Ensure that we stop the guest whenever we face a fatal or unknown exit
reason. If we stop, we also have to enforce a cpu loop exit.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
I get a warning on a signed comparison with an unsigned variable, so
let's make the variable signed and be happy.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Edgar E. Iglesias <edgar@axis.com>
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>
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>
When running with --enable-io-thread the timer we have doesn't help,
because it doesn't wake up the CPU thread. So instead we need to
actually kick it.
While at it I refined the logic a bit to not dumbly trigger a timer
every 500ms, but rather do it more often after an interrupt got injected.
If there's no level based interrupt to be expected, we don't need the
timer anyways.
This makes qemu-system-ppc with --enable-io-thread work when using KVM.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Continue vcpu execution in case emulation failure happened while vcpu
was in userspace. In this case #UD will be injected into the guest
allowing guest OS to kill offending process and continue.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This grand cleanup drops all reset and vmsave/load related
synchronization points in favor of four(!) generic hooks:
- cpu_synchronize_all_states in qemu_savevm_state_complete
(initial sync from kernel before vmsave)
- cpu_synchronize_all_post_init in qemu_loadvm_state
(writeback after vmload)
- cpu_synchronize_all_post_init in main after machine init
- cpu_synchronize_all_post_reset in qemu_system_reset
(writeback after system reset)
These writeback points + the existing one of VCPU exec after
cpu_synchronize_state map on three levels of writeback:
- KVM_PUT_RUNTIME_STATE (during runtime, other VCPUs continue to run)
- KVM_PUT_RESET_STATE (on synchronous system reset, all VCPUs stopped)
- KVM_PUT_FULL_STATE (on init or vmload, all VCPUs stopped as well)
This level is passed to the arch-specific VCPU state writing function
that will decide which concrete substates need to be written. That way,
no writer of load, save or reset functions that interact with in-kernel
KVM states will ever have to worry about synchronization again. That
also means that a lot of reasons for races, segfaults and deadlocks are
eliminated.
cpu_synchronize_state remains untouched, just as Anthony suggested. We
continue to need it before reading or writing of VCPU states that are
also tracked by in-kernel KVM subsystems.
Consequently, this patch removes many cpu_synchronize_state calls that
are now redundant, just like remaining explicit register syncs.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
For some odd reason we sometimes hang inside KVM forever. I'd guess it's
a race condition where we actually have a level triggered interrupt, but
the infrastructure can't expose that yet, so the guest ACKs it, goes to
sleep and never gets notified that there's still an interrupt pending.
As a quick workaround, let's just wake up every 500 ms. That way we can
assure that we're always reinjecting interrupts in time.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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>
My segment sync patch broke compilation on PPC32, because it was trying to
sync the SLB even though ppc32 CPUs don't have an SLB.
So let's only sync it when we're on a PP64 one!
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
While x86 only needs to sync cr0-4 to know all about its MMU state and enable
qemu to resolve virtual to physical addresses, we need to sync all of the
segment registers on PPC to know which mapping we're in.
So let's grab the segment register contents to be able to use the "x" monitor
command and also enable the gdbstub to resolve virtual addresses.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
440 and desktop codes use different input constants for interrupt indication.
Let's use the respective ones for KVM.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
We need to tell the kernel about some initial CPU state we don't have yet,
so let's use the "sregs" IOCTL for that and simply put the Processor Version
Register in there.
Now the kernel knows which guest CPU to virtualize.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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
