vmm/vmd: Fix migration with pvclock

Implement VMM_IOC_READVMPARAMS and VMM_IOC_WRITEVMPARAMS ioctls to read and
write pvclock state.

reads ok mlarkin@

2 files changed, 90 insertions, 2 deletions

diff --git a/sys/arch/amd64/amd64/vmm.c b/sys/arch/amd64/amd64/vmm.c
index 3c5e45e6409..4dadb04bbf6 100644
--- a/sys/arch/amd64/amd64/vmm.c
+++ b/sys/arch/amd64/amd64/vmm.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vmm.c,v 1.248 2019/07/08 19:57:11 mlarkin Exp $	*/
+/*	$OpenBSD: vmm.c,v 1.249 2019/07/17 05:51:07 pd Exp $	*/
 /*
  * Copyright (c) 2014 Mike Larkin <mlarkin@openbsd.org>
  *
@@ -124,6 +124,7 @@ int vm_get_info(struct vm_info_params *);
 int vm_resetcpu(struct vm_resetcpu_params *);
 int vm_intr_pending(struct vm_intr_params *);
 int vm_rwregs(struct vm_rwregs_params *, int);
+int vm_rwvmparams(struct vm_rwvmparams_params *, int);
 int vm_find(uint32_t, struct vm **);
 int vcpu_readregs_vmx(struct vcpu *, uint64_t, struct vcpu_reg_state *);
 int vcpu_readregs_svm(struct vcpu *, uint64_t, struct vcpu_reg_state *);
@@ -485,6 +486,13 @@ vmmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
 	case VMM_IOC_WRITEREGS:
 		ret = vm_rwregs((struct vm_rwregs_params *)data, 1);
 		break;
+	case VMM_IOC_READVMPARAMS:
+		ret = vm_rwvmparams((struct vm_rwvmparams_params *)data, 0);
+		break;
+	case VMM_IOC_WRITEVMPARAMS:
+		ret = vm_rwvmparams((struct vm_rwvmparams_params *)data, 1);
+		break;
+
 	default:
 		DPRINTF("%s: unknown ioctl code 0x%lx\n", __func__, cmd);
 		ret = ENOTTY;
@@ -516,6 +524,8 @@ pledge_ioctl_vmm(struct proc *p, long com)
 	case VMM_IOC_INTR:
 	case VMM_IOC_READREGS:
 	case VMM_IOC_WRITEREGS:
+	case VMM_IOC_READVMPARAMS:
+	case VMM_IOC_WRITEVMPARAMS:
 		return (0);
 	}
 
