| Message ID | 20-v1-21cc72fcfb22+a7a-iommu_all_defdom_jgg@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iommu: Make default_domain's mandatory | expand |
On Mon, 2023-05-01 at 15:03 -0300, Jason Gunthorpe wrote: > These drivers don't support IOMMU_DOMAIN_DMA, so this commit effectively > allows them to support that mode. > > The prior work to require default_domains makes this safe because every > one of these drivers is either compilation incompatible with dma-iommu.c, > or already establishing a default_domain. In both cases alloc_domain() > will never be called with IOMMU_DOMAIN_DMA for these drivers so it is safe > to drop the test. > > Removing these tests clarifies that the domain allocation path is only > about the functionality of a paging domain and has nothing to do with > policy of how the paging domain is used for UNMANAGED/DMA/DMA_FQ. > > Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> > --- > drivers/iommu/fsl_pamu_domain.c | 7 ++----- > drivers/iommu/msm_iommu.c | 7 ++----- > drivers/iommu/mtk_iommu_v1.c | 7 ++----- > drivers/iommu/omap-iommu.c | 7 ++----- > drivers/iommu/s390-iommu.c | 7 ++----- > drivers/iommu/tegra-gart.c | 7 ++----- > 6 files changed, 12 insertions(+), 30 deletions(-) > > ---8<--- > -static struct iommu_domain *s390_domain_alloc(unsigned domain_type) > +static struct iommu_domain *s390_domain_alloc_paging(struct device *dev) > { > struct s390_domain *s390_domain; > > - if (domain_type != IOMMU_DOMAIN_UNMANAGED) > - return NULL; > - > s390_domain = kzalloc(sizeof(*s390_domain), GFP_KERNEL); > if (!s390_domain) > return NULL; > @@ -447,7 +444,7 @@ void zpci_destroy_iommu(struct zpci_dev *zdev) > static const struct iommu_ops s390_iommu_ops = { > .default_domain = &s390_iommu_platform_domain, > .capable = s390_iommu_capable, > - .domain_alloc = s390_domain_alloc, > + .domain_alloc_paging = s390_domain_alloc_paging, Leaving .domain_alloc unset here leads to an OOPs with your GitHub branch (iommu_mandatory_default) when I try to use vfio-pci for KVM pass-through via the following call chain: ... vfio_group_fops_unl_ioctl() vfio_group_ioctl_set_container() vfio_container_attach_group() iommu_group_claim_dma_owner() __iommu_take_dma_ownership() __iommu_group_alloc_blocking_domain() __iommu_domain_alloc(…, IOMMU_DOMAIN_BLOCKED) The problem is that in __iommu_domain_alloc() a call to bus->iommu_ops- >domain_alloc() is attempted for IOMMU_DOMAIN_BLCOKED even if the function pointer is unset. So I tried with the obvious fix: @@ -1947,7 +1948,7 @@ static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus, if ((type == IOMMU_DOMAIN_UNMANAGED || type == IOMMU_DOMAIN_DMA) && bus->iommu_ops->domain_alloc_paging) domain = bus->iommu_ops->domain_alloc_paging(dev); - else + else if (bus->iommu_ops->domain_alloc) domain = bus->iommu_ops->domain_alloc(type); if (!domain) return NULL; This then uses the fallback of an empty IOMMU_DOMAIN_UNMANAGED and I get a working device in the guest. Also tried hot unplug where the device is taken over by the host again. I think with my DMA API conversion patches we can support blocking domains properly but for a temporary solution the above may be acceptable. > .probe_device = s390_iommu_probe_device, > .release_device = s390_iommu_release_device, > .device_group = generic_device_group,
On Tue, May 02, 2023 at 04:52:32PM +0200, Niklas Schnelle wrote: > @@ -1947,7 +1948,7 @@ static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus, > if ((type == IOMMU_DOMAIN_UNMANAGED || type == IOMMU_DOMAIN_DMA) && > bus->iommu_ops->domain_alloc_paging) > domain = bus->iommu_ops->domain_alloc_paging(dev); > - else > + else if (bus->iommu_ops->domain_alloc) > domain = bus->iommu_ops->domain_alloc(type); > if (!domain) > return NULL; Agh, yes, it should fail, this is right, I'll fold it in, thanks > This then uses the fallback of an empty IOMMU_DOMAIN_UNMANAGED and I > get a working device in the guest. Also tried hot unplug where the > device is taken over by the host again. Great, thanks, I'll add your tested-by for the s390 drivers. > I think with my DMA API > conversion patches we can support blocking domains properly but for a > temporary solution the above may be acceptable. Yes, this is a good idea, I encourage all drivers to implement at least one of BLOCKING or IDENTITY as global static singletons that can't fail - this will allow us to have cleaner error recovery flows. Jason
