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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=1777418714; l=2198; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=OqIYnMBXTw/n3yXOP4qWHqQMtRm1sk4cJiE4i/xCg1U=; b=yGRr7gPhlI8FntjxRhJIC0FMe/yThO5oZateyTY3fWyRElaN/3eb1/73b2FjJr5Y5u70mlw1J ihXyN6WyW8pD8Lsguxbj3FixDVQIszkBT6nZQ+E0TRmn+mxLz4dXdoN 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-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 05CCE40012 X-Stat-Signature: si1mxjh5rfsfonbszkunyctwcjfyscip X-HE-Tag: 1777418722-457042 X-HE-Meta: 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 P00wJBNz QU2om95pdFqTQoFfTEyX0zc+LgN8kheeXiJ+iOeZb+CPG6ce4Hu0/Mas/OUhR9UajcLO+U0pI+aOTZqS7rVWhz8n7i9CdJLlFpTqYaI/XKvKWkAinGyRc/yy5GBl3ob8i7TFbtY0bwkNOZXlNR7z6inZYVU6qGrZzIiwN5e9jx78DnUtZFHJn5oQh6jnWABVpOUemqzudPC7/YL5p46Dhzbd9+Gysn7yT/58bTyQtQsc9surhin99v1dj9AL/5FOhAHM+6poEbxHby2KPXumhM9UTSXJ3SRWoh6k31bK7TfjFLzmHrMJyLJgd4P6esn9zvmiXqqbAgy3jjW7qbVYTuqNR51vyTfEkR2/30kWxzR16cWh3bGy8Stmek5WR0L8kVC6yWZDnKYUpmsTsp5z18PHySGE+qNNhhMVsmvFeLi32K++4Spb5KzVbjg7EUzD21a1osvfa2c85gGyJRwx0HNPICg== 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 758ac24a0ff40..506219e2359eb 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -900,6 +900,7 @@ 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; @@ -907,7 +908,8 @@ 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)) { @@ -920,7 +922,8 @@ 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); @@ -930,7 +933,7 @@ 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); -- 2.54.0.545.g6539524ca2-goog