Hyper-V identifies vCPUs by Virtual Processor (VP) index which can be
queried by the guest via HV_X64_MSR_VP_INDEX msr. It is defined by the
spec as a sequential number which can't exceed the maximum number of
vCPUs per VM.
It has to be owned by QEMU in order to preserve it across migration.
However, the initial implementation in KVM didn't allow to set this
msr, and KVM used its own notion of VP index. Fortunately, the way
vCPUs are created in QEMU/KVM makes it likely that the KVM value is
equal to QEMU cpu_index.
So choose cpu_index as the value for vp_index, and push that to KVM on
kernels that support setting the msr. On older ones that don't, query
the kernel value and assert that it's in sync with QEMU.
Besides, since handling errors from vCPU init at hotplug time is
impossible, disable vCPU hotplug.
This patch also introduces accessor functions to encapsulate the mapping
between a vCPU and its vp_index.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180702134156.13404-3-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In Hyper-V-related code, vCPUs are identified by their VP (virtual
processor) index. Since it's customary for "vcpu_id" in QEMU to mean
APIC id, rename the respective variables to "vp_index" to make the
distinction clear.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180702134156.13404-2-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The definitions for Hyper-V emulation are currently taken from a header
imported from the Linux kernel.
However, as these describe a third-party protocol rather than a kernel
API, it probably wasn't a good idea to publish it in the kernel uapi.
This patch introduces a header that provides all the necessary
definitions, superseding the one coming from the kernel.
The new header supports (temporary) coexistence with the kernel one.
The constants explicitly named in the Hyper-V specification (e.g. msr
numbers) are defined in a non-conflicting way. Other constants and
types have got new names.
While at this, the protocol data structures are defined in a more
conventional way, without bitfields, enums, and excessive unions.
The code using this stuff is adjusted, too; it can now be built both
with and without the kernel header in the tree.
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20170713201522.13765-2-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove the useless is_external argument. Since the iohandler
AioContext is never used for block devices, aio_disable_external
is never called on it. This lets us remove stubs/iohandler.c.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.
Acked-by: Laurent Vivier <laurent@vivier.eu> [m68k part]
Acked-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> [tricore part]
Acked-by: Michael Walle <michael@walle.cc> [lm32 part]
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> [s390x part]
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [s390x part]
Acked-by: Eduardo Habkost <ehabkost@redhat.com> [i386 part]
Acked-by: Artyom Tarasenko <atar4qemu@gmail.com> [sparc part]
Acked-by: Richard Henderson <rth@twiddle.net> [alpha part]
Acked-by: Max Filippov <jcmvbkbc@gmail.com> [xtensa part]
Reviewed-by: David Gibson <david@gibson.dropbear.id.au> [ppc part]
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> [crisµblaze part]
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> [unicore32 part]
Signed-off-by: Thomas Huth <thuth@redhat.com>
