | 1 -
>  2 files changed, 3 deletions(-)
> 
> diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
> index e1b14b131b..1eaae3aca6 100644
> --- a/hw/s390x/s390-pci-bus.c
> +++ b/hw/s390x/s390-pci-bus.c
> @@ -745,7 +745,6 @@ static int s390_pci_msix_init(S390PCIBusDevice *pbdev)
>  
>      pos = pci_find_capability(pbdev->pdev, PCI_CAP_ID_MSIX);
>      if (!pos) {
> -        pbdev->msix.available = false;
>          return -1;
>      }
>  
> @@ -761,7 +760,6 @@ static int s390_pci_msix_init(S390PCIBusDevice *pbdev)
>      pbdev->msix.pba_bar = pba & PCI_MSIX_FLAGS_BIRMASK;
>      pbdev->msix.pba_offset = pba & ~PCI_MSIX_FLAGS_BIRMASK;
>      pbdev->msix.entries = (ctrl & PCI_MSIX_FLAGS_QSIZE) + 1;
> -    pbdev->msix.available = true;
>  
>      name = g_strdup_printf("msix-s390-%04x", pbdev->uid);
>      memory_region_init_io(&pbdev->msix_notify_mr, OBJECT(pbdev),
> diff --git a/hw/s390x/s390-pci-bus.h b/hw/s390x/s390-pci-bus.h
> index 1f7f9b5814..f47a0f2da5 100644
> --- a/hw/s390x/s390-pci-bus.h
> +++ b/hw/s390x/s390-pci-bus.h
> @@ -252,7 +252,6 @@ typedef struct ChscSeiNt2Res {
>  } QEMU_PACKED ChscSeiNt2Res;
>  
>  typedef struct S390MsixInfo {
> -    bool available;
>      uint8_t table_bar;
>      uint8_t pba_bar;
>      uint16_t entries;

OK, so that was a write-only variable? :)

Question for the IBMers: is there any change we might have a different
implementation not relying on msi-x in the future?