From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Sean Christopherson <seanjc@google.com>,
Jim Mattson <jmattson@google.com>
Cc: David Rientjes <rientjes@google.com>,
"Edgecombe, Rick P" <rick.p.edgecombe@intel.com>,
"Kleen, Andi" <andi.kleen@intel.com>,
"Yamahata, Isaku" <isaku.yamahata@intel.com>,
Erdem Aktas <erdemaktas@google.com>,
Steve Rutherford <srutherford@google.com>,
Peter Gonda <pgonda@google.com>,
David Hildenbrand <david@redhat.com>,
x86@kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [RFCv2 11/13] mm: Replace hwpoison entry with present PTE if page got unpoisoned
Date: Fri, 16 Apr 2021 18:41:04 +0300 [thread overview]
Message-ID: <20210416154106.23721-12-kirill.shutemov@linux.intel.com> (raw)
In-Reply-To: <20210416154106.23721-1-kirill.shutemov@linux.intel.com>
If the page got unpoisoned we can replace hwpoison entry with a present
PTE on page fault instead of delivering SIGBUS.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
mm/memory.c | 38 +++++++++++++++++++++++++++++++++++++-
1 file changed, 37 insertions(+), 1 deletion(-)
diff --git a/mm/memory.c b/mm/memory.c
index b15b0c582186..56f93e8e98f9 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3280,7 +3280,43 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
vmf->page = device_private_entry_to_page(entry);
ret = vmf->page->pgmap->ops->migrate_to_ram(vmf);
} else if (is_hwpoison_entry(entry)) {
- ret = VM_FAULT_HWPOISON;
+ page = hwpoison_entry_to_page(entry);
+
+ locked = lock_page_or_retry(page, vma->vm_mm, vmf->flags);
+ if (!locked) {
+ ret = VM_FAULT_RETRY;
+ goto out;
+ }
+
+ vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd,
+ vmf->address, &vmf->ptl);
+
+ if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte))) {
+ ret = 0;
+ } else if (PageHWPoison(page)) {
+ ret = VM_FAULT_HWPOISON;
+ } else {
+ /*
+ * The page is unpoisoned. Replace hwpoison
+ * entry with a present PTE.
+ */
+
+ inc_mm_counter(vma->vm_mm, mm_counter(page));
+ pte = mk_pte(page, vma->vm_page_prot);
+
+ if (PageAnon(page)) {
+ page_add_anon_rmap(page, vma,
+ vmf->address, false);
+ } else {
+ page_add_file_rmap(page, false);
+ }
+
+ set_pte_at(vma->vm_mm, vmf->address,
+ vmf->pte, pte);
+ }
+
+ pte_unmap_unlock(vmf->pte, vmf->ptl);
+ unlock_page(page);
} else {
print_bad_pte(vma, vmf->address, vmf->orig_pte, NULL);
ret = VM_FAULT_SIGBUS;
--
2.26.3
next prev parent reply other threads:[~2021-04-16 15:42 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-16 15:40 [RFCv2 00/13] TDX and guest memory unmapping Kirill A. Shutemov
2021-04-16 15:40 ` [RFCv2 01/13] x86/mm: Move force_dma_unencrypted() to common code Kirill A. Shutemov
2021-04-16 15:40 ` [RFCv2 02/13] x86/kvm: Introduce KVM memory protection feature Kirill A. Shutemov
2021-04-16 16:10 ` Borislav Petkov
2021-04-19 10:10 ` Kirill A. Shutemov
2021-04-16 15:40 ` [RFCv2 03/13] x86/kvm: Make DMA pages shared Kirill A. Shutemov
2021-04-16 15:40 ` [RFCv2 04/13] x86/kvm: Use bounce buffers for KVM memory protection Kirill A. Shutemov
2021-04-16 16:21 ` Dave Hansen
2021-04-16 15:40 ` [RFCv2 05/13] x86/kvmclock: Share hvclock memory with the host Kirill A. Shutemov
2021-04-16 15:40 ` [RFCv2 06/13] x86/realmode: Share trampoline area if KVM memory protection enabled Kirill A. Shutemov
2021-04-19 16:49 ` Dave Hansen
2021-04-16 15:41 ` [RFCv2 07/13] mm: Add hwpoison_entry_to_pfn() and hwpoison_entry_to_page() Kirill A. Shutemov
2021-04-16 15:41 ` [RFCv2 08/13] mm/gup: Add FOLL_ALLOW_POISONED Kirill A. Shutemov
2021-04-16 15:41 ` [RFCv2 09/13] shmem: Fail shmem_getpage_gfp() on poisoned pages Kirill A. Shutemov
2021-04-16 15:41 ` [RFCv2 10/13] mm: Keep page reference for hwpoison entries Kirill A. Shutemov
2021-04-16 15:41 ` Kirill A. Shutemov [this message]
2021-04-16 15:41 ` [RFCv2 12/13] KVM: passdown struct kvm to hva_to_pfn_slow() Kirill A. Shutemov
2021-04-16 15:41 ` [RFCv2 13/13] KVM: unmap guest memory using poisoned pages Kirill A. Shutemov
2021-04-16 17:30 ` Sean Christopherson
2021-04-19 11:32 ` Xiaoyao Li
2021-04-19 14:26 ` Kirill A. Shutemov
2021-04-19 16:01 ` Sean Christopherson
2021-04-19 16:40 ` Kirill A. Shutemov
2021-04-19 18:09 ` Sean Christopherson
2021-04-19 18:12 ` David Hildenbrand
2021-04-19 18:53 ` Kirill A. Shutemov
2021-04-19 20:09 ` Sean Christopherson
2021-04-19 22:57 ` Kirill A. Shutemov
2021-04-20 17:13 ` Sean Christopherson
2021-05-21 12:31 ` Kirill A. Shutemov
2021-05-26 19:46 ` Sean Christopherson
2021-05-31 20:07 ` Kirill A. Shutemov
2021-06-02 17:51 ` Sean Christopherson
2021-06-02 23:33 ` Kirill A. Shutemov
2021-06-03 19:46 ` Sean Christopherson
2021-06-04 14:29 ` Kirill A. Shutemov
2021-06-04 17:16 ` Andy Lutomirski
2021-06-04 17:54 ` Kirill A. Shutemov
2021-04-16 16:46 ` [RFCv2 00/13] TDX and guest memory unmapping Matthew Wilcox
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210416154106.23721-12-kirill.shutemov@linux.intel.com \
--to=kirill.shutemov@linux.intel.com \
--cc=andi.kleen@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=david@redhat.com \
--cc=erdemaktas@google.com \
--cc=isaku.yamahata@intel.com \
--cc=jmattson@google.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=peterz@infradead.org \
--cc=pgonda@google.com \
--cc=rick.p.edgecombe@intel.com \
--cc=rientjes@google.com \
--cc=seanjc@google.com \
--cc=srutherford@google.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).