From: David Woodhouse <dwmw@amazon.co.uk>
This is a machine property for two main reasons. One is that it allows
us to set it in default_machine_opts for the xenfv platform when not
running on actual Xen. The other is that theoretically we *could* do
this with TCG too; we'd just have to implement a bunch of the stuff that
KVM already does for us.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
hw/i386/pc.c | 32 +++++++++++++++++++++++++++
hw/i386/pc_piix.c | 10 +++++++--
include/hw/i386/pc.h | 3 +++
target/i386/kvm/kvm.c | 26 ++++++++++++++++++++++
target/i386/meson.build | 1 +
target/i386/xen.c | 49 +++++++++++++++++++++++++++++++++++++++++
target/i386/xen.h | 19 ++++++++++++++++
7 files changed, 138 insertions(+), 2 deletions(-)
create mode 100644 target/i386/xen.c
create mode 100644 target/i386/xen.h
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 546b703cb4..9bada1a8ff 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1811,6 +1811,32 @@ static void pc_machine_set_max_fw_size(Object *obj,
Visitor *v,
pcms->max_fw_size = value;
}
+static void pc_machine_get_xen_version(Object *obj, Visitor *v,
+ const char *name, void *opaque,
+ Error **errp)
+{
+ PCMachineState *pcms = PC_MACHINE(obj);
+ uint32_t value = pcms->xen_version;
+
+ visit_type_uint32(v, name, &value, errp);
+}
+
+static void pc_machine_set_xen_version(Object *obj, Visitor *v,
+ const char *name, void *opaque,
+ Error **errp)
+{
+ PCMachineState *pcms = PC_MACHINE(obj);
+ Error *error = NULL;
+ uint32_t value;
+
+ visit_type_uint32(v, name, &value, &error);
+ if (error) {
+ error_propagate(errp, error);
+ return;
+ }
+
+ pcms->xen_version = value;
+}
static void pc_machine_initfn(Object *obj)
{
@@ -1978,6 +2004,12 @@ static void pc_machine_class_init(ObjectClass *oc, void
*data)
NULL, NULL);
object_class_property_set_description(oc, PC_MACHINE_SMBIOS_EP,
"SMBIOS Entry Point type [32, 64]");
+
+ object_class_property_add(oc, "xen-version", "uint32",
+ pc_machine_get_xen_version, pc_machine_set_xen_version,
+ NULL, NULL);
+ object_class_property_set_description(oc, "xen-version",
+ "Xen version to be emulated (in XENVER_version form e.g. 0x4000a for
4.10)");
}
static const TypeInfo pc_machine_info = {
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 0ad0ed1603..13286d0739 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -876,7 +876,10 @@ static void xenfv_4_2_machine_options(MachineClass *m)
pc_i440fx_4_2_machine_options(m);
m->desc = "Xen Fully-virtualized PC";
m->max_cpus = HVM_MAX_VCPUS;
- m->default_machine_opts = "accel=xen,suppress-vmdesc=on";
+ if (xen_enabled())
+ m->default_machine_opts = "accel=xen,suppress-vmdesc=on";
+ else
+ m->default_machine_opts = "accel=kvm,xen-version=0x40002";
}
DEFINE_PC_MACHINE(xenfv_4_2, "xenfv-4.2", pc_xen_hvm_init,
@@ -888,7 +891,10 @@ static void xenfv_3_1_machine_options(MachineClass *m)
m->desc = "Xen Fully-virtualized PC";
m->alias = "xenfv";
m->max_cpus = HVM_MAX_VCPUS;
- m->default_machine_opts = "accel=xen,suppress-vmdesc=on";
+ if (xen_enabled())
+ m->default_machine_opts = "accel=xen,suppress-vmdesc=on";
+ else
+ m->default_machine_opts = "accel=kvm,xen-version=0x30001";
}
DEFINE_PC_MACHINE(xenfv, "xenfv-3.1", pc_xen_hvm_init,
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index c95333514e..9b14b18836 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -52,6 +52,9 @@ typedef struct PCMachineState {
bool default_bus_bypass_iommu;
uint64_t max_fw_size;
+ /* Xen HVM emulation */
+ uint32_t xen_version;
+
/* ACPI Memory hotplug IO base address */
hwaddr memhp_io_base;
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index a213209379..0a2069b117 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -31,6 +31,7 @@
#include "sysemu/runstate.h"
#include "kvm_i386.h"
#include "sev.h"
+#include "xen.h"
#include "hyperv.h"
#include "hyperv-proto.h"
@@ -774,6 +775,17 @@ static inline bool freq_within_bounds(int freq, int target_freq)
return false;
}
+static uint32_t kvm_arch_xen_version(MachineState *ms)
+{
+ uint32_t v = object_property_get_int(OBJECT(ms), "xen-version", NULL);
+
+ /* If it was unset, return zero */
+ if (v == (uint32_t) -1)
+ return 0;
+
+ return v;
+}
+
static int kvm_arch_set_tsc_khz(CPUState *cs)
{
X86CPU *cpu = X86_CPU(cs);
@@ -2459,6 +2471,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
{
uint64_t identity_base = 0xfffbc000;
uint64_t shadow_mem;
+ uint32_t xen_version;
int ret;
struct utsname utsname;
Error *local_err = NULL;
@@ -2513,6 +2526,19 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
}
}
+ xen_version = kvm_arch_xen_version(ms);
+ if (xen_version) {
+#ifdef CONFIG_XEN_EMU
+ ret = kvm_xen_init(s, xen_version);
+ if (ret < 0) {
+ return ret;
+ }
+#else
+ error_report("kvm: Xen support not enabled in qemu");
+ return -ENOTSUP;
+#endif
+ }
+
ret = kvm_get_supported_msrs(s);
if (ret < 0) {
return ret;
diff --git a/target/i386/meson.build b/target/i386/meson.build
index ae38dc9563..9f3ef246b8 100644
--- a/target/i386/meson.build
+++ b/target/i386/meson.build
@@ -7,6 +7,7 @@ i386_ss.add(files(
'cpu-dump.c',
))
i386_ss.add(when: 'CONFIG_SEV', if_true: files('host-cpu.c'))
+i386_ss.add(when: 'CONFIG_XEN_EMU', if_true: files('xen.c'))
# x86 cpu type
i386_ss.add(when: 'CONFIG_KVM', if_true: files('host-cpu.c'))
diff --git a/target/i386/xen.c b/target/i386/xen.c
new file mode 100644
index 0000000000..bc183dce4e
--- /dev/null
+++ b/target/i386/xen.c
@@ -0,0 +1,49 @@
+/*
+ * 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 "kvm/kvm_i386.h"
+#include "xen.h"
+
+int kvm_xen_init(KVMState *s, uint32_t xen_version)
+{
+ 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 = XEN_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 = xen_version,
+ };
+ (void)kvm_vm_ioctl(s, KVM_XEN_HVM_SET_ATTR, &ha);