On 05.11.2019 23:56, Michael S. Tsirkin wrote:
> On Tue, Nov 05, 2019 at 07:11:02PM +0300, Denis Plotnikov wrote:
>> The patch protects from creating illegal virtio device configuration
>> via direct virtqueue size property setting.
>>
>> Signed-off-by: Denis Plotnikov <dplotni...@virtuozzo.com>
>> ---
>> hw/virtio/virtio-blk-pci.c | 9 +++++++++
>> hw/virtio/virtio-scsi-pci.c | 10 ++++++++++
>> 2 files changed, 19 insertions(+)
>>
>> diff --git a/hw/virtio/virtio-blk-pci.c b/hw/virtio/virtio-blk-pci.c
>> index 60c9185c39..6177ff1df8 100644
>> --- a/hw/virtio/virtio-blk-pci.c
>> +++ b/hw/virtio/virtio-blk-pci.c
>> @@ -48,6 +48,15 @@ static void virtio_blk_pci_realize(VirtIOPCIProxy
>> *vpci_dev, Error **errp)
>> {
>> VirtIOBlkPCI *dev = VIRTIO_BLK_PCI(vpci_dev);
>> DeviceState *vdev = DEVICE(&dev->vdev);
>> + bool modern = virtio_pci_modern(vpci_dev);
>> + uint32_t queue_size = dev->vdev.conf.queue_size;
>> +
>> + if (!modern && queue_size > 128) {
>> + error_setg(errp,
>> + "too big queue size (%u, max: 128) "
>> + "for non-modern virtio device", queue_size);
>> + return;
>> + }
>
> this enables for transitional so still visible to legacy
> interface. I am guessing you want to check whether
> device is accessed through the modern interface instead.
My goal is to not break something when I'm setting the queue size > 128
(taking into account the current seabios queue size restriction to 128).
I'm not quite sure what to check. Could I ask why one want to the check
whether accessing through the modern interface and how it could be checked?
Thanks!
Denis
>> if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) {
>> vpci_dev->nvectors = dev->vdev.conf.num_queues + 1;
>> diff --git a/hw/virtio/virtio-scsi-pci.c b/hw/virtio/virtio-scsi-pci.c
>> index 2830849729..6e6790fda5 100644
>> --- a/hw/virtio/virtio-scsi-pci.c
>> +++ b/hw/virtio/virtio-scsi-pci.c
>> @@ -17,6 +17,7 @@
>>
>> #include "hw/virtio/virtio-scsi.h"
>> #include "virtio-pci.h"
>> +#include "qapi/error.h"
>>
>> typedef struct VirtIOSCSIPCI VirtIOSCSIPCI;
>>
>> @@ -47,6 +48,15 @@ static void virtio_scsi_pci_realize(VirtIOPCIProxy
>> *vpci_dev, Error **errp)
>> VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
>> DeviceState *proxy = DEVICE(vpci_dev);
>> char *bus_name;
>> + bool modern = virtio_pci_modern(vpci_dev);
>> + uint32_t virtqueue_size = vs->conf.virtqueue_size;
>> +
>> + if (!modern && virtqueue_size > 128) {
>> + error_setg(errp,
>> + "too big virtqueue size (%u, max: 128) "
>> + "for non-modern virtio device", virtqueue_size);
>> + return;
>> + }
> why? what is illegal about 256 for legacy?
>
>>
>> if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) {
>> vpci_dev->nvectors = vs->conf.num_queues + 3;
>> --
>> 2.17.0
