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| author | Ben Gardon <bgardon@google.com> | 2020-10-14 20:26:44 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-10-21 18:17:00 -0400 |
| commit | 02c00b3a2f7e86203d878ff432a5a19876049db6 (patch) | |
| tree | 27104f708676fc7ad3d2ff5fecfa9dda4b70ded0 /arch/x86/kvm/mmu/mmu.c | |
| parent | fe5db27d36017715827e9be7711332d701c6b7de (diff) | |
| download | lwn-02c00b3a2f7e86203d878ff432a5a19876049db6.tar.gz lwn-02c00b3a2f7e86203d878ff432a5a19876049db6.zip | |
kvm: x86/mmu: Allocate and free TDP MMU roots
The TDP MMU must be able to allocate paging structure root pages and track
the usage of those pages. Implement a similar, but separate system for root
page allocation to that of the x86 shadow paging implementation. When
future patches add synchronization model changes to allow for parallel
page faults, these pages will need to be handled differently from the
x86 shadow paging based MMU's root pages.
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/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 2afaf17284bb..017d37b19cf3 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -185,7 +185,7 @@ struct kvm_shadow_walk_iterator { __shadow_walk_next(&(_walker), spte)) static struct kmem_cache *pte_list_desc_cache; -static struct kmem_cache *mmu_page_header_cache; +struct kmem_cache *mmu_page_header_cache; static struct percpu_counter kvm_total_used_mmu_pages; static void mmu_spte_set(u64 *sptep, u64 spte); @@ -3132,9 +3132,13 @@ static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, return; sp = to_shadow_page(*root_hpa & PT64_BASE_ADDR_MASK); - --sp->root_count; - if (!sp->root_count && sp->role.invalid) - kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); + + if (kvm_mmu_put_root(kvm, sp)) { + if (sp->tdp_mmu_page) + kvm_tdp_mmu_free_root(kvm, sp); + else if (sp->role.invalid) + kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); + } *root_hpa = INVALID_PAGE; } @@ -3224,8 +3228,16 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) hpa_t root; unsigned i; - if (shadow_root_level >= PT64_ROOT_4LEVEL) { - root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level, true); + if (vcpu->kvm->arch.tdp_mmu_enabled) { + root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu); + + if (!VALID_PAGE(root)) + return -ENOSPC; + vcpu->arch.mmu->root_hpa = root; + } else if (shadow_root_level >= PT64_ROOT_4LEVEL) { + root = mmu_alloc_root(vcpu, 0, 0, shadow_root_level, + true); + if (!VALID_PAGE(root)) return -ENOSPC; vcpu->arch.mmu->root_hpa = root; |