Remove TDX's outdated requirement that per-CPU enabling be done via IPI function call, which was a stale artifact leftover from early versions of the TDX enablement series. The requirement that IRQs be disabled should have been dropped as part of the revamped series that relied on a the KVM rework to enable VMX at module load. In other words, the kernel's "requirement" was never a requirement at all, but instead a reflection of how KVM enabled VMX (via IPI callback) when the TDX subsystem code was merged. Note, accessing per-CPU information is safe even without disabling IRQs, as tdx_online_cpu() is invoked via a cpuhp callback, i.e. from a per-CPU thread. Link: https://lore.kernel.org/all/ZyJOiPQnBz31qLZ7@google.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/tdx.c | 9 +-------- arch/x86/virt/vmx/tdx/tdx.c | 4 ---- 2 files changed, 1 insertion(+), 12 deletions(-) diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 0c790eb0bfa6..582469118b79 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -3294,17 +3294,10 @@ int tdx_gmem_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn, bool is_private) static int tdx_online_cpu(unsigned int cpu) { - unsigned long flags; - int r; - /* Sanity check CPU is already in post-VMXON */ WARN_ON_ONCE(!(cr4_read_shadow() & X86_CR4_VMXE)); - local_irq_save(flags); - r = tdx_cpu_enable(); - local_irq_restore(flags); - - return r; + return tdx_cpu_enable(); } static int tdx_offline_cpu(unsigned int cpu) diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c index 5ce4ebe99774..dfd82fac0498 100644 --- a/arch/x86/virt/vmx/tdx/tdx.c +++ b/arch/x86/virt/vmx/tdx/tdx.c @@ -148,8 +148,6 @@ static int try_init_module_global(void) * global initialization SEAMCALL if not done) on local cpu to make this * cpu be ready to run any other SEAMCALLs. * - * Always call this function via IPI function calls. - * * Return 0 on success, otherwise errors. */ int tdx_cpu_enable(void) @@ -160,8 +158,6 @@ int tdx_cpu_enable(void) if (!boot_cpu_has(X86_FEATURE_TDX_HOST_PLATFORM)) return -ENODEV; - lockdep_assert_irqs_disabled(); - if (__this_cpu_read(tdx_lp_initialized)) return 0; -- 2.53.0.310.g728cabbaf7-goog