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 90B2E40A95F; Thu, 16 Jul 2026 10:22:20 +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=1784197342; cv=none; b=CxTlBxus522CNI5VqMbzvXp/YZTWw7fssJik6QSoP7/ZRQtvJ6s7PcjpdH+1DGuknqzTdC7eVW7lEoIwji6xG41zYBV3c2FCIJ9Y7rZIOUhxPvMLJUcDFP4YIfMA2kNrl7SxH+9iGM2oG1h/zkvQ8eT4EkPulzy0msv+QgfPUGI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784197342; c=relaxed/simple; bh=en5X+Gmc8TvyimGGC5fjEFfAJUjSA+Q3WgnPuRiMC4o=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=aOmaGvPQ/ZrH6UpSIs5ZI+RgoKpEvA49a2vR0snAZeIRLWhT3IeNrMkBrHmILDA4NOftt1ZsdKaOxZKljBNfzDmUlsPrUpM2pIJ5MCJfcn5fwRSYNQv9xlGSRheKLiXu7+n4fXUbphVZmsjo8D+jsbmAN+K/vypC48yxbZ/s9kQ= 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=qVHlpNKj; 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="qVHlpNKj" 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 C229E2F; Thu, 16 Jul 2026 03:22:15 -0700 (PDT) Received: from [10.2.197.99] (ewhatever.cambridge.arm.com [10.2.197.99]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7D5CE3F7B4; Thu, 16 Jul 2026 03:22:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1784197339; bh=en5X+Gmc8TvyimGGC5fjEFfAJUjSA+Q3WgnPuRiMC4o=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=qVHlpNKjhvKn3xQ+CNDb0jNA6crT5j1kcZIOGpapBhTks1C9/NkDV1ed8MvKjQNsD Lq0haMITs7kx1z9rHbbn4orzHSIACc33v0EXF5UvcU3sHl4iOaS8PJHMeqR4Od64ak eZpHu80hfxd7/rjOWxIrT1OkCvVZrEPQOpALUZkU= Message-ID: <96dbe4f6-a425-4118-afb8-56361e04263b@arm.com> Date: Thu, 16 Jul 2026 11:22:14 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v15 28/37] KVM: arm64: CCA: Support RSI_HOST_CALL To: Steven Price , kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Joey Gouly , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni , Gavin Shan , Shanker Donthineni , Alper Gun , "Aneesh Kumar K . V" , Emi Kisanuki , Vishal Annapurve , WeiLin.Chang@arm.com, Lorenzo Pieralisi References: <20260715142841.80544-1-steven.price@arm.com> <20260715142841.80544-29-steven.price@arm.com> Content-Language: en-US From: Suzuki K Poulose In-Reply-To: <20260715142841.80544-29-steven.price@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 15/07/2026 15:28, Steven Price wrote: > From: Joey Gouly > > Realm VMs can talk to the hypervisor using the RSI_HOST_CALL SMC. The > RMM forwards this to the host and KVM handles them as regular > hypercalls. > > Signed-off-by: Joey Gouly > Signed-off-by: Steven Price > Reviewed-by: Gavin Shan > --- minor nit: Populating the results back to the Realm is added in the Patch 14: KVM: arm64: CCA: Handle realm enter/exit May be a good idea to move to this one here ? Either ways: Reviewed-by: Suzuki K Poulose > Changes since v7: > * Avoid turning a negative return from kvm_smccc_call_handler() into a > error response to the guest. Instead propagate the error back to user > space. > Changes since v4: > * Setting GPRS is now done by kvm_rec_enter() rather than > rec_exit_host_call() (see previous patch - arm64: RME: Handle realm > enter/exit). This fixes a bug where the registers set by user space > were being ignored. > --- > arch/arm64/kvm/rmi-exit.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/arch/arm64/kvm/rmi-exit.c b/arch/arm64/kvm/rmi-exit.c > index c668cbfa971a..78d9189fd5ca 100644 > --- a/arch/arm64/kvm/rmi-exit.c > +++ b/arch/arm64/kvm/rmi-exit.c > @@ -113,6 +113,19 @@ static int rec_exit_ripas_change(struct kvm_vcpu *vcpu) > return -EFAULT; > } > > +static int rec_exit_host_call(struct kvm_vcpu *vcpu) > +{ > + int i; > + struct realm_rec *rec = &vcpu->arch.rec; > + > + vcpu->stat.hvc_exit_stat++; > + > + for (i = 0; i < REC_RUN_GPRS; i++) > + vcpu_set_reg(vcpu, i, rec->run->exit.gprs[i]); > + > + return kvm_smccc_call_handler(vcpu); > +} > + > static void update_arch_timer_irq_lines(struct kvm_vcpu *vcpu) > { > struct realm_rec *rec = &vcpu->arch.rec; > @@ -188,6 +201,8 @@ int handle_rec_exit(struct kvm_vcpu *vcpu, int rec_run_ret) > return rec_exit_psci(vcpu); > case RMI_EXIT_RIPAS_CHANGE: > return rec_exit_ripas_change(vcpu); > + case RMI_EXIT_HOST_CALL: > + return rec_exit_host_call(vcpu); > } > > kvm_pr_unimpl("Unsupported exit reason: %u\n",