[PATCH v3 35/37] KVM: nVMX: Free only the affected contexts when emulating INVEPT

From: Sean Christopherson
Date: Fri Mar 20 2020 - 17:29:51 EST


Add logic to handle_invept() to free only those roots that match the
target EPT context when emulating a single-context INVEPT.

Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 26 +++++++++++++++++++++-----
1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 92aab4166498..72e69d841531 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5185,12 +5185,14 @@ static int handle_invept(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 vmx_instruction_info, types;
- unsigned long type;
+ unsigned long type, roots_to_free;
+ struct kvm_mmu *mmu;
gva_t gva;
struct x86_exception e;
struct {
u64 eptp, gpa;
} operand;
+ int i;

if (!(vmx->nested.msrs.secondary_ctls_high &
SECONDARY_EXEC_ENABLE_EPT) ||
@@ -5222,23 +5224,37 @@ static int handle_invept(struct kvm_vcpu *vcpu)
return 1;
}

+ mmu = &vcpu->arch.guest_mmu;
+
switch (type) {
case VMX_EPT_EXTENT_CONTEXT:
if (!nested_vmx_check_eptp(vcpu, operand.eptp))
return nested_vmx_failValid(vcpu,
VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID);

- /* TODO: sync only the target EPTP context. */
- fallthrough;
+ roots_to_free = 0;
+ if (nested_ept_root_matches(mmu->root_hpa, mmu->root_cr3,
+ operand.eptp))
+ roots_to_free |= KVM_MMU_ROOT_CURRENT;
+
+ for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++) {
+ if (nested_ept_root_matches(mmu->prev_roots[i].hpa,
+ mmu->prev_roots[i].cr3,
+ operand.eptp))
+ roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i);
+ }
+ break;
case VMX_EPT_EXTENT_GLOBAL:
- kvm_mmu_free_roots(vcpu, &vcpu->arch.guest_mmu,
- KVM_MMU_ROOTS_ALL);
+ roots_to_free = KVM_MMU_ROOTS_ALL;
break;
default:
BUG_ON(1);
break;
}

+ if (roots_to_free)
+ kvm_mmu_free_roots(vcpu, mmu, roots_to_free);
+
return nested_vmx_succeed(vcpu);
}

--
2.24.1