KVM: x86/xen: register vcpu time info region

Allow the Xen emulated guest the ability to register secondary
vcpu time information. On Xen guests this is used in order to be
mapped to userspace and hence allow vdso gettimeofday to work.

Signed-off-by: Joao Martins <joao.m.martins@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 421d082d772d01462d54e02fc8c09e4fceec025b..cd65bd43fc5fed8d4065f85c70edf9ff9bf07ddf 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -524,7 +524,9 @@ struct kvm_vcpu_hv {
 struct kvm_vcpu_xen {
        u64 hypercall_rip;
        bool vcpu_info_set;
+       bool vcpu_time_info_set;
        struct gfn_to_hva_cache vcpu_info_cache;
+       struct gfn_to_hva_cache vcpu_time_info_cache;
 };
 
 struct kvm_vcpu_arch {

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 65d06d4426a225761ed12e65b5f00fc47359a737..8d849e8e99530e8e982cbe1ece94a88a91abc9a6 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2736,6 +2736,8 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
        if (vcpu->xen.vcpu_info_set)
                kvm_setup_pvclock_page(v, &vcpu->xen.vcpu_info_cache,
                                       offsetof(struct compat_vcpu_info, time));
+       if (vcpu->xen.vcpu_time_info_set)
+               kvm_setup_pvclock_page(v, &vcpu->xen.vcpu_time_info_cache, 0);
        if (v == kvm_get_vcpu(v->kvm, 0))
                kvm_hv_setup_tsc_page(v->kvm, &vcpu->hv_clock);
        return 0;

diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index c307f8b7a8a375e42da8340291496dd5dc8337b2..bd343222e7408cef4313e404bb3566a127f0be7c 100644 (file)
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -141,6 +141,17 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
                }
                break;
 
+       case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO:
+               r = kvm_gfn_to_hva_cache_init(vcpu->kvm,
+                                             &vcpu->arch.xen.vcpu_time_info_cache,
+                                             data->u.gpa,
+                                             sizeof(struct pvclock_vcpu_time_info));
+               if (!r) {
+                       vcpu->arch.xen.vcpu_time_info_set = true;
+                       kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
+               }
+               break;
+
        default:
                break;
        }
@@ -164,6 +175,13 @@ int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
                }
                break;
 
+       case KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO:
+               if (vcpu->arch.xen.vcpu_time_info_set) {
+                       data->u.gpa = vcpu->arch.xen.vcpu_time_info_cache.gpa;
+                       r = 0;
+               }
+               break;
+
        default:
                break;
        }

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index a34a35a8f354ff32dd88e3dc753fb2dffc999934..e00b15ba7b7ed41fb3bcb606facb25c84fbdb774 100644 (file)
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1618,6 +1618,7 @@ struct kvm_xen_vcpu_attr {
 };
 
 #define KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO       0x0
+#define KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO  0x1
 
 /* Secure Encrypted Virtualization command */
 enum sev_cmd_id {