x86_iommu/amd: remove V=1 check from amdvi_validate_dte()

x86_iommu/amd: remove V=1 check from amdvi_validate_dte()

Currently, the amdvi_validate_dte() assumes that a valid DTE will
always have V=1. This is not true. The V=1 means that bit[127:1] are
valid. A valid DTE can have IV=1 and V=0 (i.e address translation
disabled and interrupt remapping enabled)

Remove the V=1 check from amdvi_validate_dte(), make the caller
responsible to check for V or IV bits.

This also fixes a bug in existing code that when error is
detected during the translation we'll fail the translation
instead of assuming a passthrough mode.

Signed-off-by: Brijesh Singh <[email protected]>
Reviewed-by: Peter Xu <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Eduardo Habkost <[email protected]>
Cc: Marcel Apfelbaum <[email protected]>
Cc: Tom Lendacky <[email protected]>
Cc: Suravee Suthikulpanit <[email protected]>
Reviewed-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>