686f1d075a
- kvm-spapr-Don-t-trigger-a-CAS-reboot-for-XICS-XIVE-mode-.patch [bz#1733893] - kvm-vfio-pci-Don-t-remove-irqchip-notifier-if-not-regist.patch [bz#1782678] - kvm-virtio-don-t-enable-notifications-during-polling.patch [bz#1789301] - kvm-usbredir-Prevent-recursion-in-usbredir_write.patch [bz#1790844] - kvm-xhci-recheck-slot-status.patch [bz#1790844] - Resolves: bz#1733893 (Boot a guest with "-prom-env 'auto-boot?=false'", SLOF failed to enter the boot entry after input "boot" followed by "0 > " on VNC) - Resolves: bz#1782678 (qemu core dump after hot-unplugging the XXV710/XL710 PF) - Resolves: bz#1789301 (virtio-blk/scsi: fix notification suppression during AioContext polling) - Resolves: bz#1790844 (USB related fixes)
107 lines
3.2 KiB
Diff
107 lines
3.2 KiB
Diff
From 8f6311159977b8ee4b78172caa411d3cee4d2ae5 Mon Sep 17 00:00:00 2001
|
|
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
|
|
Date: Tue, 14 Jan 2020 20:23:30 +0000
|
|
Subject: [PATCH 4/5] usbredir: Prevent recursion in usbredir_write
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
|
|
Message-id: <20200114202331.51831-2-dgilbert@redhat.com>
|
|
Patchwork-id: 93344
|
|
O-Subject: [RHEL-AV-8.2.0 qemu-kvm PATCH 1/2] usbredir: Prevent recursion in usbredir_write
|
|
Bugzilla: 1790844
|
|
RH-Acked-by: Peter Xu <peterx@redhat.com>
|
|
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
|
|
RH-Acked-by: Gerd Hoffmann <kraxel@redhat.com>
|
|
|
|
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
|
|
|
|
I've got a case where usbredir_write manages to call back into itself
|
|
via spice; this patch causes the recursion to fail (0 bytes) the write;
|
|
this seems to avoid the deadlock I was previously seeing.
|
|
|
|
I can't say I fully understand the interaction of usbredir and spice;
|
|
but there are a few similar guards in spice and usbredir
|
|
to catch other cases especially onces also related to spice_server_char_device_wakeup
|
|
|
|
This case seems to be triggered by repeated migration+repeated
|
|
reconnection of the viewer; but my debugging suggests the migration
|
|
finished before this hits.
|
|
|
|
The backtrace of the hang looks like:
|
|
reds_handle_ticket
|
|
reds_handle_other_links
|
|
reds_channel_do_link
|
|
red_channel_connect
|
|
spicevmc_connect
|
|
usbredir_create_parser
|
|
usbredirparser_do_write
|
|
usbredir_write
|
|
qemu_chr_fe_write
|
|
qemu_chr_write
|
|
qemu_chr_write_buffer
|
|
spice_chr_write
|
|
spice_server_char_device_wakeup
|
|
red_char_device_wakeup
|
|
red_char_device_write_to_device
|
|
vmc_write
|
|
usbredirparser_do_write
|
|
usbredir_write
|
|
qemu_chr_fe_write
|
|
qemu_chr_write
|
|
qemu_chr_write_buffer
|
|
qemu_mutex_lock_impl
|
|
|
|
and we fail as we land through qemu_chr_write_buffer's lock
|
|
twice.
|
|
|
|
Bug: https://bugzilla.redhat.com/show_bug.cgi?id=1752320
|
|
|
|
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
|
|
Message-Id: <20191218113012.13331-1-dgilbert@redhat.com>
|
|
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
|
|
(cherry picked from commit 394642a8d3742c885e397d5bb5ee0ec40743cdc6)
|
|
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
|
|
---
|
|
hw/usb/redirect.c | 9 +++++++++
|
|
1 file changed, 9 insertions(+)
|
|
|
|
diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c
|
|
index e0f5ca6..97f2c3a 100644
|
|
--- a/hw/usb/redirect.c
|
|
+++ b/hw/usb/redirect.c
|
|
@@ -113,6 +113,7 @@ struct USBRedirDevice {
|
|
/* Properties */
|
|
CharBackend cs;
|
|
bool enable_streams;
|
|
+ bool in_write;
|
|
uint8_t debug;
|
|
int32_t bootindex;
|
|
char *filter_str;
|
|
@@ -290,6 +291,13 @@ static int usbredir_write(void *priv, uint8_t *data, int count)
|
|
return 0;
|
|
}
|
|
|
|
+ /* Recursion check */
|
|
+ if (dev->in_write) {
|
|
+ DPRINTF("usbredir_write recursion\n");
|
|
+ return 0;
|
|
+ }
|
|
+ dev->in_write = true;
|
|
+
|
|
r = qemu_chr_fe_write(&dev->cs, data, count);
|
|
if (r < count) {
|
|
if (!dev->watch) {
|
|
@@ -300,6 +308,7 @@ static int usbredir_write(void *priv, uint8_t *data, int count)
|
|
r = 0;
|
|
}
|
|
}
|
|
+ dev->in_write = false;
|
|
return r;
|
|
}
|
|
|
|
--
|
|
1.8.3.1
|
|
|