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 4e864f2bd59a9d56c39c0f909167df21bdb73d75..c6c84c4ef7b060d1df9cf8cc784e4b705e4abb4d 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -535,7 +535,9 @@ 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 a295fb8a897887464bbc9bc043d24154e3fcda24..0f648434796f6fed198a2d1f60d77c7a9c0a4d49 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2757,6 +2757,8 @@ 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 2db0657b333776c8649941390f5702f11b68b66c..0f045ffd9cb66c955acf3d2bdbfdf4f9ae9769da 100644 (file)
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1620,6 +1620,7 @@ 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 {