On 6/6/2024 2:57 AM, Sean Christopherson wrote:
On Mon, Jan 22, 2024, Binbin Wu wrote:
+ if (this_cpu_has(X86_FEATURE_LA57) && read_cr4() & X86_CR4_LA57)
Checking for feature support seems superfluous, e.g. LA57 should never be set if
it's unsupported. Then you can do
lam_mask = is_la57_enabled() ? LAM57_MASK : LAM48_MASK;
OK, will drop the feature check.
+ lam_mask = LAM57_MASK;
+
+ vaddr = alloc_vpage();
+ install_page(current_page_table(), virt_to_phys(alloc_page()), vaddr);
+ /*
+ * Since the stack memory address in KUT doesn't follow kernel address
+ * space partition rule, reuse the memory address for descriptor and
+ * the target address in the descriptor of invvpid.
+ */
+ operand = (struct invvpid_operand *)vaddr;
Why bother backing the virtual address? MOV needs a valid translation, but
INVVPID does not (ditto for INVLPG and INVPCID, though it might be simpler and
easier to just use the allocated address for those).
OK, will remove the unnecessary code.
+ operand->vpid = 0xffff;
+ operand->gla = (u64)vaddr;
+ operand = (struct invvpid_operand *)set_la_non_canonical((u64)operand,
+ lam_mask);
+ fault = test_for_exception(GP_VECTOR, ds_invvpid, operand);
+ report(!fault, "INVVPID (LAM on): tagged operand");
