On 09.05.25 22:54, James Houghton wrote:
On Wed, Apr 30, 2025 at 9:57 AM Fuad Tabba <tabba@xxxxxxxxxx> wrote:
+static int kvm_gmem_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct kvm_gmem *gmem = file->private_data;
+
+ if (!kvm_arch_gmem_supports_shared_mem(gmem->kvm))
+ return -ENODEV;
+
+ if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) !=
+ (VM_SHARED | VM_MAYSHARE)) {
+ return -EINVAL;
+ }
+
+ vm_flags_set(vma, VM_DONTDUMP);
Hi Fuad,
Sorry if I missed this, but why exactly do we set VM_DONTDUMP here?
Could you leave a small comment? (I see that it seems to have
originally come from Patrick? [1]) I get that guest memory VMAs
generally should have VM_DONTDUMP; is there a bigger reason?
(David replying)
I assume because we might have inaccessible parts in there that SIGBUS
on access.
get_dump_page() does ignore any errors, though (returning NULL), so
likely we don't need VM_DONTDUMP.
--
Cheers,
David / dhildenb
