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author | Marc Zyngier <maz@kernel.org> | 2021-12-16 13:06:09 +0000 |
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committer | Marc Zyngier <maz@kernel.org> | 2021-12-16 13:06:09 +0000 |
commit | 43d8ac22125e365c2df85ffff503129567350c21 (patch) | |
tree | b5b3b608c25d28716cc705714f30cbb28636c4fb /arch/arm64/kvm/hyp/nvhe/setup.c | |
parent | ce5b5b05c16802a27cbf12fbce1446eb4998f975 (diff) | |
parent | 52b28657ebd7cd20e931ce71190f235d0fa018a6 (diff) | |
download | linux-stable-43d8ac22125e365c2df85ffff503129567350c21.tar.gz linux-stable-43d8ac22125e365c2df85ffff503129567350c21.tar.bz2 linux-stable-43d8ac22125e365c2df85ffff503129567350c21.zip |
Merge branch kvm-arm64/pkvm-hyp-sharing into kvmarm-master/next
* kvm-arm64/pkvm-hyp-sharing:
: .
: Series from Quentin Perret, implementing HYP page share/unshare:
:
: This series implements an unshare hypercall at EL2 in nVHE
: protected mode, and makes use of it to unmmap guest-specific
: data-structures from EL2 stage-1 during guest tear-down.
: Crucially, the implementation of the share and unshare
: routines use page refcounts in the host kernel to avoid
: accidentally unmapping data-structures that overlap a common
: page.
: [...]
: .
KVM: arm64: pkvm: Unshare guest structs during teardown
KVM: arm64: Expose unshare hypercall to the host
KVM: arm64: Implement do_unshare() helper for unsharing memory
KVM: arm64: Implement __pkvm_host_share_hyp() using do_share()
KVM: arm64: Implement do_share() helper for sharing memory
KVM: arm64: Introduce wrappers for host and hyp spin lock accessors
KVM: arm64: Extend pkvm_page_state enumeration to handle absent pages
KVM: arm64: pkvm: Refcount the pages shared with EL2
KVM: arm64: Introduce kvm_share_hyp()
KVM: arm64: Implement kvm_pgtable_hyp_unmap() at EL2
KVM: arm64: Hook up ->page_count() for hypervisor stage-1 page-table
KVM: arm64: Fixup hyp stage-1 refcount
KVM: arm64: Refcount hyp stage-1 pgtable pages
KVM: arm64: Provide {get,put}_page() stubs for early hyp allocator
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/setup.c')
-rw-r--r-- | arch/arm64/kvm/hyp/nvhe/setup.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c index e31149965204..27af337f9fea 100644 --- a/arch/arm64/kvm/hyp/nvhe/setup.c +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -166,6 +166,7 @@ static int finalize_host_mappings_walker(u64 addr, u64 end, u32 level, enum kvm_pgtable_walk_flags flag, void * const arg) { + struct kvm_pgtable_mm_ops *mm_ops = arg; enum kvm_pgtable_prot prot; enum pkvm_page_state state; kvm_pte_t pte = *ptep; @@ -174,6 +175,15 @@ static int finalize_host_mappings_walker(u64 addr, u64 end, u32 level, if (!kvm_pte_valid(pte)) return 0; + /* + * Fix-up the refcount for the page-table pages as the early allocator + * was unable to access the hyp_vmemmap and so the buddy allocator has + * initialised the refcount to '1'. + */ + mm_ops->get_page(ptep); + if (flag != KVM_PGTABLE_WALK_LEAF) + return 0; + if (level != (KVM_PGTABLE_MAX_LEVELS - 1)) return -EINVAL; @@ -206,7 +216,8 @@ static int finalize_host_mappings(void) { struct kvm_pgtable_walker walker = { .cb = finalize_host_mappings_walker, - .flags = KVM_PGTABLE_WALK_LEAF, + .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, + .arg = pkvm_pgtable.mm_ops, }; int i, ret; @@ -241,19 +252,20 @@ void __noreturn __pkvm_init_finalise(void) if (ret) goto out; - ret = finalize_host_mappings(); - if (ret) - goto out; - pkvm_pgtable_mm_ops = (struct kvm_pgtable_mm_ops) { .zalloc_page = hyp_zalloc_hyp_page, .phys_to_virt = hyp_phys_to_virt, .virt_to_phys = hyp_virt_to_phys, .get_page = hpool_get_page, .put_page = hpool_put_page, + .page_count = hyp_page_count, }; pkvm_pgtable.mm_ops = &pkvm_pgtable_mm_ops; + ret = finalize_host_mappings(); + if (ret) + goto out; + out: /* * We tail-called to here from handle___pkvm_init() and will not return, |