Re: [PATCH 2/4 V3] Allocate pages for kdump without encryption when SME is enabled

Baoquan He
2018-06-21T01:53:53Z

On 06/16/18 at 04:27pm, Lianbo Jiang wrote:
> 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@redhat.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);

I guess you might imitate the kexec case, however kexec get pages from
buddy. Crash pages are reserved in memblock, these codes might make no sense.

> + 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
>
>
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