From: Paul Durrant <pdurrant@xxxxxxxxxx>
Add a KVM_XEN_HVM_CONFIG_DEFAULT_VCPU_INFO flag so that the VMM knows it
need only set the KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO attribute in response to
a VCPUOP_register_vcpu_info hypercall, and modify get_vcpu_info_cache()
to pass back a pointer to the shared info pfn cache (and appropriate
offset) for any of the first 32 vCPUs if the attribute has not been set.
Signed-off-by: Paul Durrant <pdurrant@xxxxxxxxxx>
---
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: x86@xxxxxxxxxx
---
arch/x86/kvm/x86.c | 3 ++-
arch/x86/kvm/xen.c | 15 +++++++++++++++
include/uapi/linux/kvm.h | 1 +
3 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4cd577d01bc4..cdce8c463a1b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4528,7 +4528,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
KVM_XEN_HVM_CONFIG_SHARED_INFO |
KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL |
KVM_XEN_HVM_CONFIG_EVTCHN_SEND |
- KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA;
+ KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA |
+ KVM_XEN_HVM_CONFIG_DEFAULT_VCPU_INFO;
if (sched_info_on())
r |= KVM_XEN_HVM_CONFIG_RUNSTATE |
KVM_XEN_HVM_CONFIG_RUNSTATE_UPDATE_FLAG;
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 892563fea40f..66050a96ba25 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -491,6 +491,21 @@ static void kvm_xen_inject_vcpu_vector(struct kvm_vcpu *v)
struct gfn_to_pfn_cache *get_vcpu_info_cache(struct kvm_vcpu *v, unsigned long *offset)
{
+ if (!v->arch.xen.vcpu_info_cache.active && v->arch.xen.vcpu_id < MAX_VIRT_CPUS) {
+ struct kvm *kvm = v->kvm;
+
+ if (offset) {
+ if (IS_ENABLED(CONFIG_64BIT) && kvm->arch.xen.long_mode)
+ *offset = offsetof(struct shared_info,
+ vcpu_info[v->arch.xen.vcpu_id]);
+ else
+ *offset = offsetof(struct compat_shared_info,
+ vcpu_info[v->arch.xen.vcpu_id]);
+ }
+
+ return &kvm->arch.xen.shinfo_cache;
+ }
+
if (offset)
*offset = 0;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index d3f371bafad8..480612f73fc2 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1283,6 +1283,7 @@ struct kvm_x86_mce {
#define KVM_XEN_HVM_CONFIG_EVTCHN_SEND (1 << 5)
#define KVM_XEN_HVM_CONFIG_RUNSTATE_UPDATE_FLAG (1 << 6)
#define KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA (1 << 7)
+#define KVM_XEN_HVM_CONFIG_DEFAULT_VCPU_INFO (1 << 8)
struct kvm_xen_hvm_config {
__u32 flags;
--
2.39.2
