From mboxrd@z Thu Jan 1 00:00:00 1970 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 2645A383364 for ; Thu, 30 Oct 2025 20:10:31 +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=1761855033; cv=none; b=Lgp2b07dKRL9DYTcO/8r/+FPzzlFW+xD5tfR6aA5AfVgYVfdex3dSTW4BYcucKiN8LOuGKgTU+tkWJTsGSqfWZC1Iiv4XXwIxtfnFkLByM+oiqMSNDSeNFw6mU1AecMbKX12D6HE7EDkqILWoIiuYS8YV378fbthiwNEdPwGBgQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761855033; c=relaxed/simple; bh=XFfT8gaTPEkUKYTdX1NH6w/tGb+C9eg2daMfkI8gFLA=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=GVEpEqlo/mayG7qtgbhSeUsiiQq88l3eXAGzFZVRySNEHv9X4cR3WINfU0jZIgEToBUMCGM+5/lQ2O0sehQx1n8efG6BASoLpSEmfQ8P1kUFIAf57SRYoYbgZjtzhxO67kyBv+kEEWaJWjlb2BOPWEZdatMEDUOcQ8cMeQPtur0= 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=cZC7+frV; 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="cZC7+frV" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-3407734d9a2so522360a91.1 for ; Thu, 30 Oct 2025 13:10:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1761855031; x=1762459831; darn=lists.linux.dev; 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=meKFn4T9FN95UHKOhoydSdUPWQIDJ02hjx7Eu38ytY8=; b=cZC7+frVxZFzTUxnDx/0btcT71+DicPEdvcNmB5B1SBZqQmtIQCBFvxd/4OlGoP9Rm mRs2/iwnRODg/qpJeOibQ+huNPU0zrTn76YN+5Qg6Kw68tOMkFeUA2CxNVnKlVYKe8gC LgGnGaqotBLp2/S7R6vOfojvdOu1eBFaLNgw0FEwoZf6BrWkhNh+aDMR49VB1H4Am22/ xSgTKdhpC61+/05qhvEBzTkNP55LuhxA1x9B8peygd0iHkdPH4XFm9/KA4BwC2sD/xZC A2A9WCahaL5FeOw3YkvpsDAiemy1bozBo4Bhyqj239mrKeUbTf9+GblEgmx6MGnNK5Jb 4Pmg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1761855031; x=1762459831; 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=meKFn4T9FN95UHKOhoydSdUPWQIDJ02hjx7Eu38ytY8=; b=FHcU0FqhTbkgzcweDnCOlINgnrkaFv/M4znRbvRrLDb7cJCwwLrBYGxweGnLwOqsaa hVVrN15llil3kFFBKIcYy11eHS8RiLsFWr0BveqfhUErz1GEq+iCoBxChtmlbKLPuv3t bI7Csre8h7OdzqlMI1SY92w1OqaCRTxlinUNUuvgCkxdfUX1Jd4228ur7jB0NWjdt/ax yPxwW05U9Y+tg8mPwWT18x91H6GP1o5R9keA7slGQWPuo1mKj5tmXkQIsurGDKjbc3MM tQ1I/jDsWCz8pSpc/mGXFm+YpkAJAJACpdiwYK+JGIYWofRl7l+YfpNfIpQlswTSF8Nq Xryw== X-Forwarded-Encrypted: i=1; AJvYcCVEjhl2M4iaXnRu10Gl93kmy6NDuJY/LIKs8G1LV9YWtoRYt9f3WhDh6S1dK78Zk//HP4gs5Ug=@lists.linux.dev X-Gm-Message-State: AOJu0YzqII7Sy3cph3AIah3m6A8cEkHB0q4JYY1wnaRQ4d0l+7Y+MeYi IGfUtDv+XeHdTavDf6hiPFEPilaYbOfhSQMu3Z0xsKoNqIYT5TFAdqpfGXKfdgcTtfbTd03NvYi 0boRyXA== X-Google-Smtp-Source: AGHT+IFHot6p8Ozw6sPTCEifBtpuZu56mTW8C+szZfak/MuPqOINRZqkxHegGZo0IYVURE2JpMgMqwrtO2U= X-Received: from pjvl22.prod.google.com ([2002:a17:90a:dd96:b0:340:6aca:917f]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:2d92:b0:340:5c38:3a56 with SMTP id 98e67ed59e1d1-340830a3a7cmr1392650a91.37.1761855030672; Thu, 30 Oct 2025 13:10:30 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 30 Oct 2025 13:09:36 -0700 In-Reply-To: <20251030200951.3402865-1-seanjc@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251030200951.3402865-1-seanjc@google.com> X-Mailer: git-send-email 2.51.1.930.gacf6e81ea2-goog Message-ID: <20251030200951.3402865-14-seanjc@google.com> Subject: [PATCH v4 13/28] 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 , Binbin Wu , Michael Roth , Yan Zhao , Vishal Annapurve , Rick Edgecombe , Ackerley Tng 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 Reviewed-by: Kai Huang 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 658e0407eb21..db64a9e8c6a5 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -1725,8 +1725,10 @@ 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; } -- 2.51.1.930.gacf6e81ea2-goog