diff options
author | Ben Gardon <bgardon@google.com> | 2020-10-14 21:26:42 +0300 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-10-22 01:17:00 +0300 |
commit | c9180b7291cf13a746aaca907b9fdd499cce1e38 (patch) | |
tree | 57db6c64271b7de89e376a8f35ce6affd9fdb4c0 /arch/x86/kvm/mmu/tdp_iter.h | |
parent | 5a9624affe7c7498fb395879d9bb613628e89e60 (diff) | |
download | linux-c9180b7291cf13a746aaca907b9fdd499cce1e38.tar.xz |
kvm: x86/mmu: Introduce tdp_iter
The TDP iterator implements a pre-order traversal of a TDP paging
structure. This iterator will be used in future patches to create
an efficient implementation of the KVM MMU for the TDP case.
Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.
This series can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
Signed-off-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu/tdp_iter.h')
-rw-r--r-- | arch/x86/kvm/mmu/tdp_iter.h | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu/tdp_iter.h b/arch/x86/kvm/mmu/tdp_iter.h new file mode 100644 index 000000000000..d629a53e1b73 --- /dev/null +++ b/arch/x86/kvm/mmu/tdp_iter.h @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0 + +#ifndef __KVM_X86_MMU_TDP_ITER_H +#define __KVM_X86_MMU_TDP_ITER_H + +#include <linux/kvm_host.h> + +#include "mmu.h" + +/* + * A TDP iterator performs a pre-order walk over a TDP paging structure. + */ +struct tdp_iter { + /* + * The iterator will traverse the paging structure towards the mapping + * for this GFN. + */ + gfn_t goal_gfn; + /* Pointers to the page tables traversed to reach the current SPTE */ + u64 *pt_path[PT64_ROOT_MAX_LEVEL]; + /* A pointer to the current SPTE */ + u64 *sptep; + /* The lowest GFN mapped by the current SPTE */ + gfn_t gfn; + /* The level of the root page given to the iterator */ + int root_level; + /* The lowest level the iterator should traverse to */ + int min_level; + /* The iterator's current level within the paging structure */ + int level; + /* A snapshot of the value at sptep */ + u64 old_spte; + /* + * Whether the iterator has a valid state. This will be false if the + * iterator walks off the end of the paging structure. + */ + bool valid; +}; + +/* + * Iterates over every SPTE mapping the GFN range [start, end) in a + * preorder traversal. + */ +#define for_each_tdp_pte(iter, root, root_level, start, end) \ + for (tdp_iter_start(&iter, root, root_level, PG_LEVEL_4K, start); \ + iter.valid && iter.gfn < end; \ + tdp_iter_next(&iter)) + +u64 *spte_to_child_pt(u64 pte, int level); + +void tdp_iter_start(struct tdp_iter *iter, u64 *root_pt, int root_level, + int min_level, gfn_t goal_gfn); +void tdp_iter_next(struct tdp_iter *iter); +void tdp_iter_refresh_walk(struct tdp_iter *iter); + +#endif /* __KVM_X86_MMU_TDP_ITER_H */ |