@@ -667,6 +677,66 @@ vm_intr_pending(struct vm_intr_params *vip)
 }
 
 /*
+ * vm_rwvmparams
+ *
+ * IOCTL handler to read/write the current vmm params like pvclock gpa, pvclock
+ * version, etc.
+ *
+ * Parameters:
+ *   vrwp: Describes the VM and VCPU to get/set the params from
+ *   dir: 0 for reading, 1 for writing
+ *
+ * Return values:
+ *  0: if successful
+ *  ENOENT: if the VM/VCPU defined by 'vpp' cannot be found
+ *  EINVAL: if an error occured reading the registers of the guest
+ */
+int
+vm_rwvmparams(struct vm_rwvmparams_params *vpp, int dir) {
+	struct vm *vm;
+	struct vcpu *vcpu;
+	int error;
+
+	/* Find the desired VM */
+	rw_enter_read(&vmm_softc->vm_lock);
+	error = vm_find(vpp->vpp_vm_id, &vm);
+
+	/* Not found? exit. */
+	if (error != 0) {
+		rw_exit_read(&vmm_softc->vm_lock);
+		return (error);
+	}
+
+	rw_enter_read(&vm->vm_vcpu_lock);
+	SLIST_FOREACH(vcpu, &vm->vm_vcpu_list, vc_vcpu_link) {
+		if (vcpu->vc_id == vpp->vpp_vcpu_id)
+			break;
+	}
+	rw_exit_read(&vm->vm_vcpu_lock);
+	rw_exit_read(&vmm_softc->vm_lock);
+
+	if (vcpu == NULL)
+		return (ENOENT);
+
+	if (dir == 0) {
+		if (vpp->vpp_mask & VM_RWVMPARAMS_PVCLOCK_VERSION)
+			vpp->vpp_pvclock_version = vcpu->vc_pvclock_version;
+		if (vpp->vpp_mask & VM_RWVMPARAMS_PVCLOCK_SYSTEM_GPA)
+			vpp->vpp_pvclock_system_gpa = \
+			    vcpu->vc_pvclock_system_gpa;
+		return (0);
+	}
+
+	if (vpp->vpp_mask & VM_RWVMPARAMS_PVCLOCK_VERSION)
+		vcpu->vc_pvclock_version = vpp->vpp_pvclock_version;
+	if (vpp->vpp_mask & VM_RWVMPARAMS_PVCLOCK_SYSTEM_GPA) {
+		vmm_init_pvclock(vcpu, vpp->vpp_pvclock_system_gpa);
+	}
+	return (0);
+
+}
+
+/*
  * vm_readregs
  *
  * IOCTL handler to read/write the current register values of a guest VCPU.
diff --git a/sys/arch/amd64/include/vmmvar.h b/sys/arch/amd64/include/vmmvar.h
index e4df09f6f92..78c477291f2 100644
--- a/sys/arch/amd64/include/vmmvar.h
+++ b/sys/arch/amd64/include/vmmvar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vmmvar.h,v 1.66 2019/05/17 19:07:16 guenther Exp $	*/
+/*	$OpenBSD: vmmvar.h,v 1.67 2019/07/17 05:51:07 pd Exp $	*/
 /*
  * Copyright (c) 2014 Mike Larkin <mlarkin@openbsd.org>
  *
@@ -525,6 +525,20 @@ struct vm_intr_params {
 	uint16_t		vip_intr;
 };
 
+#define VM_RWVMPARAMS_PVCLOCK_SYSTEM_GPA 0x1	/* read/write pvclock gpa */
+#define VM_RWVMPARAMS_PVCLOCK_VERSION	 0x2	/* read/write pvclock version */
+#define VM_RWVMPARAMS_ALL	(VM_RWVMPARAMS_PVCLOCK_SYSTEM_GPA | \
+    VM_RWVMPARAMS_PVCLOCK_VERSION)
+
+struct vm_rwvmparams_params {
+	/* Input parameters to VMM_IOC_READVMPARAMS/VMM_IOC_WRITEVMPARAMS */
+	uint32_t		vpp_vm_id;
+	uint32_t		vpp_vcpu_id;
+	uint32_t		vpp_mask;
+	paddr_t			vpp_pvclock_system_gpa;
+	uint32_t		vpp_pvclock_version;
+};
+
 #define VM_RWREGS_GPRS	0x1	/* read/write GPRs */
 #define VM_RWREGS_SREGS	0x2	/* read/write segment registers */
 #define VM_RWREGS_CRS	0x4	/* read/write CRs */
@@ -553,6 +567,10 @@ struct vm_rwregs_params {
 #define VMM_IOC_INTR _IOW('V', 6, struct vm_intr_params) /* Intr pending */
 #define VMM_IOC_READREGS _IOWR('V', 7, struct vm_rwregs_params) /* Get regs */
 #define VMM_IOC_WRITEREGS _IOW('V', 8, struct vm_rwregs_params) /* Set regs */
+/* Get VM params */
+#define VMM_IOC_READVMPARAMS _IOWR('V', 9, struct vm_rwvmparams_params)
+/* Set VM params */
+#define VMM_IOC_WRITEVMPARAMS _IOW('V', 10, struct vm_rwvmparams_params)
 
 
 /* CPUID masks */