Given real vectors $v$ and $r$ of the same size, what are the following?

1. $\inf\{v'R^{-1}v ~ \colon ~ R>0 \, , \, \text{diag}(R)= r\}$
2. $\sup\{v'Rv ~ \colon ~ R>0\, , \, \text{diag}(R)= r\}$

Note: $R > 0$ denotes positive definiteness, $x'$ denotes transpose, $\text{diag}(R)$ is the vector of the diagonal entries of matrix $R$.