From nobody Sun Feb 8 06:56:17 2026 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (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 64BB53BC4C9 for ; Thu, 15 Jan 2026 17:34:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768498473; cv=none; b=mlAcX+w6woi9kxzi19K0L4BRtsZc7tfExneqYoLVrqM4RrwkoU7VuGOsQNJZpnm5FipAl697F8HbpGlnJz0j6OOpKUCgISXqpJHCf3BPYXOq93zZErMTWUQD0Pxemcpdr/FZRIV1+fHvVDd3xI/ASElTXdqGTNC4Hyqr5M7lpbc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768498473; c=relaxed/simple; bh=lfQFiFquXqqUjK0GK5LCQjQGJHjS+fT5W9fknUTJy3E=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=DEmKS5gOImd9Zeazvvwp6hgaCpTuDtTl6fmmS6gGN85fScGxbOG3T+Lr8NQheYu+SDkcI+25EgHetDtIWtLwC6XdtBEt+jMj1ExSdXRO+j2yU6ekNbfFksoYRvx2flMx5NLTpKktZqZZFaYOZs6PECE9eC2n60iise0bshSlCq8= 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=JXUOsJZ7; arc=none smtp.client-ip=209.85.214.202 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="JXUOsJZ7" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2a0fe4ade9eso10944605ad.0 for ; Thu, 15 Jan 2026 09:34:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1768498472; x=1769103272; 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=vvhxNkHgD+GbG8VVPHPONdN8yxtGJ2U9E5Vry3vEwiU=; b=JXUOsJZ7ngjzn/UB7Q319pZzux8w4KoDVJL9Igx0jSt1b6QcfUmLEhw3uH81xEkjSz BB775Jt4fjyrXgKn7BKDZzI/xwSufXnqnOOB0rslx//YhuzpMBABz/tHx7/VbT8UoXM8 lofWxZmO2jsv+E8+nXLhsUtjhWm20YF3wGHk4ngFllDupwBnKJsw22GUqtxSyHbngwK3 ez4O0VzBWv8z4PL237Le5p8RWdF43qHe/okUwAxFn9pmKHRyfJh4LRyrOPLwPlmXg4mB a4lT2EZxZt4tGMJojiXZQM34c8xbo+KT6Asznap6mVjtTBrAZNUgOHDqrotzHI9zVNaR vY4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768498472; x=1769103272; 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=vvhxNkHgD+GbG8VVPHPONdN8yxtGJ2U9E5Vry3vEwiU=; b=e5KbpaNyisDeUWYZONMlz712NOckK1uAETaxJD/4VxXF9VxPH3c6asdWCr7SywiXo1 3m3x1BVGxeXzzhYp2daayzJdNQo88yjkdQyCeh2luZ4mR1sh8+M+j1ukZUTJUFF0gRuK Zoce37gfcErihgoyqKWwD8vrShyfJjuTMfmCXzZWS8vkADMTlFCLUb8Rlhe2IfLLJHKf d1T/ONPMpArQKWJksmpuoO4FilpOwc6sCopxyQuF5EZJ+oduu++1sRO954NOviV4zkzd 30+gB3UxgGS4VpoRDRKwGrzxZaCC/JmvaS10h+/t+f/ROo3uQKr6nhlBxt4JBNrx2+Jw Wukw== X-Forwarded-Encrypted: i=1; AJvYcCXeLaJ1nKDa7j4LmDqUFAquuca8yXofLakTitmI0uGEW1pIfDVjiJ9G8X2pnxnpj53a7YTTeFF2dYjd65w=@vger.kernel.org X-Gm-Message-State: AOJu0Yy2S7xj1dRZ54LkR3dgCMfRF3031xjH7/qU6QSFOntbO8V8jAa8 zOFViajQNuDq3+jrKLF/YzG7Y+K0mPxmPvZAdbUmCkRL6U8lFhwP0zP/fjJ3dCkepHq7Aj4lmWi aWoEieA== X-Received: from plwh22.prod.google.com ([2002:a17:902:f7d6:b0:2a1:5f23:7ddd]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:40cc:b0:2a1:388d:8ef3 with SMTP id d9443c01a7336-2a71754385emr3351055ad.18.1768498471672; Thu, 15 Jan 2026 09:34:31 -0800 (PST) Reply-To: Sean Christopherson Date: Thu, 15 Jan 2026 09:34:24 -0800 In-Reply-To: <20260115173427.716021-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260115173427.716021-1-seanjc@google.com> X-Mailer: git-send-email 2.52.0.457.g6b5491de43-goog Message-ID: <20260115173427.716021-2-seanjc@google.com> Subject: [PATCH v4 1/4] KVM: nVMX: Setup VMX MSRs on loading CPU during nested_vmx_hardware_setup() From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Xiaoyao Li , Chao Gao , Xin Li , Yosry Ahmed Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Move the call to nested_vmx_setup_ctls_msrs() from vmx_hardware_setup() to nested_vmx_hardware_setup() so that the