From nobody Mon Feb 9 15:32:42 2026 Received: from mail-pf1-f202.google.com (mail-pf1-f202.google.com [209.85.210.202]) (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 3FFFE28D8FE for ; Tue, 10 Jun 2025 22:57:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749596268; cv=none; b=aXy/y5Rg4HRealcBFqKGWyuRG0Np98UpZgeVMXOOeXHf8ByB9GHmYdG+ex+Rk0hyqqeMsIa0Du1mdbRMjGHskZ02H11AFUAOErTrJjvbHcLKgcQbSYSbm5t1w4c/yR4+IMwIDqHWIj952hTwh15rIrnCtMqcQASeGDbn6Kw7lXA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749596268; c=relaxed/simple; bh=9VEAvtUsud2CGs9vlrwfusz06B+7ZsvAKB7oC960uWQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=OcRKl/bNFIHXq73IePPOn4G9yyplDkE2OsoQc1fFjPKb/GhrOBrRqcV56bySvwDVz+iTftB3o0s4FKiFpi8UAO/fNqqwqVPPCnli1JFHjuGQpea6ZFNV8VLjzwnAloN5Ok2w9Buha3gO4YHemRw1a9JVnptDVQib67aULG2liVg= 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=ziGyi8Ma; arc=none smtp.client-ip=209.85.210.202 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="ziGyi8Ma" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-747d84fe5f8so3448880b3a.3 for ; Tue, 10 Jun 2025 15:57:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1749596266; x=1750201066; 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=sgbdhI3yd/wQ/3cQ73eXvLbLWKSkDV545uFxsAvOoCg=; b=ziGyi8Mavn6a6PdpdzWGfFzc3CBeFRC3BGD2s3dVd9sJlC5ZiL9GRhM/S69ZWV655j ormtFGCto370krwFDKu/iWosSmSyfoRdrDh/p188J77npgoe6EO66htmdNC7hNUgvNKF gF3JomtT6WVwMiWTIBwtHu2J5a87LpsfqE50wsu3UcBBRLT+eqFPHLS1e03dUNOh3NBR xU+1zW5iLQvFZHEPN5UOHgtykctpNvEwtiamJDPmGzO09nPt/LADrwEp6UxxgdXnY4El XjL/Asu+IhBcj+bvH6xEV65QLReNca0W+r6cX4r36zIGBUb6/agntTRjXyWR638m8Zv4 1u9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749596266; x=1750201066; 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=sgbdhI3yd/wQ/3cQ73eXvLbLWKSkDV545uFxsAvOoCg=; b=YkGxxAuhmR3Zeo7iME34Ztuu+z0kr+nH4zs6lG9Rzw4cU71/5Vxzc0bRdFDCptipd5 hC5dW5xbHjyU1v33PxcwW6IdKg48IX/zbwhXvb8yGoB5zZfjzLZMvswT8UYbGs2Vgwjh Ttloel1oMUPZC07CdMpfIA/LlIalkAIbSurWWrDJb7/hPwPRUGwa1sIm510MtrRbDTq1 baQPgNN24haX6ADqQ8cM/bp8l/2zvcmM6GwmFguujBFXNeCuBPu3r+ikvu+Jkmf1iOo+ /ReF/2qhAmTSprQCqA/aQoQaIKZbZ6//XLB882ZH+Ne1hHuucOjVO+MeZ3Wh7T9w1gdL 9QcQ== X-Forwarded-Encrypted: i=1; AJvYcCUmNYZNjY1W/Xv3b497eZgb+/TiEFkJYPwM0viBDGRL+pzxA9Y6mqpvK4EiG4kzPDarHgbc+VaNEU6Ez0E=@vger.kernel.org X-Gm-Message-State: AOJu0Yx1jmnhBSBqqbZaYyO4Ube2PAqBGsMZlapFEhzmmCLc02jTKTpQ k846/vPn99d3hM181XQ5OJmsdbWmzw4Ma/zFfAILAcGAJrCUZtRi/xtPVg2rdJkBDNepjcCrnMP e4Pl1qQ== X-Google-Smtp-Source: AGHT+IFoj6QRzLKrYLLSAJQ2LmKp+ObVPY/ahIVkPm5UND4Cxp0AWwCGUQGOuOLKDbn2xQa0z5KnVXCOFdg= X-Received: from pffv21.prod.google.com ([2002:aa7:8095:0:b0:746:2897:67f3]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:2d92:b0:748:32cc:eebc with SMTP id d2e1a72fcca58-7486cbd9035mr1442926b3a.17.1749596266499; Tue, 10 Jun 2025 15:57:46 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 10 Jun 2025 15:57:08 -0700 In-Reply-To: <20250610225737.156318-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250610225737.156318-1-seanjc@google.com> X-Mailer: git-send-email 2.50.0.rc0.642.g800a2b2222-goog Message-ID: <20250610225737.156318-4-seanjc@google.com> Subject: [PATCH v2 03/32] KVM: SVM: Don't BUG if setting up the MSR intercept bitmaps fails From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Chao Gao , Borislav Petkov , Xin Li , Dapeng Mi , Francesco Lavra , Manali Shukla Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" WARN and reject module loading if there is a problem with KVM's MSR interception bitmaps. Panicking the host in this situation is inexcusable since it is trivially easy to propagate the error up the stack. Signed-off-by: Sean Christopherson --- arch/x86/kvm/svm/svm.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 262eae46a396..f70211780880 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -945,7 +945,7 @@ static void svm_msr_filter_changed(struct kvm_vcpu *vcp= u) } } =20 -static void add_msr_offset(u32 offset) +static int add_msr_offset(u32 offset) { int i; =20 @@ -953,7 +953,7 @@ static void add_msr_offset(u32 offset) =20 /* Offset already in list? */ if (msrpm_offsets[i] =3D=3D offset) - return; + return 0; =20 /* Slot used by another offset? */ if (msrpm_offsets[i] !=3D MSR_INVALID) @@ -962,17 +962,13 @@ static void add_msr_offset(u32 offset) /* Add offset to list */ msrpm_offsets[i] =3D offset; =20 - return; + return 0; } =20 - /* - * If this BUG triggers the msrpm_offsets table has an overflow. Just - * increase MSRPM_OFFSETS in this case. - */ - BUG(); + return -ENOSPC; } =20 -static void init_msrpm_offsets(void) +static int init_msrpm_offsets(void) { int i; =20 @@ -982,10 +978,13 @@ static void init_msrpm_offsets(void) u32 offset; =20 offset =3D svm_msrpm_offset(direct_access_msrs[i].index); - BUG_ON(offset =3D=3D MSR_INVALID); + if (WARN_ON(offset =3D=3D MSR_INVALID)) + return -EIO; =20 - add_msr_offset(offset); + if (WARN_ON_ONCE(add_msr_offset(offset))) + return -EIO; } + return 0; } =20 void svm_copy_lbrs(struct vmcb *to_vmcb, struct vmcb *from_vmcb) @@ -5505,7 +5504,9 @@ static __init int svm_hardware_setup(void) } kvm_enable_efer_bits(EFER_NX); =20 - init_msrpm_offsets(); + r =3D init_msrpm_offsets(); + if (r) + return r; =20 kvm_caps.supported_xcr0 &=3D ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR); --=20 2.50.0.rc0.642.g800a2b2222-goog