Re: [libvirt] [PATCHv2 7/7] qemu: add support for vhost-vsock-pci

Create a new vsock endpoint by opening /dev/vhost-vsock, set the requested CID via ioctl (or assign a free one if auto='yes'), pass the file descriptor to QEMU and build the command line. https://bugzilla.redhat.com/show_bug.cgi?id=1291851 Signed-off-by: Ján Tomko <jtomko(a)redhat.com&gt; --- src/qemu/qemu_alias.c | 16 ++++++++ src/qemu/qemu_command.c | 45 ++++++++++++++++++++++ src/qemu/qemu_domain.c | 5 +++ src/qemu/qemu_domain.h | 2 +- src/qemu/qemu_process.c | 35 +++++++++++++++++ .../vhost-vsock-auto.x86_64-latest.args | 32 +++++++++++++++ .../vhost-vsock.x86_64-latest.args | 32 +++++++++++++++ tests/qemuxml2argvtest.c | 14 +++++++ 8 files changed, 180 insertions(+), 1 deletion(-) create mode 100644 tests/qemuxml2argvdata/vhost-vsock-auto.x86_64-latest.args create mode 100644 tests/qemuxml2argvdata/vhost-vsock.x86_64-latest.args

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 9da2d609e8..ef0716d683 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -9865,6 +9865,47 @@ qemuBuildSeccompSandboxCommandLine(virCommandPtr cmd, } +static int +qemuBuildVsockCommandLine(virCommandPtr cmd, + virDomainDefPtr def, + virDomainVsockDefPtr vsock, + const char *fdprefix,

+ virQEMUCapsPtr qemuCaps) +{ + qemuDomainVsockPrivatePtr priv = (qemuDomainVsockPrivatePtr)vsock->privateData; + const char *device = "vhost-vsock-pci"; + virBuffer buf = VIR_BUFFER_INITIALIZER; + char *devstr = NULL; + int ret = -1; + + virBufferAsprintf(&buf, "%s", device); + virBufferAsprintf(&buf, ",id=%s", vsock->info.alias); + virBufferAsprintf(&buf, ",guest-cid=%u", vsock->guest_cid); + virBufferAsprintf(&buf, ",vhostfd=%s%u", fdprefix, priv->vhostfd); + if (qemuBuildDeviceAddressStr(&buf, def, &vsock->info, qemuCaps) < 0) + goto cleanup; +#if 0 + if (qemuBuildVirtioOptionsStr(&buf, net->virtio, qemuCaps) < 0) + goto error; +#endif

+ + if (virBufferCheckError(&buf) < 0) + goto cleanup; + + devstr = virBufferContentAndReset(&buf); + + virCommandPassFD(cmd, priv->vhostfd, VIR_COMMAND_PASS_FD_CLOSE_PARENT); + priv->vhostfd = -1; + virCommandAddArgList(cmd, "-device", devstr, NULL); + + ret = 0; + cleanup: + virBufferFreeAndReset(&buf); + VIR_FREE(devstr); + return ret; +} + + /* * Constructs a argv suitable for launching qemu with config defined * for a given virtual machine. @@ -10111,6 +10152,10 @@ qemuBuildCommandLine(virQEMUDriverPtr driver, goto error; } + if (def->vsock && + qemuBuildVsockCommandLine(cmd, def, def->vsock, "", qemuCaps) < 0)

+ goto error; + /* In some situations, eg. VFIO passthrough, QEMU might need to lock a * significant amount of memory, so we need to set the limit accordingly */ virCommandSetMaxMemLock(cmd, qemuDomainGetMemLockLimitBytes(def));

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 174d932ae7..e318639963 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c

@@ -5975,6 +5976,36 @@ qemuProcessPrepareHostStorage(virQEMUDriverPtr driver, } +static int +qemuProcessOpenVhostVsock(virDomainVsockDefPtr vsock) +{ + qemuDomainVsockPrivatePtr priv = (qemuDomainVsockPrivatePtr)vsock->privateData; + const char *vsock_path = "/dev/vhost-vsock"; + int fd; + + if ((fd = open(vsock_path, O_RDWR)) < 0) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + "%s", _("unable to open vhost-vsock device")); + return -1; + } + + if (vsock->guest_cid) { + if (virVsockSetGuestCid(fd, vsock->guest_cid) < 0) + goto error; + } else { + if (virVsockAcquireGuestCid(fd, &vsock->guest_cid) < 0) + goto error;

+ } + + priv->vhostfd = fd; + return 0; +