From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f54.google.com (mail-ej1-f54.google.com [209.85.218.54]) (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 0D2D1286D70 for ; Wed, 10 Jun 2026 09:27:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781083627; cv=none; b=HvZv7UsVP8rku4/Nf6RifHefzRSilww1UbBfDA77Y+b6S8v1TEm35zMuXel3c692c1FpYv/plqsdQCdhV/CsolgCZK07C48PjLd/3nM0l8Ee1Mj7O93q6wjFP/KpyC0ummAdcFUSHdd8Jhnl58C6hKs75D9KJmiZgrNvztFjEsY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781083627; c=relaxed/simple; bh=Rvvl0zHsRKXsyvcXHZS6F+yj7/26A7hm2pQ/uWdBJt0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kanBvFQPrGdcQVHoB1oMqUOV250BSE72U3+3UQtkf9xNJbTpNznRaOkMT3mYJkOCGs2a4vZUNmyD7g8b6g56JJycjGHFSmuxTzNPqtVJN1RmJTup2eg+ineUFAZu7TIkvy9dqaM9wewDzYAnwmsuJ/0S7O7TRyx0X2vImrrae1I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=PHPnXPkt; arc=none smtp.client-ip=209.85.218.54 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=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="PHPnXPkt" Received: by mail-ej1-f54.google.com with SMTP id a640c23a62f3a-bef1e6423e7so750406366b.1 for ; Wed, 10 Jun 2026 02:27:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1781083624; x=1781688424; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=/a+aF2FASI2PrgPXKTQczzpNoIJIj4s5NhzwmvJ4C9o=; b=PHPnXPktY9s3eOMm+tCfpDw2CYWMYEXJwbR8JszjIKQWHT5hz/Uy0oNaSIf++RVwoZ yunLfITMpf8h+FyJ1qib195Bg1bMg+/QXwobDdhoJrzEEoUnV8BTj3vEKODdLyeTXVls 6toxyZh5bq/jJBu6XNeWaIoPdn1LV2IoxsdTW4HKdmSaqI9BgQaQq0n7z7/Dk4aFyylo i81J11727jVyFxPDbpgkrZHt+rO3+D21EgL3YFr6YGo2etKfZp4ISEqIkFrDsUepZRTe on1AO2zPxImaRVo6xwaMKYEa4+sitQDvbtlU/Iar8/7x010YaNNHF0DXKYnSCqWEWbtE UE3Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781083624; x=1781688424; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=/a+aF2FASI2PrgPXKTQczzpNoIJIj4s5NhzwmvJ4C9o=; b=Yc+k0TqhZXfb3j8EmkI8A/CQ2YJtjjhf2JVWx0jsFbuM4rNxBFSNWXmIpNxmESHwuf DjWXgDYMQO/PCHezWdkkTIFKL56fLd04cEsrn8QiH3cBHxlx9ZuRgldgNeKmDDvH8//A l4TONui/kTDdGllkNbmgVaTOxcHiFmKnJNnZ+S16IAMUlDt1kYMyI0aSMBQu6yGINBFl c23NWxXFwpYzB/d3LpoZQFwh6iFeca44AnQfq3CEGkZreQaTCH3fbDnW/iak7Q72UJPF Wdel/X6Mm/nWzewEu7hUikhBN3pSJxyQaXrenr1CvWkh0wXrSOZWBV02p3VRtZwan/8K /WUQ== X-Forwarded-Encrypted: i=1; AFNElJ8t2c0f1RilirB4DlCeUq+TT5ZH0J0JQV6P7T8JeF6H1iQsvDVbjopy6h4S6pRY6fo05G55iKQqGeIz4qA=@vger.kernel.org X-Gm-Message-State: AOJu0Yz6/2TW6GHkRzj5xfo7O+gybKHEgBTZWKsO2NRdyanm7e/EUFlR 4334gnQ4YFy5eewyiuogwU1GFvyzjwG05GYVXy8SFhjWB/wsTbs0xD1lUllwku8hWg== X-Gm-Gg: Acq92OHVb6bHkI8UXffxaFAzaomwsPQ31jbLq1MRzT0glkMLFYY4Gquo32h6EJTa9DB 9ZkcHx5iT7+0lAPtXkUT9JaH75A3JMZH6+w38GFR/CCjMN1pBoNcWxr8AtJI2FJuzIPxkh6LdqD 6ouPmokhPRW34uh54VHe/61eagXYi3FajMSGE5rtwLDhejmnKJCOm/KNobSyqIwIFTePYe/adcX zvhu0IzkLwgjbJQ+QM1khhh5ysvE1GPuoKFlhAuHjP1Zzud39KjPhNMpFodywL4s3OmQhvwLsqp JZVF4guYWoLM/Ty1VMcliRtAzEgPwY/U1pu2YrRQBEDuKY+OM6xq4e4KDJEYiFC/1+uG82z2PQ8 AxsL3Z6/SdlsVIaqkaIkyazRs+wfL1xAmW0X9EsjjHAYRrfcw89FYnBPSRpNK+iCsrQ+AJ2syAa lAo2/jjeEcfZArHovtS8LWNhv4HCuoONyrnhlHFOG4K6/BCI4A0E4S7RORlPFdRINkSDQ2KgT3u fuKeo2ErZBLqtdn X-Received: by 2002:a17:906:794c:b0:bee:dce5:739d with SMTP id a640c23a62f3a-bf3749d4005mr1209578266b.49.1781083623847; Wed, 10 Jun 2026 02:27:03 -0700 (PDT) Received: from google.com (135.91.155.104.bc.googleusercontent.com. [104.155.91.135]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-bf0522834dbsm1145247966b.27.2026.06.10.02.27.