Re: [PATCH v7 13/14] KVM: Enable and expose KVM_MEM_PRIVATE

On Tue, Jul 19, 2022 at 11:55:24AM +0200, Gupta, Pankaj wrote:

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@@ -4712,12 +4813,10 @@ static long kvm_vm_ioctl(struct file *filp, (u32 __user *)(argp + offsetof(typeof(mem), flags)))) goto out;

• if (flags & KVM_MEM_PRIVATE) {
  

• 	r = -EINVAL;
  

• 	goto out;
  

• }
  

• size = sizeof(struct kvm_userspace_memory_region);
  

• if (flags & KVM_MEM_PRIVATE)
  

• 	size = sizeof(struct kvm_userspace_memory_region_ext);
  

Not sure if we use kvm_userspace_memory_region_ext or kvm_user_mem_region, just for readability.

Somehow, but majorly for code maintainability, kvm_user_mem_region is designed to be the alias of kvm_userspace_memory_region_ext so in the code we can access the 'unpacked' fields using something like 'mem.usersapce_addr' instead of 'mem.region.userspace_addr'.

Chao

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• else
  

• 	size = sizeof(struct kvm_userspace_memory_region);
  

  if (copy_from_user(&mem, argp, size)) goto out;