Commit 71c26581 authored by Markus Armbruster's avatar Markus Armbruster
Browse files

ivshmem: Don't destroy the chardev on version mismatch 



Yes, the chardev is commonly useless after we read a bad version from
it, but destroying it is inappropriate anyway: the user created it, so
the user should be able to hold on to it as long as he likes.  We
don't destroy it on other errors.  Screwed up in commit 5105b1d8.

Stop reading instead.

Also note QEMU's behavior in ivshmem-spec.txt.

Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
Reviewed-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-16-git-send-email-armbru@redhat.com>
parent c20fc0c3

docs/specs/ivshmem-spec.txt

+3 −0
Original line number Diff line number Diff line
@@ -187,6 +187,9 @@ Each message consists of a single 8 byte little-endian signed number, 
and may be accompanied by a file descriptor via SCM_RIGHTS.  Both

client and server close the connection on error.



Note: QEMU currently doesn't close the connection right on error, but

only when the character device is destroyed.



On connect, the server sends the following messages in order:



1. The protocol version number, currently zero.  The client should

hw/misc/ivshmem.c

+1 −2
Original line number Diff line number Diff line
@@ -708,8 +708,7 @@ static void ivshmem_check_version(void *opaque, const uint8_t * buf, int size) 
    if (tmp != -1 || version != IVSHMEM_PROTOCOL_VERSION) {

        fprintf(stderr, "incompatible version, you are connecting to a ivshmem-"

                "server using a different protocol please check your setup\n");

        qemu_chr_delete(s->server_chr);

        s->server_chr = NULL;

        qemu_chr_add_handlers(s->server_chr, NULL, NULL, NULL, s);

        return;

    }