From patchwork Sat Feb 1 01:55:10 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 13956039 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (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 BDA917DA9C for ; Sat, 1 Feb 2025 01:55:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738374927; cv=none; b=iqezfAlHUPftqB8U8XOGj26zLlvYTxJtwKVno5RM1Ru2zIxnh+r6szuA21k1SVYrtogSz0f9pPDtuZaI/L2hHzI+6RqXCsAQwPSCcRAX55wrFD54rICVUKz57dUhnbiM7Bn74s7jFQSqb2VNWLES92bAoADMreU55EMKy3ax8k0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738374927; c=relaxed/simple; bh=WTPZCV619SX538Cn6Abym6cnK99EEExx7aoodOVpBsw=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=CwepP6HYejkLLuN/kVZd+xttxqsoB5QmdSlXXLRO5PYzXYGSqaeBweGrl8nLlizh0MQWUul7aaVHciOXRmHfDSYJUgLTD7+GaYph5NuTBZqke/C961jOKZr77/x6V1H0HnlCwJL/JfYAWAupiw0bQV0yKjlViezsJELA0bvG1KQ= 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=uhG4C+Js; arc=none smtp.client-ip=209.85.216.73 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="uhG4C+Js" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-2efa74481fdso5175664a91.1 for ; Fri, 31 Jan 2025 17:55:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1738374925; x=1738979725; 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=m3XOaiGIiENgl8NnCw2lngMp/lfgzjhOH8n22r5XeXs=; b=uhG4C+Jsyf7SQb5nbd/RoqDQo9efDc6yDtsZKyKZm+kR6nzG52nYL9hE1aOETaplfi GbDmZsmF2/JDGIL23IU9gjFwYdXMzTvcTVrouABvrG68Xp94rzXwHMP4u+FOy4ZUk97U z9Ypl9yVt5P2+3MiYy3W58DSP4XqnUqr2GuYMIMztqdDZdXfC2cNhAw2a6tflvkqcwAU Z0trLM7UxfFRecZvatlz4DekyTxFcZ436V4rA1I2jxKMjZSEmO2ZzdZeZ3DwghqkTkJM 61PbFxtCDitM9eyFQxqVvjleKzQWwRNiUWQjJe3fwAGp6jOGrlAL4VGHmruWkf00Oow5 /7cA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738374925; x=1738979725; 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=m3XOaiGIiENgl8NnCw2lngMp/lfgzjhOH8n22r5XeXs=; b=RMdUFA8kU82LWrKOfzy7dyCf3oiWV0WwFBDoMyhnhQjVMWCrZtIrtmo7DJUvbdmikf AcXLnD0AIuZs4AuFWO056U1w7OgchGKLegGPP+FD0PdjeSIJF+LpITRLEKhSAd688Eaz YfY6v2KGOimiMLF45tkEUWqYXMfKnwRQ5e4UohK9MuNujzcL5XqrunqhqcuhIN8LJvd6 LdvgfVRgTno0XUt/OpUtN6zqHTc/L0iVvTFQi69GkxZZqwXET7fxAthHE+2fPVP9PO4y CYuHfHOdZ/tyjhce3O4HWXvQoy3xDcNdOwRLWN7a5cxA0Y5jZiZ1LcJsQw9GrUB6M+RY I+Ew== X-Gm-Message-State: AOJu0YwDO+eO2FY09CbderNYDQ1MyGIeF5gl5USoCGKf7plM5CU/Q8/J schdwi5SbDxHz38vs8xbesDAP3Wy676bDXvQHib2cFHOuIevd8CTvdkgdrdJTRKP4NRShAY6FMz 4AA== X-Google-Smtp-Source: AGHT+IFuItppbgWp7/fYWByB+OH6h9nXO6RPKexQwfXO/X+6riuHAEF3pgKvJptYfZThPrJiMZ3r6hXCHQI= X-Received: from pjb14.prod.google.com ([2002:a17:90b:2f0e:b0:2e5:5ffc:1c36]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90a:d610:b0:2ee:4513:f1d1 with SMTP id 98e67ed59e1d1-2f83ac5e5bcmr16213901a91.23.1738374925164; Fri, 31 Jan 2025 17:55:25 -0800 (PST) Reply-To: Sean Christopherson Date: Fri, 31 Jan 2025 17:55:10 -0800 In-Reply-To: <20250201015518.689704-1-seanjc@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250201015518.689704-1-seanjc@google.com> X-Mailer: git-send-email 2.48.1.362.g079036d154-goog Message-ID: <20250201015518.689704-4-seanjc@google.com> Subject: [PATCH v2 03/11] KVM: nVMX: Allow emulating RDPID on behalf of L2 From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Return X86EMUL_CONTINUE instead X86EMUL_UNHANDLEABLE when emulating RDPID on behalf of L2 and L1 _does_ expose RDPID/RDTSCP to L2. When RDPID emulation was added by commit fb6d4d340e05 ("KVM: x86: emulate RDPID"), KVM incorrectly allowed emulation by default. Commit 07721feee46b ("KVM: nVMX: Don't emulate instructions in guest mode") fixed that flaw, but missed that RDPID emulation was relying on the common return path to allow emulation on behalf of L2. Fixes: 07721feee46b ("KVM: nVMX: Don't emulate instructions in guest mode") Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/vmx.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 3654c08cfa31..9773287acade 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -8049,18 +8049,19 @@ int vmx_check_intercept(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12 = get_vmcs12(vcpu); switch (info->intercept) { - /* - * RDPID causes #UD if disabled through secondary execution controls. - * Because it is marked as EmulateOnUD, we need to intercept it here. - * Note, RDPID is hidden behind ENABLE_RDTSCP. - */ case x86_intercept_rdpid: + /* + * RDPID causes #UD if not enabled through secondary execution + * controls (ENABLE_RDTSCP). Note, the implicit MSR access to + * TSC_AUX is NOT subject to interception, i.e. checking only + * the dedicated execution control is architecturally correct. + */ if (!nested_cpu_has2(vmcs12, SECONDARY_EXEC_ENABLE_RDTSCP)) { exception->vector = UD_VECTOR; exception->error_code_valid = false; return X86EMUL_PROPAGATE_FAULT; } - break; + return X86EMUL_CONTINUE; case x86_intercept_in: case x86_intercept_ins: