kexec: Allocate decrypted control pages for kdump if SME is enabled

BugLink: https://bugs.launchpad.net/bugs/1854216
[ Upstream commit 9cf38d5559e813cccdba8b44c82cc46ba48d0896 ]

When SME is enabled in the first kernel, it needs to allocate decrypted
pages for kdump because when the kdump kernel boots, these pages need to
be accessed decrypted in the initial boot stage, before SME is enabled.

 [ bp: clean up text. ]

Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: kexec@lists.infradead.org
Cc: tglx@linutronix.de
Cc: mingo@redhat.com
Cc: hpa@zytor.com
Cc: akpm@linux-foundation.org
Cc: dan.j.williams@intel.com
Cc: bhelgaas@google.com
Cc: baiyaowei@cmss.chinamobile.com
Cc: tiwai@suse.de
Cc: brijesh.singh@amd.com
Cc: dyoung@redhat.com
Cc: bhe@redhat.com
Cc: jroedel@suse.de
Link: https://lkml.kernel.org/r/20180930031033.22110-3-lijiang@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 8f15665ab6167c5918c7274b5dded420dce411c7..27cf24e285e0c233c9ea4be5a6d9e7691302cb25 100644 (file)
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -473,6 +473,10 @@ static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
                }
        }
 
+       /* Ensure that these pages are decrypted if SME is enabled. */
+       if (pages)
+               arch_kexec_post_alloc_pages(page_address(pages), 1 << order, 0);
+
        return pages;
 }
 
@@ -867,6 +871,7 @@ static int kimage_load_crash_segment(struct kimage *image,
                        result  = -ENOMEM;
                        goto out;
                }
+               arch_kexec_post_alloc_pages(page_address(page), 1, 0);
                ptr = kmap(page);
                ptr += maddr & ~PAGE_MASK;
                mchunk = min_t(size_t, mbytes,
@@ -884,6 +889,7 @@ static int kimage_load_crash_segment(struct kimage *image,
                        result = copy_from_user(ptr, buf, uchunk);
                kexec_flush_icache_page(page);
                kunmap(page);
+               arch_kexec_pre_free_pages(page_address(page), 1);
                if (result) {
                        result = -EFAULT;
                        goto out;