Messages in this thread | | | Date | Fri, 10 Mar 2023 17:45:20 +0100 | Subject | Re: [PATCH v1 03/14] iommufd/device: Setup MSI on kernel-managed domains | From | Eric Auger <> |
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Hi Nicolin,
On 3/9/23 11:53, Nicolin Chen wrote: > The IOMMU_RESV_SW_MSI is a kernel-managed domain thing. So, it should be > only setup on a kernel-managed domain only. If the attaching domain is a > user-managed domain, redirect the hwpt to hwpt->parent to do it correctly. > > Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> > --- > drivers/iommu/iommufd/device.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c > index f95b558f5e95..a3e7d2889164 100644 > --- a/drivers/iommu/iommufd/device.c > +++ b/drivers/iommu/iommufd/device.c > @@ -350,7 +350,8 @@ static int iommufd_group_setup_msi(struct iommufd_group *igroup, > * call iommu_get_msi_cookie() on its behalf. This is necessary to setup > * the MSI window so iommu_dma_prepare_msi() can install pages into our > * domain after request_irq(). If it is not done interrupts will not > - * work on this domain. > + * work on this domain. And the msi_cookie should be always set into the s/And the/The/ > + * kernel-managed (parent) domain. > * > * FIXME: This is conceptually broken for iommufd since we want to allow > * userspace to change the domains, eg switch from an identity IOAS to a > @@ -358,6 +359,8 @@ static int iommufd_group_setup_msi(struct iommufd_group *igroup, > * matches what the IRQ layer actually expects in a newly created > * domain. > */ > + if (hwpt->parent) > + hwpt = hwpt->parent; I guess there is a garantee the parent hwpt is necessarily a kernel-managed domain? Is it that part of the spec that enforces it? IOMMU_HWPT_ALLOC doc says: " * A user-managed HWPT will be created from a given parent HWPT via @pt_id, in * which the parent HWPT must be allocated previously via the same ioctl from a * given IOAS. " Maybe precise that in the commit msg?
Thanks
Eric > if (sw_msi_start != PHYS_ADDR_MAX && !hwpt->msi_cookie) { > rc = iommu_get_msi_cookie(hwpt->domain, sw_msi_start); > if (rc)
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