[pve-devel] [PATCH] add fw_cfg-unbreak-migration-compatibility-for-2.4 patch
Alexandre Derumier
aderumier at odiso.com
Fri Feb 19 09:13:13 CET 2016
This should fix migration from qemu 2.5 (machine 2.4) to qemu 2.4
http://lists.nongnu.org/archive/html/qemu-devel/2016-02/msg04310.html
https://forum.proxmox.com/threads/cant-live-migrate-after-dist-upgrade.26097/
Please test
Signed-off-by: Alexandre Derumier <aderumier at odiso.com>
---
...g-unbreak-migration-compatibility-for-2.4.patch | 159 +++++++++++++++++++++
debian/patches/series | 1 +
2 files changed, 160 insertions(+)
create mode 100644 debian/patches/extra/fw_cfg-unbreak-migration-compatibility-for-2.4.patch
diff --git a/debian/patches/extra/fw_cfg-unbreak-migration-compatibility-for-2.4.patch b/debian/patches/extra/fw_cfg-unbreak-migration-compatibility-for-2.4.patch
new file mode 100644
index 0000000..3426471
--- /dev/null
+++ b/debian/patches/extra/fw_cfg-unbreak-migration-compatibility-for-2.4.patch
@@ -0,0 +1,159 @@
+From patchwork Thu Feb 18 19:31:00 2016
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 8bit
+Subject: fw_cfg: unbreak migration compatibility for 2.4 and earlier machines
+From: Laszlo Ersek <lersek at redhat.com>
+X-Patchwork-Id: 584876
+Message-Id: <1455823860-22268-1-git-send-email-lersek at redhat.com>
+To: qemu-devel at nongnu.org
+Cc: =?UTF-8?q?Marc=20Mar=ED?= <markmb at redhat.com>,
+ Gerd Hoffmann <kraxel at redhat.com>,
+ Alexandre DERUMIER <aderumier at odiso.com>, qemu-stable at nongnu.org
+Date: Thu, 18 Feb 2016 20:31:00 +0100
+
+When I reviewed Marc's fw_cfg DMA patches, I completely missed that the
+way we set dma_enabled would break migration.
+
+Gerd explained the right way (see reference below): dma_enabled should be
+set to true by default, and only true->false transitions should be
+possible:
+
+- when the user requests that with
+
+ -global fw_cfg_mem.dma_enabled=off
+
+ or
+
+ -global fw_cfg_io.dma_enabled=off
+
+ as appropriate for the platform,
+
+- when HW_COMPAT_2_4 dictates it,
+
+- when board code initializes fw_cfg without requesting DMA support.
+
+Cc: Marc Marí <markmb at redhat.com>
+Cc: Gerd Hoffmann <kraxel at redhat.com>
+Cc: Alexandre DERUMIER <aderumier at odiso.com>
+Cc: qemu-stable at nongnu.org
+Ref: http://thread.gmane.org/gmane.comp.emulators.qemu/390272/focus=391042
+Ref: https://bugs.launchpad.net/qemu/+bug/1536487
+Suggested-by: Gerd Hoffmann <kraxel at redhat.com>
+Signed-off-by: Laszlo Ersek <lersek at redhat.com>
+---
+
+Notes:
+ Tested the following cases with gdb, using qemu-system-x86_64, setting a
+ breakpoint on (s->dma_enabled) in fw_cfg_init_io_dma():
+
+ * no special params (DMA enabled)
+ * -global fw_cfg_io.dma_enabled=off (DMA disabled)
+ * -M pc-i440fx-2.4 (DMA disabled), similarly with 2.3 and Q35 too
+
+ Also tested the memory mapped case in practice, using
+ qemu-system-aarch64 -M virt, -kernel / -initrd / -append, with guest
+ UEFI:
+ * no special params (DMA enabled)
+ * -global fw_cfg_mem.dma_enabled=off (DMA disabled)
+
+ Not tested:
+ * actual migration
+ * when board code doesn't request DMA support
+
+ Testing feedback from people who use migration would be nice.
+
+ include/hw/compat.h | 8 ++++++++
+ hw/nvram/fw_cfg.c | 20 ++++++++++++--------
+ 2 files changed, 20 insertions(+), 8 deletions(-)
+
+diff --git a/include/hw/compat.h b/include/hw/compat.h
+index 2ebe739fcb5c..a5dbbf8984b1 100644
+index d0b1c4f..b7973db 100644
+--- a/include/hw/compat.h
++++ b/include/hw/compat.h
+@@ -18,6 +18,14 @@
+ .driver = "virtio-pci",\
+ .property = "migrate-extra",\
+ .value = "off",\
++ },{\
++ .driver = "fw_cfg_mem",\
++ .property = "dma_enabled",\
++ .value = "off",\
++ },{\
++ .driver = "fw_cfg_io",\
++ .property = "dma_enabled",\
++ .value = "off",\
+ },
+
+ #define HW_COMPAT_2_3 \
+diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
+index 79c5742b3362..f3acb47bd4dc 100644
+--- a/hw/nvram/fw_cfg.c
++++ b/hw/nvram/fw_cfg.c
+@@ -778,17 +778,19 @@ FWCfgState *fw_cfg_init_io_dma(uint32_t iobase, uint32_t dma_iobase,
+ DeviceState *dev;
+ FWCfgState *s;
+ uint32_t version = FW_CFG_VERSION;
+- bool dma_enabled = dma_iobase && dma_as;
++ bool dma_requested = dma_iobase && dma_as;
+
+ dev = qdev_create(NULL, TYPE_FW_CFG_IO);
+ qdev_prop_set_uint32(dev, "iobase", iobase);
+ qdev_prop_set_uint32(dev, "dma_iobase", dma_iobase);
+- qdev_prop_set_bit(dev, "dma_enabled", dma_enabled);
++ if (!dma_requested) {
++ qdev_prop_set_bit(dev, "dma_enabled", false);
++ }
+
+ fw_cfg_init1(dev);
+ s = FW_CFG(dev);
+
+- if (dma_enabled) {
++ if (s->dma_enabled) {
+ /* 64 bits for the address field */
+ s->dma_as = dma_as;
+ s->dma_addr = 0;
+@@ -814,11 +816,13 @@ FWCfgState *fw_cfg_init_mem_wide(hwaddr ctl_addr,
+ SysBusDevice *sbd;
+ FWCfgState *s;
+ uint32_t version = FW_CFG_VERSION;
+- bool dma_enabled = dma_addr && dma_as;
++ bool dma_requested = dma_addr && dma_as;
+
+ dev = qdev_create(NULL, TYPE_FW_CFG_MEM);
+ qdev_prop_set_uint32(dev, "data_width", data_width);
+- qdev_prop_set_bit(dev, "dma_enabled", dma_enabled);
++ if (!dma_requested) {
++ qdev_prop_set_bit(dev, "dma_enabled", false);
++ }
+
+ fw_cfg_init1(dev);
+
+@@ -828,7 +832,7 @@ FWCfgState *fw_cfg_init_mem_wide(hwaddr ctl_addr,
+
+ s = FW_CFG(dev);
+
+- if (dma_enabled) {
++ if (s->dma_enabled) {
+ s->dma_as = dma_as;
+ s->dma_addr = 0;
+ sysbus_mmio_map(sbd, 2, dma_addr);
+@@ -873,7 +877,7 @@ static Property fw_cfg_io_properties[] = {
+ DEFINE_PROP_UINT32("iobase", FWCfgIoState, iobase, -1),
+ DEFINE_PROP_UINT32("dma_iobase", FWCfgIoState, dma_iobase, -1),
+ DEFINE_PROP_BOOL("dma_enabled", FWCfgIoState, parent_obj.dma_enabled,
+- false),
++ true),
+ DEFINE_PROP_END_OF_LIST(),
+ };
+
+@@ -913,7 +917,7 @@ static const TypeInfo fw_cfg_io_info = {
+ static Property fw_cfg_mem_properties[] = {
+ DEFINE_PROP_UINT32("data_width", FWCfgMemState, data_width, -1),
+ DEFINE_PROP_BOOL("dma_enabled", FWCfgMemState, parent_obj.dma_enabled,
+- false),
++ true),
+ DEFINE_PROP_END_OF_LIST(),
+ };
+
diff --git a/debian/patches/series b/debian/patches/series
index ffc09f1..8a61d6b 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -53,3 +53,4 @@ extra/CVE-2016-2197-ahci-null-pointer.patch
extra/CVE-2016-2198-ehci-null-pointer.patch
extra/CVE-2016-2391-usb-ohci-avoid-multiple-eof-timers.patch
extra/CVE-2016-2392-check-USB-configuration-descriptor-object.patch
+extra/fw_cfg-unbreak-migration-compatibility-for-2.4.patch
--
2.1.4
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