| Message ID | 20211130133153.444601-2-danielhb413@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | ppc/pnv.c: add a friendly warning when accel=kvm is used | expand |
On Tue, Nov 30, 2021 at 10:31:52AM -0300, Daniel Henrique Barboza wrote: > If one tries to use -machine powernv9,accel=kvm in a Power9 host, a > cryptic error will be shown: > > qemu-system-ppc64: Register sync failed... If you're using kvm-hv.ko, only "-cpu host" is possible > qemu-system-ppc64: kvm_init_vcpu: kvm_arch_init_vcpu failed (0): Invalid argument > > Appending '-cpu host' will throw another error: > > qemu-system-ppc64: invalid chip model 'host' for powernv9 machine > > The root cause is that in IBM PowerPC we have different specs for the bare-metal > and the guests. The bare-metal follows OPAL, the guests follow PAPR. The kernel > KVM modules presented in the ppc kernels implements PAPR. This means that we > can't use KVM accel when using the powernv machine, which is the emulation of > the bare-metal host. > > All that said, let's give a more informative error in this case. > > Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> > --- > hw/ppc/pnv.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c > index 71e45515f1..e5b87e8730 100644 > --- a/hw/ppc/pnv.c > +++ b/hw/ppc/pnv.c > @@ -742,6 +742,11 @@ static void pnv_init(MachineState *machine) > DriveInfo *pnor = drive_get(IF_MTD, 0, 0); > DeviceState *dev; > > + if (kvm_enabled()) { > + error_report("The powernv machine does not work with KVM acceleration"); > + exit(EXIT_FAILURE); > + } > + > /* allocate RAM */ > if (machine->ram_size < mc->default_ram_size) { > char *sz = size_to_str(mc->default_ram_size);
diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c index 71e45515f1..e5b87e8730 100644 --- a/hw/ppc/pnv.c +++ b/hw/ppc/pnv.c @@ -742,6 +742,11 @@ static void pnv_init(MachineState *machine) DriveInfo *pnor = drive_get(IF_MTD, 0, 0); DeviceState *dev; + if (kvm_enabled()) { + error_report("The powernv machine does not work with KVM acceleration"); + exit(EXIT_FAILURE); + } + /* allocate RAM */ if (machine->ram_size < mc->default_ram_size) { char *sz = size_to_str(mc->default_ram_size);
If one tries to use -machine powernv9,accel=kvm in a Power9 host, a cryptic error will be shown: qemu-system-ppc64: Register sync failed... If you're using kvm-hv.ko, only "-cpu host" is possible qemu-system-ppc64: kvm_init_vcpu: kvm_arch_init_vcpu failed (0): Invalid argument Appending '-cpu host' will throw another error: qemu-system-ppc64: invalid chip model 'host' for powernv9 machine The root cause is that in IBM PowerPC we have different specs for the bare-metal and the guests. The bare-metal follows OPAL, the guests follow PAPR. The kernel KVM modules presented in the ppc kernels implements PAPR. This means that we can't use KVM accel when using the powernv machine, which is the emulation of the bare-metal host. All that said, let's give a more informative error in this case. Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> --- hw/ppc/pnv.c | 5 +++++ 1 file changed, 5 insertions(+)