Commit Graph

5 Commits

Author SHA1 Message Date
Alexander Graf fc87e18530 KVM: PPC: Add level based interrupt logic
KVM on PowerPC used to have completely broken interrupt logic. Usually,
interrupts work by having a PIC that pulls a line up/down, so the CPU knows
that an interrupt is active. This line stays active until some action is
done to the PIC to release the line.

On KVM for PPC, we just checked if there was an interrupt pending and pulled
a line in the kernel module. We never released it though, hoping that kernel
space would just declare an interrupt as released when injected - which is
wrong.

To fix this, we need to completely redesign the interrupt injection logic.
Whenever an interrupt line gets triggered, we need to notify kernel space
that the line is up. Whenever it gets released, we do the same. This way
we can assure that the interrupt state is always known to kernel space.

This fixes random stalls in KVM guests on PowerPC that were waiting for
an interrupt while everyone else thought they received it already.

Signed-off-by: Alexander Graf <agraf@suse.de>
2010-09-05 11:50:48 +02:00
Alexander Graf 45024f094c PPC: Add PV hypercall transport through fw_cfg
On KVM for PPC we need to tell the guest which instructions to use when
doing a hypercall. The clean way to do this is to go through an ioctl
from userspace and passing it on to the guest using the device tree.

So let's do the qemu part here: read out the hypercall and pass it on
to the guest's fw_cfg so openBIOS can read it out and expose it again.

Signed-off-by: Alexander Graf <agraf@suse.de>
2010-08-26 18:13:38 +02:00
Alexander Graf dc333cd609 PPC: tell the guest about the time base frequency
Our guest systems need to know by how much the timebase increases every second,
so there usually is a "timebase-frequency" property in the cpu leaf of the
device tree.

This property is missing in OpenBIOS.

With qemu, Linux's fallback timebase speed and qemu's internal timebase speed
match up. With KVM, that is no longer true. The guest is running at the same
timebase speed as the host.

This leads to massive timing problems. On my test machine, a "sleep 2" takes
about 14 seconds with KVM enabled.

This patch exports the timebase frequency to OpenBIOS, so it can then put them
into the device tree.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-02-14 16:10:54 +02:00
aurel32 ea23bc2022 kvm/powerpc: extern one function for MPC85xx code use
Signed-off-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6427 c046a42c-6fe2-441c-8c8c-71466251a162
2009-01-24 16:35:56 +00:00
aurel32 d76d16501e target-ppc: Enable KVM for ppcemb.
Implement hooks called by generic KVM code.

Also add code that will copy the host's CPU and timebase frequencies to the
guest, which is necessary on KVM because the guest can directly access the
timebase.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Acked-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6065 c046a42c-6fe2-441c-8c8c-71466251a162
2008-12-16 10:43:58 +00:00