Messages in this thread Patch in this message |  | | Date | Tue, 5 May 2026 01:41:18 +0000 | | Subject | [PATCH 2/2] KVM: TDX: Disable pmu virtualization for TDX VMs | | From | FirstName LastName <> |
| |
From: Vishal Annapurve <vannapurve@google.com>
TDX module virtualizes PMU for TDX VMs[1]. Host has following toggles to control the PMU functionality exposed to TDX VMs: 1) Configure TD_PARAMS to allow guests to use performance monitoring. 2) Restrict the TD to a subset of the PEBS counters if supported. 3) Limit the TD to setup a certain perfmon events using basic/enhanced event filtering.
KVM will need to be enlightened to support these toggles. Explicitly disable PMU virtualization for TDX VMs by default until such a support lands.
[1] Section 15.2: https://cdrdv2.intel.com/v1/dl/getContent/733575
Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vishal Annapurve <vannapurve@google.com> --- arch/x86/kvm/vmx/tdx.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 1e47c194af53..01498c25942d 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -638,6 +638,12 @@ int tdx_vm_init(struct kvm *kvm) kvm->arch.has_private_mem = true; kvm->arch.disabled_quirks |= KVM_X86_QUIRK_IGNORE_GUEST_PAT; + /* + * PMU support is provide by the TDX-Module (if enabled for the VM). + * From KVM's perspective, the VM doesn't have a virtual PMU. + */ + kvm->arch.enable_pmu = false; + /* * Because guest TD is protected, VMM can't parse the instruction in TD. * Instead, guest uses MMIO hypercall. For unmodified device driver, -- 2.54.0.545.g6539524ca2-goog
|  |