virt: acrn: Introduce EPT mapping management

The HSM provides hypervisor services to the ACRN userspace. While
launching a User VM, ACRN userspace needs to allocate memory and request
the ACRN Hypervisor to set up the EPT mapping for the VM.

A mapping cache is introduced for accelerating the translation between
the Service VM kernel virtual address and User VM physical address.

>From the perspective of the hypervisor, the types of GPA of User VM can be
listed as following:
   1) RAM region, which is used by User VM as system ram.
   2) MMIO region, which is recognized by User VM as MMIO. MMIO region is
      used to be utilized for devices emulation.

Generally, User VM RAM regions mapping is set up before VM started and
is released in the User VM destruction. MMIO regions mapping may be set
and unset dynamically during User VM running.

To achieve this, ioctls ACRN_IOCTL_SET_MEMSEG and ACRN_IOCTL_UNSET_MEMSEG
are introduced in HSM.

Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Yu Wang <yu1.wang@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Link: https://lore.kernel.org/r/20210207031040.49576-9-shuo.a.liu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/virt/acrn/hsm.c b/drivers/virt/acrn/hsm.c
index ee5cc7413239..2c40d3dc5e94 100644
--- a/drivers/virt/acrn/hsm.c
+++ b/drivers/virt/acrn/hsm.c
@@ -48,6 +48,7 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd,
 	struct acrn_vm *vm = filp->private_data;
 	struct acrn_vm_creation *vm_param;
 	struct acrn_vcpu_regs *cpu_regs;
+	struct acrn_vm_memmap memmap;
 	int i, ret = 0;
 
 	if (vm->vmid == ACRN_INVALID_VMID && cmd != ACRN_IOCTL_CREATE_VM) {
@@ -132,6 +133,20 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd,
 				vm->vmid);
 		kfree(cpu_regs);
 		break;
+	case ACRN_IOCTL_SET_MEMSEG:
+		if (copy_from_user(&memmap, (void __user *)ioctl_param,
+				   sizeof(memmap)))
+			return -EFAULT;
+
+		ret = acrn_vm_memseg_map(vm, &memmap);
+		break;
+	case ACRN_IOCTL_UNSET_MEMSEG:
+		if (copy_from_user(&memmap, (void __user *)ioctl_param,
+				   sizeof(memmap)))
+			return -EFAULT;
+
+		ret = acrn_vm_memseg_unmap(vm, &memmap);
+		break;
 	default:
 		dev_dbg(acrn_dev.this_device, "Unknown IOCTL 0x%x!\n", cmd);
 		ret = -ENOTTY;