Commit graph

166 commits

Author SHA1 Message Date
Shameer Kolothum
c8f2eb5d41 arm/kvm: Enable support for KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE
Now that we have Eager Page Split support added for ARM in the kernel,
enable it in Qemu. This adds,
 -eager-split-size to -accel sub-options to set the eager page split chunk size.
 -enable KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE.

The chunk size specifies how many pages to break at a time, using a
single allocation. Bigger the chunk size, more pages need to be
allocated ahead of time.

Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Message-id: 20230905091246.1931-1-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2023-09-08 16:41:36 +01:00
Anton Johansson
b67be03e3a accel/kvm: Widen pc/saved_insn for kvm_sw_breakpoint
Widens the pc and saved_insn fields of kvm_sw_breakpoint from
target_ulong to vaddr. The pc argument of kvm_find_sw_breakpoint is also
widened to match.

Signed-off-by: Anton Johansson <anjo@rev.ng>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230807155706.9580-2-anjo@rev.ng>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-24 11:21:22 -07:00
Akihiko Odaki
43a5e377f4 accel/kvm: Make kvm_dirty_ring_reaper_init() void
The returned value was always zero and had no meaning.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-id: 20230727073134.134102-7-akihiko.odaki@daynix.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2023-08-22 17:31:04 +01:00
Akihiko Odaki
4625742cd2 accel/kvm: Free as when an error occurred
An error may occur after s->as is allocated, for example if the
KVM_CREATE_VM ioctl call fails.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-id: 20230727073134.134102-6-akihiko.odaki@daynix.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: tweaked commit message]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2023-08-22 17:31:04 +01:00
Akihiko Odaki
bc3e41a0e8 accel/kvm: Use negative KVM type for error propagation
On MIPS, kvm_arch_get_default_type() returns a negative value when an
error occurred so handle the case. Also, let other machines return
negative values when errors occur and declare returning a negative
value as the correct way to propagate an error that happened when
determining KVM type.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-id: 20230727073134.134102-5-akihiko.odaki@daynix.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2023-08-22 17:31:03 +01:00
Akihiko Odaki
5e0d65909c kvm: Introduce kvm_arch_get_default_type hook
kvm_arch_get_default_type() returns the default KVM type. This hook is
particularly useful to derive a KVM type that is valid for "none"
machine model, which is used by libvirt to probe the availability of
KVM.

For MIPS, the existing mips_kvm_type() is reused. This function ensures
the availability of VZ which is mandatory to use KVM on the current
QEMU.

Cc: qemu-stable@nongnu.org
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-id: 20230727073134.134102-2-akihiko.odaki@daynix.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: added doc comment for new function]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2023-08-22 17:31:02 +01:00
Gavin Shan
fe6bda58e0 kvm: Fix crash due to access uninitialized kvm_state
Runs into core dump on arm64 and the backtrace extracted from the
core dump is shown as below. It's caused by accessing uninitialized
@kvm_state in kvm_flush_coalesced_mmio_buffer() due to commit 176d073029
("hw/arm/virt: Use machine_memory_devices_init()"), where the machine's
memory region is added earlier than before.

    main
    qemu_init
    configure_accelerators
    qemu_opts_foreach
    do_configure_accelerator
    accel_init_machine
    kvm_init
    virt_kvm_type
    virt_set_memmap
    machine_memory_devices_init
    memory_region_add_subregion
    memory_region_add_subregion_common
    memory_region_update_container_subregions
    memory_region_transaction_begin
    qemu_flush_coalesced_mmio_buffer
    kvm_flush_coalesced_mmio_buffer

Fix it by bailing early in kvm_flush_coalesced_mmio_buffer() on the
uninitialized @kvm_state. With this applied, no crash is observed on
arm64.

Fixes: 176d073029 ("hw/arm/virt: Use machine_memory_devices_init()")
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20230731125946.2038742-1-gshan@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2023-07-31 14:19:43 +01:00
Isaku Yamahata
14a868c626 exec/memory: Add symbol for the min value of memory listener priority
Add MEMORY_LISTNER_PRIORITY_MIN for the symbolic value for the min value of
the memory listener instead of the hard-coded magic value 0.  Add explicit
initialization.

