From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) (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 3AF9428D8E4 for ; Tue, 10 Jun 2025 22:57:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749596268; cv=none; b=VN06QogFQbRb9L5ycYY+b2H0mypSnrvfdCN2ECJmG8wHnwWlaZdK5c36ypYBr6n4eRLRwJBvTZbZgpK2+0ZGgMmRqiqz0CmpD5enH6VtRWCSKa7LNwWaACIh38uMp/UrczjzOt5c+Z1sIri2OAecIuyxjtAVTnOmEVmAvJ+C73U= 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=209.85.210.201 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-f201.google.com with SMTP id d2e1a72fcca58-740270e168aso4844268b3a.1 for ; Tue, 10 Jun 2025 15:57:46 -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=v20npBWeWKHbNMdiUYQ6X0XNu02p4C+oyTPwxP9ONgKNEpZ0H08Pr29w9aWWjXNmKd Gk7wECBRyMheYm9f4v9piiTz/jd8UCwZciIS8ZL0mbQcEOh1bQBs++3buSG6MisblLIM IvfTFS/43OyuSCxQXPbG1Hcn4C/RVmsAPVaL5jsi7sbzszXB2wml5uV2X9vaaXZQa7QX VT/+KSPusYrMmIHXJLPYtIaIaimmIj1tvdT6BT+6wPJAyD7d7E4gAQvgfXcP4s8fh5Ne MaIsucdpMybBwbTxn7Af3tDnTvISb0hEtNIJ509ZIQQ8+bpjwIS4BwDjykRga9uvnWbI B3kQ== X-Gm-Message-State: AOJu0YzM3QV8XMuVcw1bx5oyKXS2/TNYec+zHt/UqH9MkuLcZNC31Zgk Tq408Qp86ypZwUnM/OwxK+vgTFlwpFgMtCvpHxnwFKn3BIGi5m87fvQ5Fm9PBE+5xlnM6RXKDNF eyFfECw== 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: kvm@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-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 *vcpu) } } -static void add_msr_offset(u32 offset) +static int add_msr_offset(u32 offset) { int i; @@ -953,7 +953,7 @@ static void add_msr_offset(u32 offset) /* Offset already in list? */ if (msrpm_offsets[i] == offset) - return; + return 0; /* Slot used by another offset? */ if (msrpm_offsets[i] != MSR_INVALID) @@ -962,17 +962,13 @@ static void add_msr_offset(u32 offset) /* Add offset to list */ msrpm_offsets[i] = offset; - return; + return 0; } - /* - * If this BUG triggers the msrpm_offsets table has an overflow. Just - * increase MSRPM_OFFSETS in this case. - */ - BUG(); + return -ENOSPC; } -static void init_msrpm_offsets(void) +static int init_msrpm_offsets(void) { int i; @@ -982,10 +978,13 @@ static void init_msrpm_offsets(void) u32 offset; offset = svm_msrpm_offset(direct_access_msrs[i].index); - BUG_ON(offset == MSR_INVALID); + if (WARN_ON(offset == MSR_INVALID)) + return -EIO; - add_msr_offset(offset); + if (WARN_ON_ONCE(add_msr_offset(offset))) + return -EIO; } + return 0; } 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); - init_msrpm_offsets(); + r = init_msrpm_offsets(); + if (r) + return r; kvm_caps.supported_xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR); -- 2.50.0.rc0.642.g800a2b2222-goog