KVM: x86/xen: register vcpu info

The vcpu info supersedes the per vcpu area of the shared info page and
the guest vcpus will use this instead.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 00d1233..4e864f2 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -534,6 +534,8 @@ struct kvm_vcpu_hv {
 /* Xen HVM per vcpu emulation context */
 struct kvm_vcpu_xen {
        u64 hypercall_rip;
+       bool vcpu_info_set;
+       struct gfn_to_hva_cache vcpu_info_cache;
 };
 
 struct kvm_vcpu_arch {

diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 5cbf695..2712f1a 100644 (file)
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -120,15 +120,31 @@ int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
 
 int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
 {
-       int r = -ENOENT;
+       int idx, r = -ENOENT;
 
        mutex_lock(&vcpu->kvm->lock);
+       idx = srcu_read_lock(&vcpu->kvm->srcu);
 
        switch (data->type) {
+       case KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO:
+               /* No compat necessary here. */
+               BUILD_BUG_ON(sizeof(struct vcpu_info) !=
+                            sizeof(struct compat_vcpu_info));
+
+               r = kvm_gfn_to_hva_cache_init(vcpu->kvm,
+                                             &vcpu->arch.xen.vcpu_info_cache,
+                                             data->u.gpa,
+                                             sizeof(struct vcpu_info));
+               if (!r)
+                       vcpu->arch.xen.vcpu_info_set = true;
+               break;
+
+
        default:
                break;
        }
 
+       srcu_read_unlock(&vcpu->kvm->srcu, idx);
        mutex_unlock(&vcpu->kvm->lock);
        return r;
 }
@@ -140,6 +156,13 @@ int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
        mutex_lock(&vcpu->kvm->lock);
 
        switch (data->type) {
+       case KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO:
+               if (vcpu->arch.xen.vcpu_info_set) {
+                       data->u.gpa = vcpu->arch.xen.vcpu_info_cache.gpa;
+                       r = 0;
+               }
+               break;
+
        default:
                break;
        }

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index e2b0cbd..2db0657 100644 (file)
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1614,10 +1614,13 @@ struct kvm_xen_vcpu_attr {
        __u16 type;
        __u16 pad[3];
        union {
+               __u64 gpa;
                __u64 pad[8];
        } u;
 };
 
+#define KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO       0x0
+
 /* Secure Encrypted Virtualization command */
 enum sev_cmd_id {
        /* Guest initialization commands */