> On Jun 28, 2019, at 3:14 PM, Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx> wrote:
>
> According to section "Checks on Host Segment and Descriptor-Table
> Registers" in Intel SDM vol 3C, the following checks are performed on
> vmentry of nested guests:
>
> - In the selector field for each of CS, SS, DS, ES, FS, GS and TR, the
> RPL (bits 1:0) and the TI flag (bit 2) must be 0.
> - The selector fields for CS and TR cannot be 0000H.
> - The selector field for SS cannot be 0000H if the "host address-space
> size" VM-exit control is 0.
> - On processors that support Intel 64 architecture, the base-address
> fields for FS, GS, GDTR, IDTR, and TR must contain canonical
> addresses.
>
> Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
> Reviewed-by: Karl Heubaum <karl.heubaum@xxxxxxxxxx>
> ---
> lib/x86/processor.h | 5 ++
> x86/vmx_tests.c | 159 ++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 164 insertions(+)
>
> diff --git a/lib/x86/processor.h b/lib/x86/processor.h
> index 4fef0bc..c6edc26 100644
> --- a/lib/x86/processor.h
> +++ b/lib/x86/processor.h
> @@ -461,6 +461,11 @@ static inline void write_pkru(u32 pkru)
> : : "a" (eax), "c" (ecx), "d" (edx));
> }
>
> +static u64 make_non_canonical(u64 addr)
> +{
> + return (addr | 1ull << 48);
> +}
You may wan to make it “static inline”. On my system I get:
processor.h:464:12: error: ‘make_non_canonical’ defined but not used [-Werror=unused-function]
