init: Call mem_encrypt_init() after Hyper-V hypercall init is done

Full Hyper-V initialization, including support for hypercalls, is done
as an apic_post_init callback via late_time_init().  mem_encrypt_init()
needs to make hypercalls when it marks swiotlb memory as decrypted.
But mem_encrypt_init() is currently called a few lines before
late_time_init(), so the hypercalls don't work.

Fix this by moving mem_encrypt_init() after late_time_init() and
related clock initializations. The intervening initializations don't
do any I/O that requires the swiotlb, so moving mem_encrypt_init()
slightly later has no impact.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/1678329614-3482-6-git-send-email-mikelley@microsoft.com

diff --git a/init/main.c b/init/main.c
index 4425d1783d5c21e8f1da703e503a5edc37a3d93f..7e9c0ca25643435d0589d44ed5a31e0dee1f406d 100644 (file)
--- a/init/main.c
+++ b/init/main.c
@@ -1088,14 +1088,6 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
         */
        locking_selftest();
 
-       /*
-        * This needs to be called before any devices perform DMA
-        * operations that might use the SWIOTLB bounce buffers. It will
-        * mark the bounce buffers as decrypted so that their usage will
-        * not cause "plain-text" data to be decrypted when accessed.
-        */
-       mem_encrypt_init();
-
 #ifdef CONFIG_BLK_DEV_INITRD
        if (initrd_start && !initrd_below_start_ok &&
            page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
@@ -1112,6 +1104,17 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
                late_time_init();
        sched_clock_init();
        calibrate_delay();
+
+       /*
+        * This needs to be called before any devices perform DMA
+        * operations that might use the SWIOTLB bounce buffers. It will
+        * mark the bounce buffers as decrypted so that their usage will
+        * not cause "plain-text" data to be decrypted when accessed. It
+        * must be called after late_time_init() so that Hyper-V x86/x64
+        * hypercalls work when the SWIOTLB bounce buffers are decrypted.
+        */
+       mem_encrypt_init();
+
        pid_idr_init();
        anon_vma_init();
 #ifdef CONFIG_X86