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 07ae5887afa100e313b188cde84d9eaebb21ee28..421d082d772d01462d54e02fc8c09e4fceec025b 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -523,6 +523,8 @@ 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 e5117a6117370368ff0ae7d2f863928b08c2acc5..4bc72e0b9928d1f43e12f9fc95f8ea213b72851c 100644 (file)
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -58,6 +58,7 @@ static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn)
 
 int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
 {
+       struct kvm_vcpu *v;
        int r = -ENOENT;
 
        switch (data->type) {
@@ -73,6 +74,23 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
                r = kvm_xen_shared_info_init(kvm, data->u.shared_info.gfn);
                break;
 
+       case KVM_XEN_ATTR_TYPE_VCPU_INFO:
+               v = kvm_get_vcpu_by_id(kvm, data->u.vcpu_attr.vcpu_id);
+               if (!v)
+                       return -EINVAL;
+
+               /* No compat necessary here. */
+               BUILD_BUG_ON(sizeof(struct vcpu_info) !=
+                            sizeof(struct compat_vcpu_info));
+               r = kvm_gfn_to_hva_cache_init(kvm, &v->arch.xen.vcpu_info_cache,
+                                             data->u.vcpu_attr.gpa,
+                                             sizeof(struct vcpu_info));
+               if (r)
+                       return r;
+
+               v->arch.xen.vcpu_info_set = true;
+               break;
+
        default:
                break;
        }
@@ -83,6 +101,7 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
 int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
 {
        int r = -ENOENT;
+       struct kvm_vcpu *v;
 
        switch (data->type) {
        case KVM_XEN_ATTR_TYPE_LONG_MODE:
@@ -97,6 +116,17 @@ int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
                }
                break;
 
+       case KVM_XEN_ATTR_TYPE_VCPU_INFO:
+               v = kvm_get_vcpu_by_id(kvm, data->u.vcpu_attr.vcpu_id);
+               if (!v)
+                       return -EINVAL;
+
+               if (v->arch.xen.vcpu_info_set) {
+                       data->u.vcpu_attr.gpa = v->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 0c04bb6eda099db1d2281effa3f7b78ed0317df2..5ab0063d109a442456df30087c10c7ebfdbe0050 100644 (file)
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1596,12 +1596,17 @@ struct kvm_xen_hvm_attr {
                struct {
                        __u64 gfn;
                } shared_info;
+               struct {
+                       __u32 vcpu_id;
+                       __u64 gpa;
+               } vcpu_attr;
                __u64 pad[4];
        } u;
 };
 
 #define KVM_XEN_ATTR_TYPE_LONG_MODE            0x0
 #define KVM_XEN_ATTR_TYPE_SHARED_INFO          0x1
+#define KVM_XEN_ATTR_TYPE_VCPU_INFO            0x2
 
 /* Secure Encrypted Virtualization command */
 enum sev_cmd_id {