KVM: x86/xen: Add KVM_XEN_VCPU_ATTR_TYPE_VCPU_ID

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>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220303154127.202856-12-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index b20f7d99d7022ff9cb5ee2825d115025c7d368d6..9e3408542b4125d42a46b0c513af8a55ad94e339 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -613,6 +613,7 @@ 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 {

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e6bc0b654bbbc4b774311ac8750ade8c5ee7ee66..3d7b65f33bd8e39789a46ba1fbfd5b909f72f611 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11262,6 +11262,7 @@ 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);

diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 0dae583c4a1dfa5cb78ba19cac98adcb7dc60f4f..244cf3cd858a7e77b6236d87d642b1f487c00719 100644 (file)
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -603,6 +603,15 @@ 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;
        }
@@ -678,6 +687,11 @@ 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;
        }
@@ -1377,6 +1391,11 @@ 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,

diff --git a/arch/x86/kvm/xen.h b/arch/x86/kvm/xen.h
index 852286de574e50b0798f4b498b89c79e817bd300..54d587aae85b05932dddd7c504beca638398b1d0 100644 (file)
--- a/arch/x86/kvm/xen.h
+++ b/arch/x86/kvm/xen.h
@@ -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)
 {
 }

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 623ed2cb228f7bf1f884267ec8868b3e254c167e..4b65e9f0a4d906da8939e0c6fcd43edc3ef78af5 100644 (file)
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1747,6 +1747,7 @@ struct kvm_xen_vcpu_attr {
                        __u64 time_blocked;
                        __u64 time_offline;
                } runstate;
+               __u32 vcpu_id;
        } u;
 };
 
@@ -1757,6 +1758,8 @@ 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 {