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Message-ID: <af02f7c3-4832-c23b-4454-29db8e519b8d@collabora.com>
Date:   Mon, 12 Jun 2023 09:49:41 +0200
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Subject: Re: [PATCH v4 4/9] virt: geniezone: Add irqchip support for virtual
 interrupt injection
To:     Yi-De Wu <yi-de.wu@mediatek.com>,
        Yingshiuan Pan <yingshiuan.pan@mediatek.com>,
        Ze-Yu Wang <ze-yu.wang@mediatek.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
        Matthias Brugger <matthias.bgg@gmail.com>
Cc:     linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org,
        linux-mediatek@lists.infradead.org,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Conor Dooley <conor.dooley@microchip.com>,
        Conor Dooley <conor+dt@kernel.org>,
        Trilok Soni <quic_tsoni@quicinc.com>,
        David Bradil <dbrazdil@google.com>,
        Jade Shih <jades.shih@mediatek.com>,
        Miles Chen <miles.chen@mediatek.com>,
        Ivan Tseng <ivan.tseng@mediatek.com>,
        My Chuang <my.chuang@mediatek.com>,
        Shawn Hsiao <shawn.hsiao@mediatek.com>,
        PeiLun Suei <peilun.suei@mediatek.com>,
        Liju Chen <liju-clr.chen@mediatek.com>,
        Willix Yeh <chi-shen.yeh@mediatek.com>
References: <20230609085214.31071-1-yi-de.wu@mediatek.com>
 <20230609085214.31071-5-yi-de.wu@mediatek.com>
Content-Language: en-US
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>
In-Reply-To: <20230609085214.31071-5-yi-de.wu@mediatek.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
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Precedence: bulk

Il 09/06/23 10:52, Yi-De Wu ha scritto:
> From: "Yingshiuan Pan" <yingshiuan.pan@mediatek.com>
> 
> Enable GenieZone to handle virtual interrupt injection request.
> 
> Signed-off-by: Yingshiuan Pan <yingshiuan.pan@mediatek.com>
> Signed-off-by: Liju Chen <liju-clr.chen@mediatek.com>
> Signed-off-by: Yi-De Wu <yi-de.wu@mediatek.com>
> ---
>   arch/arm64/geniezone/Makefile           |  2 +-
>   arch/arm64/geniezone/vgic.c             | 89 +++++++++++++++++++++++++
>   arch/arm64/include/uapi/asm/gzvm_arch.h |  4 ++
>   drivers/virt/geniezone/Makefile         |  2 +-
>   drivers/virt/geniezone/gzvm_common.h    | 12 ++++
>   drivers/virt/geniezone/gzvm_irqchip.c   | 13 ++++
>   drivers/virt/geniezone/gzvm_vm.c        | 77 +++++++++++++++++++++
>   include/linux/gzvm_drv.h                |  4 ++
>   include/uapi/linux/gzvm.h               | 53 +++++++++++++++
>   9 files changed, 254 insertions(+), 2 deletions(-)
>   create mode 100644 arch/arm64/geniezone/vgic.c
>   create mode 100644 drivers/virt/geniezone/gzvm_common.h
>   create mode 100644 drivers/virt/geniezone/gzvm_irqchip.c
> 
> diff --git a/arch/arm64/geniezone/Makefile b/arch/arm64/geniezone/Makefile
> index 69b0a4abeab0..0e4f1087f9de 100644
> --- a/arch/arm64/geniezone/Makefile
> +++ b/arch/arm64/geniezone/Makefile
> @@ -4,6 +4,6 @@
>   #
>   include $(srctree)/drivers/virt/geniezone/Makefile
>   
> -gzvm-y += vm.o vcpu.o
> +gzvm-y += vm.o vcpu.o vgic.o
>   
>   obj-$(CONFIG_MTK_GZVM) += gzvm.o
> diff --git a/arch/arm64/geniezone/vgic.c b/arch/arm64/geniezone/vgic.c
> new file mode 100644
> index 000000000000..9fe5049be122
> --- /dev/null
> +++ b/arch/arm64/geniezone/vgic.c
> @@ -0,0 +1,89 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2023 MediaTek Inc.
> + */
> +
> +#include <linux/irqchip/arm-gic-v3.h>
> +#include <linux/gzvm.h>
> +#include <linux/gzvm_drv.h>
> +#include "gzvm_arch_common.h"
> +
> +/* is_irq_valid() - Check the irq number and irq_type are matched */

