Re: [libvirt] PATCH: recent qemu-kvm requires -enable-kvm flag to activate VT optimization

Thanks for pointing that out. I made the changes you suggested. An updated patch is attached. btw - I'm using qemu-kvm-0.11.0, but this patch would be relevant when running any version of qemu/qemu-kvm that was released after the upstream merge of the kvm userspace.. -Steve Daniel P. Berrange wrote: diff -upr libvirt/src/qemu/qemu_conf.c libvirt-enableKVM/src/qemu/qemu_conf.c --- libvirt/src/qemu/qemu_conf.c 2009-11-17 05:37:23.973599362 -0800 +++ libvirt-enableKVM/src/qemu/qemu_conf.c 2009-11-17 05:41:40.755832169 -0800 @@ -878,6 +878,8 @@ static unsigned int qemudComputeCmdFlags flags |= QEMUD_CMD_FLAG_KQEMU; if (strstr(help, "-no-kvm")) flags |= QEMUD_CMD_FLAG_KVM; + if (strstr(help, "-enable-kvm")) + flags |= QEMUD_CMD_FLAG_ENABLE_KVM; if (strstr(help, "-no-reboot")) flags |= QEMUD_CMD_FLAG_NO_REBOOT; if (strstr(help, "-name")) @@ -1595,6 +1597,7 @@ int qemudBuildCommandLine(virConnectPtr struct utsname ut; int disableKQEMU = 0; int disableKVM = 0; + int enableKVM = 0; int qargc = 0, qarga = 0; const char **qargv = NULL; int qenvc = 0, qenva = 0; @@ -1653,6 +1656,15 @@ int qemudBuildCommandLine(virConnectPtr def->virtType == VIR_DOMAIN_VIRT_QEMU) disableKVM = 1; + /* Should explicitly enable KVM if + * 1. Guest domain is 'kvm' + * 2. The qemu binary has the -enable-kvm flag + * NOTE: user must be responsible for loading the kvm modules + */ + if ((qemuCmdFlags & QEMUD_CMD_FLAG_ENABLE_KVM) && + def->virtType == VIR_DOMAIN_VIRT_KVM) + enableKVM = 1; + /* * Need to force a 32-bit guest CPU type if * @@ -1780,6 +1792,8 @@ int qemudBuildCommandLine(virConnectPtr ADD_ARG_LIT("-no-kqemu"); if (disableKVM) ADD_ARG_LIT("-no-kvm"); + if (enableKVM) + ADD_ARG_LIT("-enable-kvm"); ADD_ARG_LIT("-m"); ADD_ARG_LIT(memory); if (def->hugepage_backed) { diff -upr libvirt/src/qemu/qemu_conf.h libvirt-enableKVM/src/qemu/qemu_conf.h --- libvirt/src/qemu/qemu_conf.h 2009-11-17 05:37:23.973599362 -0800 +++ libvirt-enableKVM/src/qemu/qemu_conf.h 2009-11-17 05:41:40.755832169 -0800 @@ -73,6 +73,7 @@ enum qemud_cmd_flags { QEMUD_CMD_FLAG_XEN_DOMID = (1 << 20), /* -xen-domid (new style xen integration) */ QEMUD_CMD_FLAG_MIGRATE_QEMU_UNIX = (1 << 21), /* Does qemu support unix domain sockets for migration? */ QEMUD_CMD_FLAG_CHARDEV = (1 << 22), /* Is the new -chardev arg available */ + QEMUD_CMD_FLAG_ENABLE_KVM = (1 << 23), /* Is the -enable-kvm flag available to "enable KVM full virtualization support" */ }; /* Main driver state */