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Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , Shuah Khan , Vishal Annapurve , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Jason Gunthorpe , Vlastimil Babka Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, Ackerley Tng X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1778185365; l=2198; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=xtpmgcfndSxNcZVTwB04xXaV1WHVzjM0+b2CjPRcVbk=; b=fdwSxOUbKsCq2DngSVKKVn3uTyf4sOf2cWXOoJ+wAwTNq1cgHAjtaBGomllK+0A4FLZxFLN6m /APdBUfVVzNDCXAXbQ5KTqGzQmbi2QO+HapCi7/nE88imakiCsic+ap X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Endpoint-Received: by B4 Relay for ackerleytng@google.com/20260225 with auth_id=649 X-Original-From: Ackerley Tng Reply-To: ackerleytng@google.com X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 7E2DE2000E X-Stat-Signature: h9kk8ppab9io38yc6a757r8xoj9wi8mj X-Rspam-User: X-HE-Tag: 1778185373-60445 X-HE-Meta: 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 F7UH6LGP CNMEEX2cKoARbkMa7DGEcyZbuk7MsljBtWU7ZxLaSqAsNuqYKxNHyEBKtJAHtRwaSQ+7Na2dV482A8QVpmP/5+JfeJiDoQAQVY69P7FMWvpecNkrOa9TlyhdVsi6IY8nTRs167XFmahr/trKIrIbESlt7eAVCyvXKutFYw0jM2L5B2Qy1q2FbM7JkDHARAa4Rzs8/xcfn32wS/60TagCFKHe56q3rxns63giFd9+ANnHnrKXufNSuOY669N3Z2u5iy0wAqHwU48crYYud4Hj9mIbeGX89SYXUYpYoFI8VKKqm2fPArCzH46jz2vJWaj9q6Z13ts0HDUAZOtFEuZb2/fwn+BHjR6aatfAJLWDdPz6iy0+jrYYOvVIuFiUHYF4Bj6ctSWYB/1NkZeET/pka8AY5tCrnc0LRdUAO1T4pcZDAjbSTTdwcN4q/zgFyuqZgMdbL0GwMktlFT18= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Ackerley Tng All-shared guest_memfd used to be only supported for non-CoCo VMs where preparation doesn't apply. INIT_SHARED is about to be supported for non-CoCo VMs in a later patch in this series. In addition, KVM_SET_MEMORY_ATTRIBUTES2 is about to be supported in guest_memfd in a later patch in this series. This means that the kvm fault handler may now call kvm_gmem_get_pfn() on a shared folio for a CoCo VM where preparation applies. Add a check to make sure that preparation is only performed for private folios. Preparation will be undone on freeing (see kvm_gmem_free_folio()) and on conversion to shared. Signed-off-by: Ackerley Tng --- virt/kvm/guest_memfd.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index 9d025f518c025..4f7c4824c3a45 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -888,6 +888,7 @@ int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot, int *max_order) { pgoff_t index = kvm_gmem_get_index(slot, gfn); + struct inode *inode; struct folio *folio; int r = 0; @@ -895,7 +896,8 @@ int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot, if (!file) return -EFAULT; - filemap_invalidate_lock_shared(file_inode(file)->i_mapping); + inode = file_inode(file); + filemap_invalidate_lock_shared(inode->i_mapping); folio = __kvm_gmem_get_pfn(file, slot, index, pfn, max_order); if (IS_ERR(folio)) { @@ -908,7 +910,8 @@ int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot, folio_mark_uptodate(folio); } - r = kvm_gmem_prepare_folio(kvm, slot, gfn, folio); + if (kvm_gmem_is_private_mem(inode, index)) + r = kvm_gmem_prepare_folio(kvm, slot, gfn, folio); folio_unlock(folio); @@ -918,7 +921,7 @@ int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot, folio_put(folio); out: - filemap_invalidate_unlock_shared(file_inode(file)->i_mapping); + filemap_invalidate_unlock_shared(inode->i_mapping); return r; } EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_gmem_get_pfn); -- 2.54.0.563.g4f69b47b94-goog