nested code can deal with ordering dependencies without having to straddle vmx_hardware_setup() and nested_vmx_hardware_setup(). Specifically, an upcoming change will sanitize the vmcs12 fields based on hardware support, and that code needs to run _before_ the MSRs are configured, because the lovely vmcs_enum MSR depends on the max support vmcs12 field. No functional change intended. Reviewed-by: Xiaoyao Li Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/nested.c | 2 ++ arch/x86/kvm/vmx/vmx.c | 2 -- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 66a3eaca6817..76b08ea7c109 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -7367,6 +7367,8 @@ __init int nested_vmx_hardware_setup(int (*exit_handl= ers[])(struct kvm_vcpu *)) { int i; =20 + nested_vmx_setup_ctls_msrs(&vmcs_config, vmx_capability.ept); + if (!cpu_has_vmx_shadow_vmcs()) enable_shadow_vmcs =3D 0; if (enable_shadow_vmcs) { diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 9e6c78a22b10..27acafd03381 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -8846,8 +8846,6 @@ __init int vmx_hardware_setup(void) * can hide/show features based on kvm_cpu_cap_has(). */ if (nested) { - nested_vmx_setup_ctls_msrs(&vmcs_config, vmx_capability.ept); - r =3D nested_vmx_hardware_setup(kvm_vmx_exit_handlers); if (r) return r; --=20 2.52.0.457.g6b5491de43-goog From nobody Sun Feb 8 06:56:17 2026 Received: from mail-pg1-f202.google.com (mail-pg1-f202.google.com [209.85.215.202]) (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 37D003C00B3 for ; Thu, 15 Jan 2026 17:34:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768498475; cv=none; b=qcP4S22IfMQfYYC+UtDOf+Wj9MyLrI636vTkvSFTS6OA6o5nTsia4wM2p47r9iq7EwVcHtLlSwoqnNmI/tsfd4Q2zhPadj4V0UKgC6rSDG5O55ifx+KpulBEhtQlj7HDcHPQ5HFxPbSOLRCLrHlK/Y19Uv3SvMWsODrKBFumH24= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768498475; c=relaxed/simple; bh=Uj7+GtEca/81U0p64u8SxgUsO2V8tN4E5VdNnTgF0A4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=GZby5ZWnP0WjVwA+vqVvEikRxYqBjUgEtLE0W6tgdEvRmpQ0rHyh7R8onP0Xx1sBf6IvCYTaMOa3x2uXXyFRfgDNQdO3fMEWVmrz4RnAwk17tJKy9iJB7OpZ/DzdrDCLb0dd6Wr2jYxDFw8YC8MAovgd1+LGJ4fyGG51e32QURw= 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=jRksQjjq; arc=none smtp.client-ip=209.85.215.202 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="jRksQjjq" Received: by mail-pg1-f202.google.com with SMTP id 41be03b00d2f7-c503d6be76fso1660091a12.0 for ; Thu, 15 Jan 2026 09:34:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1768498473; x=1769103273; 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=wKAO8ODuqhBXZiFnU/FSWUMu1T9OYdfYIUbas+YiKfU=; b=jRksQjjqhTpHrGSItSI92119HBb2j+RKbSRAEcSc7gyGBNHQmXnBRoOPmRQhwnAzmf 8+zg70Q7Y5OojGo/0JzsEuH5SPI7VQXXVQ09e8FdmnKxquf7sQghK7g2jWl0qNw7qDFM 1JyCz2/UNL2UJlzoHU8Hw3Cb7KAexNwAe6w2IhZ6jcAvl4hVTlgQetSpYTE2HLp9G0z5 SAi0F0eGQAvxsbl2GATNpeDUU1WABPDtN22CkUorvGygyLxpH6PjW3hT80cBWy8acVy8 kqsI+3L9rDcjbGSpTeq5QLoygct99e18KYbIZfScnxNjRJ3XU62c2xZJ7por3kydnsf1 TIGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768498473; x=1769103273; 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=wKAO8ODuqhBXZiFnU/FSWUMu1T9OYdfYIUbas+YiKfU=; b=cbZuLxETdbDs832BZoDLuO2p5+iwoJ15E8g0qIUZ24c1ttnqGm/EBw2yoC8MBYX25b OTVXqCIf39WsUPNsFPg10Eaq95ZZhz4pmFjd9Eypf5AudGP1jpju2n0Stfc3gnUVT5C+ cKqAEmltgtw2brZsRsl+ySKFkdvE3wi5wpvjKkRguCm6B+0QQ2dFVWRqCEx9tQEEPrlb