From cad65f222f29dffd4e91d43b230665aca813c7a6 Mon Sep 17 00:00:00 2001 From: Laine Stump Date: Sun, 8 Dec 2019 14:22:34 -0500 Subject: [PATCH] qemu: add capabilities flag for failover feature MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Presence of the virtio-net-pci option called "failover" indicates support in a qemu binary of a simplistic bonding of a virtio-net device with another PCI device. This feature allows migration of guests that have a network device assigned to a guest with VFIO, by creating a network bond device in the guest consisting of the VFIO-assigned device and a virtio-net-pci device, then temporarily (and automatically) unplugging the VFIO net device prior to migration (and hotplugging an equivalent device on the migration destination). (The feature is called "failover" because the bond device uses the vfio-pci netdev for normal guest networking, but "fails over" to the virtio-net-pci netdev once the vfio-pci device is unplugged for migration.) Full functioning of the feature also requires support in the virtio-net driver in the guest OS (since that is where the bond device resides), but if the "failover" commandline option is present for the virtio-net-pci device in qemu, at least the qemu part of the feature is available, and libvirt can add the proper options to both the virtio-net-pci and vfio-pci device commandlines to indicate qemu should attempt doing the failover during migration. This patch just adds the qemu capabilities flag "virtio-net.failover". Signed-off-by: Laine Stump Reviewed-by: Daniel P. Berrangé --- src/qemu/qemu_capabilities.c | 2 ++ src/qemu/qemu_capabilities.h | 1 + tests/qemucapabilitiesdata/caps_4.2.0.aarch64.xml | 1 + tests/qemucapabilitiesdata/caps_4.2.0.x86_64.xml | 1 + tests/qemucapabilitiesdata/caps_5.0.0.x86_64.xml | 1 + 5 files changed, 6 insertions(+) diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c index 5ff232608c..8b7fde2bcc 100644 --- a/src/qemu/qemu_capabilities.c +++ b/src/qemu/qemu_capabilities.c @@ -558,6 +558,7 @@ VIR_ENUM_IMPL(virQEMUCaps, /* 350 */ "i8042", "rng-builtin", + "virtio-net.failover", ); @@ -1305,6 +1306,7 @@ static struct virQEMUCapsStringFlags virQEMUCapsDevicePropsVirtioNet[] = { { "disable-legacy", QEMU_CAPS_VIRTIO_PCI_DISABLE_LEGACY }, { "iommu_platform", QEMU_CAPS_VIRTIO_PCI_IOMMU_PLATFORM }, { "ats", QEMU_CAPS_VIRTIO_PCI_ATS }, + { "failover", QEMU_CAPS_VIRTIO_NET_FAILOVER }, }; static struct virQEMUCapsStringFlags virQEMUCapsDevicePropsSpaprPCIHostBridge[] = { diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h index 56af9e9a0e..00c47ffd93 100644 --- a/src/qemu/qemu_capabilities.h +++ b/src/qemu/qemu_capabilities.h @@ -539,6 +539,7 @@ typedef enum { /* virQEMUCapsFlags grouping marker for syntax-check */ /* 350 */ QEMU_CAPS_DEVICE_I8042, /* PS/2 controller */ QEMU_CAPS_OBJECT_RNG_BUILTIN, /* -object rng-builtin */ + QEMU_CAPS_VIRTIO_NET_FAILOVER, /* virtio-net-*.failover */ QEMU_CAPS_LAST /* this must always be the last item */ } virQEMUCapsFlags; diff --git a/tests/qemucapabilitiesdata/caps_4.2.0.aarch64.xml b/tests/qemucapabilitiesdata/caps_4.2.0.aarch64.xml index ab81854e62..d0faa4c471 100644 --- a/tests/qemucapabilitiesdata/caps_4.2.0.aarch64.xml +++ b/tests/qemucapabilitiesdata/caps_4.2.0.aarch64.xml @@ -177,6 +177,7 @@ + 4001050 0 61700242 diff --git a/tests/qemucapabilitiesdata/caps_4.2.0.x86_64.xml b/tests/qemucapabilitiesdata/caps_4.2.0.x86_64.xml index 0361ed5bdb..faed23f5c1 100644 --- a/tests/qemucapabilitiesdata/caps_4.2.0.x86_64.xml +++ b/tests/qemucapabilitiesdata/caps_4.2.0.x86_64.xml @@ -221,6 +221,7 @@ + 4002000 0 43100242 diff --git a/tests/qemucapabilitiesdata/caps_5.0.0.x86_64.xml b/tests/qemucapabilitiesdata/caps_5.0.0.x86_64.xml index a84cbed1f7..1eef7197ef 100644 --- a/tests/qemucapabilitiesdata/caps_5.0.0.x86_64.xml +++ b/tests/qemucapabilitiesdata/caps_5.0.0.x86_64.xml @@ -222,6 +222,7 @@ + 4002050 0 43100241