Re: [PATCH v9 05/21] virt: geniezone: Add vm support

[AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>]

Il 29/01/24 09:32, Yi-De Wu ha scritto:
> From: "Yingshiuan Pan" <yingshiuan.pan@mediatek.com>
> 
> The VM component is responsible for setting up the capability and memory
> management for the protected VMs. The capability is mainly about the
> lifecycle control and boot context initialization.
> 
> Signed-off-by: Yingshiuan Pan <yingshiuan.pan@mediatek.com>
> Signed-off-by: Jerry Wang <ze-yu.wang@mediatek.com>
> Signed-off-by: Liju Chen <liju-clr.chen@mediatek.com>
> Signed-off-by: Yi-De Wu <yi-de.wu@mediatek.com>
> ---
>   MAINTAINERS                             |   1 +
>   arch/arm64/geniezone/gzvm_arch_common.h |   9 ++
>   arch/arm64/geniezone/vm.c               |  29 +++++++
>   drivers/virt/geniezone/Makefile         |   2 +-
>   drivers/virt/geniezone/gzvm_main.c      |  19 +++++
>   drivers/virt/geniezone/gzvm_vm.c        | 107 ++++++++++++++++++++++++
>   include/linux/gzvm_drv.h                |  26 ++++++
>   include/uapi/linux/gzvm.h               |  25 ++++++
>   8 files changed, 217 insertions(+), 1 deletion(-)
>   create mode 100644 drivers/virt/geniezone/gzvm_vm.c
>   create mode 100644 include/uapi/linux/gzvm.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 0cb2d0599469..3ecac8794ba9 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -9022,6 +9022,7 @@ F:	Documentation/virt/geniezone/
>   F:	arch/arm64/geniezone/
>   F:	drivers/virt/geniezone/
>   F:	include/linux/gzvm_drv.h
> +F:	include/uapi/linux/gzvm.h
>   
>   GENWQE (IBM Generic Workqueue Card)
>   M:	Frank Haverkamp <haver@linux.ibm.com>
> diff --git a/arch/arm64/geniezone/gzvm_arch_common.h b/arch/arm64/geniezone/gzvm_arch_common.h
> index f5bddcfe3a1f..fdaa7849353d 100644
> --- a/arch/arm64/geniezone/gzvm_arch_common.h
> +++ b/arch/arm64/geniezone/gzvm_arch_common.h
> @@ -9,6 +9,8 @@
>   #include <linux/arm-smccc.h>
>   
>   enum {
> +	GZVM_FUNC_CREATE_VM = 0,


	GZVM_FUNC_CREATE_VM,
	GZVM_FUNC_DESTROY_VM,

The first one will always be zero by default, subsequent members are always
incremental anyway.

> +	GZVM_FUNC_DESTROY_VM = 1,
>   	GZVM_FUNC_PROBE = 12,
>   	NR_GZVM_FUNC,
>   };
> @@ -19,6 +21,8 @@ enum {
>   	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, ARM_SMCCC_SMC_64,	\
>   			   SMC_ENTITY_MTK, (GZVM_FUNCID_START + (func)))
>   
> +#define MT_HVC_GZVM_CREATE_VM		GZVM_HCALL_ID(GZVM_FUNC_CREATE_VM)
> +#define MT_HVC_GZVM_DESTROY_VM		GZVM_HCALL_ID(GZVM_FUNC_DESTROY_VM)
>   #define MT_HVC_GZVM_PROBE		GZVM_HCALL_ID(GZVM_FUNC_PROBE)
>   
>   /**
> @@ -41,4 +45,9 @@ int gzvm_hypcall_wrapper(unsigned long a0, unsigned long a1,
>   			 unsigned long a6, unsigned long a7,
>   			 struct arm_smccc_res *res);
>   
> +static inline u16 get_vmid_from_tuple(unsigned int tuple)
> +{
> +	return (u16)(tuple >> 16);

As far as I can understand, this tuple is a union of two u16.

If you add that union, you won't even need this function anymore.

> +}
> +
>   #endif /* __GZVM_ARCH_COMMON_H__ */
> diff --git a/arch/arm64/geniezone/vm.c b/arch/arm64/geniezone/vm.c
> index e313aadec212..a15bad13c2ee 100644
> --- a/arch/arm64/geniezone/vm.c
> +++ b/arch/arm64/geniezone/vm.c
> @@ -7,9 +7,12 @@
>   #include <linux/err.h>
>   #include <linux/uaccess.h>
>   
> +#include <linux/gzvm.h>
>   #include <linux/gzvm_drv.h>
>   #include "gzvm_arch_common.h"
>   
> +#define PAR_PA47_MASK ((((1UL << 48) - 1) >> 12) << 12)

This value is unused. Anyway, isn't this just GENMASK_ULL(47, 12) ?!

> +
>   /**
>    * gzvm_hypcall_wrapper() - the wrapper for hvc calls
>    * @a0: arguments passed in registers 0
> @@ -45,3 +48,29 @@ int gzvm_arch_probe(void)
>   
>   	return 0;
>   }
> +
> +/**
> + * gzvm_arch_create_vm() - create vm
> + * @vm_type: VM type. Only supports Linux VM now.
> + *
> + * Return:
> + * * positive value	- VM ID
> + * * -ENOMEM		- Memory not enough for storing VM data
> + */
> +int gzvm_arch_create_vm(unsigned long vm_type)
> +{
> +	struct arm_smccc_res res;
> +	int ret;
> +
> +	ret = gzvm_hypcall_wrapper(MT_HVC_GZVM_CREATE_VM, vm_type, 0, 0, 0, 0,
> +				   0, 0, &res);
> +	return ret ? ret : res.a1;
> +}
> +
> +int gzvm_arch_destroy_vm(u16 vm_id)
> +{
> +	struct arm_smccc_res res;
> +
> +	return gzvm_hypcall_wrapper(MT_HVC_GZVM_DESTROY_VM, vm_id, 0, 0, 0, 0,
> +				    0, 0, &res);
> +}
> diff --git a/drivers/virt/geniezone/Makefile b/drivers/virt/geniezone/Makefile
> index 8c1f0053e773..066efddc0b9c 100644
> --- a/drivers/virt/geniezone/Makefile
> +++ b/drivers/virt/geniezone/Makefile
> @@ -6,5 +6,5 @@
>   
>   GZVM_DIR ?= ../../../drivers/virt/geniezone
>   
> -gzvm-y := $(GZVM_DIR)/gzvm_main.o
> +gzvm-y := $(GZVM_DIR)/gzvm_main.o $(GZVM_DIR)/gzvm_vm.o
>   
> diff --git a/drivers/virt/geniezone/gzvm_main.c b/drivers/virt/geniezone/gzvm_main.c
> index f7d4f0646d97..4e7d60067c55 100644
> --- a/drivers/virt/geniezone/gzvm_main.c
> +++ b/drivers/virt/geniezone/gzvm_main.c
> @@ -4,6 +4,7 @@
>    */
>   
>   #include <linux/device.h>
> +#include <linux/file.h>
>   #include <linux/kdev_t.h>
>   #include <linux/miscdevice.h>
>   #include <linux/module.h>
> @@ -40,7 +41,24 @@ int gzvm_err_to_errno(unsigned long err)
>   	return -EINVAL;
>   }
>   
> +static long gzvm_dev_ioctl(struct file *filp, unsigned int cmd,
> +			   unsigned long user_args)
> +{
> +	long ret;
> +
> +	switch (cmd) {
> +	case GZVM_CREATE_VM:
> +		ret = gzvm_dev_ioctl_create_vm(user_args);
> +		return ret;

return gzvm_dev_ioctl_create_vm(user_args);

> +	default:
> +		break;
> +	}
> +
> +	return -ENOTTY;
> +}
> +
>   static const struct file_operations gzvm_chardev_ops = {
> +	.unlocked_ioctl = gzvm_dev_ioctl,
>   	.llseek		= noop_llseek,
>   };
>   
> @@ -62,6 +80,7 @@ static int gzvm_drv_probe(struct platform_device *pdev)
>   
>   static int gzvm_drv_remove(struct platform_device *pdev)
>   {
> +	gzvm_destroy_all_vms();
>   	misc_deregister(&gzvm_dev);
>   	return 0;
>   }
> diff --git a/drivers/virt/geniezone/gzvm_vm.c b/drivers/virt/geniezone/gzvm_vm.c
> new file mode 100644
> index 000000000000..d5e850af924a
> --- /dev/null
> +++ b/drivers/virt/geniezone/gzvm_vm.c
> @@ -0,0 +1,107 @@

..snip..

> diff --git a/include/linux/gzvm_drv.h b/include/linux/gzvm_drv.h
> index 907f2f984de9..f1dce23838e4 100644
> --- a/include/linux/gzvm_drv.h
> +++ b/include/linux/gzvm_drv.h
> @@ -6,6 +6,12 @@
>   #ifndef __GZVM_DRV_H__
>   #define __GZVM_DRV_H__
>   
> +#include <linux/list.h>
> +#include <linux/mutex.h>
> +#include <linux/gzvm.h>
> +
> +#define INVALID_VM_ID   0xffff
> +
>   /*
>    * These are the definitions of APIs between GenieZone hypervisor and driver,
>    * there's no need to be visible to uapi. Furthermore, we need GenieZone
> @@ -17,9 +23,29 @@
>   #define ERR_NOT_IMPLEMENTED     (-27)
>   #define ERR_FAULT               (-40)
>   
> +/*
> + * The following data structures are for data transferring between driver and
> + * hypervisor, and they're aligned with hypervisor definitions
> + */
> +
> +struct gzvm {
> +	/* userspace tied to this vm */
> +	struct mm_struct *mm;
> +	/* lock for list_add*/

Why are you not using kerneldoc to document this structure?

After all, you're already partially documenting it.

> +	struct mutex lock;
> +	struct list_head vm_list;
> +	u16 vm_id;
> +};
> +
> +int gzvm_dev_ioctl_create_vm(unsigned long vm_type);
> +
>   int gzvm_err_to_errno(unsigned long err);
>   

Why is there a trailing space on this function sig?

Regards,
Angelo