Date: Fri, 29 Dec 2023 00:34:58 GMT From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: e9251d68b206 - stable/14 - vm_iommu_map()/unmap(): stop transiently wiring already wired pages Message-ID: <202312290034.3BT0YwJS009724@gitrepo.freebsd.org>
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The branch stable/14 has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=e9251d68b206d4ea4be4413c17e008c76dd49e79 commit e9251d68b206d4ea4be4413c17e008c76dd49e79 Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2023-12-21 00:12:37 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2023-12-29 00:33:21 +0000 vm_iommu_map()/unmap(): stop transiently wiring already wired pages (cherry picked from commit 671a00491d7ac9d6663cdc597ff8c13024eda00d) --- sys/amd64/vmm/vmm.c | 39 +++++++++++++++++++++++++-------------- 1 file changed, 25 insertions(+), 14 deletions(-) diff --git a/sys/amd64/vmm/vmm.c b/sys/amd64/vmm/vmm.c index db81f63c9614..d44adc86252d 100644 --- a/sys/amd64/vmm/vmm.c +++ b/sys/amd64/vmm/vmm.c @@ -1044,9 +1044,10 @@ vm_iommu_map(struct vm *vm) { vm_paddr_t gpa, hpa; struct mem_map *mm; - void *vp, *cookie; int i; + sx_assert(&vm->mem_segs_lock, SX_LOCKED); + for (i = 0; i < VM_MAX_MEMMAPS; i++) { mm = &vm->mem_maps[i]; if (!sysmem_mapping(vm, mm)) @@ -1060,13 +1061,24 @@ vm_iommu_map(struct vm *vm) mm->flags |= VM_MEMMAP_F_IOMMU; for (gpa = mm->gpa; gpa < mm->gpa + mm->len; gpa += PAGE_SIZE) { - vp = vm_gpa_hold_global(vm, gpa, PAGE_SIZE, - VM_PROT_WRITE, &cookie); - KASSERT(vp != NULL, ("vm(%s) could not map gpa %#lx", - vm_name(vm), gpa)); - vm_gpa_release(cookie); + hpa = pmap_extract(vmspace_pmap(vm->vmspace), gpa); + + /* + * All mappings in the vmm vmspace must be + * present since they are managed by vmm in this way. + * Because we are in pass-through mode, the + * mappings must also be wired. This implies + * that all pages must be mapped and wired, + * allowing to use pmap_extract() and avoiding the + * need to use vm_gpa_hold_global(). + * + * This could change if/when we start + * supporting page faults on IOMMU maps. + */ + KASSERT(vm_page_wired(PHYS_TO_VM_PAGE(hpa)), + ("vm_iommu_map: vm %p gpa %jx hpa %jx not wired", + vm, (uintmax_t)gpa, (uintmax_t)hpa)); - hpa = DMAP_TO_PHYS((uintptr_t)vp); iommu_create_mapping(vm->iommu, gpa, hpa, PAGE_SIZE); } } @@ -1079,9 +1091,10 @@ vm_iommu_unmap(struct vm *vm) { vm_paddr_t gpa; struct mem_map *mm; - void *vp, *cookie; int i; + sx_assert(&vm->mem_segs_lock, SX_LOCKED); + for (i = 0; i < VM_MAX_MEMMAPS; i++) { mm = &vm->mem_maps[i]; if (!sysmem_mapping(vm, mm)) @@ -1095,12 +1108,10 @@ vm_iommu_unmap(struct vm *vm) mm->gpa, mm->len, mm->flags)); for (gpa = mm->gpa; gpa < mm->gpa + mm->len; gpa += PAGE_SIZE) { - vp = vm_gpa_hold_global(vm, gpa, PAGE_SIZE, - VM_PROT_WRITE, &cookie); - KASSERT(vp != NULL, ("vm(%s) could not map gpa %#lx", - vm_name(vm), gpa)); - vm_gpa_release(cookie); - + KASSERT(vm_page_wired(PHYS_TO_VM_PAGE(pmap_extract( + vmspace_pmap(vm->vmspace), gpa))), + ("vm_iommu_unmap: vm %p gpa %jx not wired", + vm, (uintmax_t)gpa)); iommu_remove_mapping(vm->iommu, gpa, PAGE_SIZE); } }
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