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

lijiang
2018-06-21T05:06:15Z

在 2018年06月21日 09:53, Baoquan He 写道:
> 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.
>
Thanks for your comments.
We have changed the attribute of pages, so the original attribute of pages will be
restored when they free.

Thanks.
Lianbo
>> + 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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