/**
  * is_irq_valid() - Check if the IRQ number and type are matched
  * @irq:      interrupt number
  * @irq_type: interrupt type
  */

> +static bool is_irq_valid(u32 irq, u32 irq_type)
> +{
> +	switch (irq_type) {
> +	case GZVM_IRQ_TYPE_CPU:
> +		/*  0 ~ 15: SGI */
> +		if (likely(irq <= GZVM_IRQ_CPU_FIQ))
> +			return true;
> +		break;
> +	case GZVM_IRQ_TYPE_PPI:
> +		/* 16 ~ 31: PPI */
> +		if (likely(irq >= GZVM_VGIC_NR_SGIS && irq < GZVM_VGIC_NR_PRIVATE_IRQS))
> +			return true;
> +		break;
> +	case GZVM_IRQ_TYPE_SPI:
> +		/* 32 ~ : SPT */
> +		if (likely(irq >= GZVM_VGIC_NR_PRIVATE_IRQS))
> +			return true;
> +		break;
> +	default:
> +		return false;
> +	}
> +	return false;
> +}
> +
> +/**
> + * gzvm_vgic_inject_irq() - Inject virtual interrupt to a VM
> + * @vcpu_idx: vcpu index, only valid if PPI
> + * @irq: irq number
> + * @level: 1 if true else 0
> + */
> +static int gzvm_vgic_inject_irq(struct gzvm *gzvm, unsigned int vcpu_idx, u32 irq_type,
> +				u32 irq, bool level)
> +{
> +	unsigned long a1 = assemble_vm_vcpu_tuple(gzvm->vm_id, vcpu_idx);
> +	struct arm_smccc_res res;
> +
> +	if (!unlikely(is_irq_valid(irq, irq_type)))
> +		return -EINVAL;
> +
> +	gzvm_hypcall_wrapper(MT_HVC_GZVM_IRQ_LINE, a1, irq, level,
> +			     0, 0, 0, 0, &res);
> +	if (res.a0) {
> +		pr_err("Failed to set IRQ level (%d) to irq#%u on vcpu %d with ret=%d\n",
> +		       level, irq, vcpu_idx, (int)res.a0);
> +		return -EFAULT;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * gzvm_vgic_inject_spi() - Inject virtual spi interrupt
> + *
> + * @spi_irq: This is spi interrupt number (starts from 0 instead of 32)
> + *
> + * Return 0 if succeed else other negative values indicating each errors
> + */
> +static int gzvm_vgic_inject_spi(struct gzvm *gzvm, unsigned int vcpu_idx,
> +				u32 spi_irq, bool level)
> +{
> +	return gzvm_vgic_inject_irq(gzvm, 0, GZVM_IRQ_TYPE_SPI,
> +				    spi_irq + GZVM_VGIC_NR_PRIVATE_IRQS, level);
> +}
> +
> +int gzvm_arch_create_device(gzvm_id_t vm_id, struct gzvm_create_device *gzvm_dev)
> +{
> +	struct arm_smccc_res res;
> +
> +	return gzvm_hypcall_wrapper(MT_HVC_GZVM_CREATE_DEVICE, vm_id,
> +				    virt_to_phys(gzvm_dev), 0, 0, 0, 0, 0, &res);
> +}
> +
> +int gzvm_arch_inject_irq(struct gzvm *gzvm, unsigned int vcpu_idx, u32 irq_type,
> +			 u32 irq, bool level)
> +{
> +	/* default use spi */
> +	return gzvm_vgic_inject_spi(gzvm, vcpu_idx, irq, level);
> +}
> diff --git a/arch/arm64/include/uapi/asm/gzvm_arch.h b/arch/arm64/include/uapi/asm/gzvm_arch.h
> index e45e8e9e1bea..efee0354711e 100644
> --- a/arch/arm64/include/uapi/asm/gzvm_arch.h
> +++ b/arch/arm64/include/uapi/asm/gzvm_arch.h
> @@ -46,4 +46,8 @@
