Hi Peter,
On 1/14/20 8:04 PM, Peter Xu wrote:
> On Thu, Jan 09, 2020 at 03:43:15PM +0100, Eric Auger wrote:
>> The event queue allows to report asynchronous errors.
>> The translate function now injects faults when relevant.
>>
>> Signed-off-by: Eric Auger <eric.au...@redhat.com>
>>
>> ---
>>
>> v11 -> v12:
>> - reporting the addr associated with the fault and set the
>> VIRTIO_IOMMU_FAULT_F_ADDRESS flag.
>> - added cpu_to_le<n>
>>
>> v10 -> v11:
>> - change a virtio_error into an error_report_once
>> (no buffer available for output faults)
>> ---
>> hw/virtio/trace-events | 1 +
>> hw/virtio/virtio-iommu.c | 73 +++++++++++++++++++++++++++++++++++++---
>> 2 files changed, 69 insertions(+), 5 deletions(-)
>>
>> diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
>> index 095aa8b509..e83500bee9 100644
>> --- a/hw/virtio/trace-events
>> +++ b/hw/virtio/trace-events
>> @@ -72,3 +72,4 @@ virtio_iommu_put_endpoint(uint32_t ep_id) "Free
>> endpoint=%d"
>> virtio_iommu_get_domain(uint32_t domain_id) "Alloc domain=%d"
>> virtio_iommu_put_domain(uint32_t domain_id) "Free domain=%d"
>> virtio_iommu_translate_out(uint64_t virt_addr, uint64_t phys_addr, uint32_t
>> sid) "0x%"PRIx64" -> 0x%"PRIx64 " for sid=%d"
>> +virtio_iommu_report_fault(uint8_t reason, uint32_t flags, uint32_t
>> endpoint, uint64_t addr) "FAULT reason=%d flags=%d endpoint=%d address
>> =0x%"PRIx64
>> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
>> index d192bcb505..09193970ee 100644
>> --- a/hw/virtio/virtio-iommu.c
>> +++ b/hw/virtio/virtio-iommu.c
>> @@ -477,6 +477,51 @@ out:
>> }
>> }
>>
>> +static void virtio_iommu_report_fault(VirtIOIOMMU *viommu, uint8_t reason,
>> + int flags, uint32_t endpoint,
>> + uint64_t address)
>> +{
>> + VirtIODevice *vdev = &viommu->parent_obj;
>> + VirtQueue *vq = viommu->event_vq;
>> + struct virtio_iommu_fault fault;
>> + VirtQueueElement *elem;
>> + size_t sz;
>> +
>> + memset(&fault, 0, sizeof(fault));
>> + fault.reason = reason;
>> + fault.flags = cpu_to_le32(flags);
>> + fault.endpoint = cpu_to_le32(endpoint);
>> + fault.address = cpu_to_le64(address);
>> +
>> + for (;;) {
>> + elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
>> +
>> + if (!elem) {
>> + error_report_once(
>> + "no buffer available in event queue to report event");
>
> (Should this also be a guest issue? IIRC you are still using a
> mixture of both qemu_log_mask and error_report()... I'll stop
> commenting on this, assuming that you prefer both ways to be used...)
I've just removed the qemu_log_mask in virtio_iommu_unmap(). So now you
should not find any qemu_log_mask anymore. Sorry for the oversight.
>
>> + return;
>> + }
>> +
>> + if (iov_size(elem->in_sg, elem->in_num) < sizeof(fault)) {
>> + virtio_error(vdev, "error buffer of wrong size");
>> + virtqueue_detach_element(vq, elem, 0);
>> + g_free(elem);
>> + continue;
>
> If virtio_error(), should we stop rather than continue?
My understanding is the buffer just popped had a wrong size so it is not
usable. We skip it we try to use another one if any. Does it make sense?
