| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20251029165222.00004c06@huawei.com>
Date: Wed, 29 Oct 2025 16:52:22 +0000
From: Jonathan Cameron <jonathan.cameron@...wei.com>
To: "Aneesh Kumar K.V (Arm)" <aneesh.kumar@...nel.org>
CC: <linux-coco@...ts.linux.dev>, <kvmarm@...ts.linux.dev>,
<linux-pci@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<dan.j.williams@...el.com>, <aik@....com>, <lukas@...ner.de>, Samuel Ortiz
<sameo@...osinc.com>, Xu Yilun <yilun.xu@...ux.intel.com>, Jason Gunthorpe
<jgg@...pe.ca>, Suzuki K Poulose <Suzuki.Poulose@....com>, Steven Price
<steven.price@....com>, Bjorn Helgaas <helgaas@...nel.org>, Catalin Marinas
<catalin.marinas@....com>, Marc Zyngier <maz@...nel.org>, Will Deacon
<will@...nel.org>, Oliver Upton <oliver.upton@...ux.dev>, Jeremy Linton
<jeremy.linton@....com>, Greg KH <gregkh@...uxfoundation.org>, Mark Rutland
<mark.rutland@....com>, Lorenzo Pieralisi <lpieralisi@...nel.org>, "Sudeep
Holla" <sudeep.holla@....com>
Subject: Re: [PATCH RESEND v2 02/12] firmware: smccc: coco: Manage arm-smccc
platform device and CCA auxiliary drivers
On Mon, 27 Oct 2025 15:25:52 +0530
"Aneesh Kumar K.V (Arm)" <aneesh.kumar@...nel.org> wrote:
> Make the SMCCC driver responsible for registering the arm-smccc platform
> device and after confirming the relevant SMCCC function IDs, create
> the arm_cca_guest auxiliary device.
>
> Also update the arm-cca-guest driver to use the auxiliary device
> interface instead of the platform device (arm-cca-dev). The removal of
> the platform device registration will follow in a subsequent patch,
> allowing this change to be applied without immediately breaking existing
> userspace dependencies [1].
>
> [1] https://lore.kernel.org/all/4a7d84b2-2ec4-4773-a2d5-7b63d5c683cf@arm.com
> Cc: Jeremy Linton <jeremy.linton@....com>
> Cc: Greg KH <gregkh@...uxfoundation.org>
> Cc: Mark Rutland <mark.rutland@....com>
> Cc: Lorenzo Pieralisi <lpieralisi@...nel.org>
> Cc: Sudeep Holla <sudeep.holla@....com>
> Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@...nel.org>
> ---
> arch/arm64/include/asm/rsi.h | 2 +-
> arch/arm64/kernel/rsi.c | 2 +-
> drivers/firmware/smccc/Kconfig | 1 +
> drivers/firmware/smccc/smccc.c | 37 ++++++++++++
> drivers/virt/coco/arm-cca-guest/Kconfig | 1 +
> drivers/virt/coco/arm-cca-guest/Makefile | 2 +
> .../{arm-cca-guest.c => arm-cca.c} | 57 +++++++++----------
> 7 files changed, 71 insertions(+), 31 deletions(-)
> rename drivers/virt/coco/arm-cca-guest/{arm-cca-guest.c => arm-cca.c} (85%)
>
> diff --git a/drivers/firmware/smccc/Kconfig b/drivers/firmware/smccc/Kconfig
> index 15e7466179a6..2b6984757241 100644
> --- a/drivers/firmware/smccc/Kconfig
> +++ b/drivers/firmware/smccc/Kconfig
> @@ -8,6 +8,7 @@ config HAVE_ARM_SMCCC
> config HAVE_ARM_SMCCC_DISCOVERY
> bool
> depends on ARM_PSCI_FW
> + select AUXILIARY_BUS
> default y
> help
> SMCCC v1.0 lacked discoverability and hence PSCI v1.0 was updated
> diff --git a/drivers/firmware/smccc/smccc.c b/drivers/firmware/smccc/smccc.c
> index bdee057db2fd..3dbf0d067cc5 100644
> --- a/drivers/firmware/smccc/smccc.c
> +++ b/drivers/firmware/smccc/smccc.c
> @@ -10,7 +10,12 @@
> #include <linux/arm-smccc.h>
> #include <linux/kernel.h>
> #include <linux/platform_device.h>
> +#include <linux/auxiliary_bus.h>
> +
> #include <asm/archrandom.h>
> +#ifdef CONFIG_ARM64
> +#include <asm/rsi_cmds.h>
> +#endif
>
> static u32 smccc_version = ARM_SMCCC_VERSION_1_0;
> static enum arm_smccc_conduit smccc_conduit = SMCCC_CONDUIT_NONE;
> @@ -81,10 +86,42 @@ bool arm_smccc_hypervisor_has_uuid(const uuid_t *hyp_uuid)
> }
> EXPORT_SYMBOL_GPL(arm_smccc_hypervisor_has_uuid);
>
> +#ifdef CONFIG_ARM64
I'm not keen on seeing ifdefs in a file where it isn't already local style.
This is probably better done with a second c file, appropriate header
and Kconfig / Makefile magic to control whether it is built.
> +static void __init register_rsi_device(struct platform_device *pdev)
> +{
> + unsigned long ver_lower, ver_higher;
> + unsigned long ret = rsi_request_version(RSI_ABI_VERSION,
> + &ver_lower,
> + &ver_higher);
> +
> + if (ret == RSI_SUCCESS)
Better to have error case out of line.
if (ret != RSI_SUCCESS)
return;
__devm_auxiliary_device_create(
It's both more natural for reviewers of the code and makes it easier to stick
other things after this code later if that makes sense.
> + __devm_auxiliary_device_create(&pdev->dev,
> + "arm_cca_guest", RSI_DEV_NAME, NULL, 0);
> +
> +}
> +#else
> +static void __init register_rsi_device(struct platform_device *pdev)
> +{
> +
> +}
> +#endif
> diff --git a/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c b/drivers/virt/coco/arm-cca-guest/arm-cca.c
> similarity index 85%
> rename from drivers/virt/coco/arm-cca-guest/arm-cca-guest.c
> rename to drivers/virt/coco/arm-cca-guest/arm-cca.c
> index 0c9ea24a200c..dc96171791db 100644
> --- a/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c
> +++ b/drivers/virt/coco/arm-cca-guest/arm-cca.c
> +static int cca_devsec_tsm_probe(struct auxiliary_device *adev,
> + const struct auxiliary_device_id *id)
> {
> int ret;
>
> if (!is_realm_world())
> return -ENODEV;
>
> - ret = tsm_report_register(&arm_cca_tsm_ops, NULL);
> - if (ret < 0)
> + ret = tsm_report_register(&arm_cca_tsm_report_ops, NULL);
> + if (ret < 0) {
> pr_err("Error %d registering with TSM\n", ret);
We have a device, so maybe flip to dev_err() or better yet
return dev_err_probe(&adev->dev, ret, "Error registering with TSM\n");
That's convenient to use in a probe() even if the deferral bits are relevant and
it prints a nice string for the ret.
> + return ret;
> + }
>
> - return ret;
> -}
> -module_init(arm_cca_guest_init);
> + ret = devm_add_action_or_reset(&adev->dev, unregister_cca_tsm_report, NULL);
> + if (ret < 0) {
> + pr_err("Error %d registering devm action\n", ret);
return dev_err_probe() here as well.
> + return ret;
Powered by blists - more mailing lists