| Message ID | 20230201152018.1270226-1-alvaro.karsz@solid-run.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vhost-vdpa: print error when vhost_vdpa_alloc_domain fails | expand |
On Wed, Feb 01, 2023 at 05:20:18PM +0200, Alvaro Karsz wrote: > Add a print explaining why vhost_vdpa_alloc_domain failed if the device > is not IOMMU cache coherent capable. > > Without this print, we have no hint why the operation failed. > > For example: > > $ virsh start <domain> > error: Failed to start domain <domain> > error: Unable to open '/dev/vhost-vdpa-<idx>' for vdpa device: > Unknown error 524 > > Suggested-by: Eugenio Perez Martin <eperezma@redhat.com> > Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com> I'm not sure this is a good idea. Userspace is not supposed to be able to trigger dev_err. > --- > drivers/vhost/vdpa.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c > index 23db92388393..56287506aa0d 100644 > --- a/drivers/vhost/vdpa.c > +++ b/drivers/vhost/vdpa.c > @@ -1151,8 +1151,11 @@ static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v) > if (!bus) > return -EFAULT; > > - if (!device_iommu_capable(dma_dev, IOMMU_CAP_CACHE_COHERENCY)) > + if (!device_iommu_capable(dma_dev, IOMMU_CAP_CACHE_COHERENCY)) { > + dev_err(&v->dev, > + "Failed to allocate domain, device is not IOMMU cache coherent capable\n"); > return -ENOTSUPP; > + } > > v->domain = iommu_domain_alloc(bus); > if (!v->domain) > -- > 2.34.1
> I'm not sure this is a good idea. Userspace is not supposed to be > able to trigger dev_err. dev_warn then?
On Wed, Feb 01, 2023 at 05:54:53PM +0200, Alvaro Karsz wrote: > > I'm not sure this is a good idea. Userspace is not supposed to be > > able to trigger dev_err. > > dev_warn then? dev_warn_once is ok.
> > dev_warn then? > > dev_warn_once is ok. Ok, thanks I'll send a new version tomorrow.
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index 23db92388393..56287506aa0d 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -1151,8 +1151,11 @@ static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v) if (!bus) return -EFAULT; - if (!device_iommu_capable(dma_dev, IOMMU_CAP_CACHE_COHERENCY)) + if (!device_iommu_capable(dma_dev, IOMMU_CAP_CACHE_COHERENCY)) { + dev_err(&v->dev, + "Failed to allocate domain, device is not IOMMU cache coherent capable\n"); return -ENOTSUPP; + } v->domain = iommu_domain_alloc(bus); if (!v->domain)
Add a print explaining why vhost_vdpa_alloc_domain failed if the device is not IOMMU cache coherent capable. Without this print, we have no hint why the operation failed. For example: $ virsh start <domain> error: Failed to start domain <domain> error: Unable to open '/dev/vhost-vdpa-<idx>' for vdpa device: Unknown error 524 Suggested-by: Eugenio Perez Martin <eperezma@redhat.com> Signed-off-by: Alvaro Karsz <alvaro.karsz@solid-run.com> --- drivers/vhost/vdpa.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)