qemu/target/i386/hyperv.c
Roman Kagan e9688fabc3 hyperv: ensure VP index equal to QEMU cpu_index
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>
2018-07-16 16:58:16 +02:00

152 lines
4.2 KiB
C

/*
* QEMU KVM Hyper-V support
*
* Copyright (C) 2015 Andrey Smetanin <asmetanin@virtuozzo.com>
*
* Authors:
* Andrey Smetanin <asmetanin@virtuozzo.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "qemu/main-loop.h"
#include "hyperv.h"
#include "hyperv-proto.h"
uint32_t hyperv_vp_index(X86CPU *cpu)
{
return CPU(cpu)->cpu_index;
}
X86CPU *hyperv_find_vcpu(uint32_t vp_index)
{
return X86_CPU(qemu_get_cpu(vp_index));
}
int kvm_hv_handle_exit(X86CPU *cpu, struct kvm_hyperv_exit *exit)
{
CPUX86State *env = &cpu->env;
switch (exit->type) {
case KVM_EXIT_HYPERV_SYNIC:
if (!cpu->hyperv_synic) {
return -1;
}
/*
* For now just track changes in SynIC control and msg/evt pages msr's.
* When SynIC messaging/events processing will be added in future
* here we will do messages queues flushing and pages remapping.
*/
switch (exit->u.synic.msr) {
case HV_X64_MSR_SCONTROL:
env->msr_hv_synic_control = exit->u.synic.control;
break;
case HV_X64_MSR_SIMP:
env->msr_hv_synic_msg_page = exit->u.synic.msg_page;
break;
case HV_X64_MSR_SIEFP:
env->msr_hv_synic_evt_page = exit->u.synic.evt_page;
break;
default:
return -1;
}
return 0;
case KVM_EXIT_HYPERV_HCALL: {
uint16_t code;
code = exit->u.hcall.input & 0xffff;
switch (code) {
case HV_POST_MESSAGE:
case HV_SIGNAL_EVENT:
default:
exit->u.hcall.result = HV_STATUS_INVALID_HYPERCALL_CODE;
return 0;
}
}
default:
return -1;
}
}
static void kvm_hv_sint_ack_handler(EventNotifier *notifier)
{
HvSintRoute *sint_route = container_of(notifier, HvSintRoute,
sint_ack_notifier);
event_notifier_test_and_clear(notifier);
if (sint_route->sint_ack_clb) {
sint_route->sint_ack_clb(sint_route);
}
}
HvSintRoute *kvm_hv_sint_route_create(uint32_t vp_index, uint32_t sint,
HvSintAckClb sint_ack_clb)
{
HvSintRoute *sint_route;
int r, gsi;
sint_route = g_malloc0(sizeof(*sint_route));
r = event_notifier_init(&sint_route->sint_set_notifier, false);
if (r) {
goto err;
}
r = event_notifier_init(&sint_route->sint_ack_notifier, false);
if (r) {
goto err_sint_set_notifier;
}
event_notifier_set_handler(&sint_route->sint_ack_notifier,
kvm_hv_sint_ack_handler);
gsi = kvm_irqchip_add_hv_sint_route(kvm_state, vp_index, sint);
if (gsi < 0) {
goto err_gsi;
}
r = kvm_irqchip_add_irqfd_notifier_gsi(kvm_state,
&sint_route->sint_set_notifier,
&sint_route->sint_ack_notifier, gsi);
if (r) {
goto err_irqfd;
}
sint_route->gsi = gsi;
sint_route->sint_ack_clb = sint_ack_clb;
sint_route->vp_index = vp_index;
sint_route->sint = sint;
return sint_route;
err_irqfd:
kvm_irqchip_release_virq(kvm_state, gsi);
err_gsi:
event_notifier_set_handler(&sint_route->sint_ack_notifier, NULL);
event_notifier_cleanup(&sint_route->sint_ack_notifier);
err_sint_set_notifier:
event_notifier_cleanup(&sint_route->sint_set_notifier);
err:
g_free(sint_route);
return NULL;
}
void kvm_hv_sint_route_destroy(HvSintRoute *sint_route)
{
kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state,
&sint_route->sint_set_notifier,
sint_route->gsi);
kvm_irqchip_release_virq(kvm_state, sint_route->gsi);
event_notifier_set_handler(&sint_route->sint_ack_notifier, NULL);
event_notifier_cleanup(&sint_route->sint_ack_notifier);
event_notifier_cleanup(&sint_route->sint_set_notifier);
g_free(sint_route);
}
int kvm_hv_sint_route_set_sint(HvSintRoute *sint_route)
{
return event_notifier_set(&sint_route->sint_set_notifier);
}