The vfio_iommu_spapr_tce driver advertises kernel's support for
v1 and v2 IOMMU support, however it is not always possible to use
the requested IOMMU type. For example, a pseries host platform does not
support dynamic DMA windows so v2 cannot initialize and QEMU fails to
start.
This adds a fallback to the v1 IOMMU if v2 cannot be used.
Fixes: 318f67ce1371 "vfio: spapr: Add DMA memory preregistering (SPAPR IOMMU v2)"
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v2:
* updated commit log
---
hw/vfio/common.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 7b2924c..cd81cc9 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1040,6 +1040,11 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
v2 ? VFIO_SPAPR_TCE_v2_IOMMU : VFIO_SPAPR_TCE_IOMMU;
ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type);
if (ret) {
+ container->iommu_type = VFIO_SPAPR_TCE_IOMMU;
+ v2 = false;
+ ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type);
+ }
+ if (ret) {
error_setg_errno(errp, errno, "failed to set iommu for container");
ret = -errno;
goto free_container_exit;
--
2.11.0
On Tue, Dec 12, 2017 at 04:16:19PM +1100, Alexey Kardashevskiy wrote: > The vfio_iommu_spapr_tce driver advertises kernel's support for > v1 and v2 IOMMU support, however it is not always possible to use > the requested IOMMU type. For example, a pseries host platform does not > support dynamic DMA windows so v2 cannot initialize and QEMU fails to > start. > > This adds a fallback to the v1 IOMMU if v2 cannot be used. > > Fixes: 318f67ce1371 "vfio: spapr: Add DMA memory preregistering (SPAPR IOMMU v2)" > Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Alex, will you take this through your tree, or should I take it through mine? > --- > Changes: > v2: > * updated commit log > > --- > hw/vfio/common.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > index 7b2924c..cd81cc9 100644 > --- a/hw/vfio/common.c > +++ b/hw/vfio/common.c > @@ -1040,6 +1040,11 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, > v2 ? VFIO_SPAPR_TCE_v2_IOMMU : VFIO_SPAPR_TCE_IOMMU; > ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type); > if (ret) { > + container->iommu_type = VFIO_SPAPR_TCE_IOMMU; > + v2 = false; > + ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type); > + } > + if (ret) { > error_setg_errno(errp, errno, "failed to set iommu for container"); > ret = -errno; > goto free_container_exit; -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
On 15/12/17 17:01, David Gibson wrote: > On Tue, Dec 12, 2017 at 04:16:19PM +1100, Alexey Kardashevskiy wrote: >> The vfio_iommu_spapr_tce driver advertises kernel's support for >> v1 and v2 IOMMU support, however it is not always possible to use >> the requested IOMMU type. For example, a pseries host platform does not >> support dynamic DMA windows so v2 cannot initialize and QEMU fails to >> start. >> >> This adds a fallback to the v1 IOMMU if v2 cannot be used. >> >> Fixes: 318f67ce1371 "vfio: spapr: Add DMA memory preregistering (SPAPR IOMMU v2)" >> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> > > Reviewed-by: David Gibson <david@gibson.dropbear.id.au> > > Alex, will you take this through your tree, or should I take it > through mine? It is already in upstream. > >> --- >> Changes: >> v2: >> * updated commit log >> >> --- >> hw/vfio/common.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/hw/vfio/common.c b/hw/vfio/common.c >> index 7b2924c..cd81cc9 100644 >> --- a/hw/vfio/common.c >> +++ b/hw/vfio/common.c >> @@ -1040,6 +1040,11 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as, >> v2 ? VFIO_SPAPR_TCE_v2_IOMMU : VFIO_SPAPR_TCE_IOMMU; >> ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type); >> if (ret) { >> + container->iommu_type = VFIO_SPAPR_TCE_IOMMU; >> + v2 = false; >> + ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type); >> + } >> + if (ret) { >> error_setg_errno(errp, errno, "failed to set iommu for container"); >> ret = -errno; >> goto free_container_exit; > -- Alexey
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