virtio-pci: use generic logic for command access
PATCH 1/1 virtio-pci: use generic logic for command access
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 <[email protected]>
--- hw/virtio-pci.c | 18 +++++++++--------- 1 files changed, 9 insertions(+), 9 deletions(-)
hw/virtio-pci.c +9 -9
@@ -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); }
Signature · 1 line
1.7.5.53.gc233e