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virtio-pci: use generic logic for command access

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In practice, guests don't generate config requests
that cross a word boundary, so the logic to
detect command word access is correct because
PCI_COMMAND is 0x4. But depending on this is
tricky, further, it will break with guests
that do try to generate a misaligned access
as we pass it to devices without splitting.

Better to use the generic range_covers_byte for this.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2011-07-27 11:08:20 +03:00
parent 42e4126b79
commit 1129714ff4
1 changed files with 9 additions and 9 deletions
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18
hw/virtio-pci.c
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@ -27,6 +27,7 @@
#include "kvm.h"
#include "blockdev.h"
#include "virtio-pci.h"
#include "range.h"
/* from Linux's linux/virtio_pci.h */
@ -516,17 +517,16 @@ static void virtio_write_config(PCIDevice *pci_dev, uint32_t address,
{
VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
if (PCI_COMMAND == address) {
if (!(val & PCI_COMMAND_MASTER)) {
if (!(proxy->flags & VIRTIO_PCI_FLAG_BUS_MASTER_BUG)) {
virtio_pci_stop_ioeventfd(proxy);
virtio_set_status(proxy->vdev,
proxy->vdev->status & ~VIRTIO_CONFIG_S_DRIVER_OK);
}
}
pci_default_write_config(pci_dev, address, val, len);
if (range_covers_byte(address, len, PCI_COMMAND) &&
!(pci_dev->config[PCI_COMMAND] & PCI_COMMAND_MASTER) &&
!(proxy->flags & VIRTIO_PCI_FLAG_BUS_MASTER_BUG)) {
virtio_pci_stop_ioeventfd(proxy);
virtio_set_status(proxy->vdev,
proxy->vdev->status & ~VIRTIO_CONFIG_S_DRIVER_OK);
}
pci_default_write_config(pci_dev, address, val, len);
msix_write_config(pci_dev, address, val, len);
}