This allows passing the KVM device node to use as a file
descriptor via /dev/fdset/XX. Passing the device node to
use as a file descriptor allows running qemu unprivileged
even when the user running qemu is not in the kvm group
on distributions where access to /dev/kvm is gated behind
membership of the kvm group (as long as the process invoking
qemu is able to open /dev/kvm and passes the file descriptor
to qemu).
Signed-off-by: Daan De Meyer <daan.j.demeyer@gmail.com>
Message-ID: <20231021134015.1119597-1-daan.j.demeyer@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
NR_IOBUS_DEVS was increased to 200 in Linux 2.6.34. By Linux 3.5 it had
increased to 1000 and later ioeventfds were changed to not count against
the limit. But the earlier limit of 200 would already be enough for
kvm_check_many_ioeventfds() to be true, so remove the check.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is a remnant of pre-VFIO device assignment; it is not defined
anymore by Linux and not used by QEMU.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This was introduced in KVM in Linux 3.5, we can require it unconditionally
in kvm_irqchip_send_msi(). However, not all architectures have to implement
it so check it only in x86, the only architecture that ever had MSI injection
but not KVM_CAP_SIGNAL_MSI.
ARM uses it to detect the presence of the ITS emulation in the kernel,
introduced in Linux 4.8. Assume that it's there and possibly fail when
realizing the arm-its-kvm device.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Let's return the number of free slots instead of only checking if there
is a free slot. While at it, check all address spaces, which will also
consider SMM under x86 correctly.
This is a preparation for memory devices that consume multiple memslots.
Message-ID: <20230926185738.277351-5-david@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
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>
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>
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>
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>
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>
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>
Provide a name field for all the memory listeners. It can be used to identify
which memory listener is which.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210817013553.30584-2-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cache it too because we'll reference it more frequently in the future.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-8-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kvm_physical_sync_dirty_bitmap() calculates the ramblock offset in an
awkward way from the MemoryRegionSection that passed in from the
caller. The truth is for each KVMSlot the ramblock offset never
change for the lifecycle. Cache the ramblock offset for each KVMSlot
into the structure when the KVMSlot is created.
With that, we can further simplify kvm_physical_sync_dirty_bitmap()
with a helper to sync KVMSlot dirty bitmap to the ramblock dirty
bitmap of a specific KVMSlot.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-6-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Provide a helper kvm_slot_get_dirty_log() to make the function
kvm_physical_sync_dirty_bitmap() clearer. We can even cache the as_id
into KVMSlot when it is created, so that we don't even need to pass it
down every time.
Since at it, remove return value of kvm_physical_sync_dirty_bitmap()
because it should never fail.
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-5-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Per-kml slots_lock will bring some trouble if we want to take all slots_lock of
all the KMLs, especially when we're in a context that we could have taken some
of the KML slots_lock, then we even need to figure out what we've taken and
what we need to take.
Make this simple by merging all KML slots_lock into a single slots lock.
Per-kml slots_lock isn't anything that helpful anyway - so far only x86 has two
address spaces (so, two slots_locks). All the rest archs will be having one
address space always, which means there's actually one slots_lock so it will be
the same as before.
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210506160549.130416-3-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move QOM macros close to the KVMState typedef.
This will make future conversion to OBJECT_DECLARE* easier.
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Tested-By: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20200825192110.3528606-42-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
kvm_hwpoison_page_add() and kvm_unpoison_all() will both
be used by X86 and ARM platforms, so moving them into
"accel/kvm/kvm-all.c" to avoid duplicate code.
For architectures that don't use the poison-list functionality
the reset handler will harmlessly do nothing, so let's register
the kvm_unpoison_all() function in the generic kvm_init() function.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
Acked-by: Xiang Zheng <zhengxiang9@huawei.com>
Message-id: 20200512030609.19593-8-gengdongjiu@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Max memslot size supported by kvm on s390 is 8Tb,
move logic of splitting RAM in chunks upto 8T to KVM code.
