Re: [RFC PATCH] kvm: x86/vmx: Use kzalloc for cached_vmcs12

[Paolo Bonzini]

On 23/01/19 19:33, Tom Roeder wrote:
> 
> Even in vmx_set_nested_state, there are about 30 lines of code in
> between enter_vmx_operation and copy_from_user, and there are a couple
> of cases that cause vmx_set_nested_state to return with an error. So if
> we want to fix this by handling all the error paths, I think it might be
> cleanest to convert vmx_set_nested_state to use goto error handling,
> since that would allow us to clear the allocated memory in one place.

I prefer to have kzalloc, and change vmx_get_nested_state to copy the
whole page including the trailing zeroes.

Paolo