qemu-kvm needs -enable-kvm flag for VT optimization

Recent qemu releases require command option '-enable-qemu' in order
for the kvm functionality be activated. Libvirt needs to pass this flag
to qemu when starting a domain. Note that without the option,
even if both the kernel and qemu support KVM, KVM will not be activated
and VMs will be very slow.

* src/qemu/qemu_conf.h src/qemu/qemu_conf.c: parse the extra command
  line option from help and add it when running kvm
* tests/qemuhelptest.c: this modified the flags output for qemu-0.10.5
  and qemu-kvm-0.11.0-rc2 regression tests
This commit is contained in:
Steve Yarmie 2009-11-20 15:41:05 +01:00 committed by Daniel Veillard
parent 264f3ddac9
commit b827338a72
3 changed files with 19 additions and 2 deletions

View File

@ -878,6 +878,8 @@ static unsigned int qemudComputeCmdFlags(const char *help,
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 conn,
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 conn,
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 conn,
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) {

View File

@ -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 */

View File

@ -121,7 +121,8 @@ mymain(int argc, char **argv)
QEMUD_CMD_FLAG_DRIVE_FORMAT |
QEMUD_CMD_FLAG_DRIVE_SERIAL |
QEMUD_CMD_FLAG_VGA |
QEMUD_CMD_FLAG_0_10,
QEMUD_CMD_FLAG_0_10 |
QEMUD_CMD_FLAG_ENABLE_KVM,
10005, 0, 0);
DO_TEST("qemu-kvm-0.10.5",
QEMUD_CMD_FLAG_VNC_COLON |
@ -177,7 +178,8 @@ mymain(int argc, char **argv)
QEMUD_CMD_FLAG_VGA |
QEMUD_CMD_FLAG_0_10 |
QEMUD_CMD_FLAG_PCIDEVICE |
QEMUD_CMD_FLAG_MEM_PATH,
QEMUD_CMD_FLAG_MEM_PATH |
QEMUD_CMD_FLAG_ENABLE_KVM,
10092, 1, 0);
return ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE;