2020-08-05 19:58:59

by yulei zhang

Subject: [RFC 4/9] Add release function for direct build ept when guest VM exit

From: Yulei Zhang <[email protected]>

Release the pre-pinned memory in direct build ept when guest VM
exit.

Signed-off-by: Yulei Zhang <[email protected]>
---
arch/x86/kvm/mmu/mmu.c | 39 ++++++++++++++++++++++++++++++---------
1 file changed, 30 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 539974183653..df703deac928 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4360,8 +4360,11 @@ static void __kvm_mmu_new_cr3(struct kvm_vcpu *vcpu, gpa_t new_cr3,

void kvm_mmu_new_cr3(struct kvm_vcpu *vcpu, gpa_t new_cr3, bool skip_tlb_flush)
{
- __kvm_mmu_new_cr3(vcpu, new_cr3, kvm_mmu_calc_root_page_role(vcpu),
- skip_tlb_flush);
+ if (!vcpu->arch.direct_build_tdp)
+ __kvm_mmu_new_cr3(vcpu, new_cr3, kvm_mmu_calc_root_page_role(vcpu),
+ skip_tlb_flush);
+ else
+ vcpu->arch.mmu->root_hpa = INVALID_PAGE;
}
EXPORT_SYMBOL_GPL(kvm_mmu_new_cr3);

@@ -5204,10 +5207,16 @@ EXPORT_SYMBOL_GPL(kvm_mmu_load);

void kvm_mmu_unload(struct kvm_vcpu *vcpu)
{
- kvm_mmu_free_roots(vcpu, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL);
- WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root_hpa));
- kvm_mmu_free_roots(vcpu, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL);
- WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root_hpa));
+
+ if (!vcpu->arch.direct_build_tdp) {
+ kvm_mmu_free_roots(vcpu, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL);
+ WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root_hpa));
+ kvm_mmu_free_roots(vcpu, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL);
+ WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root_hpa));
+ }
+
+ vcpu->arch.direct_build_tdp = false;
+ vcpu->arch.mmu->root_hpa = INVALID_PAGE;
}
EXPORT_SYMBOL_GPL(kvm_mmu_unload);

@@ -6510,6 +6519,14 @@ void kvm_direct_tdp_remove_page_table(struct kvm *kvm, struct kvm_memory_slot *s
kvm_flush_remote_tlbs(kvm);
}

+void kvm_direct_tdp_release_global_root(struct kvm *kvm)
+{
+ if (kvm->arch.global_root_hpa)
+ __kvm_walk_global_page(kvm, kvm->arch.global_root_hpa, kvm_x86_ops.get_tdp_level(NULL));
+
+ return;
+}
+
/*
* Calculate mmu pages needed for kvm.
*/
@@ -6536,9 +6553,13 @@ unsigned long kvm_mmu_calculate_default_mmu_pages(struct kvm *kvm)

void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
{
- kvm_mmu_unload(vcpu);
- free_mmu_pages(&vcpu->arch.root_mmu);
- free_mmu_pages(&vcpu->arch.guest_mmu);
+ if (vcpu->arch.direct_build_tdp) {
+ vcpu->arch.mmu->root_hpa = INVALID_PAGE;
+ } else {
+ kvm_mmu_unload(vcpu);
+ free_mmu_pages(&vcpu->arch.root_mmu);
+ free_mmu_pages(&vcpu->arch.guest_mmu);
+ }
mmu_free_memory_caches(vcpu);
}

--
2.17.1