> From: Peter Xu <peterx@xxxxxxxxxx> > Sent: Wednesday, February 12, 2020 3:32 AM > To: Liu, Yi L <yi.l.liu@xxxxxxxxx> > Subject: Re: [RFC v3 12/25] vfio/common: add pasid_alloc/free support > > On Wed, Jan 29, 2020 at 04:16:43AM -0800, Liu, Yi L wrote: > > From: Liu Yi L <yi.l.liu@xxxxxxxxx> > > > > This patch adds VFIO pasid alloc/free support to allow host intercept > > in PASID allocation for VM by adding VFIO implementation of > > DualStageIOMMUOps.pasid_alloc/free callbacks. > > > > Cc: Kevin Tian <kevin.tian@xxxxxxxxx> > > Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> > > Cc: Peter Xu <peterx@xxxxxxxxxx> > > Cc: Eric Auger <eric.auger@xxxxxxxxxx> > > Cc: Yi Sun <yi.y.sun@xxxxxxxxxxxxxxx> > > Cc: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx> > > Cc: Alex Williamson <alex.williamson@xxxxxxxxxx> > > Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx> > > --- > > hw/vfio/common.c | 42 > ++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 42 insertions(+) > > > > diff --git a/hw/vfio/common.c b/hw/vfio/common.c index > > a07824b..014f4e7 100644 > > --- a/hw/vfio/common.c > > +++ b/hw/vfio/common.c > > @@ -1179,7 +1179,49 @@ static int vfio_get_iommu_type(VFIOContainer > *container, > > return -EINVAL; > > } > > > > +static int vfio_ds_iommu_pasid_alloc(DualStageIOMMUObject *dsi_obj, > > + uint32_t min, uint32_t max, uint32_t *pasid) > > +{ > > + VFIOContainer *container = container_of(dsi_obj, VFIOContainer, dsi_obj); > > + struct vfio_iommu_type1_pasid_request req; > > + unsigned long argsz; > > + > > + argsz = sizeof(req); > > + req.argsz = argsz; > > + req.flags = VFIO_IOMMU_PASID_ALLOC; > > + req.alloc_pasid.min = min; > > + req.alloc_pasid.max = max; > > + > > + if (ioctl(container->fd, VFIO_IOMMU_PASID_REQUEST, &req)) { > > + error_report("%s: %d, alloc failed", __func__, -errno); > > + return -errno; > > Note that errno is prone to change by other syscalls. Better cache it right after > the ioctl. > > > + } > > + *pasid = req.alloc_pasid.result; > > + return 0; > > +} > > + > > +static int vfio_ds_iommu_pasid_free(DualStageIOMMUObject *dsi_obj, > > + uint32_t pasid) { > > + VFIOContainer *container = container_of(dsi_obj, VFIOContainer, dsi_obj); > > + struct vfio_iommu_type1_pasid_request req; > > + unsigned long argsz; > > + > > + argsz = sizeof(req); > > + req.argsz = argsz; > > + req.flags = VFIO_IOMMU_PASID_FREE; > > + req.free_pasid = pasid; > > + > > + if (ioctl(container->fd, VFIO_IOMMU_PASID_REQUEST, &req)) { > > + error_report("%s: %d, free failed", __func__, -errno); > > + return -errno; > > Same here. Got the two comments. Thanks, Regards, Yi Liu