Re: [PATCH v9 03/27] gunyah: Common types and error codes for Gunyah hypercalls

Greg Kroah-Hartman
2023-01-30T09:59:19Z

On Fri, Jan 20, 2023 at 02:46:02PM -0800, Elliot Berman wrote:
> Add architecture-independent standard error codes, types, and macros for
> Gunyah hypercalls.
>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
> ---
> MAINTAINERS | 1 +
> include/linux/gunyah.h | 74 ++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 75 insertions(+)
> create mode 100644 include/linux/gunyah.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d9205cb9e988..f1e07e39b2f5 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -9048,6 +9048,7 @@ L: linux-arm-msm@vger.kernel.org
> S: Supported
> F: Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml
> F: Documentation/virt/gunyah/
> +F: include/linux/gunyah.h
>
> HABANALABS PCI DRIVER
> M: Oded Gabbay <ogabbay@kernel.org>
> diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
> new file mode 100644
> index 000000000000..985c6086348e
> --- /dev/null
> +++ b/include/linux/gunyah.h
> @@ -0,0 +1,74 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#ifndef _LINUX_GUNYAH_H
> +#define _LINUX_GUNYAH_H
> +
> +#include <linux/errno.h>
> +#include <linux/limits.h>
> +
> +/* Common Gunyah macros */

Macros?

> +#define GH_CAPID_INVAL U64_MAX
> +#define GH_VMID_ROOT_VM 0xff

These are all simple defines :)

> +
> +#define GH_ERROR_OK 0
> +
> +#define GH_ERROR_UNIMPLEMENTED -1
> +#define GH_ERROR_RETRY -2

All of these values, they come from the hypervisor?

And then you:

> +static inline int gh_remap_error(int gh_error)
> +{
> + switch (gh_error) {
> + case GH_ERROR_OK:
> + return 0;
> + case GH_ERROR_NOMEM:
> + return -ENOMEM;
> + case GH_ERROR_DENIED:
> + case GH_ERROR_CSPACE_CAP_NULL:
> + case GH_ERROR_CSPACE_CAP_REVOKED:
> + case GH_ERROR_CSPACE_WRONG_OBJ_TYPE:
> + case GH_ERROR_CSPACE_INSUF_RIGHTS:
> + case GH_ERROR_CSPACE_FULL:
> + return -EACCES;
> + case GH_ERROR_BUSY:
> + case GH_ERROR_IDLE:
> + return -EBUSY;
> + case GH_ERROR_IRQ_BOUND:
> + case GH_ERROR_IRQ_UNBOUND:
> + case GH_ERROR_MSGQUEUE_FULL:
> + case GH_ERROR_MSGQUEUE_EMPTY:
> + return -EPERM;
> + default:
> + return -EINVAL;
> + }
> +}

Convert it to a Linux-kernel related value?

If so, please say that in the documentation here (where the value came
from, etc...)

Also, why isn't gh_error an enumerated type so you can have some type
safety and it's obvious when a value comes from the hypervisor what it
should be and should not be.

thanks,

greg k-h