From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3D74D31326B; Sat, 18 Apr 2026 10:34:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776508479; cv=none; b=qGG0iuN9jO3+7i/00GJm5s3iHZMrJQvm2vGoXmdDwDnpqw39Mn+UsRF4nqCClf42Cysx7C7G/qWytifsUCpPQ2fcE6AB3Trdwz1nq5t6hkXbgjNDVibM3rn8ngmHIHj+u9TfIFFXS8/PDeRp82w774c53h8Lj+4+6owlslhh7XA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776508479; c=relaxed/simple; bh=Ciycx8QqHb67sqchL+YA+/lrYPi38l87mnERhghqxMs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Vs5lJTh4VKfWm8ZLsWrTkbBfPoXwu58cEFpJP0Oa7dWcors8Gz8fayEYvgc0KatvauKBlT0VgPQAPYpBafglzaOYGVeE+Bi4Nmz3Yc6Ep0HdfpZvOoerHjIi/Lj67vMFue2St6xus+NV/wL9y9vMtIr4w+hIi4Ol5COnfnxDLqo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=JKK5K+Om; arc=none smtp.client-ip=217.140.110.172 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) header.d=arm.com header.i=@arm.com header.b="JKK5K+Om" 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 C5A601764; Sat, 18 Apr 2026 03:34:29 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.1.197.6]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C27643F7D8; Sat, 18 Apr 2026 03:34:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1776508475; bh=Ciycx8QqHb67sqchL+YA+/lrYPi38l87mnERhghqxMs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JKK5K+OmEERf3Ey1f9imniEVj3Xa2H4WCBBD0cVwO/iRQ6G1M1uI03ZJaaDRNbCP2 2QWiZECceul4y+JU1g5Jm+oLecljKqseZJpgPCKktH2oemMRsQWUFqaKqXnNEpzjBQ e8jdnRcY1c4a2J1f5NY2s5/CXyCqNGfk9zY9/IS4= Date: Sat, 18 Apr 2026 11:34:30 +0100 From: Yeoreum Yun To: Marc Zyngier Cc: linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, zohar@linux.ibm.com, roberto.sassu@huawei.com, dmitry.kasatkin@gmail.com, eric.snowberg@oracle.com, peterhuewe@gmx.de, jarkko@kernel.org, jgg@ziepe.ca, sudeep.holla@kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org Subject: Re: [RFC PATCH 4/4] firmware: arm_ffa: check pkvm initailised when initailise ffa driver Message-ID: References: <20260417175759.3191279-1-yeoreum.yun@arm.com> <20260417175759.3191279-5-yeoreum.yun@arm.com> <87se8sbozv.wl-maz@kernel.org> 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: <87se8sbozv.wl-maz@kernel.org> Hi Marc, > On Fri, 17 Apr 2026 18:57:59 +0100, > Yeoreum Yun wrote: > > > > When pKVM is enabled, the FF-A driver must be initialized after pKVM. > > Otherwise, pKVM cannot negotiate the FF-A version or > > obtain RX/TX buffer information, leading to failures in FF-A calls. > > > > During FF-A driver initialization, check whether pKVM has been initialized. > > If not, defer probing of the FF-A driver. > > > > Signed-off-by: Yeoreum Yun > > --- > > arch/arm64/kvm/arm.c | 1 + > > drivers/firmware/arm_ffa/driver.c | 12 ++++++++++++ > > 2 files changed, 13 insertions(+) > > > > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > > index 410ffd41fd73..0f517b1c05cd 100644 > > --- a/arch/arm64/kvm/arm.c > > +++ b/arch/arm64/kvm/arm.c > > @@ -119,6 +119,7 @@ bool is_kvm_arm_initialised(void) > > { > > return kvm_arm_initialised; > > } > > +EXPORT_SYMBOL(is_kvm_arm_initialised); > > EXPORT_SYMBOL_GPL(), please. Okay. > > > > > int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) > > { > > diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c > > index 02c76ac1570b..2647d6554afd 100644 > > --- a/drivers/firmware/arm_ffa/driver.c > > +++ b/drivers/firmware/arm_ffa/driver.c > > @@ -42,6 +42,8 @@ > > #include > > #include > > > > +#include > > + > > #include "common.h" > > > > #define FFA_DRIVER_VERSION FFA_VERSION_1_2 > > @@ -2035,6 +2037,16 @@ static int __init ffa_init(void) > > u32 buf_sz; > > size_t rxtx_bufsz = SZ_4K; > > > > + /* > > + * When pKVM is enabled, the FF-A driver must be initialized > > + * after pKVM initialization. Otherwise, pKVM cannot negotiate > > + * the FF-A version or obtain RX/TX buffer information, > > + * which leads to failures in FF-A calls. > > + */ > > + if (IS_ENABLED(CONFIG_KVM) && is_protected_kvm_enabled() && > > + !is_kvm_arm_initialised()) > > + return -EPROBE_DEFER; > > + > > That's still fundamentally wrong: pkvm is not ready until > finalize_pkvm() has finished, and that's not indicated by > is_kvm_arm_initialised(). Thanks. I miss the TSC bit set in here. IMHO, I'd like to make an new state check function -- is_pkvm_arm_initialised() so that ff-a driver to know whether pkvm is initialised. or any other suggestion? Thanks. -- Sincerely, Yeoreum Yun