No functional change intended.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <29f88477fe82eb774bcfcae7f65ea21995f865f2.1687279702.git.isaku.yamahata@intel.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2023-06-28 14:27:59 +02:00
Isaku Yamahata
8be0461d37 exec/memory: Add symbol for memory listener priority for device backend
Add MEMORY_LISTENER_PRIORITY_DEV_BACKEND for the symbolic value
for memory listener to replace the hard-coded value 10 for the
device backend.

No functional change intended.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <8314d91688030d7004e96958f12e2c83fb889245.1687279702.git.isaku.yamahata@intel.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2023-06-28 14:27:59 +02:00
Isaku Yamahata
5369a36c4f exec/memory: Add symbolic value for memory listener priority for accel
Add MEMORY_LISTNER_PRIORITY_ACCEL for the symbolic value for the memory
listener to replace the hard-coded value 10 for accel.

No functional change intended.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <feebe423becc6e2aa375f59f6abce9a85bc15abb.1687279702.git.isaku.yamahata@intel.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2023-06-28 14:27:59 +02:00
Marcelo Tosatti
3b6f485275 kvm: reuse per-vcpu stats fd to avoid vcpu interruption
A regression has been detected in latency testing of KVM guests.
More specifically, it was observed that the cyclictest
numbers inside of an isolated vcpu (running on isolated pcpu) are:

Where a maximum of 50us is acceptable.

The implementation of KVM_GET_STATS_FD uses run_on_cpu to query
per vcpu statistics, which interrupts the vcpu (and is unnecessary).

To fix this, open the per vcpu stats fd on vcpu initialization,
and read from that fd from QEMU's main thread.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-06-26 10:23:01 +02:00
Gavin Shan
856e23a0fb kvm: Enable dirty ring for arm64
arm64 has different capability from x86 to enable the dirty ring, which
is KVM_CAP_DIRTY_LOG_RING_ACQ_REL. Besides, arm64 also needs the backup
bitmap extension (KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP) when 'kvm-arm-gicv3'
or 'arm-its-kvm' device is enabled. Here the extension is always enabled
and the unnecessary overhead to do the last stage of dirty log synchronization
when those two devices aren't used is introduced, but the overhead should
be very small and acceptable. The benefit is cover future cases where those
two devices are used without modifying the code.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <20230509022122.20888-5-gshan@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:51 +02:00
Gavin Shan
3794cb9485 kvm: Add helper kvm_dirty_ring_init()
Due to multiple capabilities associated with the dirty ring for different
architectures: KVM_CAP_DIRTY_{LOG_RING, LOG_RING_ACQ_REL} for x86 and
arm64 separately. There will be more to be done in order to support the
dirty ring for arm64.

Lets add helper kvm_dirty_ring_init() to enable the dirty ring. With this,
the code looks a bit clean.

No functional change intended.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
Message-Id: <20230509022122.20888-4-gshan@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:50 +02:00
Gavin Shan
b20cc77692 kvm: Synchronize the backup bitmap in the last stage
In the last stage of live migration or memory slot removal, the
backup bitmap needs to be synchronized when it has been enabled.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
Message-Id: <20230509022122.20888-3-gshan@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:50 +02:00
Gavin Shan
1e493be587 migration: Add last stage indicator to global dirty log
The global dirty log synchronization is used when KVM and dirty ring
are enabled. There is a particularity for ARM64 where the backup
bitmap is used to track dirty pages in non-running-vcpu situations.
It means the dirty ring works with the combination of ring buffer
and backup bitmap. The dirty bits in the backup bitmap needs to
collected in the last stage of live migration.

In order to identify the last stage of live migration and pass it
down, an extra parameter is added to the relevant functions and
callbacks. This last stage indicator isn't used until the dirty
ring is enabled in the subsequent patches.

