On 1/5/22 2:27 PM, Dave Hansen wrote:
On 1/5/22 11:52, Brijesh Singh wrote:
for (; vaddr < vaddr_end; vaddr += PMD_SIZE) {
+ /*
+ * When SEV-SNP is active then transition the page to
shared in the RMP
+ * table so that it is consistent with the page table
attribute change.
+ */
+ early_snp_set_memory_shared(__pa(vaddr), __pa(vaddr),
PTRS_PER_PMD);
Shouldn't the first argument be vaddr as below?
Nope, sme_postprocess_startup() is called while we are fixing the
initial page table and running with identity mapping (so va == pa).
I'm not sure I've ever seen a line of code that wanted a comment so badly.
The early_snp_set_memory_shared() call the PVALIDATE instruction to
clear the validated bit from the BSS region. The PVALIDATE instruction
needs a virtual address, so we need to use the identity mapped virtual
address so that PVALIDATE can clear the validated bit. I will add more
comments to clarify it.
-Brijesh
