Re: [libvirt PATCH v4 1/3] add QEMU_CAPS_TCG_DISABLED and probe conditionally

On 4/22/20 11:50 PM, Tobin Feldman-Fitzthum wrote: > Only probe QEMU binary with accel=tcg if TCG is not disabled. > Similarly, only add a VIR_DOMAIN_VIRT_QEMU guest if TCG > is available. > > Signed-off-by: Tobin Feldman-Fitzthum <tobin(a)linux.vnet.ibm.com&gt; > --- > src/qemu/qemu_capabilities.c | 22 ++++++++++++++-------- > src/qemu/qemu_capabilities.h | 1 + > 2 files changed, 15 insertions(+), 8 deletions(-) > > diff --git a/src/qemu/qemu_capabilities.c > b/src/qemu/qemu_capabilities.c > index fe311048d4..c56b2d8f0e 100644 > --- a/src/qemu/qemu_capabilities.c > +++ b/src/qemu/qemu_capabilities.c > @@ -573,6 +573,7 @@ VIR_ENUM_IMPL(virQEMUCaps, > "fsdev.multidevs", > "virtio.packed", > "pcie-root-port.hotplug", > + "tcg-disabled", > ); > @@ -1014,13 +1015,16 @@ virQEMUCapsInitGuestFromBinary(virCapsPtr > caps, > virCapabilitiesAddGuestFeatureWithToggle(guest, > VIR_CAPS_GUEST_FEATURE_TYPE_DISKSNAPSHOT, > true, false); > - if (virCapabilitiesAddGuestDomain(guest, > - VIR_DOMAIN_VIRT_QEMU, > - NULL, > - NULL, > - 0, > - NULL) == NULL) > - goto cleanup; > + if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_TCG_DISABLED)) { > + if (virCapabilitiesAddGuestDomain(guest, > + VIR_DOMAIN_VIRT_QEMU, > + NULL, > + NULL, > + 0, > + NULL) == NULL) { > + goto cleanup; > + } > + } > if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_KVM)) { > if (virCapabilitiesAddGuestDomain(guest, > @@ -2295,7 +2299,8 @@ bool > virQEMUCapsIsVirtTypeSupported(virQEMUCapsPtr qemuCaps, > virDomainVirtType virtType) > { > - if (virtType == VIR_DOMAIN_VIRT_QEMU) > + if (virtType == VIR_DOMAIN_VIRT_QEMU && > + !virQEMUCapsGet(qemuCaps, QEMU_CAPS_TCG_DISABLED)) > return true; > if (virtType == VIR_DOMAIN_VIRT_KVM && > @@ -5150,6 +5155,7 @@ virQEMUCapsInitQMP(virQEMUCapsPtr qemuCaps, > * off. > */ > if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_KVM) && > + !virQEMUCapsGet(qemuCaps, QEMU_CAPS_TCG_DISABLED) && > virQEMUCapsInitQMPSingle(qemuCaps, libDir, runUid, runGid, > true) < 0) > return -1; > diff --git a/src/qemu/qemu_capabilities.h > b/src/qemu/qemu_capabilities.h > index 1681fc79a8..abc4ee82cb 100644 > --- a/src/qemu/qemu_capabilities.h > +++ b/src/qemu/qemu_capabilities.h > @@ -554,6 +554,7 @@ typedef enum { /* virQEMUCapsFlags grouping marker > for syntax-check */ > QEMU_CAPS_FSDEV_MULTIDEVS, /* fsdev.multidevs */ > QEMU_CAPS_VIRTIO_PACKED_QUEUES, /* virtio.packed */ > QEMU_CAPS_PCIE_ROOT_PORT_HOTPLUG, /* pcie-root-port.hotplug */ > + QEMU_CAPS_TCG_DISABLED, /* QEMU does not support TCG */ Actually, I think this should be a positive capability, e.g. QEMU_CAPS_TCG to reflect whether QEMU supports TCG or not. I can do the change locally before pushing, if you agree with the change. Michal