jThE4MyICF7xNlUmM1DfC9+77Vdzs1uy6w0fifH7Nr/0xqoH0srCrPqHiA2nYhDQjK8T M7bU3syhzj9LCIl57bjj/w7TlamhSmLRdRcTf7NwLUcRIV9w7rqm/PtGzF8Qv7PGDBvk gvEQ== X-Forwarded-Encrypted: i=1; AJvYcCVX1ISzXcAA7LDAyVlCH9N+vL6vp/PoVr7NV575OAp8BQjvCg2b8CZIOc4yv+CTgxiuqGLOJskDzFxLIng=@vger.kernel.org X-Gm-Message-State: AOJu0YzWTn0mLVy7SEsDhMvIV+hIBOO9Tq0YKVLhHcYJ0Gh1bWP147M2 nsKbevsEvQFFKowZ+Tbhv6s3NsezLks5eH9ALv0meYCZUgQjL8bp9994Ew5X/hXZngtVkF+jrz+ B+QVSJg== X-Received: from pgjz17.prod.google.com ([2002:a63:e551:0:b0:b6b:90a5:d43]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:1796:b0:38d:f661:992c with SMTP id adf61e73a8af0-38dfe63cd19mr488958637.35.1768498473537; Thu, 15 Jan 2026 09:34:33 -0800 (PST) Reply-To: Sean Christopherson Date: Thu, 15 Jan 2026 09:34:25 -0800 In-Reply-To: <20260115173427.716021-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260115173427.716021-1-seanjc@google.com> X-Mailer: git-send-email 2.52.0.457.g6b5491de43-goog Message-ID: <20260115173427.716021-3-seanjc@google.com> Subject: [PATCH v4 2/4] KVM: VMX: Add a wrapper around ROL16() to get a vmcs12 from a field encoding From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Xiaoyao Li , Chao Gao , Xin Li , Yosry Ahmed Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add a wrapper macro, ENC_TO_VMCS12_IDX(), to get a vmcs12 index given a field encoding in anticipation of adding a macro to get from a vmcs12 index back to the field encoding. And because open coding ROL16(n, 6) everywhere is gross. No functional change intended. Suggested-by: Xiaoyao Li Reviewed-by: Xiaoyao Li Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/hyperv_evmcs.c | 2 +- arch/x86/kvm/vmx/hyperv_evmcs.h | 2 +- arch/x86/kvm/vmx/vmcs.h | 1 + arch/x86/kvm/vmx/vmcs12.c | 4 ++-- arch/x86/kvm/vmx/vmcs12.h | 2 +- 5 files changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/vmx/hyperv_evmcs.c b/arch/x86/kvm/vmx/hyperv_evmc= s.c index 904bfcd1519b..cc728c9a3de5 100644 --- a/arch/x86/kvm/vmx/hyperv_evmcs.c +++ b/arch/x86/kvm/vmx/hyperv_evmcs.c @@ -7,7 +7,7 @@ #include "hyperv_evmcs.h" =20 #define EVMCS1_OFFSET(x) offsetof(struct hv_enlightened_vmcs, x) -#define EVMCS1_FIELD(number, name, clean_field)[ROL16(number, 6)] =3D \ +#define EVMCS1_FIELD(number, name, clean_field)[ENC_TO_VMCS12_IDX(number)]= =3D \ {EVMCS1_OFFSET(name), clean_field} =20 const struct evmcs_field vmcs_field_to_evmcs_1[] =3D { diff --git a/arch/x86/kvm/vmx/hyperv_evmcs.h b/arch/x86/kvm/vmx/hyperv_evmc= s.h index 6536290f4274..fc7c4e7bd1bf 100644 --- a/arch/x86/kvm/vmx/hyperv_evmcs.h +++ b/arch/x86/kvm/vmx/hyperv_evmcs.h @@ -130,7 +130,7 @@ static __always_inline int evmcs_field_offset(unsigned = long field, u16 *clean_field) { const struct evmcs_field *evmcs_field; - unsigned int index =3D ROL16(field, 6); + unsigned int index =3D ENC_TO_VMCS12_IDX(field); =20 if (unlikely(index >=3D nr_evmcs_1_fields)) return -ENOENT; diff --git a/arch/x86/kvm/vmx/vmcs.h b/arch/x86/kvm/vmx/vmcs.h index b25625314658..9aa204c87661 100644 --- a/arch/x86/kvm/vmx/vmcs.h +++ b/arch/x86/kvm/vmx/vmcs.h @@ -12,6 +12,7 @@ #include "capabilities.h" =20 #define ROL16(val, n) ((u16)(((u16)(val) << (n)) | ((u16)(val) >> (16 - (n= ))))) +#define ENC_TO_VMCS12_IDX(enc) ROL16(enc, 6) =20 struct vmcs_hdr { u32 revision_id:31; diff --git a/arch/x86/kvm/vmx/vmcs12.c b/arch/x86/kvm/vmx/vmcs12.c index 4233b5ca9461..c2ac9e1a50b3 100644 --- a/arch/x86/kvm/vmx/vmcs12.c +++ b/arch/x86/kvm/vmx/vmcs12.c @@ -4,10 +4,10 @@ #include "vmcs12.h" =20 #define VMCS12_OFFSET(x) offsetof(struct vmcs12, x) -#define FIELD(number, name) [ROL16(number, 6)] =3D VMCS12_OFFSET(name) +#define FIELD(number, name) [ENC_TO_VMCS12_IDX(number)] =3D VMCS12_OFFSET(= name) #define FIELD64(number, name) \ FIELD(number, name), \ - [ROL16(number##_HIGH, 6)] =3D VMCS12_OFFSET(name) + sizeof(u32) + [ENC_TO_VMCS12_IDX(number##_HIGH)] =3D VMCS12_OFFSET(name) + sizeof(u32) =20 const unsigned short vmcs12_field_offsets[] =3D { FIELD(VIRTUAL_PROCESSOR_ID, virtual_processor_id), diff --git a/arch/x86/kvm/vmx/vmcs12.h b/arch/x86/kvm/vmx/vmcs12.h index 4ad6b16525b9..7a5fdd9b27ba 100644 --- a/arch/x86/kvm/vmx/vmcs12.h +++ b/arch/x86/kvm/vmx/vmcs12.h @@ -385,7 +385,7 @@ static inline short get_vmcs12_field_offset(unsigned lo= ng field) if (field >> 15) return -ENOENT; =20 - index =3D ROL16(field, 6); + index =3D ENC_TO_VMCS12_IDX(field); if (index >=3D nr_vmcs12_fields) return -ENOENT; =20 --=20 2.52.0.457.g6b5491de43-goog From nobody Sun Feb 8 06:56:17 2026 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (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 DA52B3C1975 for ; Thu, 15 Jan 2026 17:34:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768498477; cv=none; b=W2O0O8o1nAOHClbtnYMKUftvot5w4i+mvMPiCf2lymFzdm815IB56Q3+7XrTbqE5tGutHM0h06TcQoZPO7YwdqYALWZpVto/nIbR5X0eAWLmfaEbO7phLtMBO6K1ptIESTVSWwkDFbHIwK3j7irYluMGpguxFai9tFjGbZrPR70= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768498477; c=relaxed/simple; bh=a29kfVQbaPp7CL6nh43UYnA2FIvtz0V5vUDDoqZnygQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=eHAnP8qDoSYXALk5UxO+MtcHwjAXoBNstYEaLt+HPAWOvSaWSxknX0yDY809m1908OPbRPInw4YMcfiQKMImm1iUaKFZ4g3jugSphsRw90gldMtpmgwKbX7yYUglokvg0T3T4QtvXJVxPGkU4zv1dsXKHndtvcvBVDWuw95ok4Y= 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=lcBnO4k1; arc=none smtp.client-ip=209.85.214.202 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="lcBnO4k1" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2a0a4b748a0so25275605ad.1 for ; Thu, 15 Jan 2026 09:34:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1768498475; x=1769103275; 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=GknNrx0RB+4hyuco2A9oXPYAJzVu+spP9PFyC46nLS8=; b=lcBnO4k1kooy/26mQXocVka8Fg+9kCHQd6V4rVbiy1Wbb574Ze50qWNH2vIaufjv/Q 7TteYie8TSoJojTkVdlRY3D7SIf1HTAHRazgeK0g7vMp9us7PZ5cKT41zo9yj8b8eUOH FpRYSRH//kYL30CaVck034mcgIk43rlwUbf7JHvlOzbgjBcYRPEkBh2J9NDKEch+F0+F IvYXcXr/Wd2nZ/RlJ7PvLDomW/Vx7s86UxZSi/rnJobu03+t1u/x2NsDokHv22bA49lq Z8DcAxU1KJLgHQrBFoKJbGX5qyL5KOMR6+3f+ZSMNK9abTbzuvOL011Sq+AYH1kPWb/t 9rrQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768498475; x=1769103275; 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=GknNrx0RB+4hyuco2A9oXPYAJzVu+spP9PFyC46nLS8=; b=ZLe8Duax4Lu/bAYZIvRTyicdx7/62UTafxQ1pRyWqRtavsLOTSEq3TcfbtCqUgOHlB StQhVsbr+hfCsIXt4y4iJAT+Ion/UZLDEW88ecIwe5bN0MQEpKEcv0u1cQpJEELJgUhQ JGH6VdcPX3xaDO/AgMDmZaI1Rf9XqIXcBPWRtz6eiS3Ezn1e9jNbQeG0wQh8dxF8+LYF jMz25jmmHk5EHMp+ROap6kHBOqOvOM6tR/OA3xbchkXUwe3UE73Yjxx+XsjHq7Zz9LPA mfMx/5ZpnFqday2a+tQnDwzxmrW3fdZxfDdFInxyKlX+3OHnyzD58d/6er5Ocm+mB9cO FIoQ== X-Forwarded-Encrypted: i=1; AJvYcCVq7+h8Eyo8FP6Qq/Ai6soTPDp4m3JZ1CjyzooOeF5pAoEbQGuet2mNNMrh2SqHvgco/nvbUpdfg15aksU=@vger.kernel.org