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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 619D0C433FE for ; Thu, 11 Nov 2021 21:12:27 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 0574961057 for ; Thu, 11 Nov 2021 21:12:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0574961057 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id A943F4B1F8; Thu, 11 Nov 2021 16:12:26 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id La2oGdeEiazn; Thu, 11 Nov 2021 16:12:25 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 27BF04B232; Thu, 11 Nov 2021 16:12:22 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 1D5134B1E3 for ; Thu, 11 Nov 2021 16:12:21 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id BUAA7EVrkZ3B for ; Thu, 11 Nov 2021 16:12:19 -0500 (EST) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 7039C4B1E4 for ; Thu, 11 Nov 2021 16:12:19 -0500 (EST) Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 97BE561037; Thu, 11 Nov 2021 21:12:18 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1mlHMm-004tjr-OU; Thu, 11 Nov 2021 21:12:16 +0000 From: Marc Zyngier To: Paolo Bonzini Subject: [PATCH 4/4] KVM: arm64: Fix host stage-2 finalization Date: Thu, 11 Nov 2021 21:11:35 +0000 Message-Id: <20211111211135.3991240-5-maz@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211111211135.3991240-1-maz@kernel.org> References: <20211111211135.3991240-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: pbonzini@redhat.com, alexandru.elisei@arm.com, catalin.marinas@arm.com, tabba@google.com, james.morse@arm.com, mark.rutland@arm.com, qperret@google.com, rdunlap@infradead.org, suzuki.poulose@arm.com, will@kernel.org, yuehaibing@huawei.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Cc: kvm@vger.kernel.org, Will Deacon , Catalin Marinas , Randy Dunlap , YueHaibing , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu From: Quentin Perret We currently walk the hypervisor stage-1 page-table towards the end of hyp init in nVHE protected mode and adjust the host page ownership attributes in its stage-2 in order to get a consistent state from both point of views. The walk is done on the entire hyp VA space, and expects to only ever find page-level mappings. While this expectation is reasonable in the half of hyp VA space that maps memory with a fixed offset (see the loop in pkvm_create_mappings_locked()), it can be incorrect in the other half where nothing prevents the usage of block mappings. For instance, on systems where memory is physically aligned at an address that happens to maps to a PMD aligned VA in the hyp_vmemmap, kvm_pgtable_hyp_map() will install block mappings when backing the hyp_vmemmap, which will later cause finalize_host_mappings() to fail. Furthermore, it should be noted that all pages backing the hyp_vmemmap are also mapped in the 'fixed offset range' of the hypervisor, which implies that finalize_host_mappings() will walk both aliases and update the host stage-2 attributes twice. The order in which this happens is unpredictable, though, since the hyp VA layout is highly dependent on the position of the idmap page, hence resulting in a fragile mess at best. In order to fix all of this, let's restrict the finalization walk to only cover memory regions in the 'fixed-offset range' of the hyp VA space and nothing else. This not only fixes a correctness issue, but will also result in a slighlty faster hyp initialization overall. Fixes: 2c50166c62ba ("KVM: arm64: Mark host bss and rodata section as shared") Signed-off-by: Quentin Perret Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20211108154636.393384-1-qperret@google.com --- arch/arm64/kvm/hyp/nvhe/setup.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c index 862c7b514e20..578f71798c2e 100644 --- a/arch/arm64/kvm/hyp/nvhe/setup.c +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -178,7 +178,7 @@ static int finalize_host_mappings_walker(u64 addr, u64 end, u32 level, phys = kvm_pte_to_phys(pte); if (!addr_is_memory(phys)) - return 0; + return -EINVAL; /* * Adjust the host stage-2 mappings to match the ownership attributes @@ -207,8 +207,18 @@ static int finalize_host_mappings(void) .cb = finalize_host_mappings_walker, .flags = KVM_PGTABLE_WALK_LEAF, }; + int i, ret; + + for (i = 0; i < hyp_memblock_nr; i++) { + struct memblock_region *reg = &hyp_memory[i]; + u64 start = (u64)hyp_phys_to_virt(reg->base); + + ret = kvm_pgtable_walk(&pkvm_pgtable, start, reg->size, &walker); + if (ret) + return ret; + } - return kvm_pgtable_walk(&pkvm_pgtable, 0, BIT(pkvm_pgtable.ia_bits), &walker); + return 0; } void __noreturn __pkvm_init_finalise(void) -- 2.30.2 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm