
Don't expect read(2) can always read as many as it's told. CC: Richard Henderson <richard.henderson@linaro.org> CC: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>