From: Joao Martins <joao.m.mart...@oracle.com>
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.mart...@oracle.com>
[dwmw2: Obtain xen_version from KVM property, make it automatic]
Signed-off-by: David Woodhouse <d...@amazon.co.uk>
Reviewed-by: Paul Durrant <p...@xen.org>
---
target/i386/cpu.c | 1 +
target/i386/cpu.h | 2 +
target/i386/kvm/kvm.c | 77 ++++++++++++++++++++++++++++++++++++++-
target/i386/kvm/xen-emu.c | 4 +-
target/i386/kvm/xen-emu.h | 13 ++++++-
5 files changed, 91 insertions(+), 6 deletions(-)
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 4d2b8d0444..eb5a466d4e 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -7070,6 +7070,7 @@ static Property x86_cpu_properties[] = {
* own cache information (see x86_cpu_load_def()).
*/
DEFINE_PROP_BOOL("legacy-cache", X86CPU, legacy_cache, true),
+ DEFINE_PROP_BOOL("xen-vapic", X86CPU, xen_vapic, false),
/*
* From "Requirements for Implementing the Microsoft
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index d4bc19577a..c6c57baed5 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1964,6 +1964,8 @@ struct ArchCPU {
int32_t thread_id;
int32_t hv_max_vps;
+
+ bool xen_vapic;
};
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index aa6eac7cad..2b3daabf7b 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -22,6 +22,7 @@
#include <linux/kvm.h>
#include "standard-headers/asm-x86/kvm_para.h"
+#include "hw/xen/interface/arch-x86/cpuid.h"
#include "cpu.h"
#include "host-cpu.h"
@@ -1804,7 +1805,77 @@ int kvm_arch_init_vcpu(CPUState *cs)
has_msr_hv_hypercall = true;
}
- if (cpu->expose_kvm) {
+ if (cs->kvm_state->xen_version) {
+#ifdef CONFIG_XEN_EMU
+ struct kvm_cpuid_entry2 *xen_max_leaf;
+
+ memcpy(signature, "XenVMMXenVMM", 12);
+
+ xen_max_leaf = c = &cpuid_data.entries[cpuid_i++];
+ c->function = kvm_base + XEN_CPUID_SIGNATURE;
+ c->eax = kvm_base + XEN_CPUID_TIME;
+ c->ebx = signature[0];
+ c->ecx = signature[1];
+ c->edx = signature[2];
+
+ c = &cpuid_data.entries[cpuid_i++];
+ c->function = kvm_base + XEN_CPUID_VENDOR;
+ c->eax = cs->kvm_state->xen_version;
+ c->ebx = 0;
+ c->ecx = 0;
+ c->edx = 0;
+
+ c = &cpuid_data.entries[cpuid_i++];
+ c->function = kvm_base + XEN_CPUID_HVM_MSR;
+ /* Number of hypercall-transfer pages */
+ c->eax = 1;
+ /* Hypercall MSR base address */
+ if (hyperv_enabled(cpu)) {
+ c->ebx = XEN_HYPERCALL_MSR_HYPERV;
+ kvm_xen_init(cs->kvm_state, c->ebx);
+ } else {
+ c->ebx = XEN_HYPERCALL_MSR;
+ }
+ c->ecx = 0;
+ c->edx = 0;
+
+ c = &cpuid_data.entries[cpuid_i++];
+ c->function = kvm_base + XEN_CPUID_TIME;
+ c->eax = ((!!tsc_is_stable_and_known(env) << 1) |
+ (!!(env->features[FEAT_8000_0001_EDX] & CPUID_EXT2_RDTSCP) << 2));
+ /* default=0 (emulate if necessary) */
+ c->ebx = 0;
+ /* guest tsc frequency */
+ c->ecx = env->user_tsc_khz;
+ /* guest tsc incarnation (migration count) */
+ c->edx = 0;
+
+ c = &cpuid_data.entries[cpuid_i++];
+ c->function = kvm_base + XEN_CPUID_HVM;
+ xen_max_leaf->eax = kvm_base + XEN_CPUID_HVM;
+ if (cs->kvm_state->xen_version >= XEN_VERSION(4, 5)) {
+ c->function = kvm_base + XEN_CPUID_HVM;
+
+ if (cpu->xen_vapic) {
+ c->eax |= XEN_HVM_CPUID_APIC_ACCESS_VIRT;
+ c->eax |= XEN_HVM_CPUID_X2APIC_VIRT;
+ }
+
+ c->eax |= XEN_HVM_CPUID_IOMMU_MAPPINGS;
+
+ if (cs->kvm_state->xen_version >= XEN_VERSION(4, 6)) {
+ c->eax |= XEN_HVM_CPUID_VCPU_ID_PRESENT;
+ c->ebx = cs->cpu_index;
+ }
+ }
+
+ kvm_base += 0x100;
+#else /* CONFIG_XEN_EMU */
+ /* This should never happen as kvm_arch_init() would have died first.
*/
+ fprintf(stderr, "Cannot enable Xen CPUID without Xen support\n");
+ abort();
+#endif
+ } else if (cpu->expose_kvm) {
memcpy(signature, "KVMKVMKVM\0\0\0", 12);
c = &cpuid_data.entries[cpuid_i++];
c->function = KVM_CPUID_SIGNATURE | kvm_base;
@@ -2524,7 +2595,9 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
error_report("kvm: Xen support only available in PC machine");
return -ENOTSUP;
}
- ret = kvm_xen_init(s);
+ /* hyperv_enabled() doesn't work yet. */
+ uint32_t msr = XEN_HYPERCALL_MSR;
+ ret = kvm_xen_init(s, msr);
if (ret < 0) {
return ret;
}
diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
index b556d903aa..34d5bc1bc9 100644
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -15,12 +15,12 @@
#include "kvm/kvm_i386.h"
#include "xen-emu.h"
-int kvm_xen_init(KVMState *s)
+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 = XEN_HYPERCALL_MSR,
+ .msr = hypercall_msr,
.flags = KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL,
};
int xen_caps, ret;
diff --git a/target/i386/kvm/xen-emu.h b/target/i386/kvm/xen-emu.h
index 4f31bd96cb..2101df0182 100644
--- a/target/i386/kvm/xen-emu.h
+++ b/target/i386/kvm/xen-emu.h
@@ -12,8 +12,17 @@
#ifndef QEMU_I386_KVM_XEN_EMU_H
#define QEMU_I386_KVM_XEN_EMU_H
-#define XEN_HYPERCALL_MSR 0x40000000
+#define XEN_HYPERCALL_MSR 0x40000000
+#define XEN_HYPERCALL_MSR_HYPERV 0x40000200
-int kvm_xen_init(KVMState *s);
+#define XEN_CPUID_SIGNATURE 0
+#define XEN_CPUID_VENDOR 1
+#define XEN_CPUID_HVM_MSR 2
+#define XEN_CPUID_TIME 3
+#define XEN_CPUID_HVM 4
+
+#define XEN_VERSION(maj, min) ((maj) << 16 | (min))
+
+int kvm_xen_init(KVMState *s, uint32_t hypercall_msr);
#endif /* QEMU_I386_KVM_XEN_EMU_H */
--
2.39.0
