On Tue, Jul 02, 2024 at 07:58:11PM +0000, Ashish Kalra wrote:
> +static void unshare_all_bss_decrypted_memory(void)
> +{
> + unsigned long vaddr, vaddr_end;
> + unsigned int level;
> + unsigned int npages;
> + pte_t *pte;
> +
> + vaddr = (unsigned long)__start_bss_decrypted;
> + vaddr_end = (unsigned long)__start_bss_decrypted_unused;
> + npages = (vaddr_end - vaddr) >> PAGE_SHIFT;
> + for (; vaddr < vaddr_end; vaddr += PAGE_SIZE) {
> + pte = lookup_address(vaddr, &level);
> + if (!pte || !pte_decrypted(*pte) || pte_none(*pte))
> + continue;
> +
> + set_pte_enc(pte, level, (void *)vaddr);
> + }
> + vaddr = (unsigned long)__start_bss_decrypted;
> + snp_set_memory_private(vaddr, npages);
> +}
Merge the whole unsharing dance into a single function:
diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
index 5013c3afb0c4..f263ceada006 100644
--- a/arch/x86/coco/sev/core.c
+++ b/arch/x86/coco/sev/core.c
@@ -1049,58 +1049,47 @@ static bool make_pte_private(pte_t *pte, unsigned long addr, int pages, int leve
return true;
}
-static void unshare_all_bss_decrypted_memory(void)
-{
- unsigned long vaddr, vaddr_end;
- unsigned int level;
- unsigned int npages;
- pte_t *pte;
-
- vaddr = (unsigned long)__start_bss_decrypted;
- vaddr_end = (unsigned long)__start_bss_decrypted_unused;
- npages = (vaddr_end - vaddr) >> PAGE_SHIFT;
- for (; vaddr < vaddr_end; vaddr += PAGE_SIZE) {
- pte = lookup_address(vaddr, &level);
- if (!pte || !pte_decrypted(*pte) || pte_none(*pte))
- continue;
-
- set_pte_enc(pte, level, (void *)vaddr);
- }
- vaddr = (unsigned long)__start_bss_decrypted;
- snp_set_memory_private(vaddr, npages);
-}
-
+/* Walk the direct mapping and convert all shared memory back to private. */
static void unshare_all_memory(void)
{
- unsigned long addr, end;
-
- /*
- * Walk direct mapping and convert all shared memory back to private.
- */
+ unsigned long addr, end, size;
+ unsigned int npages, level;
+ pte_t *pte;
+ /* Unshare the direct mapping. */
addr = PAGE_OFFSET;
end = PAGE_OFFSET + get_max_mapped();
while (addr < end) {
- unsigned long size;
- unsigned int level;
- pte_t *pte;
-
pte = lookup_address(addr, &level);
size = page_level_size(level);
- if (pte && pte_decrypted(*pte) && !pte_none(*pte)) {
- int pages = size / PAGE_SIZE;
-
- if (!make_pte_private(pte, addr, pages, level)) {
- pr_err("Failed to unshare range %#lx-%#lx\n",
- addr, addr + size);
- }
+ if (!pte || !pte_decrypted(*pte) || pte_none(*pte)) {
+ addr += size;
+ continue;
}
- addr += size;
+
+ npages = size / PAGE_SIZE;
+
+ if (!make_pte_private(pte, addr, npages, level))
+ pr_err("Failed to unshare range %#lx-%#lx\n",
+ addr, addr + size);
}
- unshare_all_bss_decrypted_memory();
+ /* Unshare all bss decrypted memory. */
+ addr = (unsigned long)__start_bss_decrypted;
+ end = (unsigned long)__start_bss_decrypted_unused;
+ npages = (end - addr) >> PAGE_SHIFT;
+
+ for (; addr < end; addr += PAGE_SIZE) {
+ pte = lookup_address(addr, &level);
+ if (!pte || !pte_decrypted(*pte) || pte_none(*pte))
+ continue;
+
+ set_pte_enc(pte, level, (void *)addr);
+ }
+ addr = (unsigned long)__start_bss_decrypted;
+ snp_set_memory_private(addr, npages);
__flush_tlb_all();
@@ -1114,8 +1103,9 @@ void snp_kexec_begin(void)
if (!IS_ENABLED(CONFIG_KEXEC_CORE))
return;
+
/*
- * Crash kernel reaches here with interrupts disabled: can't wait for
+ * Crash kernel ends up here with interrupts disabled: can't wait for
* conversions to finish.
*
* If race happened, just report and proceed.
@@ -1124,7 +1114,6 @@ void snp_kexec_begin(void)
pr_warn("Failed to stop shared<->private conversions\n");
}
-/* Walk direct mapping and convert all shared memory back to private */
void snp_kexec_finish(void)
{
struct sev_es_runtime_data *data;
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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