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Revert "virtio-pci: fix migration for pci bus master"
This reverts commit 4d43d3f3c8
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Reported to break PPC guests.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
parent
8ce3c44c92
commit
45363e46ae
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@ -86,6 +86,9 @@
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* 12 is historical, and due to x86 page size. */
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* 12 is historical, and due to x86 page size. */
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#define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12
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#define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12
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/* Flags track per-device state like workarounds for quirks in older guests. */
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#define VIRTIO_PCI_FLAG_BUS_MASTER_BUG (1 << 0)
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static void virtio_pci_bus_new(VirtioBusState *bus, size_t bus_size,
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static void virtio_pci_bus_new(VirtioBusState *bus, size_t bus_size,
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VirtIOPCIProxy *dev);
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VirtIOPCIProxy *dev);
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@ -320,6 +323,14 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val)
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proxy->pci_dev.config[PCI_COMMAND] |
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proxy->pci_dev.config[PCI_COMMAND] |
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PCI_COMMAND_MASTER, 1);
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PCI_COMMAND_MASTER, 1);
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}
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}
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/* Linux before 2.6.34 sets the device as OK without enabling
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the PCI device bus master bit. In this case we need to disable
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some safety checks. */
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if ((val & VIRTIO_CONFIG_S_DRIVER_OK) &&
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!(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) {
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proxy->flags |= VIRTIO_PCI_FLAG_BUS_MASTER_BUG;
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}
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break;
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break;
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case VIRTIO_MSI_CONFIG_VECTOR:
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case VIRTIO_MSI_CONFIG_VECTOR:
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msix_vector_unuse(&proxy->pci_dev, vdev->config_vector);
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msix_vector_unuse(&proxy->pci_dev, vdev->config_vector);
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@ -469,18 +480,13 @@ static void virtio_write_config(PCIDevice *pci_dev, uint32_t address,
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VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
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VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
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VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
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VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
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uint8_t cmd = proxy->pci_dev.config[PCI_COMMAND];
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pci_default_write_config(pci_dev, address, val, len);
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pci_default_write_config(pci_dev, address, val, len);
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if (range_covers_byte(address, len, PCI_COMMAND) &&
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if (range_covers_byte(address, len, PCI_COMMAND) &&
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!(pci_dev->config[PCI_COMMAND] & PCI_COMMAND_MASTER) &&
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!(pci_dev->config[PCI_COMMAND] & PCI_COMMAND_MASTER) &&
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(cmd & PCI_COMMAND_MASTER)) {
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!(proxy->flags & VIRTIO_PCI_FLAG_BUS_MASTER_BUG)) {
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/* Bus driver disables bus mastering - make it act
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* as a kind of reset to render the device quiescent. */
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virtio_pci_stop_ioeventfd(proxy);
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virtio_pci_stop_ioeventfd(proxy);
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virtio_reset(vdev);
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virtio_set_status(vdev, vdev->status & ~VIRTIO_CONFIG_S_DRIVER_OK);
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msix_unuse_all_vectors(&proxy->pci_dev);
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}
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}
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}
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}
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@ -889,19 +895,11 @@ static void virtio_pci_vmstate_change(DeviceState *d, bool running)
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VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
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VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
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if (running) {
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if (running) {
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/* Linux before 2.6.34 drives the device without enabling
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/* Try to find out if the guest has bus master disabled, but is
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the PCI device bus master bit. Enable it automatically
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in ready state. Then we have a buggy guest OS. */
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for the guest. This is a PCI spec violation but so is
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if ((vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) &&
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initiating DMA with bus master bit clear.
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!(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) {
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Note: this only makes a difference when migrating
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proxy->flags |= VIRTIO_PCI_FLAG_BUS_MASTER_BUG;
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across QEMU versions from an old QEMU, as for new QEMU
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bus master and driver bits are always in sync.
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TODO: consider enabling conditionally for compat machine types. */
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if (vdev->status & (VIRTIO_CONFIG_S_ACKNOWLEDGE |
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VIRTIO_CONFIG_S_DRIVER)) {
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pci_default_write_config(&proxy->pci_dev, PCI_COMMAND,
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proxy->pci_dev.config[PCI_COMMAND] |
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PCI_COMMAND_MASTER, 1);
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}
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}
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virtio_pci_start_ioeventfd(proxy);
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virtio_pci_start_ioeventfd(proxy);
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} else {
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} else {
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@ -1042,6 +1040,7 @@ static void virtio_pci_reset(DeviceState *qdev)
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virtio_pci_stop_ioeventfd(proxy);
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virtio_pci_stop_ioeventfd(proxy);
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virtio_bus_reset(bus);
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virtio_bus_reset(bus);
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msix_unuse_all_vectors(&proxy->pci_dev);
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msix_unuse_all_vectors(&proxy->pci_dev);
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proxy->flags &= ~VIRTIO_PCI_FLAG_BUS_MASTER_BUG;
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}
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}
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static Property virtio_pci_properties[] = {
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static Property virtio_pci_properties[] = {
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