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[Qemu-devel] [PULL 27/40] ivshmem: Rely on server sending the ID right a
From: |
Markus Armbruster |
Subject: |
[Qemu-devel] [PULL 27/40] ivshmem: Rely on server sending the ID right after the version |
Date: |
Fri, 18 Mar 2016 18:01:14 +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>
Message-Id: <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] [PULL 29/40] ivshmem: Simplify how we cope with short reads from server, (continued)
- [Qemu-devel] [PULL 29/40] ivshmem: Simplify how we cope with short reads from server, Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 19/40] ivshmem: Clean up MSI-X conditions, Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 35/40] ivshmem: Replace int role_val by OnOffAuto master, Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 13/40] ivshmem: Clean up after commit 9940c32, Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 02/40] ivshmem-server: Fix and clean up command line help, Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 23/40] ivshmem: Disentangle ivshmem_read(), Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 16/40] ivshmem: Fix harmless misuse of Error, Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 17/40] ivshmem: Failed realize() can leave migration blocker behind, Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 25/40] ivshmem: Receive shared memory synchronously in realize(), Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 30/40] ivshmem: Tighten check of property "size", Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 27/40] ivshmem: Rely on server sending the ID right after the version,
Markus Armbruster <=
- [Qemu-devel] [PULL 37/40] ivshmem: Clean up after the previous commit, Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 28/40] ivshmem: Drop the hackish test for UNIX domain chardev, Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 31/40] ivshmem: Implement shm=... with a memory backend, Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 21/40] ivshmem: Assert interrupts are set up once, Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 40/40] contrib/ivshmem-server: Print "not for production" warning, Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 34/40] qdev: New DEFINE_PROP_ON_OFF_AUTO, Markus Armbruster, 2016/03/18
- [Qemu-devel] [PULL 36/40] ivshmem: Split ivshmem-plain, ivshmem-doorbell off ivshmem, Markus Armbruster, 2016/03/18
- Re: [Qemu-devel] [PULL 00/40] ivshmem: Fixes, cleanups, device model split, Peter Maydell, 2016/03/21