From nobody Thu Apr 2 23:54:04 2026 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 65F7229B22F for ; Sat, 14 Feb 2026 01:27:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771032445; cv=none; b=DKURwiNrVnz8Gt/uvMneRQYW2LC2XeRjeDttwoIlsPO2GEcGhGEdS+JFtcK7DF0FgY3ZZOCWJdGhbt1ihKPrjLHYBvB0dQJ0aXKQ9Z+JQzc469Jds8jT4uYh1cK/dxMhn8JXKicFhTX1lFMtsbVfoF+nTtclbZ7HntAq2LbhbiU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771032445; c=relaxed/simple; bh=hftPp1cgH316yfhw8k/dPrCnpI6uxskVDDg5/T2D/XQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=NGFRq2tNULGaxVDCzyOYQkBtjsERIR/a1962ndCZ4rccL/1tvrBLr/F4XAJNM4DyzhrnFVj5DxnwHR26UaygzI6szQ788Spotb1Xk0ocrjEypQvF28espux4VpONqmSU+YeG5vNFaKiG7pg0U7iQoQKTGphAPZTn+rvvCipDvEM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=ODe2sKw8; arc=none smtp.client-ip=209.85.216.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ODe2sKw8" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-3562370038dso1400519a91.3 for ; Fri, 13 Feb 2026 17:27:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1771032444; x=1771637244; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=H80q9SD+282s080Ud0tbsBB2WQnuDfalKG9TFAGQvtU=; b=ODe2sKw8XoEK7CQYt+oCiLu5mLNoyuVj1bq+LvEAPbVmd7QLJjArvXZ9OHfsTmlrbn m7Se4Odc9ibeOBJ6ztQ6uNQXaPXElwac8G4qk/2g1vFwmdd67izJuA0opxTy+94nssVV CLNwOsDyI29nKRzGm1kVry8CmORq5gGhQLfXL92CJgKkNry4PSPbVNDDWu2pkh+EzKv/ cL03Q+MVhTVSH7PymNRyqlR2q/e8EIjhi7uR8TxNQtOyX0Cj03IYxNzjoSJOAxtqIB0f 9uyqsF+3OT1utCHsc/Kt4RCT7DSJvvMKb/1zcsBtPO89Yo26Z7MXAMfav0bgkNabM/yR zCKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771032444; x=1771637244; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=H80q9SD+282s080Ud0tbsBB2WQnuDfalKG9TFAGQvtU=; b=wi8+IsxVpkKRRQbSCXaaLaRJEBe2wQXj6Dbga10fHASEfBg4choKY4fPiwkFfLovJk NA9ISIaoCnlo7u8LrgyEj8joWVpVUTS02OKPIC65laW5jD7nUv8NsbpVMwvqQ2kxjfpN UVGud5KGMBx88xHKnEilPyevdKNZ4hGMX/ns0FPxUXUHVcYXkAZcCEaOhvmCJT516ZUI 4wWaPZSdrfViHx/CPBf0rGf4N1mUUCP9SMiSwZyZOnw9z5FWNG1eDolP7JqvG7YOaoXS 2zv+7Hv7w8tIGpo5UMUAOyJRYH2QsKiForAVru6BZYwwlspr2wCWuyqkfeqT5cI1cehX /e5g== X-Gm-Message-State: AOJu0Yyg6o5Lo4RCAcOlJN6ODubo6GiDzaVoRL8WOb9C862XlYx++kkL NbwwCmu5PQhd1JChQ2pbkVtUmg5Fp2NR6I2+XDaSxXCdblW8KVZtBy0CZrv8t0pe43V9TIkTFNv nz0U64g== X-Received: from pgvt5.prod.google.com ([2002:a65:64c5:0:b0:c65:e24e:cef1]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:43a5:b0:38e:9cc5:218c with SMTP id adf61e73a8af0-3946c8be39amr3465099637.54.1771032443485; Fri, 13 Feb 2026 17:27:23 -0800 (PST) Reply-To: Sean Christopherson Date: Fri, 13 Feb 2026 17:26:56 -0800 In-Reply-To: <20260214012702.2368778-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260214012702.2368778-1-seanjc@google.com> X-Mailer: git-send-email 2.53.0.310.g728cabbaf7-goog Message-ID: <20260214012702.2368778-11-seanjc@google.com> Subject: [PATCH v3 10/16] x86/virt/tdx: Drop the outdated requirement that TDX be enabled in IRQ context From: Sean Christopherson To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Kiryl Shutsemau , Peter Zijlstra , Arnaldo Carvalho de Melo , Namhyung Kim , Sean Christopherson , Paolo Bonzini Cc: linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org, linux-perf-users@vger.kernel.org, Chao Gao , Xu Yilun , Dan Williams Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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) =20 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)); =20 - local_irq_save(flags); - r =3D tdx_cpu_enable(); - local_irq_restore(flags); - - return r; + return tdx_cpu_enable(); } =20 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; =20 - lockdep_assert_irqs_disabled(); - if (__this_cpu_read(tdx_lp_initialized)) return 0; =20 --=20 2.53.0.310.g728cabbaf7-goog