No functional change intended.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
Message-Id: <20230509022122.20888-2-gshan@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-05-18 08:53:50 +02:00
Peter Xu
56adee407f kvm: dirty-ring: Fix race with vcpu creation
It's possible that we want to reap a dirty ring on a vcpu that is during
creation, because the vcpu is put onto list (CPU_FOREACH visible) before
initialization of the structures.  In this case:

qemu_init_vcpu
    x86_cpu_realizefn
        cpu_exec_realizefn
            cpu_list_add      <---- can be probed by CPU_FOREACH
        qemu_init_vcpu
            cpus_accel->create_vcpu_thread(cpu);
                kvm_init_vcpu
                    map kvm_dirty_gfns  <--- kvm_dirty_gfns valid

Don't try to reap dirty ring on vcpus during creation or it'll crash.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2124756
Reported-by: Xiaohui Li <xiaohli@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1d14deb6684bcb7de1c9633c5bd21113988cc698.1676563222.git.huangy81@chinatelecom.cn>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-04-04 18:46:46 +02:00
David Woodhouse
e16aff4cc2 kvm/i386: Add xen-evtchn-max-pirq property
The default number of PIRQs is set to 256 to avoid issues with 32-bit MSI
devices. Allow it to be increased if the user desires.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01 09:09:22 +00:00
David Woodhouse
6f43f2ee49 kvm/i386: Add xen-gnttab-max-frames property
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01 09:07:52 +00:00
David Woodhouse
61491cf441 i386/kvm: Add xen-version KVM accelerator property and init KVM Xen support
This just initializes the basic Xen support in KVM for now. Only permitted
on TYPE_PC_MACHINE because that's where the sysbus devices for Xen heap
overlay, event channel, grant tables and other stuff will exist. There's
no point having the basic hypercall support if nothing else works.

Provide sysemu/kvm_xen.h and a kvm_xen_get_caps() which will be used
later by support devices.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01 08:22:49 +00:00
Philippe Mathieu-Daudé
2459d4209f accel/kvm: Silent -Wmissing-field-initializers warning
Silent when compiling with -Wextra:

  ../accel/kvm/kvm-all.c:2291:17: warning: missing field 'num' initializer [-Wmissing-field-initializers]
        { NULL, }
                ^

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20221220143532.24958-3-philmd@linaro.org>
2023-02-27 22:29:01 +01:00
Philippe Mathieu-Daudé
55b5b8e928 gdbstub: Use vaddr type for generic insert/remove_breakpoint() API
Both insert/remove_breakpoint() handlers are used in system and
user emulation. We can not use the 'hwaddr' type on user emulation,
we have to use 'vaddr' which is defined as "wide enough to contain
any #target_ulong virtual address".

gdbstub.c doesn't require to include "exec/hwaddr.h" anymore.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20221216215519.5522-4-philmd@linaro.org>
2023-02-27 22:29:01 +01:00
Markus Armbruster
aa09b3d5f8 stats: Move QMP commands from monitor/ to stats/
This moves these commands from MAINTAINERS section "QMP" to new
section "Stats".  Status is Orphan.  Volunteers welcome!

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230124121946.1139465-23-armbru@redhat.com>
2023-02-04 07:56:54 +01:00
David Hildenbrand
f39b7d2b96 kvm: Atomic memslot updates
If we update an existing memslot (e.g., resize, split), we temporarily
remove the memslot to re-add it immediately afterwards. These updates
are not atomic, especially not for KVM VCPU threads, such that we can
get spurious faults.

Let's inhibit most KVM ioctls while performing relevant updates, such
that we can perform the update just as if it would happen atomically
without additional kernel support.

We capture the add/del changes and apply them in the notifier commit
stage instead. There, we can check for overlaps and perform the ioctl
inhibiting only if really required (-> overlap).

To keep things simple we don't perform additional checks that wouldn't
actually result in an overlap -- such as !RAM memory regions in some
cases (see kvm_set_phys_mem()).

To minimize cache-line bouncing, use a separate indicator
(in_ioctl_lock) per CPU.  Also, make sure to hold the kvm_slots_lock
while performing both actions (removing+re-adding).

We have to wait until all IOCTLs were exited and block new ones from
getting executed.

This approach cannot result in a deadlock as long as the inhibitor does
not hold any locks that might hinder an IOCTL from getting finished and
exited - something fairly unusual. The inhibitor will always hold the BQL.

