From 7d390a9da8233fd32ccdf132726712a72a990b26 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 10 Jun 2025 16:20:03 -0700 Subject: [PATCH] KVM: TDX: Use kvm_arch_vcpu.host_debugctl to restore the host's DEBUGCTL Use the kvm_arch_vcpu.host_debugctl snapshot to restore DEBUGCTL after running a TD vCPU. The final TDX series rebase was mishandled, likely due to commit fb71c7959356 ("KVM: x86: Snapshot the host's DEBUGCTL in common x86") deleting the same line of code from vmx.h, i.e. creating a semantic conflict of sorts, but no syntactic conflict. Using the version in kvm_vcpu_arch picks up the ulong => u64 fix (which isn't relevant to TDX) as well as the IRQ fix from commit 189ecdb3e112 ("KVM: x86: Snapshot the host's DEBUGCTL after disabling IRQs"). Link: https://lore.kernel.org/all/20250307212053.2948340-10-pbonzini@redhat.com Cc: Adrian Hunter Fixes: 8af099037527 ("KVM: TDX: Save and restore IA32_DEBUGCTL") Reviewed-by: Adrian Hunter Link: https://lore.kernel.org/r/20250610232010.162191-2-seanjc@google.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/common.h | 2 -- arch/x86/kvm/vmx/tdx.c | 6 ++---- 2 files changed, 2 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/vmx/common.h b/arch/x86/kvm/vmx/common.h index a0c5e8781c336..bc5ece76533ae 100644 --- a/arch/x86/kvm/vmx/common.h +++ b/arch/x86/kvm/vmx/common.h @@ -53,8 +53,6 @@ struct vcpu_vt { #ifdef CONFIG_X86_64 u64 msr_host_kernel_gs_base; #endif - - unsigned long host_debugctlmsr; }; #ifdef CONFIG_KVM_INTEL_TDX diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index f31ccdeb905b4..4d2426ab67471 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -785,8 +785,6 @@ void tdx_prepare_switch_to_guest(struct kvm_vcpu *vcpu) else vt->msr_host_kernel_gs_base = read_msr(MSR_KERNEL_GS_BASE); - vt->host_debugctlmsr = get_debugctlmsr(); - vt->guest_state_loaded = true; } @@ -1062,8 +1060,8 @@ fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu, bool force_immediate_exit) tdx_vcpu_enter_exit(vcpu); - if (vt->host_debugctlmsr & ~TDX_DEBUGCTL_PRESERVED) - update_debugctlmsr(vt->host_debugctlmsr); + if (vcpu->arch.host_debugctl & ~TDX_DEBUGCTL_PRESERVED) + update_debugctlmsr(vcpu->arch.host_debugctl); tdx_load_host_xsave_state(vcpu); tdx->guest_entered = true; -- 2.47.2