Install an event handler on the vEVENTQ fd to read and propagate host generated vIOMMU events to the guest.
The handler runs in QEMU’s main loop, using a non-blocking fd registered via qemu_set_fd_handler(). Signed-off-by: Shameer Kolothum <[email protected]> --- hw/arm/smmuv3-accel.c | 62 +++++++++++++++++++++++++++++++++++++++++++ hw/arm/smmuv3-accel.h | 2 ++ 2 files changed, 64 insertions(+) diff --git a/hw/arm/smmuv3-accel.c b/hw/arm/smmuv3-accel.c index 210e7ebf36..e6c81c4786 100644 --- a/hw/arm/smmuv3-accel.c +++ b/hw/arm/smmuv3-accel.c @@ -383,6 +383,62 @@ static SMMUv3AccelDevice *smmuv3_accel_get_dev(SMMUState *bs, SMMUPciBus *sbus, return accel_dev; } +static void smmuv3_accel_event_read(void *opaque) +{ + SMMUv3State *s = opaque; + SMMUv3AccelState *s_accel = s->s_accel; + SMMUViommu *vsmmu = s_accel->vsmmu; + struct iommu_vevent_arm_smmuv3 *vevent; + struct iommufd_vevent_header *hdr; + ssize_t readsz = sizeof(*hdr) + sizeof(*vevent); + uint8_t buf[sizeof(*hdr) + sizeof(*vevent)]; + uint32_t last_seq = vsmmu->last_event_seq; + ssize_t bytes; + Evt evt = {}; + + bytes = read(vsmmu->veventq->veventq_fd, buf, readsz); + if (bytes <= 0) { + if (errno == EAGAIN || errno == EINTR) { + return; + } + error_report("vEVENTQ: read failed (%s)", strerror(errno)); + return; + } + + if (bytes < readsz) { + error_report("vEVENTQ: incomplete read (%zd/%zd bytes)", bytes, readsz); + return; + } + + hdr = (struct iommufd_vevent_header *)buf; + if (hdr->flags & IOMMU_VEVENTQ_FLAG_LOST_EVENTS) { + error_report("vEVENTQ has lost events"); + return; + } + + vevent = (struct iommu_vevent_arm_smmuv3 *)(buf + sizeof(*hdr)); + /* Check sequence in hdr for lost events if any */ + if (vsmmu->event_start) { + uint32_t expected = (last_seq == INT_MAX) ? 0 : last_seq + 1; + + if (hdr->sequence != expected) { + uint32_t delta; + + if (hdr->sequence >= last_seq) { + delta = hdr->sequence - last_seq; + } else { + /* Handle wraparound from INT_MAX */ + delta = (INT_MAX - last_seq) + hdr->sequence + 1; + } + error_report("vEVENTQ: detected lost %u event(s)", delta - 1); + } + } + vsmmu->last_event_seq = hdr->sequence; + vsmmu->event_start = true; + memcpy(&evt, vevent, sizeof(evt)); + smmuv3_propagate_event(s, &evt); +} + static void smmuv3_accel_free_veventq(SMMUViommu *vsmmu) { IOMMUFDVeventq *veventq = vsmmu->veventq; @@ -390,6 +446,8 @@ static void smmuv3_accel_free_veventq(SMMUViommu *vsmmu) if (!veventq) { return; } + qemu_set_fd_handler(veventq->veventq_fd, NULL, NULL, NULL); + close(veventq->veventq_fd); iommufd_backend_free_id(vsmmu->iommufd, veventq->veventq_id); g_free(veventq); vsmmu->veventq = NULL; @@ -433,6 +491,10 @@ bool smmuv3_accel_alloc_veventq(SMMUv3State *s, Error **errp) veventq->veventq_fd = veventq_fd; veventq->viommu = &vsmmu->viommu; vsmmu->veventq = veventq; + + /* Set up event handler for veventq fd */ + fcntl(veventq_fd, F_SETFL, O_NONBLOCK); + qemu_set_fd_handler(veventq_fd, smmuv3_accel_event_read, NULL, s); return true; } diff --git a/hw/arm/smmuv3-accel.h b/hw/arm/smmuv3-accel.h index 740253bc34..6ed5f3b821 100644 --- a/hw/arm/smmuv3-accel.h +++ b/hw/arm/smmuv3-accel.h @@ -23,6 +23,8 @@ typedef struct SMMUViommu { IOMMUFDBackend *iommufd; IOMMUFDViommu viommu; IOMMUFDVeventq *veventq; + uint32_t last_event_seq; + bool event_start; uint32_t bypass_hwpt_id; uint32_t abort_hwpt_id; QLIST_HEAD(, SMMUv3AccelDevice) device_list; -- 2.43.0
