On Wed, Dec 11, 2024 at 08:15:35AM +0000, Tian, Kevin wrote: > > From: Nicolin Chen <nicolinc@xxxxxxxxxx> > > Sent: Wednesday, December 4, 2024 6:10 AM > > > > Use it to store all vSMMU-related data. The vsid (Virtual Stream ID) will > > be the first use case. Then, add a rw_semaphore to protect it. > > > > Also add a pair of arm_smmu_attach_prepare/commit_vmaster helpers and > > put > > them in the existing arm_smmu_attach_prepare/commit(). Note that identity > > and blocked ops don't call arm_smmu_attach_prepare/commit(), thus > > simply > > call the new helpers at the top. > > Probably a dumb question. viommu is tied to a nested parent domain > which cannot be identity or blocked. Why do we need to change them > too? For identity/blocked domains, prepare() would return 0 without allocating a vmaster pointer, so later on commit() would update master->vmaster with a NULL, i.e. it's a cleanup routine when switching from a paging/dma domain to an identity/blocked one. I will update the commit message to make this clear. Thanks Nic