>   #define GZVM_REG_ARM_CORE		(0x0010 << GZVM_REG_ARM_COPROC_SHIFT)
>   #define GZVM_REG_ARM_CORE_REG(name)	(offsetof(struct gzvm_regs, name) / sizeof(__u32))
>   
> +#define GZVM_VGIC_NR_SGIS		16
> +#define GZVM_VGIC_NR_PPIS		16
> +#define GZVM_VGIC_NR_PRIVATE_IRQS	(GZVM_VGIC_NR_SGIS + GZVM_VGIC_NR_PPIS)
> +
>   #endif /* __GZVM_ARCH_H__ */
> diff --git a/drivers/virt/geniezone/Makefile b/drivers/virt/geniezone/Makefile
> index 8ebf2db0c970..67ba3ed76ea7 100644
> --- a/drivers/virt/geniezone/Makefile
> +++ b/drivers/virt/geniezone/Makefile
> @@ -7,5 +7,5 @@
>   GZVM_DIR ?= ../../../drivers/virt/geniezone
>   
>   gzvm-y := $(GZVM_DIR)/gzvm_main.o $(GZVM_DIR)/gzvm_vm.o \
> -	  $(GZVM_DIR)/gzvm_vcpu.o
> +	  $(GZVM_DIR)/gzvm_vcpu.o $(GZVM_DIR)/gzvm_irqchip.o
>   
> diff --git a/drivers/virt/geniezone/gzvm_common.h b/drivers/virt/geniezone/gzvm_common.h
> new file mode 100644
> index 000000000000..d0e39ded79e6
> --- /dev/null
> +++ b/drivers/virt/geniezone/gzvm_common.h
> @@ -0,0 +1,12 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2023 MediaTek Inc.
> + */
> +
> +#ifndef __GZ_COMMON_H__
> +#define __GZ_COMMON_H__
> +
> +int gzvm_irqchip_inject_irq(struct gzvm *gzvm, unsigned int vcpu_idx,
> +			    u32 irq_type, u32 irq, bool level);
> +
> +#endif /* __GZVM_COMMON_H__ */
> diff --git a/drivers/virt/geniezone/gzvm_irqchip.c b/drivers/virt/geniezone/gzvm_irqchip.c
> new file mode 100644
> index 000000000000..134bca3ab247
> --- /dev/null
> +++ b/drivers/virt/geniezone/gzvm_irqchip.c
> @@ -0,0 +1,13 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2023 MediaTek Inc.
> + */
> +
> +#include <linux/gzvm_drv.h>
> +#include "gzvm_common.h"
> +
> +int gzvm_irqchip_inject_irq(struct gzvm *gzvm, unsigned int vcpu_idx,
> +			    u32 irq_type, u32 irq, bool level)
> +{
> +	return gzvm_arch_inject_irq(gzvm, vcpu_idx, irq_type, irq, level);
> +}
> diff --git a/drivers/virt/geniezone/gzvm_vm.c b/drivers/virt/geniezone/gzvm_vm.c
> index f777c3bdb5ac..0cab67b0bdf8 100644
> --- a/drivers/virt/geniezone/gzvm_vm.c
> +++ b/drivers/virt/geniezone/gzvm_vm.c
> @@ -12,6 +12,7 @@
>   #include <linux/platform_device.h>
>   #include <linux/slab.h>
>   #include <linux/gzvm_drv.h>
> +#include "gzvm_common.h"
>   
>   static DEFINE_MUTEX(gzvm_list_lock);
>   static LIST_HEAD(gzvm_list);
> @@ -250,6 +251,68 @@ gzvm_vm_ioctl_set_memory_region(struct gzvm *gzvm,
>   	return register_memslot_addr_range(gzvm, memslot);
>   }
>   
> +static int gzvm_vm_ioctl_irq_line(struct gzvm *gzvm,
> +				  struct gzvm_irq_level *irq_level)
> +{
> +	u32 irq = irq_level->irq;
> +	unsigned int irq_type, vcpu_idx, irq_num;

Is there any reason why you're not using fixed size types here?

