From mboxrd@z Thu Jan 1 00:00:00 1970 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 AAE0327E076 for ; Fri, 17 Oct 2025 00:33:08 +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=1760661190; cv=none; b=btOay9ExteRdfu9lghq7293bTAVySlfoNdZ2Nl7ZtTHs74BEWP18EpkG1uvH+YC8G3C+yOLCnpblh+KBeGBSjxmDB3gYytZhchpz+//NmKmy5acDwvzQECR7Ivq/OlrOq7rgJu5ZmRfUjhyuAf4oEHrVgTNZeZy6XmEqLVN4DWg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760661190; c=relaxed/simple; bh=wYAEXPYHa2xMErFCIfNovZ590pxCtOKCG7ZgmLDnGp4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Wb/y5LH8b3Q7MGEK2ZGI4cEM568YpReqX+74VpuLgdXksmNtk+75Oe/Z2GMgHhLWInbUCvX+M9j3UeYRM25yRCXB6ODpDmstJBHYwAQ7hcqqf9MCmWhvbPG8h3ujrteaVfyTrI3vsSrLoXXMfY5d8eCyMMJlV1r4MER2+jp1rOU= 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=meXA5Rbt; 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="meXA5Rbt" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-33428befc5bso1886094a91.0 for ; Thu, 16 Oct 2025 17:33:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1760661188; x=1761265988; 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=Ylyqozer80U4wIAhCrbCm8kORDI60jP8QTvjhJUGpZY=; b=meXA5Rbtcn2dDXKmEbm8JEbkRlcsdIn3bhSbm4/TT6Wk9tTRL9sZ/PreDT6aGziq4s MdjRT4PmL+YtuWnTf1Kijw2abNvPZljInMlM5nQpenjN9mlpcOV6ZXTOTaaONyTlNv3j NWi1babo8bn8p9Ym74NUNfyckVpgrSLizXex2+ZuprpHw04PIkFbJErTi26CSxpbOL+a xDhoH4UzTFTnXRbz1Buezwbm0MgYmFjPdv+Qsf0AOatgRLT1u442D6dCjlgg0K3RoaF6 AvZpcSCsI4MmO0Uq+Ey73ioAwoMRJ06uHNeEV7TJXQAmRE8cs2wnICGOBlwRohwwafB9 wSUA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760661188; x=1761265988; 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=Ylyqozer80U4wIAhCrbCm8kORDI60jP8QTvjhJUGpZY=; b=HPAJ8YJBroIzJnKgtt49DL6/D0ibIg9QuHcX12tgipX0Mz04IfPtZcSf/4xJRWP4Au rrPh5+dG7fOT8jkBuaTuxU6+sLkD4LPPmk6frhIR0zUg2qIfLGCi2ILWZrJ5P37G3GCk vn/ID7N9rf+HYoLQuGI1W313pL38Ie8gGkQJG6AB52vZMxv70lpiGpVVZV6mhDh+s4NF XrG/0XjHo4bKzVFUtgTKyf21G8RrxIEKALcmsSRcLSUxTDPQdYCeA/L+6vnLBp5oosS0 l/vn3n/CdwGp2sr4SIeWcspLPvnwp1XbUzkLAPPAJKZSDoe+TPlERITfGGaQ7FrVxNV1 p2ig== X-Forwarded-Encrypted: i=1; AJvYcCUjslorPiRLeAjiALFg45dUu0d7Vv/AR+YxIlfA992IU+loMCJf4hMOJ/h4+AbTqd9zGzv1ORdXSRvv@vger.kernel.org X-Gm-Message-State: AOJu0YxhqHD+M/AmtbFf76j4sbUm1IPn3aqtACK5+JPwE3yBtzyXHm/P Pzuo/GyjitrkcQxRbERuLBs/1XJ3osq9kOSit5u6l8xUtuBAvzyywjRNFHRd5205dplmZ/nvr5o ib7IM2w== X-Google-Smtp-Source: AGHT+IFv5wQBYU08VlWSJ3YEyBvWx6CUl5P/6vzeOVA3OyqdlNjTdwYkeUoBdZlGjRBJoj7p6GD6I+E30lo= X-Received: from pjbnc11.prod.google.com ([2002:a17:90b:37cb:b0:33b:caf7:2442]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:3f8c:b0:32b:a2b9:b200 with SMTP id 98e67ed59e1d1-33bcf87ab38mr1930441a91.13.1760661187797; Thu, 16 Oct 2025 17:33:07 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 16 Oct 2025 17:32:29 -0700 In-Reply-To: <20251017003244.186495-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-mips@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251017003244.186495-1-seanjc@google.com> X-Mailer: git-send-email 2.51.0.858.gf9c4a03a3a-goog Message-ID: <20251017003244.186495-12-seanjc@google.com> Subject: [PATCH v3 11/25] KVM: TDX: Avoid a double-KVM_BUG_ON() in tdx_sept_zap_private_spte() From: Sean Christopherson To: Marc Zyngier , Oliver Upton , Tianrui Zhao , Bibo Mao , Huacai Chen , Madhavan Srinivasan , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Sean Christopherson , Paolo Bonzini , "Kirill A. Shutemov" Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, x86@kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, Ira Weiny , Kai Huang , Michael Roth , Yan Zhao , Vishal Annapurve , Rick Edgecombe , Ackerley Tng , Binbin Wu Content-Type: text/plain; charset="UTF-8" Return -EIO immediately from tdx_sept_zap_private_spte() if the number of to-be-added pages underflows, so that the following "KVM_BUG_ON(err, kvm)" isn't also triggered. Isolating the check from the "is premap error" if-statement will also allow adding a lockdep assertion that premap errors are encountered if and only if slots_lock is held. Reviewed-by: Rick Edgecombe Reviewed-by: Binbin Wu Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/tdx.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index f5cbcbf4e663..220989a1e085 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -1721,8 +1721,10 @@ static int tdx_sept_zap_private_spte(struct kvm *kvm, gfn_t gfn, err = tdh_mem_range_block(&kvm_tdx->td, gpa, tdx_level, &entry, &level_state); tdx_no_vcpus_enter_stop(kvm); } - if (tdx_is_sept_zap_err_due_to_premap(kvm_tdx, err, entry, level) && - !KVM_BUG_ON(!atomic64_read(&kvm_tdx->nr_premapped), kvm)) { + if (tdx_is_sept_zap_err_due_to_premap(kvm_tdx, err, entry, level)) { + if (KVM_BUG_ON(!atomic64_read(&kvm_tdx->nr_premapped), kvm)) + return -EIO; + atomic64_dec(&kvm_tdx->nr_premapped); return 0; } -- 2.51.0.858.gf9c4a03a3a-goog