AFAIKs, one possible candidate would be userfaultfd. If a page cannot be
placed (e.g., during postcopy), because we're waiting for a lock, or if the
userfaultfd thread cannot process a fault, because it is waiting for a
lock, there could be a deadlock. However, the BQL is not applicable here,
because any other guest memory access while holding the BQL would already
result in a deadlock.

Nothing else in the kernel should block forever and wait for userspace
intervention.

Note: pause_all_vcpus()/resume_all_vcpus() or
start_exclusive()/end_exclusive() cannot be used, as they either drop
the BQL or require to be called without the BQL - something inhibitors
cannot handle. We need a low-level locking mechanism that is
deadlock-free even when not releasing the BQL.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Tested-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20221111154758.1372674-4-eesposit@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-11 09:59:39 +01:00
Emanuele Giuseppe Esposito
a27dd2de68 KVM: keep track of running ioctls
Using the new accel-blocker API, mark where ioctls are being called
in KVM. Next, we will implement the critical section that will take
care of performing memslots modifications atomically, therefore
preventing any new ioctl from running and allowing the running ones
to finish.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20221111154758.1372674-3-eesposit@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-11 09:59:39 +01:00
Markus Armbruster
d1c81c3496 qapi: Use returned bool to check for failure (again)
Commit 012d4c96e2 changed the visitor functions taking Error ** to
return bool instead of void, and the commits following it used the new
return value to simplify error checking.  Since then a few more uses
in need of the same treatment crept in.  Do that.  All pretty
mechanical except for

* balloon_stats_get_all()

  This is basically the same transformation commit 012d4c96e2 applied
  to the virtual walk example in include/qapi/visitor.h.

* set_max_queue_size()

  Additionally replace "goto end of function" by return.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221121085054.683122-10-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2022-12-14 16:19:35 +01:00
Chenyi Qiang
e2e69f6bb9 i386: add notify VM exit support
There are cases that malicious virtual machine can cause CPU stuck (due
to event windows don't open up), e.g., infinite loop in microcode when
nested #AC (CVE-2015-5307). No event window means no event (NMI, SMI and
IRQ) can be delivered. It leads the CPU to be unavailable to host or
other VMs. Notify VM exit is introduced to mitigate such kind of
attacks, which will generate a VM exit if no event window occurs in VM
non-root mode for a specified amount of time (notify window).

A new KVM capability KVM_CAP_X86_NOTIFY_VMEXIT is exposed to user space
so that the user can query the capability and set the expected notify
window when creating VMs. The format of the argument when enabling this
capability is as follows:
  Bit 63:32 - notify window specified in qemu command
  Bit 31:0  - some flags (e.g. KVM_X86_NOTIFY_VMEXIT_ENABLED is set to
              enable the feature.)

Users can configure the feature by a new (x86 only) accel property:
    qemu -accel kvm,notify-vmexit=run|internal-error|disable,notify-window=n

The default option of notify-vmexit is run, which will enable the
capability and do nothing if the exit happens. The internal-error option
raises a KVM internal error if it happens. The disable option does not
enable the capability. The default value of notify-window is 0. It is valid
only when notify-vmexit is not disabled. The valid range of notify-window
is non-negative. It is even safe to set it to zero since there's an
internal hardware threshold to be added to ensure no false positive.

Because a notify VM exit may happen with VM_CONTEXT_INVALID set in exit
qualification (no cases are anticipated that would set this bit), which
means VM context is corrupted. It would be reflected in the flags of
KVM_EXIT_NOTIFY exit. If KVM_NOTIFY_CONTEXT_INVALID bit is set, raise a KVM
internal error unconditionally.

Acked-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Message-Id: <20220929072014.20705-5-chenyi.qiang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-11 09:36:00 +02:00
Chenyi Qiang
5f8a6bce1f kvm: expose struct KVMState
Expose struct KVMState out of kvm-all.c so that the field of struct
KVMState can be accessed when defining target-specific accelerator
properties.

Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Message-Id: <20220929072014.20705-4-chenyi.qiang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-11 09:36:00 +02:00
Paolo Bonzini
3dba0a335c kvm: allow target-specific accelerator properties
Several hypervisor capabilities in KVM are target-specific.  When exposed
to QEMU users as accelerator properties (i.e. -accel kvm,prop=value), they
should not be available for all targets.

