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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: D954C1F38F X-Spam-Score: -3.01 X-Rspamd-Action: no action X-Spamd-Result: default: False [-3.01 / 50.00]; BAYES_HAM(-3.00)[100.00%]; SUSPICIOUS_RECIPS(1.50)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.cz:s=susede2_rsa,suse.cz:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; FROM_HAS_DN(0.00)[]; DKIM_SIGNED(0.00)[suse.cz:s=susede2_rsa,suse.cz:s=susede2_ed25519]; FUZZY_BLOCKED(0.00)[rspamd.com]; ARC_NA(0.00)[]; RBL_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:104:10:150:64:97:from]; TO_DN_SOME(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_CC(0.00)[redhat.com,kernel.org,ellerman.id.au,brainfault.org,sifive.com,dabbelt.com,eecs.berkeley.edu,google.com,zeniv.linux.org.uk,infradead.org,linux-foundation.org,intel.com,linux.intel.com,digikod.net,maciej.szmigiero.name,amd.com,oracle.com,gmail.com,arm.com,quicinc.com,huawei.com,linux.dev,amazon.co.uk,nvidia.com]; DKIM_TRACE(0.00)[suse.cz:+]; SPAMHAUS_XBL(0.00)[2a07:de40:b281:104:10:150:64:97:from]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCPT_COUNT_GT_50(0.00)[60]; RCVD_COUNT_TWO(0.00)[2]; FROM_EQ_ENVFROM(0.00)[]; RCVD_TLS_ALL(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; TAGGED_RCPT(0.00)[]; RECEIVED_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:106:10:150:64:167:received]; ASN(0.00)[asn:25478, ipnet:::/0, country:RU]; RCVD_VIA_SMTP_AUTH(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.cz:mid,suse.cz:dkim,imap1.dmz-prg2.suse.org:rdns,imap1.dmz-prg2.suse.org:helo] X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Spam-Flag: NO X-Spam-Level: On 2/20/25 12:25, David Hildenbrand wrote: > On 11.02.25 13:11, Fuad Tabba wrote: >> Before transitioning a guest_memfd folio to unshared, thereby >> disallowing access by the host and allowing the hypervisor to >> transition its view of the guest page as private, we need to be >> sure that the host doesn't have any references to the folio. >> >> This patch introduces a new type for guest_memfd folios, which >> isn't activated in this series but is here as a placeholder and >> to facilitate the code in the next patch. This will be used in >> the future to register a callback that informs the guest_memfd >> subsystem when the last reference is dropped, therefore knowing >> that the host doesn't have any remaining references. >> >> Signed-off-by: Fuad Tabba >> --- > > [...] > >> static const char *page_type_name(unsigned int page_type) >> diff --git a/mm/swap.c b/mm/swap.c >> index 47bc1bb919cc..241880a46358 100644 >> --- a/mm/swap.c >> +++ b/mm/swap.c >> @@ -38,6 +38,10 @@ >> #include >> #include >> >> +#ifdef CONFIG_KVM_GMEM_SHARED_MEM >> +#include >> +#endif >> + >> #include "internal.h" >> >> #define CREATE_TRACE_POINTS >> @@ -101,6 +105,11 @@ static void free_typed_folio(struct folio *folio) >> case PGTY_hugetlb: >> free_huge_folio(folio); >> return; >> +#endif >> +#ifdef CONFIG_KVM_GMEM_SHARED_MEM >> + case PGTY_guestmem: >> + kvm_gmem_handle_folio_put(folio); >> + return; > > Hm, if KVM is built as a module, will that work? Or would we need the Good catch, I guess not? > core-mm guest_memfd shim that would always be compiled into the core and > decouple KVM from guest_memfd ("library")? That could also help avoid exporting the mpol symbols in the NUMA mempolicy series?