1 files changed, 55 insertions, 0 deletions
diff --git a/pkgs/applications/virtualization/cloud-hypervisor/vhost/0002-devices-vhost-user-add-protocol-flag-for-shmem.patch b/pkgs/applications/virtualization/cloud-hypervisor/vhost/0002-devices-vhost-user-add-protocol-flag-for-shmem.patch
new file mode 100644
index 00000000000..87e29939715
--- /dev/null
+++ b/pkgs/applications/virtualization/cloud-hypervisor/vhost/0002-devices-vhost-user-add-protocol-flag-for-shmem.patch
@@ -0,0 +1,55 @@
+From ee17b58f30e65a37a0526a4df60f9810fa19b138 Mon Sep 17 00:00:00 2001
+From: David Stevens <stevensd@chromium.org>
+Date: Thu, 13 Oct 2022 10:37:47 +0900
+Subject: [PATCH 2/2] devices: vhost-user: add protocol flag for shmem
+
+Add a vhost protocol feature flag for shared memory region support. This
+is necessary to avoid sending the GET_SHARED_MEMORY_REGIONS message to
+backends which don't support it.
+
+BUG=b:252901073
+TEST=crosvm device wl
+
+Change-Id: I044926e982526c3c76063b5386cab0db72524707
+Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/3951472
+Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
+Commit-Queue: David Stevens <stevensd@chromium.org>
+(cherry-picked from commit 60aa43629ae9be2cc3df37c648ab7e0e5ff2172c)
+Signed-off-by: Alyssa Ross <hi@alyssa.is>
+---
+ src/vhost_user/master.rs  | 5 +++++
+ src/vhost_user/message.rs | 2 ++
+ 2 files changed, 7 insertions(+)
+
+diff --git a/src/vhost_user/master.rs b/src/vhost_user/master.rs
+index deab6a7..2bbf8d6 100644
+--- a/src/vhost_user/master.rs
++++ b/src/vhost_user/master.rs
+@@ -357,6 +357,11 @@ impl VhostUserMaster for Master {
+     fn set_protocol_features(&mut self, features: VhostUserProtocolFeatures) -> Result<()> {
+         let mut node = self.node();
+         node.check_feature(VhostUserVirtioFeatures::PROTOCOL_FEATURES)?;
++        if features.contains(VhostUserProtocolFeatures::SHARED_MEMORY_REGIONS)
++            && !features.contains(VhostUserProtocolFeatures::SLAVE_REQ)
++        {
++            return error_code(VhostUserError::FeatureMismatch);
++        }
+         let val = VhostUserU64::new(features.bits());
+         let hdr = node.send_request_with_body(MasterReq::SET_PROTOCOL_FEATURES, &val, None)?;
+         // Don't wait for ACK here because the protocol feature negotiation process hasn't been
+diff --git a/src/vhost_user/message.rs b/src/vhost_user/message.rs
+index adb485b..09362fb 100644
+--- a/src/vhost_user/message.rs
++++ b/src/vhost_user/message.rs
+@@ -417,6 +417,8 @@ bitflags! {
+         const CONFIGURE_MEM_SLOTS = 0x0000_8000;
+         /// Support reporting status.
+         const STATUS = 0x0001_0000;
++        /// Support shared memory regions.
++        const SHARED_MEMORY_REGIONS = 0x0002_0000;
+     }
+ }
+ 
+-- 
+2.37.1
+