X-Gm-Message-State: AOJu0YwjRq1m+V7qer4DtoS0LiNnvkqTBm7WdaweV/k10Ajxa443hnQf ZXt5XIknAayGzVMTpqfEdZ8G7+zNe9jpEpWcH/XYH5dTUYS1EODeahqTtPoP8UPWHMiEZrWu2JB MY315QQ== X-Received: from pleg22.prod.google.com ([2002:a17:902:e396:b0:29f:272e:e3bb]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:fae:b0:2a0:cb8d:2ed8 with SMTP id d9443c01a7336-2a7175a2473mr2488235ad.30.1768498475237; Thu, 15 Jan 2026 09:34:35 -0800 (PST) Reply-To: Sean Christopherson Date: Thu, 15 Jan 2026 09:34:26 -0800 In-Reply-To: <20260115173427.716021-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260115173427.716021-1-seanjc@google.com> X-Mailer: git-send-email 2.52.0.457.g6b5491de43-goog Message-ID: <20260115173427.716021-4-seanjc@google.com> Subject: [PATCH v4 3/4] KVM: nVMX: Disallow access to vmcs12 fields that aren't supported by "hardware" From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Xiaoyao Li , Chao Gao , Xin Li , Yosry Ahmed Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Disallow access (VMREAD/VMWRITE), both emulated and via a shadow VMCS, to VMCS fields that the loaded incarnation of KVM doesn't support, e.g. due to lack of hardware support, as a middle ground between allowing access to any vmcs12 field defined by KVM (current behavior) and gating access based on the userspace-defined vCPU model (the most functionally correct, but very costly, implementation). Disallowing access to unsupported fields helps a tiny bit in terms of closing the virtualization hole (see below), but the main motivation is to avoid having to weed out unsupported fields when synchronizing between vmcs12 and a shadow VMCS. Because shadow VMCS accesses are done via VMREAD and VMWRITE, KVM _must_ filter out unsupported fields (or eat VMREAD/VMWRITE failures), and filtering out just shadow VMCS fields is about the same amount of effort, and arguably much more confusing. As a bonus, this also fixes a KVM-Unit-Test failure bug when running on _hardware_ without support for TSC Scaling, which fails with the same signature as the bug fixed by commit ba1f82456ba8 ("KVM: nVMX: Dynamically compute max VMCS index for vmcs12"): FAIL: VMX_VMCS_ENUM.MAX_INDEX expected: 19, actual: 17 Dynamically computing the max VMCS index only resolved the issue where KVM was hardcoding max index, but for CPUs with TSC Scaling, that was "good enough". Reviewed-by: Chao Gao Reviewed-by: Xin Li Cc: Xiaoyao Li Cc: Yosry Ahmed Link: https://lore.kernel.org/all/20251026201911.505204-22-xin@zytor.com Link: https://lore.kernel.org/all/YR2Tf9WPNEzrE7Xg@google.com Signed-off-by: Sean Christopherson Reviewed-by: Xiaoyao Li --- arch/x86/kvm/vmx/nested.c | 18 ++++++---- arch/x86/kvm/vmx/vmcs.h | 8 +++++ arch/x86/kvm/vmx/vmcs12.c | 70 +++++++++++++++++++++++++++++++++++++-- arch/x86/kvm/vmx/vmcs12.h | 6 ++-- 4 files changed, 92 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 76b08ea7c109..34d54edb2851 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -86,6 +86,9 @@ static void init_vmcs_shadow_fields(void) pr_err("Missing field from shadow_read_only_field %x\n", field + 1); =20 + if (get_vmcs12_field_offset(field) < 0) + continue; + clear_bit(field, vmx_vmread_bitmap); if (field & 1) #ifdef CONFIG_X86_64 @@ -111,6 +114,9 @@ static void init_vmcs_shadow_fields(void) field <=3D GUEST_TR_AR_BYTES, "Update vmcs12_write_any() to drop reserved