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-rw-r--r--arch/x86/include/asm/kvm_host.h2
-rw-r--r--arch/x86/include/uapi/asm/hyperv.h2
-rw-r--r--arch/x86/kvm/hyperv.c103
-rw-r--r--arch/x86/kvm/hyperv.h1
-rw-r--r--arch/x86/kvm/x86.c10
5 files changed, 117 insertions, 1 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index b605a5b6a30c..df6720fc57e6 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -754,6 +754,8 @@ struct kvm_hv {
u64 hv_crash_ctl;
HV_REFERENCE_TSC_PAGE tsc_ref;
+
+ struct idr conn_to_evt;
};
enum kvm_irqchip_mode {
diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
index 099414345865..31d7a0a91f50 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -303,7 +303,9 @@ enum HV_GENERIC_SET_FORMAT {
#define HV_STATUS_INVALID_HYPERCALL_CODE 2
#define HV_STATUS_INVALID_HYPERCALL_INPUT 3
#define HV_STATUS_INVALID_ALIGNMENT 4
+#define HV_STATUS_INVALID_PARAMETER 5
#define HV_STATUS_INSUFFICIENT_MEMORY 11
+#define HV_STATUS_INVALID_PORT_ID 17
#define HV_STATUS_INVALID_CONNECTION_ID 18
#define HV_STATUS_INSUFFICIENT_BUFFERS 19
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 015fb06c7522..53bd1913b6fd 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -29,6 +29,7 @@
#include <linux/kvm_host.h>
#include <linux/highmem.h>
#include <linux/sched/cputime.h>
+#include <linux/eventfd.h>
#include <asm/apicdef.h>
#include <trace/events/kvm.h>
@@ -1226,6 +1227,43 @@ static int kvm_hv_hypercall_complete_userspace(struct kvm_vcpu *vcpu)
return 1;
}
+static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, bool fast, u64 param)
+{
+ struct eventfd_ctx *eventfd;
+
+ if (unlikely(!fast)) {
+ int ret;
+ gpa_t gpa = param;
+
+ if ((gpa & (__alignof__(param) - 1)) ||
+ offset_in_page(gpa) + sizeof(param) > PAGE_SIZE)
+ return HV_STATUS_INVALID_ALIGNMENT;
+
+ ret = kvm_vcpu_read_guest(vcpu, gpa, &param, sizeof(param));
+ if (ret < 0)
+ return HV_STATUS_INVALID_ALIGNMENT;
+ }
+
+ /*
+ * Per spec, bits 32-47 contain the extra "flag number". However, we
+ * have no use for it, and in all known usecases it is zero, so just
+ * report lookup failure if it isn't.
+ */
+ if (param & 0xffff00000000ULL)
+ return HV_STATUS_INVALID_PORT_ID;
+ /* remaining bits are reserved-zero */
+ if (param & ~KVM_HYPERV_CONN_ID_MASK)
+ return HV_STATUS_INVALID_HYPERCALL_INPUT;
+
+ /* conn_to_evt is protected by vcpu->kvm->srcu */
+ eventfd = idr_find(&vcpu->kvm->arch.hyperv.conn_to_evt, param);
+ if (!eventfd)
+ return HV_STATUS_INVALID_PORT_ID;
+
+ eventfd_signal(eventfd, 1);
+ return HV_STATUS_SUCCESS;
+}
+
int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
{
u64 param, ingpa, outgpa, ret;
@@ -1276,8 +1314,12 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
case HVCALL_NOTIFY_LONG_SPIN_WAIT:
kvm_vcpu_on_spin(vcpu, true);
break;
- case HVCALL_POST_MESSAGE:
case HVCALL_SIGNAL_EVENT:
+ res = kvm_hvcall_signal_event(vcpu, fast, ingpa);
+ if (res != HV_STATUS_INVALID_PORT_ID)
+ break;
+ /* maybe userspace knows this conn_id: fall through */