Add a hook for targets to add their own properties to -accel kvm, for
now no such property is defined.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220929072014.20705-3-chenyi.qiang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-10 09:23:16 +02:00
Alex Bennée
c7f1c53735 accel/kvm: move kvm_update_guest_debug to inline stub
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220929114231.583801-47-alex.bennee@linaro.org>
2022-10-06 11:53:41 +01:00
Alex Bennée
a48e7d9e52 gdbstub: move guest debug support check to ops
This removes the final hard coding of kvm_enabled() in gdbstub and
moves the check to an AccelOps.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Mads Ynddal <mads@ynddal.dk>
Message-Id: <20220929114231.583801-46-alex.bennee@linaro.org>
2022-10-06 11:53:41 +01:00
Alex Bennée
ae7467b1ac gdbstub: move breakpoint logic to accel ops
As HW virtualization requires specific support to handle breakpoints
lets push out special casing out of the core gdbstub code and into
AccelOpsClass. This will make it easier to add other accelerator
support and reduces some of the stub shenanigans.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Mads Ynddal <mads@ynddal.dk>
Message-Id: <20220929114231.583801-45-alex.bennee@linaro.org>
2022-10-06 11:53:41 +01:00
Alex Bennée
3b7a93880a gdbstub: move sstep flags probing into AccelClass
The support of single-stepping is very much dependent on support from
the accelerator we are using. To avoid special casing in gdbstub move
the probing out to an AccelClass function so future accelerators can
put their code there.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Mads Ynddal <mads@ynddal.dk>
Message-Id: <20220929114231.583801-44-alex.bennee@linaro.org>
2022-10-06 11:53:41 +01:00
Paolo Bonzini
21adec30f6 kvm: fix memory leak on failure to read stats descriptors
Reported by Coverity as CID 1490142.  Since the size is constant and the
lifetime is the same as the StatsDescriptors struct, embed the struct
directly instead of using a separate allocation.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-09-18 09:17:40 +02:00
Paolo Bonzini
52281c6d11 KVM: use store-release to mark dirty pages as harvested
The following scenario can happen if QEMU sets more RESET flags while
the KVM_RESET_DIRTY_RINGS ioctl is ongoing on another host CPU:

    CPU0                     CPU1               CPU2
    ------------------------ ------------------ ------------------------
                                                fill gfn0
                                                store-rel flags for gfn0
                                                fill gfn1
                                                store-rel flags for gfn1
    load-acq flags for gfn0
    set RESET for gfn0
    load-acq flags for gfn1
    set RESET for gfn1
    do ioctl! ----------->
                             ioctl(RESET_RINGS)
                                                fill gfn2
                                                store-rel flags for gfn2
    load-acq flags for gfn2
    set RESET for gfn2
                             process gfn0
                             process gfn1
                             process gfn2
    do ioctl!
    etc.

The three load-acquire in CPU0 synchronize with the three store-release
in CPU2, but CPU0 and CPU1 are only synchronized up to gfn1 and CPU1
may miss gfn2's fields other than flags.

The kernel must be able to cope with invalid values of the fields, and
userspace *will* invoke the ioctl once more.  However, once the RESET flag
is cleared on gfn2, it is lost forever, therefore in the above scenario
CPU1 must read the correct value of gfn2's fields.

Therefore RESET must be set with a store-release, that will synchronize
with KVM's load-acquire in CPU1.

Cc: Gavin Shan <gshan@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-09-18 09:17:40 +02:00
Paolo Bonzini
4802bf910e KVM: dirty ring: add missing memory barrier
The KVM_DIRTY_GFN_F_DIRTY flag ensures that the entry is valid.  If
the read of the fields are not ordered after the read of the flag,
QEMU might see stale values.

Cc: Gavin Shan <gshan@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-09-01 08:37:04 +02:00
Paolo Bonzini
a9197ad210 kvm: fix segfault with query-stats-schemas and -M none
-M none creates a guest without a vCPU, causing the following error:

$ ./qemu-system-x86_64 -qmp stdio -M none -accel kvm
{execute:qmp_capabilities}
{"return": {}}
{execute: query-stats-schemas}
Segmentation fault (core dumped)

Fix it by not querying the vCPU stats if first_cpu is NULL.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-08-18 14:08:24 +02:00
Cornelia Huck
47c182fe8b kvm: don't use perror() without useful errno
perror() is designed to append the decoded errno value to a
string. This, however, only makes sense if we called something that
actually sets errno prior to that.