Thanks
Eric
>
>> + }
>> + break;
>> + }
>> + /* we have a buffer to fill in */
>> + sz = iov_from_buf(elem->in_sg, elem->in_num, 0,
>> + &fault, sizeof(fault));
>> + assert(sz == sizeof(fault));
>> +
>> + trace_virtio_iommu_report_fault(reason, flags, endpoint, address);
>> + virtqueue_push(vq, elem, sz);
>> + virtio_notify(vdev, vq);
>> + g_free(elem);
>> +
>> +}
>> +
>> static IOMMUTLBEntry virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr
>> addr,
>> IOMMUAccessFlags flag,
>> int iommu_idx)
>> @@ -485,9 +530,10 @@ static IOMMUTLBEntry
>> virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr,
>> VirtIOIOMMUInterval interval, *mapping_key;
>> VirtIOIOMMUMapping *mapping_value;
>> VirtIOIOMMU *s = sdev->viommu;
>> + bool read_fault, write_fault;
>> VirtIOIOMMUEndpoint *ep;
>> + uint32_t sid, flags;
>> bool bypass_allowed;
>> - uint32_t sid;
>> bool found;
>>
>> interval.low = addr;
>> @@ -513,6 +559,9 @@ static IOMMUTLBEntry
>> virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr,
>> if (!ep) {
>> if (!bypass_allowed) {
>> error_report_once("%s sid=%d is not known!!", __func__, sid);
>> + virtio_iommu_report_fault(s, VIRTIO_IOMMU_FAULT_R_UNKNOWN,
>> + VIRTIO_IOMMU_FAULT_F_ADDRESS,
>> + sid, addr);
>> } else {
>> entry.perm = flag;
>> }
>> @@ -524,6 +573,9 @@ static IOMMUTLBEntry
>> virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr,
>> error_report_once("%s %02x:%02x.%01x not attached to any
>> domain",
>> __func__, PCI_BUS_NUM(sid),
>> PCI_SLOT(sid), PCI_FUNC(sid));
>> + virtio_iommu_report_fault(s, VIRTIO_IOMMU_FAULT_R_DOMAIN,
>> + VIRTIO_IOMMU_FAULT_F_ADDRESS,
>> + sid, addr);
>> } else {
>> entry.perm = flag;
>> }
>> @@ -536,15 +588,26 @@ static IOMMUTLBEntry
>> virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr,
>> if (!found) {
>> error_report_once("%s no mapping for 0x%"PRIx64" for sid=%d",
>> __func__, addr, sid);
>> + virtio_iommu_report_fault(s, VIRTIO_IOMMU_FAULT_R_MAPPING,
>> + VIRTIO_IOMMU_FAULT_F_ADDRESS,
>> + sid, addr);
>> goto unlock;
>> }
>>
>> - if (((flag & IOMMU_RO) &&
>> - !(mapping_value->flags & VIRTIO_IOMMU_MAP_F_READ)) ||
>> - ((flag & IOMMU_WO) &&
>> - !(mapping_value->flags & VIRTIO_IOMMU_MAP_F_WRITE))) {
>> + read_fault = (flag & IOMMU_RO) &&
>> + !(mapping_value->flags & VIRTIO_IOMMU_MAP_F_READ);
>> + write_fault = (flag & IOMMU_WO) &&
>> + !(mapping_value->flags & VIRTIO_IOMMU_MAP_F_WRITE);
>> +
>> + flags = read_fault ? VIRTIO_IOMMU_FAULT_F_READ : 0;
>> + flags |= write_fault ? VIRTIO_IOMMU_FAULT_F_WRITE : 0;
>> + if (flags) {
>> error_report_once("%s permission error on 0x%"PRIx64"(%d):
>> allowed=%d",
>> __func__, addr, flag, mapping_value->flags);
>> + flags |= VIRTIO_IOMMU_FAULT_F_ADDRESS;
>> + virtio_iommu_report_fault(s, VIRTIO_IOMMU_FAULT_R_MAPPING,
>> + flags | VIRTIO_IOMMU_FAULT_F_ADDRESS,
>> + sid, addr);
>> goto unlock;
>> }
>> entry.translated_addr = addr - mapping_key->low +
>> mapping_value->phys_addr;
>> --
>> 2.20.1
>>
>