bits from AR_BYTES"); =20 + if (get_vmcs12_field_offset(field) < 0) + continue; + /* * PML and the preemption timer can be emulated, but the * processor cannot vmwrite to fields that don't exist @@ -7034,12 +7040,6 @@ void nested_vmx_set_vmcs_shadowing_bitmap(void) } } =20 -/* - * Indexing into the vmcs12 uses the VMCS encoding rotated left by 6. Undo - * that madness to get the encoding for comparison. - */ -#define VMCS12_IDX_TO_ENC(idx) ((u16)(((u16)(idx) >> 6) | ((u16)(idx) << 1= 0))) - static u64 nested_vmx_calc_vmcs_enum_msr(void) { /* @@ -7367,6 +7367,12 @@ __init int nested_vmx_hardware_setup(int (*exit_hand= lers[])(struct kvm_vcpu *)) { int i; =20 + /* + * Note! The set of supported vmcs12 fields is consumed by both VMX + * MSR and shadow VMCS setup. + */ + nested_vmx_setup_vmcs12_fields(); + nested_vmx_setup_ctls_msrs(&vmcs_config, vmx_capability.ept); =20 if (!cpu_has_vmx_shadow_vmcs()) diff --git a/arch/x86/kvm/vmx/vmcs.h b/arch/x86/kvm/vmx/vmcs.h index 9aa204c87661..66d747e265b1 100644 --- a/arch/x86/kvm/vmx/vmcs.h +++ b/arch/x86/kvm/vmx/vmcs.h @@ -11,7 +11,15 @@ =20 #include "capabilities.h" =20 +/* + * Indexing into the vmcs12 uses the VMCS encoding rotated left by 6 as a = very + * rudimentary compression of the range of indices. The compression ratio= is + * good enough to allow KVM to use a (very sparsely populated) array witho= ut + * wasting too much memory, while the "algorithm" is fast enough to be use= d to + * lookup vmcs12 fields on-demand, e.g. for emulation. + */ #define ROL16(val, n) ((u16)(((u16)(val) << (n)) | ((u16)(val) >> (16 - (n= ))))) +#define VMCS12_IDX_TO_ENC(idx) ROL16(idx, 10) #define ENC_TO_VMCS12_IDX(enc) ROL16(enc, 6) =20 struct vmcs_hdr { diff --git a/arch/x86/kvm/vmx/vmcs12.c b/arch/x86/kvm/vmx/vmcs12.c index c2ac9e1a50b3..1ebe67c384ad 100644 --- a/arch/x86/kvm/vmx/vmcs12.c +++ b/arch/x86/kvm/vmx/vmcs12.c @@ -9,7 +9,7 @@ FIELD(number, name), \ [ENC_TO_VMCS12_IDX(number##_HIGH)] =3D VMCS12_OFFSET(name) + sizeof(u32) =20 -const unsigned short vmcs12_field_offsets[] =3D { +static const u16 kvm_supported_vmcs12_field_offsets[] __initconst =3D { FIELD(VIRTUAL_PROCESSOR_ID, virtual_processor_id), FIELD(POSTED_INTR_NV, posted_intr_nv), FIELD(GUEST_ES_SELECTOR, guest_es_selector), @@ -158,4 +158,70 @@ const unsigned short vmcs12_field_offsets[] =3D { FIELD(HOST_SSP, host_ssp), FIELD(HOST_INTR_SSP_TABLE, host_ssp_tbl), }; -const unsigned int nr_vmcs12_fields =3D ARRAY_SIZE(vmcs12_field_offsets); + +u16 vmcs12_field_offsets[ARRAY_SIZE(kvm_supported_vmcs12_field_offsets)] _= _ro_after_init; +unsigned int nr_vmcs12_fields __ro_after_init; + +#define VMCS12_CASE64(enc) case enc##_HIGH: case enc + +static __init bool cpu_has_vmcs12_field(unsigned int idx) +{ + switch (VMCS12_IDX_TO_ENC(idx)) { + case VIRTUAL_PROCESSOR_ID: + return cpu_has_vmx_vpid(); + case POSTED_INTR_NV: + return cpu_has_vmx_posted_intr(); + VMCS12_CASE64(TSC_MULTIPLIER): + return cpu_has_vmx_tsc_scaling(); + case TPR_THRESHOLD: + VMCS12_CASE64(VIRTUAL_APIC_PAGE_ADDR): + return cpu_has_vmx_tpr_shadow(); + VMCS12_CASE64(APIC_ACCESS_ADDR): + return cpu_has_vmx_virtualize_apic_accesses(); + VMCS12_CASE64(POSTED_INTR_DESC_ADDR): + return cpu_has_vmx_posted_intr(); + case GUEST_INTR_STATUS: + return cpu_has_vmx_virtual_intr_delivery(); + VMCS12_CASE64(VM_FUNCTION_CONTROL): + VMCS12_CASE64(EPTP_LIST_ADDRESS): + return