qemu/target/i386/kvm/xen-emu.c
Joao Martins f66b8a83c5 i386/kvm: handle Xen HVM cpuid leaves
Introduce support for emulating CPUID for Xen HVM guests. It doesn't make
sense to advertise the KVM leaves to a Xen guest, so do Xen unconditionally
when the xen-version machine property is set.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
[dwmw2: Obtain xen_version from KVM property, make it automatic]
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
2023-03-01 08:22:49 +00:00

59 lines
1.6 KiB
C

/*
* Xen HVM emulation support in KVM
*
* Copyright © 2019 Oracle and/or its affiliates. All rights reserved.
* Copyright © 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* 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 "sysemu/kvm_int.h"
#include "sysemu/kvm_xen.h"
#include "kvm/kvm_i386.h"
#include "xen-emu.h"
int kvm_xen_init(KVMState *s, uint32_t hypercall_msr)
{
const int required_caps = KVM_XEN_HVM_CONFIG_HYPERCALL_MSR |
KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL | KVM_XEN_HVM_CONFIG_SHARED_INFO;
struct kvm_xen_hvm_config cfg = {
.msr = hypercall_msr,
.flags = KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL,
};
int xen_caps, ret;
xen_caps = kvm_check_extension(s, KVM_CAP_XEN_HVM);
if (required_caps & ~xen_caps) {
error_report("kvm: Xen HVM guest support not present or insufficient");
return -ENOSYS;
}
if (xen_caps & KVM_XEN_HVM_CONFIG_EVTCHN_SEND) {
struct kvm_xen_hvm_attr ha = {
.type = KVM_XEN_ATTR_TYPE_XEN_VERSION,
.u.xen_version = s->xen_version,
};
(void)kvm_vm_ioctl(s, KVM_XEN_HVM_SET_ATTR, &ha);
cfg.flags |= KVM_XEN_HVM_CONFIG_EVTCHN_SEND;
}
ret = kvm_vm_ioctl(s, KVM_XEN_HVM_CONFIG, &cfg);
if (ret < 0) {
error_report("kvm: Failed to enable Xen HVM support: %s",
strerror(-ret));
return ret;
}
s->xen_caps = xen_caps;
return 0;
}
uint32_t kvm_xen_get_caps(void)
{
return kvm_state->xen_caps;
}