On Tue, 2023-05-02 at 12:25 -0300, Jason Gunthorpe wrote: > On Tue, May 02, 2023 at 04:52:32PM +0200, Niklas Schnelle wrote: > > @@ -1947,7 +1948,7 @@ static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus, > > if ((type == IOMMU_DOMAIN_UNMANAGED || type == IOMMU_DOMAIN_DMA) && > > bus->iommu_ops->domain_alloc_paging) > > domain = bus->iommu_ops->domain_alloc_paging(dev); > > - else > > + else if (bus->iommu_ops->domain_alloc) > > domain = bus->iommu_ops->domain_alloc(type); > > if (!domain) > > return NULL; > > Agh, yes, it should fail, this is right, I'll fold it in, thanks > > > This then uses the fallback of an empty IOMMU_DOMAIN_UNMANAGED and I > > get a working device in the guest. Also tried hot unplug where the > > device is taken over by the host again. > > Great, thanks, I'll add your tested-by for the s390 drivers. Yes and with the above change feel free to add my for this patch and see my other reply for the s390 specific change. Acked-by: Niklas Schnelle <schnelle@linux.ibm.com> # s390 (I've recently been added as additional S390 IOMMU (PCI) maintainer)
diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c index 4c65f1adfe7511..641e89f7d7f444 100644 --- a/drivers/iommu/fsl_pamu_domain.c +++ b/drivers/iommu/fsl_pamu_domain.c @@ -192,13 +192,10 @@ static void fsl_pamu_domain_free(struct iommu_domain *domain) kmem_cache_free(fsl_pamu_domain_cache, dma_domain); } -static struct iommu_domain *fsl_pamu_domain_alloc(unsigned type) +static struct iommu_domain *fsl_pamu_domain_alloc_paging(struct device *dev) { struct fsl_dma_domain *dma_domain; - if (type != IOMMU_DOMAIN_UNMANAGED) - return NULL; - dma_domain = kmem_cache_zalloc(fsl_pamu_domain_cache, GFP_KERNEL); if (!dma_domain) return NULL; @@ -473,7 +470,7 @@ static struct iommu_device *fsl_pamu_probe_device(struct device *dev) static const struct iommu_ops fsl_pamu_ops = { .default_domain = &fsl_pamu_platform_domain, .capable = fsl_pamu_capable, - .domain_alloc = fsl_pamu_domain_alloc, + .domain_alloc_paging = fsl_pamu_domain_alloc_paging, .probe_device = fsl_pamu_probe_device, .device_group = fsl_pamu_device_group, .default_domain_ops = &(const struct iommu_domain_ops) { diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c index 26ed81cfeee897..a163cee0b7242d 100644 --- a/drivers/iommu/msm_iommu.c +++ b/drivers/iommu/msm_iommu.c @@ -302,13 +302,10 @@ static void __program_context(void __iomem *base, int ctx, SET_M(base, ctx, 1); } -static struct iommu_domain *msm_iommu_domain_alloc(unsigned type) +static struct iommu_domain *msm_iommu_domain_alloc_paging(struct device *dev) { struct msm_priv *priv; - if (type != IOMMU_DOMAIN_UNMANAGED) - return NULL; - priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) goto fail_nomem; @@ -691,7 +688,7 @@ irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id) static struct iommu_ops msm_iommu_ops = { .identity_domain = &msm_iommu_identity_domain, - .domain_alloc = msm_iommu_domain_alloc, + .domain_alloc_paging = msm_iommu_domain_alloc_paging, .probe_device = msm_iommu_probe_device, .device_group = generic_device_group, .pgsize_bitmap = MSM_IOMMU_PGSIZES, diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c index 7c0c1d50df5f75..67e044c1a7d93b 100644 --- a/drivers/iommu/mtk_iommu_v1.c +++ b/drivers/iommu/mtk_iommu_v1.c @@ -270,13 +270,10 @@ static int mtk_iommu_v1_domain_finalise(struct mtk_iommu_v1_data *data) return 0; } -static struct iommu_domain *mtk_iommu_v1_domain_alloc(unsigned type) +static struct iommu_domain *mtk_iommu_v1_domain_alloc_paging(struct device *dev) { struct mtk_iommu_v1_domain *dom; - if (type != IOMMU_DOMAIN_UNMANAGED) - return NULL; - dom = kzalloc(sizeof(*dom), GFP_KERNEL); if (!dom) return NULL; @@ -585,7 +582,7 @@ static int mtk_iommu_v1_hw_init(const struct mtk_iommu_v1_data *data) static const struct iommu_ops mtk_iommu_v1_ops = { .identity_domain = &mtk_iommu_v1_identity_domain, - .domain_alloc = mtk_iommu_v1_domain_alloc, + .domain_alloc_paging = mtk_iommu_v1_domain_alloc_paging, .probe_device = mtk_iommu_v1_probe_device, .probe_finalize = mtk_iommu_v1_probe_finalize, .release_device = mtk_iommu_v1_release_device, diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c index 34340ef15241bc..fcf99bd195b32e 100644 --- a/drivers/iommu/omap-iommu.c +++ b/drivers/iommu/omap-iommu.c @@ -1580,13 +1580,10 @@ static struct iommu_domain omap_iommu_identity_domain = { .ops = &omap_iommu_identity_ops, }; -static struct iommu_domain *omap_iommu_domain_alloc(unsigned type) +static struct iommu_domain *omap_iommu_domain_alloc_paging(struct device *dev) { struct omap_iommu_domain *omap_domain; - if (type != IOMMU_DOMAIN_UNMANAGED) - return NULL; - omap_domain = kzalloc(sizeof(*omap_domain), GFP_KERNEL); if (!omap_domain) return NULL; @@ -1748,7 +1745,7 @@ static struct iommu_group *omap_iommu_device_group(struct device *dev) static const struct iommu_ops omap_iommu_ops = { .identity_domain = &omap_iommu_identity_domain, - .domain_alloc = omap_iommu_domain_alloc, + .domain_alloc_paging = omap_iommu_domain_alloc_paging, .probe_device = omap_iommu_probe_device, .release_device = omap_iommu_release_device, .device_group = omap_iommu_device_group, diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c index f0c867c57a5b9b..5695ad71d60e24 100644 --- a/drivers/iommu/s390-iommu.c +++ b/drivers/iommu/s390-iommu.c @@ -39,13 +39,10 @@ static bool s390_iommu_capable(struct device *dev, enum iommu_cap cap) } } -static struct iommu_domain *s390_domain_alloc(unsigned domain_type) +static struct iommu_domain *s390_domain_alloc_paging(struct device *dev) { struct s390_domain *s390_domain; - if (domain_type != IOMMU_DOMAIN_UNMANAGED) - return NULL; - s390_domain = kzalloc(sizeof(*s390_domain), GFP_KERNEL); if (!s390_domain) return NULL; @@ -447,7 +444,7 @@ void zpci_destroy_iommu(struct zpci_dev *zdev) static const struct iommu_ops s390_iommu_ops = { .default_domain = &s390_iommu_platform_domain, .capable = s390_iommu_capable, - .domain_alloc = s390_domain_alloc, + .domain_alloc_paging = s390_domain_alloc_paging, .probe_device = s390_iommu_probe_device, .release_device = s390_iommu_release_device, .device_group = generic_device_group, diff --git a/drivers/iommu/tegra-gart.c b/drivers/iommu/tegra-gart.c index 09865889ff2480..b90801dddef413 100644 --- a/drivers/iommu/tegra-gart.c +++ b/drivers/iommu/tegra-gart.c @@ -167,13 +167,10 @@ static struct iommu_domain gart_iommu_platform_domain = { .ops = &gart_iommu_platform_ops, }; -static struct iommu_domain *gart_iommu_domain_alloc(unsigned type) +static struct iommu_domain *gart_iommu_domain_alloc_paging(struct device *dev) { struct iommu_domain *domain; - if (type != IOMMU_DOMAIN_UNMANAGED) - return NULL; - domain = kzalloc(sizeof(*domain), GFP_KERNEL); if (domain) { domain->geometry.aperture_start = gart_handle->iovmm_base; @@ -294,7 +291,7 @@ static void gart_iommu_sync(struct iommu_domain *domain, static const struct iommu_ops gart_iommu_ops = { .default_domain = &gart_iommu_platform_domain, - .domain_alloc = gart_iommu_domain_alloc, + .domain_alloc_paging = gart_iommu_domain_alloc_paging, .probe_device = gart_iommu_probe_device, .device_group = generic_device_group, .pgsize_bitmap = GART_IOMMU_PGSIZES,
These drivers don't support IOMMU_DOMAIN_DMA, so this commit effectively allows them to support that mode. The prior work to require default_domains makes this safe because every one of these drivers is either compilation incompatible with dma-iommu.c, or already establishing a default_domain. In both cases alloc_domain() will never be called with IOMMU_DOMAIN_DMA for these drivers so it is safe to drop the test. Removing these tests clarifies that the domain allocation path is only about the functionality of a paging domain and has nothing to do with policy of how the paging domain is used for UNMANAGED/DMA/DMA_FQ. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> --- drivers/iommu/fsl_pamu_domain.c | 7 ++----- drivers/iommu/msm_iommu.c | 7 ++----- drivers/iommu/mtk_iommu_v1.c | 7 ++----- drivers/iommu/omap-iommu.c | 7 ++----- drivers/iommu/s390-iommu.c | 7 ++----- drivers/iommu/tegra-gart.c | 7 ++----- 6 files changed, 12 insertions(+), 30 deletions(-)