This way it will hide KVM specific restrictions in KVM code
and won't affect board level design decisions. Which would allow
us to avoid misusing memory_region_allocate_system_memory() API
and eventually use a single hostmem backend for guest RAM.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20190924144751.24149-4-imammedo@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
In my "build everything" tree, changing sysemu/sysemu.h triggers a
recompile of some 5400 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
Almost a third of its inclusions are actually superfluous. Delete
them. Downgrade two more to qapi/qapi-types-run-state.h, and move one
from char/serial.h to char/serial.c.
hw/semihosting/config.c, monitor/monitor.c, qdev-monitor.c, and
stubs/semihost.c define variables declared in sysemu/sysemu.h without
including it. The compiler is cool with that, but include it anyway.
This doesn't reduce actual use much, as it's still included into
widely included headers. The next commit will tackle that.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-27-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
migration/qemu-file.h neglects to include it even though it needs
ram_addr_t. Fix that. Drop a few superfluous inclusions elsewhere.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-14-armbru@redhat.com>
Back in 2016, we discussed[1] rules for headers, and these were
generally liked:
1. Have a carefully curated header that's included everywhere first. We
got that already thanks to Peter: osdep.h.
2. Headers should normally include everything they need beyond osdep.h.
If exceptions are needed for some reason, they must be documented in
the header. If all that's needed from a header is typedefs, put
those into qemu/typedefs.h instead of including the header.
3. Cyclic inclusion is forbidden.
This patch gets include/ closer to obeying 2.
It's actually extracted from my "[RFC] Baby steps towards saner
headers" series[2], which demonstrates a possible path towards
checking 2 automatically. It passes the RFC test there.
[1] Message-ID: <87h9g8j57d.fsf@blackfin.pond.sub.org>
https://lists.nongnu.org/archive/html/qemu-devel/2016-03/msg03345.html
[2] Message-Id: <20190711122827.18970-1-armbru@redhat.com>
https://lists.nongnu.org/archive/html/qemu-devel/2019-07/msg02715.html
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-2-armbru@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Introduce KVMMemoryListener.slots_lock to protect the slots inside the
kvm memory listener. Currently it is close to useless because all the
KVM code path now is always protected by the BQL. But it'll start to
make sense in follow up patches where we might do remote dirty bitmap
clear and also we'll update the per-slot cached dirty bitmap even
without the BQL. So let's prepare for it.
We can also use per-slot lock for above reason but it seems to be an
overkill. Let's just use this bigger one (which covers all the slots
of a single address space) but anyway this lock is still much smaller
than the BQL.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20190603065056.25211-10-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
When synchronizing dirty bitmap from kernel KVM we do it in a
per-kvmslot fashion and we allocate the userspace bitmap for each of
the ioctl. This patch instead make the bitmap cache be persistent
then we don't need to g_malloc0() every time.
More importantly, the cached per-kvmslot dirty bitmap will be further
used when we want to add support for the KVM_CLEAR_DIRTY_LOG and this
cached bitmap will be used to guarantee we won't clear any unknown
dirty bits otherwise that can be a severe data loss issue for
migration code.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190603065056.25211-9-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
According to KVM commit 75d61fbc, it needs to delete the slot before
changing the KVM_MEM_READONLY flag. But QEMU commit 235e8982 only check
whether KVM_MEM_READONLY flag is set instead of changing. It doesn't
need to delete the slot if the KVM_MEM_READONLY flag is not changed.
This fixes a issue that migrating a VM at the OVMF startup stage and
VM is executing the codes in rom. Between the deleting and adding the
slot in kvm_set_user_memory_region, there is a chance that guest access
rom and trap to KVM, then KVM can't find the corresponding memslot.
While KVM (on ARM) injects an abort to guest due to the broken hva, then
guest will get stuck.
Signed-off-by: Shannon Zhao <zhaoshenglong@huawei.com>
Message-Id: <1526462314-19720-1-git-send-email-zhaoshenglong@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make kvm_memory_listener_register public, and assign a kernel
address space id to each KVMMemoryListener.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
No semantic change, but s->slots moves into a new struct
KVMMemoryListener. KVM's memory listener becomes a member of struct
KVMState, and becomes of type KVMMemoryListener.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
i386 code will have to define a different KVMMemoryListener. Create
an internal header so that KVMSlot is not exposed outside.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