> +	bool level = irq_level->level;
> +
> +	irq_type = (irq >> GZVM_IRQ_TYPE_SHIFT) & GZVM_IRQ_TYPE_MASK;
> +	vcpu_idx = (irq >> GZVM_IRQ_VCPU_SHIFT) & GZVM_IRQ_VCPU_MASK;

Why aren't you using bitfield macros here?

#define GZVM_IRQ_LINE_TYPE	GENMASK(27, 24)
#define ..........

irq_type = FIELD_GET(GZVM_IRQ_LINE_TYPE, irq);
vcpu_idx = FIELD_GET(GZVM_IRQ_LINE_VCPU, irq);
vcpu2_idx = FIELD_GET(GZVM_IRQ_LINE_VCPU, irq) * (GZVM_IRQ_VCPU_MASK + 1);
irq_num = FIELD_GET(GZVM_IRQ_LINE_NUM, irq);

return gzvm_irqchip_inject_irq(gzvm, vcpu_idx + vcpu2_idx, irq_type, irq_num,
			       level);

> +	vcpu_idx += ((irq >> GZVM_IRQ_VCPU2_SHIFT) & GZVM_IRQ_VCPU2_MASK) *
> +		(GZVM_IRQ_VCPU_MASK + 1);
> +	irq_num = (irq >> GZVM_IRQ_NUM_SHIFT) & GZVM_IRQ_NUM_MASK;
> +
> +	return gzvm_irqchip_inject_irq(gzvm, vcpu_idx, irq_type, irq_num,
> +				       level);
> +}
> +
> +static int gzvm_vm_ioctl_create_device(struct gzvm *gzvm, void __user *argp)
> +{
> +	struct gzvm_create_device *gzvm_dev;
> +	void *dev_data = NULL;
> +	int ret;
> +
> +	gzvm_dev = (struct gzvm_create_device *)alloc_pages_exact(PAGE_SIZE,
> +								  GFP_KERNEL);
> +	if (!gzvm_dev)
> +		return -ENOMEM;
> +	if (copy_from_user(gzvm_dev, argp, sizeof(*gzvm_dev))) {
> +		ret = -EFAULT;
> +		goto err_free_dev;
> +	}
> +
> +	if (gzvm_dev->attr_addr != 0 && gzvm_dev->attr_size != 0) {
> +		size_t attr_size = gzvm_dev->attr_size;
> +		void __user *attr_addr = (void __user *)gzvm_dev->attr_addr;
> +
> +		/* Size of device specific data should not be over a page. */
> +		if (attr_size > PAGE_SIZE)
> +			return -EINVAL;
> +
> +		dev_data = alloc_pages_exact(attr_size, GFP_KERNEL);
> +		if (!dev_data) {
> +			ret = -ENOMEM;
> +			goto err_free_dev;
> +		}
> +
> +		if (copy_from_user(dev_data, attr_addr, attr_size)) {
> +			ret = -EFAULT;
> +			goto err_free_dev_data;
> +		}
> +		gzvm_dev->attr_addr = virt_to_phys(dev_data);
> +	}
> +
> +	ret = gzvm_arch_create_device(gzvm->vm_id, gzvm_dev);
> +err_free_dev_data:
> +	if (dev_data)
> +		free_pages_exact(dev_data, 0);
> +err_free_dev:
> +	free_pages_exact(gzvm_dev, 0);
> +	return ret;
> +}
> +
>   static int gzvm_vm_ioctl_enable_cap(struct gzvm *gzvm,
>   				    struct gzvm_enable_cap *cap,
>   				    void __user *argp)
> @@ -284,6 +347,20 @@ static long gzvm_vm_ioctl(struct file *filp, unsigned int ioctl,
>   		ret = gzvm_vm_ioctl_set_memory_region(gzvm, &userspace_mem);
>   		break;
>   	}
> +	case GZVM_IRQ_LINE: {
> +		struct gzvm_irq_level irq_event;
> +
> +		ret = -EFAULT;
> +		if (copy_from_user(&irq_event, argp, sizeof(irq_event)))
> +			goto out;
> +
> +		ret = gzvm_vm_ioctl_irq_line(gzvm, &irq_event);
> +		break;
> +	}
> +	case GZVM_CREATE_DEVICE: {
> +		ret = gzvm_vm_ioctl_create_device(gzvm, argp);
> +		break;
> +	}