For the callers that check for split irqchip support that is not the
case, and we end up with confusing error messages that end in
"success". Use error_report() instead.

Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20220728142446.438177-1-cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-07-29 00:15:02 +02:00
Peter Maydell
d12dd9c7ee accel/kvm: Avoid Coverity warning in query_stats()
Coverity complains that there is a codepath in the query_stats()
function where it can leak the memory pointed to by stats_list.  This
can only happen if the caller passes something other than
STATS_TARGET_VM or STATS_TARGET_VCPU as the 'target', which no
callsite does.  Enforce this assumption using g_assert_not_reached(),
so that if we have a future bug we hit the assert rather than
silently leaking memory.

Resolves: Coverity CID 1490140
Fixes: cc01a3f4ca ("kvm: Support for querying fd-based stats")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220719134853.327059-1-peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-07-22 19:01:44 +02:00
Peter Maydell
5288bee45f * Boolean statistics for KVM
* Fix build on Haiku
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Merge tag 'for-upstream' of https://gitlab.com/bonzini/qemu into staging

* Boolean statistics for KVM
* Fix build on Haiku

# gpg: Signature made Tue 19 Jul 2022 10:32:34 BST
# gpg:                using RSA key F13338574B662389866C7682BFFBD25F78C7AE83
# gpg:                issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* tag 'for-upstream' of https://gitlab.com/bonzini/qemu:
  util: Fix broken build on Haiku
  kvm: add support for boolean statistics
  monitor: add support for boolean statistics

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-07-21 11:13:01 +01:00
Hyman Huang(黄勇)
baa609832e softmmu/dirtylimit: Implement virtual CPU throttle
Setup a negative feedback system when vCPU thread
handling KVM_EXIT_DIRTY_RING_FULL exit by introducing
throttle_us_per_full field in struct CPUState. Sleep
throttle_us_per_full microseconds to throttle vCPU
if dirtylimit is in service.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <977e808e03a1cef5151cae75984658b6821be618.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-07-20 12:15:08 +01:00
Hyman Huang(黄勇)
4a06a7cc05 accel/kvm/kvm-all: Introduce kvm_dirty_ring_size function
Introduce kvm_dirty_ring_size util function to help calculate
dirty ring ful time.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Acked-by: Peter Xu <peterx@redhat.com>
Message-Id: <f9ce1f550bfc0e3a1f711e17b1dbc8f701700e56.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-07-20 12:15:08 +01:00
Hyman Huang(黄勇)
1667e2b97b accel/kvm/kvm-all: Refactor per-vcpu dirty ring reaping
Add a non-required argument 'CPUState' to kvm_dirty_ring_reap so
that it can cover single vcpu dirty-ring-reaping scenario.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <c32001242875e83b0d9f78f396fe2dcd380ba9e8.1656177590.git.huangy81@chinatelecom.cn>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-07-20 12:15:08 +01:00
Paolo Bonzini
105bb7cdbe kvm: add support for boolean statistics
The next version of Linux will introduce boolean statistics, which
can only have 0 or 1 values.  Convert them to the new QAPI fields
added in the previous commit.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-07-18 18:51:32 +02:00
Miaoqian Lin
f696b74b15 accel: kvm: Fix memory leak in find_stats_descriptors
This function doesn't release descriptors in one error path,
result in memory leak. Call g_free() to release it.

Fixes: cc01a3f4ca ("kvm: Support for querying fd-based stats")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Message-Id: <20220624063159.57411-1-linmq006@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-07-08 11:03:36 +02:00
Paolo Bonzini
cf7405bc02 qmp: add filtering of statistics by name
Allow retrieving only a subset of statistics.  This can be useful
for example in order to plot a subset of the statistics many times
a second: KVM publishes ~40 statistics for each vCPU on x86; retrieving
and serializing all of them would be useless.

