gwj / at91sam9263 · Commits

Dirty logs currently get written with native "long" size. On little endian
it doesn't matter if we use uint64_t instead though, because we'd still end
up using the right bytes.

On big endian, this does become a bigger problem, so we need to ensure that
kernel and userspace talk the same language, which means getting rid of "long"
and using a defined size instead.

So I decided to use 64 bit types at all times. This doesn't break existing
targets but will in conjunction with a patch I'll send to the KVM ML make
dirty logs work with 32 bit userspace on 64 kernel with big endian.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

KVM can have an in-kernel pit or irqchip. While we don't implement it
yet, having a way for test for it (that always returns zero) will allow us
to reuse code in qemu-kvm that tests for it.

Signed-off-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

on_vcpu is a qemu-kvm function that will make sure that a specific
piece of code will run on a requested cpu. We don't need that because
we're restricted to -smp 1 right now, but those days are likely to end soon.

So for the benefit of having qemu-kvm share more code with us, I'm
introducing our own version of on_vcpu(). Right now, we either run
a function on the current cpu, or abort the execution, because it would
mean something is seriously wrong.

As an example code, I "ported" kvm_update_guest_debug to use it,
with some slight differences from qemu-kvm.

This is probably 0.12 material

Signed-off-by: Glauber Costa <glommer@redhat.com>
CC: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Some KVM platforms don't support dirty logging yet, like IA64 and PPC,
so in order to still have screen updates on those, we need to fake it.

This patch just tells the getter function for dirty bitmaps, that all
pages within a slot are dirty when the slot has dirty logging enabled.

That way we can implement dirty logging on those platforms sometime when
it drags down performance, but share the rest of the code with dirty
logging capable platforms.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

This fixes a warning I stumbled across while compiling qemu on PPC64.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

This reverts commit 8217606e (and
updates later added users of qemu_register_reset), we solved the
problem it originally addressed less invasively.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

During startup and after reset we have to synchronize user space to the
in-kernel KVM state. Namely, we need to transfer the VCPU registers when
they change due to VCPU as well as APIC reset.

This patch refactors the required hooks so that kvm_init_vcpu registers
its own per-VCPU reset handler and adds a cpu_synchronize_state to the
APIC reset. That way we no longer depend on the new reset order (and can
drop this disliked interface again) and we can even drop a KVM hook in
main().

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

User space may only inject interrupts during kvm_arch_pre_run if
ready_for_interrupt_injection is set in kvm_run. But that field is
updated on exit from KVM_RUN, so we must ensure that we enter the
kernel after potentially queuing an interrupt, otherwise we risk to
loose one - like it happens with the current code against latest
kernel modules (since kvm-86) that started to queue only a single
interrupt.

Fix the problem by reordering kvm_cpu_exec.

Credits go to Gleb Natapov for analyzing the issue in details.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Users complained that it is not obvious what to do when kvm refuses to
build or run due to an unsupported host kernel, so let's improve the
hints.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

Save and restore all so far neglected KVM-specific CPU states. Handling
the TSC stabilizes migration in KVM mode. The interrupt_bitmap and
mp_state are currently unused, but will become relevant for in-kernel
irqchip support. By including proper saving/restoring already, we avoid
having to increment CPU_SAVE_VERSION later on once again.

v2:
 - initialize mp_state runnable (for the boot CPU)

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Use standard callback with highest order to synchronize VCPU on reset
after all device callbacks were execute. This allows to remove the
special kvm hook in qemu_system_reset.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Extend kvm_physical_sync_dirty_bitmap() so that is can sync across
multiple slots. Useful for updating the whole dirty log during
migration. Moreover, properly pass down errors the whole call chain.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

The buffer passed to KVM_GET_DIRTY_LOG requires one bit per page. Fix
the size calculation in kvm_physical_sync_dirty_bitmap accordingly,
avoiding allocation of extremly oversized buffers.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Introduce a global dirty logging flag that enforces logging for all
slots. This can be used by the live migration code to enable/disable
global logging withouth destroying the per-slot setting.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Only apply the workaround for broken slot joining in KVM when the
capability was not found that signals the corresponding fix existence.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Right now, if you try e.g. '-smp 2' you just get 'failed to
initialize KVM'.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

Avi Kivity wrote:
> Suggest wrapping in a function and hiding it deep inside kvm-all.c.
>

Done in v2:

---------->

If the KVM MMU is asynchronous (kernel does not support MMU_NOTIFIER),
we have to avoid COW for the guest memory. Otherwise we risk serious
breakage when guest pages change there physical locations due to COW
after fork. Seen when forking smbd during runtime via -smb.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

There is no need to reject an unaligned memory region registration if
the region will be I/O memory and it will not split an existing KVM
slot. This fixes KVM support on PPC.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

This reworks the slot management to handle more patterns of
cpu_register_physical_memory*, finally allowing to reset KVM guests (so
far address remapping on reset broke the slot management).

We could actually handle all possible ones without failing, but a KVM
kernel bug in older versions would force us to track all previous
fragmentations and maintain them (as that bug prevents registering
larger slots that overlap also deleted ones). To remain backward
compatible but avoid overly complicated workarounds, we apply a simpler
workaround that covers all currently used patterns.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7139 c046a42c-6fe2-441c-8c8c-71466251a162

Fail loudly if we run out of memory slot.

