Commit Graph

132 Commits

Author SHA1 Message Date
Jan Kiszka
8d2ba1fb9c kvm: Rework VCPU synchronization
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>
2009-06-29 14:18:07 -05:00
Jan Kiszka
8c14c17395 kvm: Fix IRQ injection into full queue
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>
2009-06-16 15:36:47 -05:00
Jan Kiszka
168ccc11c3 kvm: Improve upgrade notes when facing unsupported kernels
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>
2009-06-07 16:40:22 +03:00
Jan Kiszka
f8d926e9cd kvm: x86: Save/restore KVM-specific CPU states
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>
2009-05-22 10:50:34 -05:00
Jan Kiszka
d33a1810d7 kvm: Rework VCPU reset
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>
2009-05-22 10:50:34 -05:00
Jan Kiszka
151f7749f2 kvm: Rework dirty bitmap synchronization
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>
2009-05-22 10:50:33 -05:00
Jan Kiszka
62518b8b1d kvm: Fix dirty log temporary buffer size
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>
2009-05-22 10:50:33 -05:00
Jan Kiszka
4495d6a745 kvm: Introduce kvm_set_migration_log
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>
2009-05-22 10:50:33 -05:00
Jan Kiszka
e69917e29a kvm: Conditionally apply workaround for KVM slot handling bug
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>
2009-05-22 10:50:32 -05:00
Mark McLoughlin
9f8fd69460 kvm: add error message for when SMP is requested
Right now, if you try e.g. '-smp 2' you just get 'failed to
initialize KVM'.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
2009-05-20 09:24:23 -05:00
Anthony Liguori
ad7b8b3310 Introduce kvm_check_extension to check if KVM extensions are supported
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-08 15:42:42 -05:00
Jan Kiszka
6f0437e8de kvm: Avoid COW if KVM MMU is asynchronous
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>
2009-05-01 09:44:11 -05:00
Jan Kiszka
e6f4afe029 kvm: Relax aligment check of kvm_set_phys_mem
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>
2009-05-01 09:38:33 -05:00
aliguori
6152e2ae43 kvm: improve handling of overlapping slots (Jan Kiszka)
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
2009-04-17 14:26:33 +00:00
aliguori
d3f8d37fe2 kvm: Add sanity checks to slot management (Jan Kiszka)
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
2009-04-17 14:26:29 +00:00
aliguori
494ada4234 kvm: Cleanup unmap condition in kvm_set_phys_mem (Jan Kiszka)
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
2009-04-17 14:26:25 +00:00
pbrook
5579c7f37e Remove code phys_ram_base uses.
Signed-off-by: Paul Brook <paul@codesourcery.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7085 c046a42c-6fe2-441c-8c8c-71466251a162
2009-04-11 14:47:08 +00:00
aliguori
e22a25c936 Guest debugging support for KVM (Jan Kiszka)
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
2009-03-12 20:12:48 +00:00
aurel32
be214e6c05 Fix race condition on access to env->interrupt_request
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
2009-03-06 21:48:00 +00:00
aliguori
1eec614b36 toplevel: remove error handling from qemu_malloc() callers (Avi Kivity)
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
2009-02-05 22:06:18 +00:00
aurel32
a9c11522bb KVM: Silence unused s warning
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
2008-12-18 22:42:51 +00:00
aliguori
f5d6f51ba6 kvm: sync vcpu state during initialization (Hollis Blanchard)
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
2008-12-15 22:20:42 +00:00
aliguori
f65ed4c152 KVM: Coalesced MMIO support
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
2008-12-09 20:09:57 +00:00
aliguori
d85dc283fa Disable KVM support if the kernel modules have broken memory slot handling
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
2008-12-09 19:59:09 +00:00
aliguori
bd3220870f Add virtio-balloon support
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
2008-12-04 20:33:06 +00:00
aliguori
5832d1f2f5 kvm: Introduce kvm logging interface (Glauber Costa)
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
2008-11-24 19:36:26 +00:00
aliguori
34fc643fd3 Make KVMSlot a real structure
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
2008-11-19 17:41:58 +00:00
aliguori
a3d6841ff8 kvm: de-register mem region for MMIO (Glauber Costa)
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
2008-11-19 15:09:54 +00:00
aliguori
62d60e8cc4 Make KVM slot management more robust
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
2008-11-18 15:41:18 +00:00
aliguori
984b518147 Define kvm_ioctl in the same way as ioctl
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
2008-11-13 19:21:00 +00:00
aliguori
becfc39041 KVM: simplify kvm_cpu_exec hook
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
2008-11-10 15:55:14 +00:00
aliguori
053304480a Add missing files to KVM commit.
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
2008-11-05 16:29:27 +00:00