[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [RfC PATCH] virtio-pci: place msix regions in modern vi
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [RfC PATCH] virtio-pci: place msix regions in modern virtio bar |
Date: |
Fri, 23 Jan 2015 15:33:41 +0200 |
On Fri, Jan 23, 2015 at 01:29:43PM +0100, Gerd Hoffmann wrote:
> Only for legacy-free virtio devices, to avoid unpleasent
> surprises with old drivers.
>
> mtree snippet:
>
> 00000000fea00000-00000000fea7ffff (prio 1, RW): virtio-pci
> 00000000fea00000-00000000fea00fff (prio 0, RW): virtio-pci-common
> 00000000fea01000-00000000fea01fff (prio 0, RW): virtio-pci-isr
> 00000000fea02000-00000000fea02fff (prio 0, RW): virtio-pci-device
> 00000000fea03000-00000000fea42fff (prio 0, RW): virtio-pci-notify
> 00000000fea7e000-00000000fea7e02f (prio 0, RW): msix-table
> 00000000fea7f000-00000000fea7f007 (prio 0, RW): msix-pba
>
> Applies on top of mst's virtio-1.0 branch, plus my three virtio-pci
> patches posted to the list yesterday.
>
> Signed-off-by: Gerd Hoffmann <address@hidden>
Hmm what's the point here?
I wanted to make the modern BAR prefetcheable, so it can
be a full 64-bit one, this is impossible with the MSI-X
BAR.
This requires keeping it separate though.
Again, if we start running of BARs we'll consider our options
then, these things are easy to change.
> ---
> hw/virtio/virtio-pci.c | 39 +++++++++++++++++++++++++++------------
> 1 file changed, 27 insertions(+), 12 deletions(-)
>
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index ba1405f..934ca7a 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -1235,7 +1235,7 @@ static void virtio_pci_device_plugged(DeviceState *d)
> bool modern = !(proxy->flags & VIRTIO_PCI_FLAG_DISABLE_MODERN);
> int modern_mem_bar;
> uint8_t *config;
> - uint32_t size;
> + uint32_t modern_mem_size, legacy_io_size;
>
> config = proxy->pci_dev.config;
> if (proxy->class_code) {
> @@ -1339,9 +1339,10 @@ static void virtio_pci_device_plugged(DeviceState *d)
> virtio_pci_add_mem_cap(proxy, ¬ify.cap);
>
> virtio_add_feature(&proxy->host_features, VIRTIO_F_VERSION_1);
> + modern_mem_size = 2 * QEMU_VIRTIO_PCI_QUEUE_MEM_MULT *
> + VIRTIO_PCI_QUEUE_MAX;
> memory_region_init(&proxy->modern_bar, OBJECT(proxy), "virtio-pci",
> - 2 * QEMU_VIRTIO_PCI_QUEUE_MEM_MULT *
> - VIRTIO_PCI_QUEUE_MAX);
> + modern_mem_size);
> memory_region_init_io(&proxy->common, OBJECT(proxy),
> &common_ops,
> proxy,
> @@ -1369,25 +1370,39 @@ static void virtio_pci_device_plugged(DeviceState *d)
> &proxy->modern_bar);
> }
>
> - if (proxy->nvectors &&
> - msix_init_exclusive_bar(&proxy->pci_dev, proxy->nvectors, 1)) {
> - error_report("unable to init msix vectors to %" PRIu32,
> - proxy->nvectors);
> - proxy->nvectors = 0;
> + if (proxy->nvectors) {
> + if (modern && modern_mem_bar == 0) {
> + if (msix_init(&proxy->pci_dev, proxy->nvectors,
> + &proxy->modern_bar, modern_mem_bar,
> + modern_mem_size - 0x2000,
> + &proxy->modern_bar, modern_mem_bar,
> + modern_mem_size - 0x1000,
> + 0x90)) {
> + error_report("unable to init msix vectors to %" PRIu32,
> + proxy->nvectors);
> + proxy->nvectors = 0;
> + }
> + } else {
> + if (msix_init_exclusive_bar(&proxy->pci_dev, proxy->nvectors,
> 1)) {
> + error_report("unable to init msix vectors to %" PRIu32,
> + proxy->nvectors);
> + proxy->nvectors = 0;
> + }
> + }
> }
>
> proxy->pci_dev.config_write = virtio_write_config;
>
> if (legacy) {
> - size = VIRTIO_PCI_REGION_SIZE(&proxy->pci_dev)
> + legacy_io_size = VIRTIO_PCI_REGION_SIZE(&proxy->pci_dev)
> + virtio_bus_get_vdev_config_len(bus);
> - if (size & (size - 1)) {
> - size = 1 << qemu_fls(size);
> + if (legacy_io_size & (legacy_io_size - 1)) {
> + legacy_io_size = 1 << qemu_fls(legacy_io_size);
> }
>
> memory_region_init_io(&proxy->bar, OBJECT(proxy),
> &virtio_pci_config_ops,
> - proxy, "virtio-pci", size);
> + proxy, "virtio-pci", legacy_io_size);
>
> pci_register_bar(&proxy->pci_dev, 0, PCI_BASE_ADDRESS_SPACE_IO,
> &proxy->bar);
> --
> 1.8.3.1