Another use will be in HMP in the following patch; implementing the
filter in the backend is easy enough that it was deemed okay to make
this a public interface.

Example:

{ "execute": "query-stats",
  "arguments": {
    "target": "vcpu",
    "vcpus": [ "/machine/unattached/device[2]",
               "/machine/unattached/device[4]" ],
    "providers": [
      { "provider": "kvm",
        "names": [ "l1d_flush", "exits" ] } } }

{ "return": {
    "vcpus": [
      { "path": "/machine/unattached/device[2]"
        "providers": [
          { "provider": "kvm",
            "stats": [ { "name": "l1d_flush", "value": 41213 },
                       { "name": "exits", "value": 74291 } ] } ] },
      { "path": "/machine/unattached/device[4]"
        "providers": [
          { "provider": "kvm",
            "stats": [ { "name": "l1d_flush", "value": 16132 },
                       { "name": "exits", "value": 57922 } ] } ] } ] } }

Extracted from a patch by Mark Kanda.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-14 16:50:30 +02:00
Paolo Bonzini
068cc51d42 qmp: add filtering of statistics by provider
Allow retrieving the statistics from a specific provider only.
This can be used in the future by HMP commands such as "info
sync-profile" or "info profile".  The next patch also adds
filter-by-provider capabilities to the HMP equivalent of
query-stats, "info stats".

Example:

{ "execute": "query-stats",
  "arguments": {
    "target": "vm",
    "providers": [
      { "provider": "kvm" } ] } }

The QAPI is a bit more verbose than just a list of StatsProvider,
so that it can be subsequently extended with filtering of statistics
by name.

If a provider is specified more than once in the filter, each request
will be included separately in the output.

Extracted from a patch by Mark Kanda.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-14 16:50:30 +02:00
Paolo Bonzini
467ef823d8 qmp: add filtering of statistics by target vCPU
Introduce a simple filtering of statistics, that allows to retrieve
statistics for a subset of the guest vCPUs.  This will be used for
example by the HMP monitor, in order to retrieve the statistics
for the currently selected CPU.

Example:
{ "execute": "query-stats",
  "arguments": {
    "target": "vcpu",
    "vcpus": [ "/machine/unattached/device[2]",
               "/machine/unattached/device[4]" ] } }

Extracted from a patch by Mark Kanda.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-14 16:50:30 +02:00
Mark Kanda
cc01a3f4ca kvm: Support for querying fd-based stats
Add support for querying fd-based KVM stats - as introduced by Linux kernel
commit:

cb082bfab59a ("KVM: stats: Add fd-based API to read binary stats data")

This allows the user to analyze the behavior of the VM without access
to debugfs.

Signed-off-by: Mark Kanda <mark.kanda@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-14 16:50:30 +02:00
Peter Maydell
9323e79f10 Fix 'writeable' typos
We have about 30 instances of the typo/variant spelling 'writeable',
and over 500 of the more common 'writable'.  Standardize on the
latter.

Change produced with:

  sed -i -e 's/\([Ww][Rr][Ii][Tt]\)[Ee]\([Aa][Bb][Ll][Ee]\)/\1\2/g' $(git grep -il writeable)

and then hand-undoing the instance in linux-headers/linux/kvm.h.

Most of these changes are in comments or documentation; the
exceptions are:
 * a local variable in accel/hvf/hvf-accel-ops.c
 * a local variable in accel/kvm/kvm-all.c
 * the PMCR_WRITABLE_MASK macro in target/arm/internals.h
 * the EPT_VIOLATION_GPA_WRITABLE macro in target/i386/hvf/vmcs.h
   (which is never used anywhere)
 * the AR_TYPE_WRITABLE_MASK macro in target/i386/hvf/vmx.h
   (which is never used anywhere)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Message-id: 20220505095015.2714666-1-peter.maydell@linaro.org
2022-06-08 19:38:47 +01:00
Marc-André Lureau
8e3b0cbb72 Replace qemu_real_host_page variables with inlined functions
Replace the global variables with inlined helper functions. getpagesize() is very
likely annotated with a "const" function attribute (at least with glibc), and thus
optimization should apply even better.

This avoids the need for a constructor initialization too.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-12-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06 10:50:38 +02:00