On Thu, Aug 28, 2025 at 12:16:18PM +0300, Vitaly Kuznetsov wrote: > Azure CVM instance types featuring a paravisor hang upon kdump. The > investigation shows that makedumpfile causes a hang when it steps on a page > which was previously share with the host > (HVCALL_MODIFY_SPARSE_GPA_PAGE_HOST_VISIBILITY). The new kernel has no > knowledge of these 'special' regions (which are Vmbus connection pages, > GPADL buffers, ...). There are several ways to approach the issue: > - Convey the knowledge about these regions to the new kernel somehow. > - Unshare these regions before accessing in the new kernel (it is unclear > if there's a way to query the status for a given GPA range). > - Unshare these regions before jumping to the new kernel (which this patch > implements). > > To make the procedure as robust as possible, store PFN ranges of shared > regions in a linked list instead of storing GVAs and re-using > hv_vtom_set_host_visibility(). This also allows to avoid memory allocation > on the kdump/kexec path. > > Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com>
No fixes tag for this one? Should it be marked as a stable backport? Thanks, Wei