+ case HVCALL_POST_MESSAGE:
/* don't bother userspace if it has no way to handle it */
if (!vcpu_to_synic(vcpu)->active) {
res = HV_STATUS_INVALID_HYPERCALL_CODE;
@@ -1305,8 +1347,67 @@ set_result:
void kvm_hv_init_vm(struct kvm *kvm)
{
mutex_init(&kvm->arch.hyperv.hv_lock);
+ idr_init(&kvm->arch.hyperv.conn_to_evt);
}
void kvm_hv_destroy_vm(struct kvm *kvm)
{
+ struct eventfd_ctx *eventfd;
+ int i;
+
+ idr_for_each_entry(&kvm->arch.hyperv.conn_to_evt, eventfd, i)
+ eventfd_ctx_put(eventfd);
+ idr_destroy(&kvm->arch.hyperv.conn_to_evt);
+}
+
+static int kvm_hv_eventfd_assign(struct kvm *kvm, u32 conn_id, int fd)
+{
+ struct kvm_hv *hv = &kvm->arch.hyperv;
+ struct eventfd_ctx *eventfd;
+ int ret;
+
+ eventfd = eventfd_ctx_fdget(fd);
+ if (IS_ERR(eventfd))
+ return PTR_ERR(eventfd);
+
+ mutex_lock(&hv->hv_lock);
+ ret = idr_alloc(&hv->conn_to_evt, eventfd, conn_id, conn_id + 1,
+ GFP_KERNEL);
+ mutex_unlock(&hv->hv_lock);
+
+ if (ret >= 0)
+ return 0;
+
+ if (ret == -ENOSPC)
+ ret = -EEXIST;
+ eventfd_ctx_put(eventfd);
+ return ret;
+}
+
+static int kvm_hv_eventfd_deassign(struct kvm *kvm, u32 conn_id)
+{
+ struct kvm_hv *hv = &kvm->arch.hyperv;
+ struct eventfd_ctx *eventfd;
+
+ mutex_lock(&hv->hv_lock);
+ eventfd = idr_remove(&hv->conn_to_evt, conn_id);
+ mutex_unlock(&hv->hv_lock);
+
+ if (!eventfd)
+ return -ENOENT;
+
+ synchronize_srcu(&kvm->srcu);
+ eventfd_ctx_put(eventfd);
+ return 0;
+}
+
+int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args)
+{
+ if ((args->flags & ~KVM_HYPERV_EVENTFD_DEASSIGN) ||
+ (args->conn_id & ~KVM_HYPERV_CONN_ID_MASK))
+ return -EINVAL;
+
+ if (args->flags == KVM_HYPERV_EVENTFD_DEASSIGN)
+ return kvm_hv_eventfd_deassign(kvm, args->conn_id);
+ return kvm_hv_eventfd_assign(kvm, args->conn_id, args->fd);
}
diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h
index cc2468244ca2..837465d69c6d 100644
--- a/arch/x86/kvm/hyperv.h
+++ b/arch/x86/kvm/hyperv.h
@@ -90,5 +90,6 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm,
void kvm_hv_init_vm(struct kvm *kvm);
void kvm_hv_destroy_vm(struct kvm *kvm);
+int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args);
#endif
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fee833c4a132..3b6b7ee9fa8f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2809,6 +2809,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_HYPERV_SYNIC:
case KVM_CAP_HYPERV_SYNIC2:
case KVM_CAP_HYPERV_VP_INDEX:
+ case KVM_CAP_HYPERV_EVENTFD:
case KVM_CAP_PCI_SEGMENT:
case KVM_CAP_DEBUGREGS:
case KVM_CAP_X86_ROBUST_SINGLESTEP:
@@ -4482,6 +4483,15 @@ set_identity_unlock:
r = kvm_x86_ops->mem_enc_unreg_region(kvm, &region);
break;
}
+ case KVM_HYPERV_EVENTFD: {
+ struct kvm_hyperv_eventfd hvevfd;
+
+ r = -EFAULT;
+ if (copy_from_user(&hvevfd, argp, sizeof(hvevfd)))
+ goto out;
+ r = kvm_vm_ioctl_hv_eventfd(kvm, &hvevfd);
+ break;
+ }
default:
r = -ENOTTY;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-16 11:52:07 +0000