Revision c81131db
| b/hw/virtio-pci.c | ||
|---|---|---|
| 79 | 79 |
* 12 is historical, and due to x86 page size. */ |
| 80 | 80 |
#define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12 |
| 81 | 81 |
|
| 82 |
/* We can catch some guest bugs inside here so we continue supporting older |
|
| 83 |
guests. */ |
|
| 84 |
#define VIRTIO_PCI_BUG_BUS_MASTER (1 << 0) |
|
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|
|
| 82 | 86 |
/* QEMU doesn't strictly need write barriers since everything runs in |
| 83 | 87 |
* lock-step. We'll leave the calls to wmb() in though to make it obvious for |
| 84 | 88 |
* KVM or if kqemu gets SMP support. |
| ... | ... | |
| 90 | 94 |
typedef struct {
|
| 91 | 95 |
PCIDevice pci_dev; |
| 92 | 96 |
VirtIODevice *vdev; |
| 97 |
uint32_t bugs; |
|
| 93 | 98 |
uint32_t addr; |
| 94 | 99 |
uint32_t class_code; |
| 95 | 100 |
uint32_t nvectors; |
| ... | ... | |
| 144 | 149 |
if (proxy->vdev->config_vector != VIRTIO_NO_VECTOR) {
|
| 145 | 150 |
return msix_vector_use(&proxy->pci_dev, proxy->vdev->config_vector); |
| 146 | 151 |
} |
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|
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/* Try to find out if the guest has bus master disabled, but is |
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in ready state. Then we have a buggy guest OS. */ |
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if (!(proxy->vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) && |
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!(proxy->pci_dev.config[PCI_COMMAND] & PCI_COMMAND_MASTER)) {
|
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proxy->bugs |= VIRTIO_PCI_BUG_BUS_MASTER; |
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} |
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| 147 | 159 |
return 0; |
| 148 | 160 |
} |
| 149 | 161 |
|
| ... | ... | |
| 168 | 180 |
VirtIOPCIProxy *proxy = container_of(d, VirtIOPCIProxy, pci_dev.qdev); |
| 169 | 181 |
virtio_reset(proxy->vdev); |
| 170 | 182 |
msix_reset(&proxy->pci_dev); |
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proxy->bugs = 0; |
|
| 171 | 184 |
} |
| 172 | 185 |
|
| 173 | 186 |
static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val) |
| ... | ... | |
| 211 | 224 |
virtio_reset(proxy->vdev); |
| 212 | 225 |
msix_unuse_all_vectors(&proxy->pci_dev); |
| 213 | 226 |
} |
| 227 |
|
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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->bugs |= VIRTIO_PCI_BUG_BUS_MASTER; |
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} |
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| 214 | 235 |
break; |
| 215 | 236 |
case VIRTIO_MSI_CONFIG_VECTOR: |
| 216 | 237 |
msix_vector_unuse(&proxy->pci_dev, vdev->config_vector); |
| ... | ... | |
| 377 | 398 |
|
| 378 | 399 |
if (PCI_COMMAND == address) {
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| 379 | 400 |
if (!(val & PCI_COMMAND_MASTER)) {
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proxy->vdev->status &= ~VIRTIO_CONFIG_S_DRIVER_OK; |
|
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if (!(proxy->bugs & VIRTIO_PCI_BUG_BUS_MASTER)) {
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proxy->vdev->status &= ~VIRTIO_CONFIG_S_DRIVER_OK; |
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} |
|
| 381 | 404 |
} |
| 382 | 405 |
} |
| 383 | 406 |
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