Re: [PATCH v18 053/121] KVM: x86/mmu: TDX: Do not enable page track for TD guest

From: Binbin Wu
Date: Sun Feb 04 2024 - 03:46:54 EST




On 1/23/2024 7:53 AM, isaku.yamahata@xxxxxxxxx wrote:
From: Yan Zhao <yan.y.zhao@xxxxxxxxx>

TDX does not support write protection and hence page track.
Though !tdp_enabled and kvm_shadow_root_allocated(kvm) are always false
for TD guest, should also return false when external write tracking is
enabled.

Nit:
The preferred shortlog prefix format is "KVM: <topic>:", remove "TDX" from
the shortlog?
"KVM: x86/mmu: Do not enable page track for TD guest" should be OK.

Reviewed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>


Cc: Yuan Yao <yuan.yao@xxxxxxxxxxxxxxx>
Signed-off-by: Yan Zhao <yan.y.zhao@xxxxxxxxx>
---
arch/x86/kvm/mmu/page_track.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c
index c87da11f3a04..ce698ab213c1 100644
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -22,6 +22,9 @@
bool kvm_page_track_write_tracking_enabled(struct kvm *kvm)
{
+ if (kvm->arch.vm_type == KVM_X86_TDX_VM)
+ return false;
+
return IS_ENABLED(CONFIG_KVM_EXTERNAL_WRITE_TRACKING) ||
!tdp_enabled || kvm_shadow_root_allocated(kvm);
}