cpu_has_vmx_vmfunc(); + VMCS12_CASE64(EPT_POINTER): + return cpu_has_vmx_ept(); + VMCS12_CASE64(XSS_EXIT_BITMAP): + return cpu_has_vmx_xsaves(); + VMCS12_CASE64(ENCLS_EXITING_BITMAP): + return cpu_has_vmx_encls_vmexit(); + VMCS12_CASE64(GUEST_IA32_PERF_GLOBAL_CTRL): + VMCS12_CASE64(HOST_IA32_PERF_GLOBAL_CTRL): + return cpu_has_load_perf_global_ctrl(); + case SECONDARY_VM_EXEC_CONTROL: + return cpu_has_secondary_exec_ctrls(); + case GUEST_S_CET: + case GUEST_SSP: + case GUEST_INTR_SSP_TABLE: + case HOST_S_CET: + case HOST_SSP: + case HOST_INTR_SSP_TABLE: + return cpu_has_load_cet_ctrl(); + + /* KVM always emulates PML and the VMX preemption timer in software. */ + case GUEST_PML_INDEX: + case VMX_PREEMPTION_TIMER_VALUE: + default: + return true; + } +} + +void __init nested_vmx_setup_vmcs12_fields(void) +{ + unsigned int i; + + for (i =3D 0; i < ARRAY_SIZE(kvm_supported_vmcs12_field_offsets); i++) { + if (!kvm_supported_vmcs12_field_offsets[i] || + !cpu_has_vmcs12_field(i)) + continue; + + vmcs12_field_offsets[i] =3D kvm_supported_vmcs12_field_offsets[i]; + nr_vmcs12_fields =3D i + 1; + } +} diff --git a/arch/x86/kvm/vmx/vmcs12.h b/arch/x86/kvm/vmx/vmcs12.h index 7a5fdd9b27ba..21cd1b75e4fd 100644 --- a/arch/x86/kvm/vmx/vmcs12.h +++ b/arch/x86/kvm/vmx/vmcs12.h @@ -374,8 +374,10 @@ static inline void vmx_check_vmcs12_offsets(void) CHECK_OFFSET(guest_pml_index, 996); } =20 -extern const unsigned short vmcs12_field_offsets[]; -extern const unsigned int nr_vmcs12_fields; +extern u16 vmcs12_field_offsets[] __ro_after_init; +extern unsigned int nr_vmcs12_fields __ro_after_init; + +void __init nested_vmx_setup_vmcs12_fields(void); =20 static inline short get_vmcs12_field_offset(unsigned long field) { --=20 2.52.0.457.g6b5491de43-goog From nobody Sun Feb 8 06:56:17 2026 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (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 757793C1997 for ; Thu, 15 Jan 2026 17:34:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768498478; cv=none; b=jPPnCsI1WLjQNbqXEz19IQts6m4Iio9HB43HAgzHJQp7YXFGco2gK5hVjkUnaSyjp142CM524ZHzkhyKtcYU1/z6amLBjAY/lDS35Cey03iekth/93mnXSGv5ZRheR5nniVeVpNgFYT1RUDwI9DW4Fj5sfsOhPA6+aVG7/I45s8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768498478; c=relaxed/simple; bh=XILqFVmOsaW9D6OaK0VES3uHC4bLdcRi1kimGLm++So=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=pGjnmb5pLMd69TLhwcZr5lb7dspxNh0ebP1yI67nWACc+rCPWw8Gis3R/2wuFnd4Y9M1/UaHfujFcmjClIoi3CfOagM8ulQ/0PDzAg+S9YEiZmLVlT07dSBGeX4l7ATFeb0GeyR7qfAW8Pu5CsEzMR93ejHh/eszZvNqc+8Kx2k= 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=kjNrjhea; arc=none smtp.client-ip=209.85.214.202 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="kjNrjhea" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-29f8e6a5de4so11470985ad.2 for ; Thu, 15 Jan 2026 09:34:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1768498477; x=1769103277; 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=vronXy/BR0vEwHHg+fBfUJp9qb/Nw8vk6MBcNfoFOWE=; b=kjNrjhea56eEcbQmXdWswXfhHj8tOp0lVbFQlYYT7Q/8cBcDPpZ8JnCnwsJRaL0W7I MQj0o/JdNZZ2pNdtmQ6Ggm2+gTCQW/htDQdHuZwKCRWcGN6ImwO2FFaQd+zc6aMI/StO tpVWwBKzuxYOt/Qk5/pWfO4OzFr2gy9lYUuahOh5AWPDe2cp1UcRp0OvJf7VOFZnx6Zq OIpAdvD8N2rxaUIzGub56QKaS1h/99FbBFodqmXlE3GQxr+sGmfJNnX5YaCzzemqyXab WwxWXXhjEo/ARcR9yjz1f8jDS6szjhEMWg05fTQ/jXc0tJtsTuCBX0/LiLpKdkg6Htqh +DqQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768498477; x=1769103277; 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=vronXy/BR0vEwHHg+fBfUJp9qb/Nw8vk6MBcNfoFOWE=; b=e6rQiEi9AjJ+4LWYPW08guqM/pvqZ9ElmOuFJuY5eaJlSxBEn44WT8SXse3/Kr5rz6 Y44q+rDilpk+CD77HXrwDC0ZqH7FqVGt7hQl5OqOdE40x9ARgVR1Nse8JR7EthR1Bp8w 6X37vi3YOG7D1GkXF2eSqolY1GPT2RfYjhVFS3KL+2T4sLqhY4V1gyGe6BAjt4H3qsvu QcUWJpvadx69i/5y8OXn0F/rYGmk6FQ6GAXt/5Di6V1kUwocW8zpOzxzRtPLicZ1u9PS ci2Qg5QHyYGDwtfOEPobpDe+NpNLgJKmSlhnsTVkarfJxhPU7zrgVnSsgmsjB81BQ9KK QPRA== X-Forwarded-Encrypted: i=1; AJvYcCXIM1T2DfxTq0UbFpz/aEjvAGAqRzY2KzNl2IxTwqPUx1IKFD+UpBuoVraxDjO/SbrRlkSl2yUNoMkZtv8=@vger.kernel.org X-Gm-Message-State: AOJu0Yw+gJgBeZWxX5dEaZqnLHcqEcS3FlRBC0+TkDPi2n6HIff14Fj5 7cdDfJAUWbBgWZc4pgDfKkgYdrnXPsfUKgTYAkAhDn8y4w6V5lfFcoSn6qfWFDXPoBFoFN9CwOq xcQTNXg== X-Received: from plyw10.prod.google.com ([2002:a17:902:d70a:b0:2a2:f514:2116]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:903:40cc:b0:2a1:388d:8ef3 with SMTP id d9443c01a7336-2a71754385emr3353485ad.18.1768498476771; Thu, 15 Jan 2026 09:34:36 -0800 (PST) Reply-To: Sean Christopherson Date: Thu, 15 Jan 2026 09:34:27 -0800 In-Reply-To: <20260115173427.716021-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260115173427.716021-1-seanjc@google.com> X-Mailer: git-send-email 2.52.0.457.g6b5491de43-goog Message-ID: <20260115173427.716021-5-seanjc@google.com> Subject: [PATCH v4 4/4] KVM: nVMX: Remove explicit filtering of GUEST_INTR_STATUS from shadow VMCS fields From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Xiaoyao Li , Chao Gao , Xin Li , Yosry Ahmed Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Drop KVM's filtering of GUEST_INTR_STATUS when generating the shadow VMCS bitmap now that KVM drops GUEST_INTR_STATUS from the set of supported vmcs12 fields if the field isn't supported by hardware, and initialization of the shadow VMCS fields omits unsupported vmcs12 fields. Note, there is technically a small functional change here, as the vmcs12 filtering only requires support for Virtual Interrupt Delivery, whereas the shadow VMCS code being removed required "full" APICv support, i.e. required Virtual Interrupt Delivery *and* APIC Register Virtualizaton *and* Posted Interrupt support. Opportunistically tweak the comment to more precisely explain why the PML and VMX preemption timer fields need to be explicitly checked. Signed-off-by: Sean Christopherson Reviewed-by: Xiaoyao Li --- arch/x86/kvm/vmx/nested.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 34d54edb2851..edbe99a85286 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -118,9 +118,10 @@ static void init_vmcs_shadow_fields(void) continue; =20 /* - * PML and the preemption timer can be emulated, but the - * processor cannot vmwrite to fields that don't exist - * on bare metal. + * KVM emulates PML and the VMX preemption timer irrespective + * of hardware support, but shadowing their related VMCS fields + * requires hardware support as the CPU will reject VMWRITEs to + * fields that don't exist. */ switch (field) { case GUEST_PML_INDEX: @@ -131,10 +132,6 @@ static void init_vmcs_shadow_fields(void) if (!cpu_has_vmx_preemption_timer()) continue; break; - case GUEST_INTR_STATUS: - if (!cpu_has_vmx_apicv()) - continue; - break; default: break; } --=20 2.52.0.457.g6b5491de43-goog