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[Qemu-devel] [PATCH v3 27/40] ivshmem: Rely on server sending the ID rig
From: |
Markus Armbruster |
Subject: |
[Qemu-devel] [PATCH v3 27/40] ivshmem: Rely on server sending the ID right after the version |
Date: |
Tue, 15 Mar 2016 19:34:42 +0100 |
The protocol specification (ivshmem-spec.txt, formerly
ivshmem_device_spec.txt) has always required the ID message to be sent
right at the beginning, and ivshmem-server has always complied. The
device, however, accepts it out of order. If an interrupt setup
arrived before it, though, it would be misinterpreted as connect
notification. Fix the latent bug by relying on the spec and
ivshmem-server's actual behavior.
Signed-off-by: Markus Armbruster <address@hidden>
Reviewed-by: Marc-André Lureau <address@hidden>
---
hw/misc/ivshmem.c | 27 ++++++++++++++++++++++++---
1 file changed, 24 insertions(+), 3 deletions(-)
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index 7f439c3..da32a74 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -653,8 +653,6 @@ static void process_msg(IVShmemState *s, int64_t msg, int
fd, Error **errp)
if (fd >= 0) {
process_msg_connect(s, msg, fd, errp);
- } else if (s->vm_id == -1) {
- s->vm_id = msg;
} else {
process_msg_disconnect(s, msg, errp);
}
@@ -722,6 +720,30 @@ static void ivshmem_recv_setup(IVShmemState *s, Error
**errp)
}
/*
+ * ivshmem-server sends the remaining initial messages in a fixed
+ * order, but the device has always accepted them in any order.
+ * Stay as compatible as practical, just in case people use
+ * servers that behave differently.
+ */
+
+ /*
+ * ivshmem_device_spec.txt has always required the ID message
+ * right here, and ivshmem-server has always complied. However,
+ * older versions of the device accepted it out of order, but
+ * broke when an interrupt setup message arrived before it.
+ */
+ msg = ivshmem_recv_msg(s, &fd, &err);
+ if (err) {
+ error_propagate(errp, err);
+ return;
+ }
+ if (fd != -1 || msg < 0 || msg > IVSHMEM_MAX_PEERS) {
+ error_setg(errp, "server sent invalid ID message");
+ return;
+ }
+ s->vm_id = msg;
+
+ /*
* Receive more messages until we got shared memory.
*/
do {
@@ -956,7 +978,6 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error
**errp)
/* we allocate enough space for 16 peers and grow as needed */
resize_peers(s, 16);
- s->vm_id = -1;
pci_register_bar(dev, 2, attr, &s->bar);
--
2.4.3
- [Qemu-devel] [PATCH v3 11/40] ivshmem: Add missing newlines to debug printfs, (continued)
- [Qemu-devel] [PATCH v3 11/40] ivshmem: Add missing newlines to debug printfs, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 23/40] ivshmem: Disentangle ivshmem_read(), Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 22/40] ivshmem: Simplify rejection of invalid peer ID from server, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 35/40] ivshmem: Replace int role_val by OnOffAuto master, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 15/40] ivshmem: Don't destroy the chardev on version mismatch, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 21/40] ivshmem: Assert interrupts are set up once, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 33/40] ivshmem: Inline check_shm_size() into its only caller, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 40/40] contrib/ivshmem-server: Print "not for production" warning, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 27/40] ivshmem: Rely on server sending the ID right after the version,
Markus Armbruster <=
- [Qemu-devel] [PATCH v3 26/40] ivshmem: Propagate errors through ivshmem_recv_setup(), Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 10/40] ivshmem: Rewrite specification document, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 36/40] ivshmem: Split ivshmem-plain, ivshmem-doorbell off ivshmem, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 30/40] ivshmem: Tighten check of property "size", Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 01/40] target-ppc: Document TOCTTOU in hugepage support, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 16/40] ivshmem: Fix harmless misuse of Error, Markus Armbruster, 2016/03/15
- [Qemu-devel] [PATCH v3 34/40] qdev: New DEFINE_PROP_ON_OFF_AUTO, Markus Armbruster, 2016/03/15