Re: [PATCH v7 07/18] virt: acrn: Introduce an ioctl to set vCPU registers state
From: Greg Kroah-Hartman
Date: Fri Jan 08 2021 - 10:32:47 EST
On Wed, Jan 06, 2021 at 03:50:44PM +0800, shuo.a.liu@xxxxxxxxx wrote:
> From: Shuo Liu <shuo.a.liu@xxxxxxxxx>
>
> A virtual CPU of User VM has different context due to the different
> registers state. ACRN userspace needs to set the virtual CPU
> registers state (e.g. giving a initial registers state to a virtual
> BSP of a User VM).
>
> HSM provides an ioctl ACRN_IOCTL_SET_VCPU_REGS to do the virtual CPU
> registers state setting. The ioctl passes the registers state from ACRN
> userspace to the hypervisor directly.
>
> Signed-off-by: Shuo Liu <shuo.a.liu@xxxxxxxxx>
> Reviewed-by: Zhi Wang <zhi.a.wang@xxxxxxxxx>
> Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> Cc: Zhi Wang <zhi.a.wang@xxxxxxxxx>
> Cc: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
> Cc: Yu Wang <yu1.wang@xxxxxxxxx>
> Cc: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
> drivers/virt/acrn/hsm.c | 21 ++++++++++-
> drivers/virt/acrn/hypercall.h | 13 +++++++
> include/uapi/linux/acrn.h | 69 +++++++++++++++++++++++++++++++++++
> 3 files changed, 102 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/virt/acrn/hsm.c b/drivers/virt/acrn/hsm.c
> index 5fd933471683..2d04ebaa43f8 100644
> --- a/drivers/virt/acrn/hsm.c
> +++ b/drivers/virt/acrn/hsm.c
> @@ -9,6 +9,7 @@
> * Yakui Zhao <yakui.zhao@xxxxxxxxx>
> */
>
> +#include <linux/io.h>
> #include <linux/mm.h>
> #include <linux/module.h>
> #include <linux/slab.h>
> @@ -46,7 +47,8 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd,
> {
> struct acrn_vm *vm = filp->private_data;
> struct acrn_vm_creation *vm_param;
> - int ret = 0;
> + struct acrn_vcpu_regs *cpu_regs;
> + int i, ret = 0;
>
> if (vm->vmid == ACRN_INVALID_VMID && cmd != ACRN_IOCTL_CREATE_VM) {
> dev_dbg(acrn_dev.this_device,
> @@ -100,6 +102,23 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd,
> case ACRN_IOCTL_DESTROY_VM:
> ret = acrn_vm_destroy(vm);
> break;
> + case ACRN_IOCTL_SET_VCPU_REGS:
> + cpu_regs = memdup_user((void __user *)ioctl_param,
> + sizeof(struct acrn_vcpu_regs));
> + if (IS_ERR(cpu_regs))
> + return PTR_ERR(cpu_regs);
> +
> + for (i = 0; i < ARRAY_SIZE(cpu_regs->reserved); i++)
> + if (cpu_regs->reserved[i])
> + return -EINVAL;
> +
> + ret = hcall_set_vcpu_regs(vm->vmid, virt_to_phys(cpu_regs));
> + if (ret < 0)
> + dev_dbg(acrn_dev.this_device,
> + "Failed to set regs state of VM%u!\n",
> + vm->vmid);
> + kfree(cpu_regs);
> + break;
> default:
> dev_dbg(acrn_dev.this_device, "Unknown IOCTL 0x%x!\n", cmd);
> ret = -ENOTTY;
> diff --git a/drivers/virt/acrn/hypercall.h b/drivers/virt/acrn/hypercall.h
> index 426b66cadb1f..f29cfae08862 100644
> --- a/drivers/virt/acrn/hypercall.h
> +++ b/drivers/virt/acrn/hypercall.h
> @@ -19,6 +19,7 @@
> #define HC_START_VM _HC_ID(HC_ID, HC_ID_VM_BASE + 0x02)
> #define HC_PAUSE_VM _HC_ID(HC_ID, HC_ID_VM_BASE + 0x03)
> #define HC_RESET_VM _HC_ID(HC_ID, HC_ID_VM_BASE + 0x05)
> +#define HC_SET_VCPU_REGS _HC_ID(HC_ID, HC_ID_VM_BASE + 0x06)
>
> /**
> * hcall_create_vm() - Create a User VM
> @@ -75,4 +76,16 @@ static inline long hcall_reset_vm(u64 vmid)
> return acrn_hypercall1(HC_RESET_VM, vmid);
> }
>
> +/**
> + * hcall_set_vcpu_regs() - Set up registers of virtual CPU of a User VM
> + * @vmid: User VM ID
> + * @regs_state: Service VM GPA of registers state
> + *
> + * Return: 0 on success, <0 on failure
> + */
> +static inline long hcall_set_vcpu_regs(u64 vmid, u64 regs_state)
> +{
> + return acrn_hypercall2(HC_SET_VCPU_REGS, vmid, regs_state);
> +}
> +
> #endif /* __ACRN_HSM_HYPERCALL_H */
> diff --git a/include/uapi/linux/acrn.h b/include/uapi/linux/acrn.h
> index e1608b8a50a2..d5d66b93586e 100644
> --- a/include/uapi/linux/acrn.h
> +++ b/include/uapi/linux/acrn.h
> @@ -35,6 +35,73 @@ struct acrn_vm_creation {
> __u64 cpu_affinity;
> };
>
> +struct acrn_gp_regs {
> + __le64 rax;
> + __le64 rcx;
> + __le64 rdx;
> + __le64 rbx;
> + __le64 rsp;
> + __le64 rbp;
> + __le64 rsi;
> + __le64 rdi;
> + __le64 r8;
> + __le64 r9;
> + __le64 r10;
> + __le64 r11;
> + __le64 r12;
> + __le64 r13;
> + __le64 r14;
> + __le64 r15;
> +};
> +
> +struct acrn_descriptor_ptr {
> + __le16 limit;
> + __le64 base;
> + __le16 reserved[3];
> +} __attribute__ ((__packed__));
> +
> +struct acrn_regs {
> + struct acrn_gp_regs gprs;
> + struct acrn_descriptor_ptr gdt;
> + struct acrn_descriptor_ptr idt;
> +
> + __le64 rip;
> + __le64 cs_base;
> + __le64 cr0;
> + __le64 cr4;
> + __le64 cr3;
> + __le64 ia32_efer;
> + __le64 rflags;
> + __le64 reserved_64[4];
> +
> + __le32 cs_ar;
> + __le32 cs_limit;
> + __le32 reserved_32[3];
> +
> + __le16 cs_sel;
> + __le16 ss_sel;
> + __le16 ds_sel;
> + __le16 es_sel;
> + __le16 fs_sel;
> + __le16 gs_sel;
> + __le16 ldt_sel;
> + __le16 tr_sel;
> +};
No documentation of what these variables are anywhere?
What about the reserved slots, what must they be set to?
> +
> +/**
> + * struct acrn_vcpu_regs - Info of vCPU registers state
> + * @vcpu_id: vCPU ID
> + * @reserved: Reserved and must be 0
You actually checked this, nice!
thanks,
greg k-h