From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.140.110.172 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793360531; b=fTscusbrMD2+PA44N1jyiW4CttGto2Le3Eg67+XZkRrcOfj097Te7iP9bmw+dr6hVBIy VyBfhnF5+yErktj6qUpq0B3wR1y6n8iH1exyUeNy/yvnBMqGNwh0fACe4cP7ietlVhaKt ij2CfMu4TL1UUM13diqurTNyND3o6w+seWn/xmpG+8LvC7W09m78k/JY7kEfxgs8/v1dh PpCSslXZVNFzGxQV4MKuyni3OcvIKoSmMG5+0HWUPZlL8U73gzSMTAg7S1mt3zmGoC9wX fnL2vsbMTHXqBcifbCGu7huOaj5IiRYtxLO5CW3SnlFXhuM2rEVETMody+lVpB6P4lA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793360531; h=DMARC-Filter:Received:Received:DKIM-Signature:From:To:Cc:Subject: Date:Message-ID:X-Mailer:In-Reply-To:References:MIME-Version: Content-Type:Content-Disposition:Content-Transfer-Encoding; bh=r6oWs9NRS8dj5BRdE3SOboRlekQH4GrocVOda0uMj/o=; b=PnYX3T+dUVtb/FTJcSuiocGGwZHXRhhNn8dxoE/4NlLHWI3bps9N4Tu+FGrgCla6EJ9Y NEwp9V2+i73n4tToZCgate9yGSF/Y/lFUtK9B0G3c4zNlDYhwY1lYAl3y5UAqdR2YW73n nt5A73zDF3zgeAZXt3XpGlP9wS+pthFK3dNdoCrHkrQy2U4ErUJbgBwZSpqTn6DxFXq0r fTfwT7jzr3ToHaTJb5Y1fbsxX2wOzfbEpzeSnOk5HUz79hEaOMd137lXMapOnoPFokmpo 0xs3L2hlw1sjKtKevP9QRTyeZnfCj5QZvrRJLWN9B5rN9ohUf+1L6cszNys4pneMDig== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=XIVYestp; arc=none smtp.remote-ip=217.140.110.172 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 01838606A31A for ; Fri, 30 Oct 2026 11:42:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 01838606A31A Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=XIVYestp Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 203521596; Fri, 30 Oct 2026 04:42:07 -0700 (PDT) Received: from LeoBrasDK.cambridge.arm.com (LeoBrasDK.cambridge.arm.com [10.2.212.21]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B86A03F7B4; Fri, 30 Oct 2026 04:42:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1793360530; bh=TryfSyMJmpjHJWemiNgo4MBnrsZct6ejB9ZK29wCuRI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XIVYestpCiqkWkpRrm7MMoeveYoA5FIQIuL/wKTNRlmW9R/fz0++XawOSAjqlO8Xy 6Oe7eykXf0SSQhKGDWSu4I/x7OTqVZ4S1lauXoLjNrGaFP13bMuZg8DoxKgM6Lw1gH Zhlv37cZ4yULbIomkP4C4YA8e8Zu7yMJb2FV7GWw= From: Leonardo Bras To: Wei-Lin Chang Cc: Leonardo Bras , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, Marc Zyngier , Oliver Upton , Fuad Tabba , Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Mark Rutland , Gavin Shan , stable@vger.kernel.org Subject: Re: [PATCH v2 1/2] KVM: arm64: Fix dirty logging detection in ring-only mode Date: Fri, 30 Oct 2026 11:42:03 +0000 Message-ID: X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261029175238.3214788-2-weilin.chang@arm.com> References: <20261029175238.3214788-1-weilin.chang@arm.com> <20261029175238.3214788-2-weilin.chang@arm.com> X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: 8bit On Thu, Oct 29, 2026 at 05:52:37PM +0000, Wei-Lin Chang wrote: > When checking whether a memslot has dirty logging enabled, the > KVM_MEM_LOG_DIRTY_PAGES flag is the source of truth. Previously in > memslot_is_logging() we were testing the dirty bitmap only and did not > consider dirty ring. > > With the ring and no bitmap, a logged memslot can still get block > mappings, so guest writes to most of a block are never logged and a > migration can copy stale memory. > > Fix this by using kvm_slot_dirty_track_enabled() instead which checks > KVM_MEM_LOG_DIRTY_PAGES, within memslot_is_logging(). > > Fixes: 9cb1096f8590 ("KVM: arm64: Enable ring-based dirty memory tracking") > Reviewed-by: Fuad Tabba > Tested-by: Fuad Tabba > Signed-off-by: Wei-Lin Chang > Cc: stable@vger.kernel.org > --- > arch/arm64/kvm/mmu.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > index 705f6d84770e..c7df646af79f 100644 > --- a/arch/arm64/kvm/mmu.c > +++ b/arch/arm64/kvm/mmu.c > @@ -176,7 +176,7 @@ static int kvm_mmu_split_huge_pages(struct kvm *kvm, phys_addr_t addr, > > static bool memslot_is_logging(struct kvm_memory_slot *memslot) > { > - return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY); > + return kvm_slot_dirty_track_enabled(memslot) && !(memslot->flags & KVM_MEM_READONLY); > } > > static int pkvm_flush_remote_tlbs(struct kvm *kvm) > -- > 2.43.0 > Reviewed-by: Leonardo Bras Awesome, thanks for taking the suggestion! Leo