Subject: Re: [PATCH v11 08/21] virt: geniezone: Add vcpu support

From: Simon Horman <[email-masked]>
Date: Fri, 31 May 2024 21:36:12 +0100

On Wed, May 29, 2024 at 04:42:26PM +0800, Liju-clr Chen wrote:
> From: Yi-De Wu <[email-masked]>
> 
> From: "Yingshiuan Pan" <[email-masked]>

nit: I think there should be at most one From line,
     denoting the author of the patch. Based on the Signed-off-by
     lines I assume that is Yingshiuan Pan.

     If there are multiple authors perhaps
     the Co-developed-by tag should be used below.

     And on that note, it's not clear to me what the significance
     of the Signed-off-by lines, other than that of
     Yingshiuan Pan (presumed author) and Liju Chen (sender) are.
     I'd suggest deleting them unless they are
     accompanied by Co-developed-by tags.

     And, lastly, the sender's signed-off-by line should come last.

     See: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#sign-your-work-the-developer-s-certificate-of-origin

> 
> VMM use this interface to create vcpu instance which is a fd, and this
> fd will be for any vcpu operations, such as setting vcpu registers and
> accepts the most important ioctl GZVM_VCPU_RUN which requests GenieZone
> hypervisor to do context switch to execute VM's vcpu context.
> 
> Signed-off-by: Yingshiuan Pan <[email-masked]>
> Signed-off-by: Jerry Wang <[email-masked]>
> Signed-off-by: kevenny hsieh <[email-masked]>
> Signed-off-by: Liju Chen <[email-masked]>
> Signed-off-by: Yi-De Wu <[email-masked]>

...

> diff --git a/drivers/virt/geniezone/Makefile b/drivers/virt/geniezone/Makefile
> index 25614ea3dea2..9cc453c0819b 100644
> --- a/drivers/virt/geniezone/Makefile
> +++ b/drivers/virt/geniezone/Makefile
> @@ -6,4 +6,5 @@
>  
>  GZVM_DIR ?= ../../../drivers/virt/geniezone
>  
> -gzvm-y := $(GZVM_DIR)/gzvm_main.o $(GZVM_DIR)/gzvm_vm.o
> +gzvm-y := $(GZVM_DIR)/gzvm_main.o $(GZVM_DIR)/gzvm_vm.o \
> +	  $(GZVM_DIR)/gzvm_vcpu.o
> diff --git a/drivers/virt/geniezone/gzvm_vcpu.c b/drivers/virt/geniezone/gzvm_vcpu.c
> new file mode 100644
> index 000000000000..1aca13fef422
> --- /dev/null
> +++ b/drivers/virt/geniezone/gzvm_vcpu.c
> @@ -0,0 +1,249 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2023 MediaTek Inc.
> + */
> +
> +#include <asm/sysreg.h>

nit: It's not clear to me that sysreg.h needs to be included in this file.

> +#include <linux/anon_inodes.h>
> +#include <linux/device.h>
> +#include <linux/file.h>
> +#include <linux/mm.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/soc/mediatek/gzvm_drv.h>
> +
> +/* maximum size needed for holding an integer */
> +#define ITOA_MAX_LEN 12
> +
> +static long gzvm_vcpu_update_one_reg(struct gzvm_vcpu *vcpu,
> +				     void __user *argp,
> +				     bool is_write)
> +{
> +	struct gzvm_one_reg reg;
> +	void __user *reg_addr;
> +	u64 data = 0;
> +	u64 reg_size;
> +	long ret;
> +
> +	if (copy_from_user(&reg, argp, sizeof(reg)))
> +		return -EFAULT;
> +
> +	reg_addr = (void __user *)reg.addr;

nit: Perhaps u64_to_user_ptr() is appropriate here.

     Also in gzvm_vm_ioctl_create_device() in patch 09/21.

> +	reg_size = (reg.id & GZVM_REG_SIZE_MASK) >> GZVM_REG_SIZE_SHIFT;
> +	reg_size = BIT(reg_size);
> +
> +	if (reg_size != 1 && reg_size != 2 && reg_size != 4 && reg_size != 8)
> +		return -EINVAL;
> +
> +	if (is_write) {
> +		/* GZ hypervisor would filter out invalid vcpu register access */
> +		if (copy_from_user(&data, reg_addr, reg_size))
> +			return -EFAULT;
> +	} else {
> +		return -EOPNOTSUPP;
> +	}
> +
> +	ret = gzvm_arch_vcpu_update_one_reg(vcpu, reg.id, is_write, &data);
> +
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}

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