[PATCH 10/15] KVM: X86: Skip allocating pae_root for vcpu->arch.guest_mmu when !tdp_enabled

Lai Jiangshan
2021-11-18T11:12:43Z

It is never used.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
---
arch/x86/kvm/mmu/mmu.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 8f0035517450..e1fe8af874ef 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5501,6 +5501,10 @@ static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu)
for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++)
mmu->prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID;

+ /* vcpu->arch.guest_mmu isn't used when !tdp_enabled. */
+ if (!tdp_enabled && mmu == &vcpu->arch.guest_mmu)
+ return 0;
+
/*
* When using PAE paging, the four PDPTEs are treated as 'root' pages,
* while the PDP table is a per-vCPU construct that's allocated at MMU
--
2.19.1.6.gb485710b