From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3336FC3DA49 for ; Sat, 27 Jul 2024 00:07:12 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20230601 header.b=dDIPgNRU; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4WW4gL6StGz3frK for ; Sat, 27 Jul 2024 10:07:10 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20230601 header.b=dDIPgNRU; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=flex--seanjc.bounces.google.com (client-ip=2607:f8b0:4864:20::b49; helo=mail-yb1-xb49.google.com; envelope-from=37jakzgykdckxjfsohlttlqj.htrqnszcuuh-ijaqnxyx.teqfgx.twl@flex--seanjc.bounces.google.com; receiver=lists.ozlabs.org) Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4WW4MN37xRz3dW3 for ; Sat, 27 Jul 2024 09:53:20 +1000 (AEST) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-e03a5534d58so416065276.1 for ; Fri, 26 Jul 2024 16:53:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1722037998; x=1722642798; darn=lists.ozlabs.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=F7WgJlT5NNtid7p2jwFbPV8b+lTnD+3vJbPsQDaWDdo=; b=dDIPgNRUucdifYv0O9z4lEjYQh3q/QbUfmLPEQdDmk9put/sGxjVxaLwOVOaY0yy+A s+NYo9Ftur6kgRTBCe9nyTIWkFdgriJ56eRJkS7LAJYtxC2XxCVsxqd1Z6mWFJnTRqyZ CyWQIwDi4dr2h6+kHyHqfiNDItPktRFQ+SdRysQi1ZE99UopcfQp3IFnD/8/K9SiU31W L67X2A/VrUsJREkkD5CUWhJX8iVIwKNKbyREKom3fO74X7gyTRQzP/M2dVMdWrN1LGax Y+xyu0mKGcmP1bmabhOg5epICiBZ0II2/RO+V6W1Ae3ifhNpqfutYv7pIEi6b9POhGpc sdsw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722037998; x=1722642798; 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=F7WgJlT5NNtid7p2jwFbPV8b+lTnD+3vJbPsQDaWDdo=; b=qCN6kczqRxHCu4ELsZZsAEfovP6S2xbpV2pSs3C+omlyiKNCbRP9oczkV8PM2cLLBw QmHMTXP6Y/zKn2YGhI37pNNdb5g4veyHBkZLT5Fgz73e36MKu9+zB7KfmE9mzIvKOUbc DHq7r7ifoLma0eR8abF5XjoYbjCmxcu3cP/U/3Zimk2mlNE2UKakJwGfRZmAXfmi3iBK rDl3MQ9RK0tyC/QMM2lwTUYPNlVk+5FpX5Clg7igVnLRlsC/sm0H63rIY3HtPwWfSnXt 7btFVJbnfeTUnVfcysh1MrMifYdbvjtDJPl8XjJZi4y+VXrGi4D3GRU+TdJloiteN9rG IGHQ== X-Forwarded-Encrypted: i=1; AJvYcCWPIOuPqykGITrWuiT5Oitimdc2JBeQ67WdXB1tWjy64KaomWmzeuW2ye10WenKcnynVDAwl4vYAXY6vXZjMD7f7RX8zF6SdCIjeD3x6A== X-Gm-Message-State: AOJu0YxatjUNaPVnal4Iwb7h9f9tsKpt83A51m7kKAqD7JqD1JEgp+PV 2vXGJf6JhC8w0D/i/G3eQ50NxpMXDRvE8ILIwv+WVdsWpILPyV2Tz3pnpR0l7GaIcZ9QQVRtxGP yCw== X-Google-Smtp-Source: AGHT+IHz6CGF/LJ/2Irg7XXoFs/UlO9MjKavvm7YGPRddocT798mRWwGF7hDBEuQel+TJyAfnYN45In/DfE= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6902:120b:b0:e0b:4dd5:397e with SMTP id 3f1490d57ef6-e0b5455c058mr1734276.7.1722037998118; Fri, 26 Jul 2024 16:53:18 -0700 (PDT) Date: Fri, 26 Jul 2024 16:51:29 -0700 In-Reply-To: <20240726235234.228822-1-seanjc@google.com> Mime-Version: 1.0 References: <20240726235234.228822-1-seanjc@google.com> X-Mailer: git-send-email 2.46.0.rc1.232.g9752f9e123-goog Message-ID: <20240726235234.228822-21-seanjc@google.com> Subject: [PATCH v12 20/84] KVM: Use NULL for struct page pointer to indicate mremapped memory From: Sean Christopherson To: Paolo Bonzini , Marc Zyngier , Oliver Upton , Tianrui Zhao , Bibo Mao , Huacai Chen , Michael Ellerman , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Sean Christopherson Content-Type: text/plain; charset="UTF-8" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Sean Christopherson Cc: kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, David Matlack , David Stevens , loongarch@lists.linux.dev, kvmarm@lists.linux.dev, linux-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Drop yet another unnecessary magic page value from KVM, as there's zero reason to use a poisoned pointer to indicate "no page". If KVM uses a NULL page pointer, the kernel will explode just as quickly as if KVM uses a poisoned pointer. Never mind the fact that such usage would be a blatant and egregious KVM bug. Signed-off-by: Sean Christopherson --- include/linux/kvm_host.h | 4 ---- virt/kvm/kvm_main.c | 4 ++-- 2 files changed, 2 insertions(+), 6 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index f42e030f69a4..a5dcb72bab00 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -273,16 +273,12 @@ enum { READING_SHADOW_PAGE_TABLES, }; -#define KVM_UNMAPPED_PAGE ((void *) 0x500 + POISON_POINTER_DELTA) - struct kvm_host_map { /* * Only valid if the 'pfn' is managed by the host kernel (i.e. There is * a 'struct page' for it. When using mem= kernel parameter some memory * can be used as guest memory but they are not managed by host * kernel). - * If 'pfn' is not managed by the host kernel, this field is - * initialized to KVM_UNMAPPED_PAGE. */ struct page *page; void *hva; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 67a50b87bb87..3d717a131906 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3088,7 +3088,7 @@ void kvm_release_pfn(kvm_pfn_t pfn, bool dirty) int kvm_vcpu_map(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map) { - map->page = KVM_UNMAPPED_PAGE; + map->page = NULL; map->hva = NULL; map->gfn = gfn; @@ -3114,7 +3114,7 @@ void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty) if (!map->hva) return; - if (map->page != KVM_UNMAPPED_PAGE) + if (map->page) kunmap(map->page); #ifdef CONFIG_HAS_IOMEM else -- 2.46.0.rc1.232.g9752f9e123-goog