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Jun 2026 02:27:03 -0700 (PDT) Date: Wed, 10 Jun 2026 10:26:59 +0100 From: Vincent Donnefort To: Sebastian Ene Cc: catalin.marinas@arm.com, maz@kernel.org, oupton@kernel.org, will@kernel.org, joey.gouly@arm.com, korneld@google.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, android-kvm@google.com, mrigendra.chaubey@gmail.com, perlarsen@google.com, suzuki.poulose@arm.com, yuzenghui@huawei.com Subject: Re: [PATCH v2 0/7] KVM: arm64: Forward FFA_NOTIFICATION* calls to TrustZone Message-ID: References: <20260608165549.1479409-1-sebastianene@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260608165549.1479409-1-sebastianene@google.com> On Mon, Jun 08, 2026 at 04:55:42PM +0000, Sebastian Ene wrote: > Remove the FFA_NOTIFICATION* calls from the blocklist used by the pKVM > FF-A proxy. This restriction was preventing the use of asynchronous > signaling mechanisms defined by the Arm FF-A specification to > communicate with the secure services. > While these calls are markes as optional, there is no reason why the > hypervisor proxy would block them because: > > 1. Host is the Sole Non-Secure Endpoint: The Host operates as the > only Non-Secure VM ID (VM ID 0) recognized by the Secure World. > Because all forwarded notifications are inherently attributed to > the Host by the SPMC, there is no risk of VM ID spoofing > originating from the Normal World. > > 2. No Memory Pointers or Addresses: The FFA_NOTIFICATION_* ABIs > operate strictly via register-based parameters, passing only > VM IDs, VCPU IDs, flags, and bitmaps. Because these calls do > not contain memory addresses, offsets, or pointers, forwarding > them doesn't pose a risk of memory-based confused deputy attack > (e.g., tricking the SPMC into overwriting protected memory). > > While the pKVM proxy behaves as a relayer, it doesn't currently have its > own FF-A ID(only the host has the ID 0). The behavior of the setup > flow is covered by the spec in the: '10.9 Notification support without > a Hypervisor'. As it is only a relayer. Is it really important to check SBZ arguments and fields on behalf of Trustzone? It doesn't feel it brings any security. If the host passes broken arguments, I don't believe this puts pKVM at risk. Does it? > > --- > Changes in v2: > - enforce the MBZ/SBZ fields > - split the calls into separate patches > - rebase on 7.1-rc7 > > Link to v1: > https://lore.kernel.org/all/20260501114447.2389222-2-sebastianene@google.com/ > > Sebastian Ene (7): > KVM: arm64: Support FFA_NOTIFICATION_BITMAP_CREATE in host handler > KVM: arm64: Support FFA_NOTIFICATION_BITMAP_DESTROY in host handler > KVM: arm64: Support FFA_NOTIFICATION_BIND in host handler > KVM: arm64: Support FFA_NOTIFICATION_UNBIND in host handler > KVM: arm64: Support FFA_NOTIFICATION_SET in host handler > KVM: arm64: Support FFA_NOTIFICATION_GET in host handler > KVM: arm64: Support FFA_NOTIFICATION_INFO_GET in host handler > > arch/arm64/kvm/hyp/nvhe/ffa.c | 190 ++++++++++++++++++++++++++++++++-- > 1 file changed, 182 insertions(+), 8 deletions(-) > > -- > 2.54.0.1064.gd145956f57-goog >