Make sure that dirty log start/stop works with consistent memory regions
by reporting invalid parameters. This reveals several inconsistencies in
the vga code, patch to fix them follows later in this series.

And, for simplicity reasons, also catch and report unaligned memory
regions passed to kvm_set_phys_mem (KVM works on page basis).

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7138 c046a42c-6fe2-441c-8c8c-71466251a162

Testing for TLB_MMIO on unmap makes no sense as A) that flag belongs to
CPUTLBEntry and not to io_memory slots or physical addresses and B) we
already use a different condition before mapping. So make this test
consistent.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7137 c046a42c-6fe2-441c-8c8c-71466251a162

Signed-off-by: Paul Brook <paul@codesourcery.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7085 c046a42c-6fe2-441c-8c8c-71466251a162

This is a backport of the guest debugging support for the KVM
accelerator that is now part of the KVM tree. It implements the reworked
KVM kernel API for guest debugging (KVM_CAP_SET_GUEST_DEBUG) which is
not yet part of any mainline kernel but will probably be 2.6.30 stuff.
So far supported is x86, but PPC is expected to catch up soon.

Core features are:
 - unlimited soft-breakpoints via code patching
 - hardware-assisted x86 breakpoints and watchpoints

Changes in this version:
 - use generic hook cpu_synchronize_state to transfer registers between
   user space and kvm
 - push kvm_sw_breakpoints into KVMState

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6825 c046a42c-6fe2-441c-8c8c-71466251a162

env->interrupt_request is accessed as the bit level from both main code
and signal handler, making a race condition possible even on CISC CPU.
This causes freeze of QEMU under high load when running the dyntick
clock.

The patch below move the bit corresponding to CPU_INTERRUPT_EXIT in a
separate variable, declared as volatile sig_atomic_t, so it should be
work even on RISC CPU.

We may want to move the cpu_interrupt(env, CPU_INTERRUPT_EXIT) case in
its own function and get rid of CPU_INTERRUPT_EXIT. That can be done
later, I wanted to keep the patch short for easier review.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6728 c046a42c-6fe2-441c-8c8c-71466251a162

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6531 c046a42c-6fe2-441c-8c8c-71466251a162

Move s under #ifdef to avoid compiler warning.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6086 c046a42c-6fe2-441c-8c8c-71466251a162

Currently on x86, qemu initializes CPUState but KVM ignores it and does its
own vcpu initialization. However, PowerPC KVM needs to be able to set the
initial register state to support the -kernel and -append options.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6060 c046a42c-6fe2-441c-8c8c-71466251a162

MMIO exits are more expensive in KVM or Xen than in QEMU because they 
involve, at least, privilege transitions.  However, MMIO write 
operations can be effectively batched if those writes do not have side 
effects.

Good examples of this include VGA pixel operations when in a planar 
mode.  As it turns out, we can get a nice boost in other areas too.  
Laurent mentioned a 9.7% performance boost in iperf with the coalesced 
MMIO changes for the e1000 when he originally posted this work for KVM.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5961 c046a42c-6fe2-441c-8c8c-71466251a162

Prior to kvm-80, memory slot deletion was broken in the KVM kernel 
modules.  In kvm-81, a new capability is introduced to signify that this
problem has been fixed.

Since we rely on being able to delete memory slots, refuse to work with 
any kernel module that does not have this capability present.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5960 c046a42c-6fe2-441c-8c8c-71466251a162

This adds a VirtIO based balloon driver.  It uses madvise() to actually balloon
the memory when possible.

Until 2.6.27, KVM forced memory pinning so we must disable ballooning unless the
kernel actually supports it when using KVM.  It's always safe when using TCG.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5874 c046a42c-6fe2-441c-8c8c-71466251a162

Introduce functions to control logging of memory regions.
We select regions based on its start address, a
guest_physical_addr (target_phys_addr_t, in qemu nomenclature).

The main user of this interface right now is VGA optimization
(a way of reducing the number of mmio exits).

Signed-off-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5792 c046a42c-6fe2-441c-8c8c-71466251a162

struct kvm_userspace_memory_region does not use QEMU friendly types to 
define memory slots.  This results in lots of ugly casting with warnings 
on 32-bit platforms.

This patch introduces a proper KVMSlot structure that uses QEMU types to
describe memory slots.  This eliminates many of the casts and isolates 
the type conversions to one spot.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5755 c046a42c-6fe2-441c-8c8c-71466251a162

Besides unassigned memory, we also don't care about MMIO.
So if we're giving an MMIO area that is already registered,
wipe it out.

Signed-off-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5753 c046a42c-6fe2-441c-8c8c-71466251a162

KVM keeps track of physical memory based on slots in the kernel.  The current
code that translates QEMU memory mappings to slots work but is not robust
in the fact of reregistering partial regions of memory.

This patch does the right thing for reregistering partial regions of memory.  It
also prevents QEMU from using KVM private slots.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5734 c046a42c-6fe2-441c-8c8c-71466251a162

The third argument to ioctl is a ... which allows any value to be passed.  In
practice, glibc always treats the argument as a void *.

Do the same thing for the kvm ioctls to keep things consistent with a
traditional ioctl.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5715 c046a42c-6fe2-441c-8c8c-71466251a162

We don't need to use cpu_loop_exit() because we never use the 
condition codes so everything can be folded into a single case.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5669 c046a42c-6fe2-441c-8c8c-71466251a162

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5629 c046a42c-6fe2-441c-8c8c-71466251a162