Re: [PATCH v19 056/130] KVM: x86/tdp_mmu: Init role member of struct kvm_mmu_page at allocation

From: Edgecombe, Rick P
Date: Sat Apr 20 2024 - 15:05:35 EST


On Wed, 2024-03-20 at 17:11 -0700, Rick Edgecombe wrote:
> @@ -1378,6 +1375,8 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct
> kvm_page_fault *fault)
>                  * needs to be split.
>                  */
>                 sp = tdp_mmu_alloc_sp(vcpu);
> +               if (!(raw_gfn & kvm_gfn_shared_mask(kvm)))
> +                       kvm_mmu_alloc_private_spt(vcpu, sp);

This will try to allocate the private SP for normal VMs (which have a zero
shared mask), it should be:

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index efed70580922..585c80fb62c5 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1350,7 +1350,7 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct
kvm_page_fault *fault)
* needs to be split.
*/
sp = tdp_mmu_alloc_sp(vcpu);
- if (!(raw_gfn & kvm_gfn_shared_mask(kvm)))
+ if (kvm_is_private_gpa(kvm, raw_gfn << PAGE_SHIFT))
kvm_mmu_alloc_private_spt(vcpu, sp);
tdp_mmu_init_child_sp(sp, &iter);