KVM: x86/xen: Add KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID
authorDavid Woodhouse <dwmw@amazon.co.uk>
Tue, 8 Feb 2022 20:04:39 +0000 (20:04 +0000)
committerDavid Woodhouse <dwmw@amazon.co.uk>
Wed, 9 Feb 2022 22:20:44 +0000 (22:20 +0000)
In order to intercept hypercalls such as VCPUOP_set_singleshot_timer, we
need to be aware of the Xen CPU numbering.

This looks a lot like the Hyper-V handling of vpidx, for obvious reasons.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
arch/x86/include/asm/kvm_host.h
arch/x86/kvm/x86.c
arch/x86/kvm/xen.c
arch/x86/kvm/xen.h
include/uapi/linux/kvm.h

index dca0842d6926a4d3b69aa5867763326ba112793c..3c58d0bf5f9b241541fcaee5715c74a7aa91e0d5 100644 (file)
@@ -608,6 +608,7 @@ struct kvm_vcpu_xen {
        u64 runstate_entry_time;
        u64 runstate_times[4];
        unsigned long evtchn_pending_sel;
+       u32 vcpu_id; /* The Xen / ACPI vCPU ID */
 };
 
 struct kvm_vcpu_arch {
index a54bd731cf414144e145db0d85edd4cf63d5107a..2143c2652f8fd47aecf8bca173c362aac19f978c 100644 (file)
@@ -11141,6 +11141,7 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 
        vcpu->arch.arch_capabilities = kvm_get_arch_capabilities();
        vcpu->arch.msr_platform_info = MSR_PLATFORM_INFO_CPUID_FAULT;
+       kvm_xen_init_vcpu(vcpu);
        kvm_vcpu_mtrr_init(vcpu);
        vcpu_load(vcpu);
        kvm_set_tsc_khz(vcpu, max_tsc_khz);
index 3df44c996d6690fe357e7e0aeb872cd0c96acabb..8ee4bc648bcbb7be64b838b502f2a0760c7ce488 100644 (file)
@@ -605,6 +605,15 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
                r = 0;
                break;
 
+       case KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID:
+               if (data->u.vcpu_id >= KVM_MAX_VCPUS)
+                       r = -EINVAL;
+               else {
+                       vcpu->arch.xen.vcpu_id = data->u.vcpu_id;
+                       r = 0;
+               }
+               break;
+
        default:
                break;
        }
@@ -680,6 +689,11 @@ int kvm_xen_vcpu_get_attr(struct kvm_vcpu *vcpu, struct kvm_xen_vcpu_attr *data)
                r = -EINVAL;
                break;
 
+       case KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID:
+               data->u.vcpu_id = vcpu->arch.xen.vcpu_id;
+               r = 0;
+               break;
+
        default:
                break;
        }
@@ -785,6 +799,32 @@ int kvm_xen_hvm_config(struct kvm *kvm, struct kvm_xen_hvm_config *xhc)
        return 0;
 }
 
+static struct kvm_vcpu *kvm_xen_vcpu_by_id(struct kvm *kvm, u32 vcpu_id,
+                                          struct kvm_vcpu *vcpu)
+{
+       unsigned long i;
+
+       if (vcpu && vcpu->arch.xen.vcpu_id == vcpu_id)
+               return vcpu;
+
+       if (vcpu_id >= KVM_MAX_VCPUS)
+               return NULL;
+
+       /* Try the matching index first */
+       if (!vcpu || vcpu->vcpu_idx == vcpu_id) {
+               vcpu = kvm_get_vcpu(kvm, vcpu_id);
+
+               if (vcpu && vcpu->arch.xen.vcpu_id == vcpu_id)
+                       return vcpu;
+       }
+
+       kvm_for_each_vcpu(i, vcpu, kvm)
+               if (vcpu->arch.xen.vcpu_id == vcpu_id)
+                       return vcpu;
+
+       return NULL;
+}
+
 static int kvm_xen_hypercall_set_result(struct kvm_vcpu *vcpu, u64 result)
 {
        kvm_rax_write(vcpu, result);
@@ -1358,6 +1398,11 @@ static bool kvm_xen_hcall_evtchn_send(struct kvm_vcpu *vcpu, u64 param, u64 *r)
        return true;
 }
 
+void kvm_xen_init_vcpu(struct kvm_vcpu *vcpu)
+{
+       vcpu->arch.xen.vcpu_id = vcpu->vcpu_idx;
+}
+
 void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu)
 {
        kvm_gfn_to_pfn_cache_destroy(vcpu->kvm,
index 852286de574e50b0798f4b498b89c79e817bd300..54d587aae85b05932dddd7c504beca638398b1d0 100644 (file)
@@ -25,6 +25,7 @@ int kvm_xen_write_hypercall_page(struct kvm_vcpu *vcpu, u64 data);
 int kvm_xen_hvm_config(struct kvm *kvm, struct kvm_xen_hvm_config *xhc);
 void kvm_xen_init_vm(struct kvm *kvm);
 void kvm_xen_destroy_vm(struct kvm *kvm);
+void kvm_xen_init_vcpu(struct kvm_vcpu *vcpu);
 void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu);
 int kvm_xen_set_evtchn_fast(struct kvm_xen_evtchn *xe,
                            struct kvm *kvm);
@@ -75,6 +76,10 @@ static inline void kvm_xen_destroy_vm(struct kvm *kvm)
 {
 }
 
+static inline void kvm_xen_init_vcpu(struct kvm_vcpu *vcpu)
+{
+}
+
 static inline void kvm_xen_destroy_vcpu(struct kvm_vcpu *vcpu)
 {
 }
index c0d6f49e3fd837af6b67aa2dcda0d3ae6649543b..284645e1a872dcba272994700f3defdd5af91e1e 100644 (file)
@@ -1739,6 +1739,7 @@ struct kvm_xen_vcpu_attr {
                        __u64 time_blocked;
                        __u64 time_offline;
                } runstate;
+               __u32 vcpu_id;
        } u;
 };
 
@@ -1749,6 +1750,8 @@ struct kvm_xen_vcpu_attr {
 #define KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT        0x3
 #define KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA   0x4
 #define KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST 0x5
+/* Available with KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_EVTCHN_SEND */
+#define KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID         0x6
 
 /* Secure Encrypted Virtualization command */
 enum sev_cmd_id {