linux-kernel - [PATCH 2/4 V3] Allocate pages for kdump without encryption when SME is enabled

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Date:   Sat, 16 Jun 2018 16:27:12 +0800
From:   Lianbo Jiang <lijiang@...hat.com>
To:     linux-kernel@...r.kernel.org
Cc:     iommu@...ts.linux-foundation.org, kexec@...ts.infradead.org,
        thomas.lendacky@....com, dyoung@...hat.com
Subject: [PATCH 2/4 V3] Allocate pages for kdump without encryption when SME is enabled

When SME is enabled in the first kernel, we will allocate pages
for kdump without encryption in order to be able to boot the
second kernel in the same manner as kexec, which helps to keep
the same code style.

Signed-off-by: Lianbo Jiang <lijiang@...hat.com>
---
 kernel/kexec_core.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 20fef1a..3c22a9b 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -471,6 +471,16 @@ static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
 		}
 	}
 
+	if (pages) {
+		unsigned int count, i;
+
+		pages->mapping = NULL;
+		set_page_private(pages, order);
+		count = 1 << order;
+		for (i = 0; i < count; i++)
+			SetPageReserved(pages + i);
+		arch_kexec_post_alloc_pages(page_address(pages), 1 << order, 0);
+	}
 	return pages;
 }
 
@@ -865,6 +875,7 @@ 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,
@@ -882,6 +893,7 @@ 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;
-- 
2.9.5