>   	case GZVM_ENABLE_CAP: {
>   		struct gzvm_enable_cap cap;
>   
> diff --git a/include/linux/gzvm_drv.h b/include/linux/gzvm_drv.h
> index 7768bd35113a..842a026df9f3 100644
> --- a/include/linux/gzvm_drv.h
> +++ b/include/linux/gzvm_drv.h
> @@ -109,6 +109,10 @@ int gzvm_arch_create_vcpu(gzvm_id_t vm_id, int vcpuid, void *run);
>   int gzvm_arch_vcpu_run(struct gzvm_vcpu *vcpu, __u64 *exit_reason);
>   int gzvm_arch_destroy_vcpu(gzvm_id_t vm_id, int vcpuid);
>   
> +int gzvm_arch_create_device(gzvm_id_t vm_id, struct gzvm_create_device *gzvm_dev);
> +int gzvm_arch_inject_irq(struct gzvm *gzvm, unsigned int vcpu_idx, u32 irq_type,
> +			 u32 irq, bool level);
> +
>   extern struct miscdevice *gzvm_debug_dev;
>   
>   #endif /* __GZVM_DRV_H__ */
> diff --git a/include/uapi/linux/gzvm.h b/include/uapi/linux/gzvm.h
> index 38b3f20114ab..279b52192366 100644
> --- a/include/uapi/linux/gzvm.h
> +++ b/include/uapi/linux/gzvm.h
> @@ -61,6 +61,59 @@ struct gzvm_userspace_memory_region {
>   #define GZVM_SET_USER_MEMORY_REGION _IOW(GZVM_IOC_MAGIC, 0x46, \
>   					 struct gzvm_userspace_memory_region)
>   
> +/* for GZVM_IRQ_LINE, irq field index values */
> +#define GZVM_IRQ_VCPU2_SHIFT		28
> +#define GZVM_IRQ_VCPU2_MASK		0xf
> +#define GZVM_IRQ_TYPE_SHIFT		24
> +#define GZVM_IRQ_TYPE_MASK		0xf
> +#define GZVM_IRQ_VCPU_SHIFT		16
> +#define GZVM_IRQ_VCPU_MASK		0xff
> +#define GZVM_IRQ_NUM_SHIFT		0
> +#define GZVM_IRQ_NUM_MASK		0xffff
> +
> +/* irq_type field */
> +#define GZVM_IRQ_TYPE_CPU		0
> +#define GZVM_IRQ_TYPE_SPI		1
> +#define GZVM_IRQ_TYPE_PPI		2
> +
> +/* out-of-kernel GIC cpu interrupt injection irq_number field */
> +#define GZVM_IRQ_CPU_IRQ		0
> +#define GZVM_IRQ_CPU_FIQ		1
> +
> +struct gzvm_irq_level {
> +	union {
> +		__u32 irq;
> +		__s32 status;
> +	};
> +	__u32 level;
> +};
> +
> +#define GZVM_IRQ_LINE              _IOW(GZVM_IOC_MAGIC,  0x61, \
> +					struct gzvm_irq_level)
> +
> +enum gzvm_device_type {
> +	GZVM_DEV_TYPE_ARM_VGIC_V3_DIST,
> +	GZVM_DEV_TYPE_ARM_VGIC_V3_REDIST,
> +	GZVM_DEV_TYPE_MAX,
> +};
> +

Please use kerneldoc.

> +struct gzvm_create_device {
> +	__u32 dev_type;			/* device type */
> +	__u32 id;			/* out: device id */
> +	__u64 flags;			/* device specific flags */
> +	__u64 dev_addr;			/* device ipa address in VM's view */
> +	__u64 dev_reg_size;		/* device register range size */
> +	/*
> +	 * If user -> kernel, this is user virtual address of device specific
> +	 * attributes (if needed). If kernel->hypervisor, this is ipa.
> +	 */
> +	__u64 attr_addr;
> +	__u64 attr_size;		/* size of device specific attributes */
> +};
> +
> +#define GZVM_CREATE_DEVICE	   _IOWR(GZVM_IOC_MAGIC,  0xe0, \
> +					struct gzvm_create_device)
> +
>   /**
>    * ioctls for vcpu fds
>    */

Regards,
Angelo