On Mon, Jan 22, 2024, Binbin Wu wrote:
> +static inline bool lam_u48_active(void)
> +{
> + return (read_cr3() & CR3_LAM_BITS_MASK) == X86_CR3_LAM_U48;
> +}
> +
> +static inline bool lam_u57_active(void)
> +{
> + return !!(read_cr3() & X86_CR3_LAM_U57);
> +}
Same comments as the supervisor patches.
> +static void test_lam_user_mode(bool has_lam, u64 lam_mask, u64 mem, u64 mmio)
> +{
> + unsigned r;
> + bool raised_vector;
> + unsigned long cr3 = read_cr3() & ~CR3_LAM_BITS_MASK;
> + u64 flags = 0;
> +
> + if (is_la57())
> + flags |= FLAGS_LA57;
> +
> + if (has_lam) {
> + if (lam_mask == LAM48_MASK) {
> + r = write_cr3_safe(cr3 | X86_CR3_LAM_U48);
> + report((r == 0) && lam_u48_active(), "Set LAM_U48");
!r is the preferred style
> + } else {
> + r = write_cr3_safe(cr3 | X86_CR3_LAM_U57);
> + report((r == 0) && lam_u57_active(), "Set LAM_U57");
> + }
> + }
> + if (lam_u48_active() || lam_u57_active())
> + flags |= FLAGS_LAM_ACTIVE;
> +
> + run_in_user((usermode_func)test_ptr, GP_VECTOR, flags, lam_mask, mem,
> + false, &raised_vector);
Ah, this is why test_ptr() doesn't recompute things. Hrm. Ah, I think we can at
least compute the mask dynamically, e.g. test_ptr() just need to know if LAM48
and/or LAM57 is enabled, right?
> + run_in_user((usermode_func)test_ptr, GP_VECTOR, flags, lam_mask, mmio,
> + true, &raised_vector);
> +}
