diff options
| author | Marcel Apfelbaum <marcel@redhat.com> | 2016-09-07 18:02:25 +0300 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2016-09-09 20:58:34 +0300 |
| commit | d9997d89a4a09a330a056929d06d4b7b0b7a8239 (patch) | |
| tree | 5e4e10bea0a4a1c27cde5ba67458a52bbd4c3a84 /hw/virtio/virtio-pci.c | |
| parent | 14c985cffa6cb177fc01a163d8bcf227c104718c (diff) | |
| download | qemu-d9997d89a4a09a330a056929d06d4b7b0b7a8239.tar.gz | |
virtio-pci: reduce modern_mem_bar size
Currently each VQ Notification Virtio Capability is allocated
on a different page. The idea is to enable split drivers within
guests, however there are no known plans to do that.
The allocation will result in a 8MB BAR, more than various
guest firmwares pre-allocates for PCI Bridges hotplug process.
Reserve 4 bytes per VQ by default and add a new parameter
"page-per-vq" to be used with split drivers.
Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/virtio/virtio-pci.c')
| -rw-r--r-- | hw/virtio/virtio-pci.c | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index 268fd8ebb2..89bc196580 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -294,6 +294,12 @@ static void virtio_pci_ioeventfd_set_disabled(DeviceState *d, bool disabled) #define QEMU_VIRTIO_PCI_QUEUE_MEM_MULT 0x1000 +static inline int virtio_pci_queue_mem_mult(struct VirtIOPCIProxy *proxy) +{ + return (proxy->flags & VIRTIO_PCI_FLAG_PAGE_PER_VQ) ? + QEMU_VIRTIO_PCI_QUEUE_MEM_MULT : 4; +} + static int virtio_pci_ioeventfd_assign(DeviceState *d, EventNotifier *notifier, int n, bool assign) { @@ -307,7 +313,7 @@ static int virtio_pci_ioeventfd_assign(DeviceState *d, EventNotifier *notifier, MemoryRegion *modern_mr = &proxy->notify.mr; MemoryRegion *modern_notify_mr = &proxy->notify_pio.mr; MemoryRegion *legacy_mr = &proxy->bar; - hwaddr modern_addr = QEMU_VIRTIO_PCI_QUEUE_MEM_MULT * + hwaddr modern_addr = virtio_pci_queue_mem_mult(proxy) * virtio_get_queue_index(vq); hwaddr legacy_addr = VIRTIO_PCI_QUEUE_NOTIFY; @@ -1370,7 +1376,8 @@ static void virtio_pci_notify_write(void *opaque, hwaddr addr, uint64_t val, unsigned size) { VirtIODevice *vdev = opaque; - unsigned queue = addr / QEMU_VIRTIO_PCI_QUEUE_MEM_MULT; + VirtIOPCIProxy *proxy = VIRTIO_PCI(DEVICE(vdev)->parent_bus->parent); + unsigned queue = addr / virtio_pci_queue_mem_mult(proxy); if (queue < VIRTIO_QUEUE_MAX) { virtio_queue_notify(vdev, queue); @@ -1609,7 +1616,7 @@ static void virtio_pci_device_plugged(DeviceState *d, Error **errp) struct virtio_pci_notify_cap notify = { .cap.cap_len = sizeof notify, .notify_off_multiplier = - cpu_to_le32(QEMU_VIRTIO_PCI_QUEUE_MEM_MULT), + cpu_to_le32(virtio_pci_queue_mem_mult(proxy)), }; struct virtio_pci_cfg_cap cfg = { .cap.cap_len = sizeof cfg, @@ -1744,8 +1751,7 @@ static void virtio_pci_realize(PCIDevice *pci_dev, Error **errp) proxy->device.type = VIRTIO_PCI_CAP_DEVICE_CFG; proxy->notify.offset = 0x3000; - proxy->notify.size = - QEMU_VIRTIO_PCI_QUEUE_MEM_MULT * VIRTIO_QUEUE_MAX; + proxy->notify.size = virtio_pci_queue_mem_mult(proxy) * VIRTIO_QUEUE_MAX; proxy->notify.type = VIRTIO_PCI_CAP_NOTIFY_CFG; proxy->notify_pio.offset = 0x0; @@ -1754,8 +1760,8 @@ static void virtio_pci_realize(PCIDevice *pci_dev, Error **errp) /* subclasses can enforce modern, so do this unconditionally */ memory_region_init(&proxy->modern_bar, OBJECT(proxy), "virtio-pci", - 2 * QEMU_VIRTIO_PCI_QUEUE_MEM_MULT * - VIRTIO_QUEUE_MAX); + /* PCI BAR regions must be powers of 2 */ + pow2ceil(proxy->notify.offset + proxy->notify.size)); memory_region_init_alias(&proxy->modern_cfg, OBJECT(proxy), @@ -1833,6 +1839,8 @@ static Property virtio_pci_properties[] = { VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY_BIT, false), DEFINE_PROP_BIT("x-disable-pcie", VirtIOPCIProxy, flags, VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT, false), + DEFINE_PROP_BIT("page-per-vq", VirtIOPCIProxy, flags, + VIRTIO_PCI_FLAG_PAGE_PER_VQ_BIT, false), DEFINE_PROP_END_OF_LIST(), }; |