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authorJohn Baldwin <jhb@FreeBSD.org>2022-11-18 18:06:08 +0000
committerJohn Baldwin <jhb@FreeBSD.org>2022-11-18 18:25:39 +0000
commitee98f99d7a68b284a669fefb969cbfc31df2d0ab (patch)
treef64e2e8bd1e6240cdaf242f5eb66cd341564e9df
parent98568a005a193ce2c37702a8377ddd10c570e452 (diff)
downloadsrc-ee98f99d7a68.tar.gz
src-ee98f99d7a68.zip
vmm: Convert VM_MAXCPU into a loader tunable hw.vmm.maxcpu.
The default is now the number of physical CPUs in the system rather than 16. Reviewed by: corvink, markj Differential Revision: https://reviews.freebsd.org/D37175
-rw-r--r--sys/amd64/include/vmm.h6
-rw-r--r--sys/amd64/vmm/intel/vmx.c10
-rw-r--r--sys/amd64/vmm/vmm.c29
-rw-r--r--sys/amd64/vmm/vmm_stat.c2
4 files changed, 35 insertions, 12 deletions
diff --git a/sys/amd64/include/vmm.h b/sys/amd64/include/vmm.h
index c6194c32b095..fddc15d2f17c 100644
--- a/sys/amd64/include/vmm.h
+++ b/sys/amd64/include/vmm.h
@@ -218,6 +218,8 @@ struct vmm_ops {
extern const struct vmm_ops vmm_ops_intel;
extern const struct vmm_ops vmm_ops_amd;
+extern u_int vm_maxcpu; /* maximum virtual cpus */
+
int vm_create(const char *name, struct vm **retvm);
struct vcpu *vm_alloc_vcpu(struct vm *vm, int vcpuid);
void vm_disable_vcpu_creation(struct vm *vm);
@@ -481,10 +483,6 @@ int vcpu_trace_exceptions(struct vcpu *vcpu);
int vcpu_trap_wbinvd(struct vcpu *vcpu);
#endif /* KERNEL */
-#ifdef _KERNEL
-#define VM_MAXCPU 16 /* maximum virtual cpus */
-#endif
-
/*
* Identifiers for optional vmm capabilities
*/
diff --git a/sys/amd64/vmm/intel/vmx.c b/sys/amd64/vmm/intel/vmx.c
index 52573416ded7..baf62c1f8e8a 100644
--- a/sys/amd64/vmm/intel/vmx.c
+++ b/sys/amd64/vmm/intel/vmx.c
@@ -519,11 +519,11 @@ vpid_free(int vpid)
panic("vpid_free: invalid vpid %d", vpid);
/*
- * VPIDs [0,VM_MAXCPU] are special and are not allocated from
+ * VPIDs [0,vm_maxcpu] are special and are not allocated from
* the unit number allocator.
*/
- if (vpid > VM_MAXCPU)
+ if (vpid > vm_maxcpu)
free_unr(vpid_unr, vpid);
}
@@ -550,7 +550,7 @@ vpid_alloc(int vcpuid)
/*
* If the unit number allocator does not have enough unique
- * VPIDs then we need to allocate from the [1,VM_MAXCPU] range.
+ * VPIDs then we need to allocate from the [1,vm_maxcpu] range.
*
* These VPIDs are not be unique across VMs but this does not
* affect correctness because the combined mappings are also
@@ -572,13 +572,13 @@ vpid_init(void)
* VPID 0 is required when the "enable VPID" execution control is
* disabled.
*
- * VPIDs [1,VM_MAXCPU] are used as the "overflow namespace" when the
+ * VPIDs [1,vm_maxcpu] are used as the "overflow namespace" when the
* unit number allocator does not have sufficient unique VPIDs to
* satisfy the allocation.
*
* The remaining VPIDs are managed by the unit number allocator.
*/
- vpid_unr = new_unrhdr(VM_MAXCPU + 1, 0xffff, NULL);
+ vpid_unr = new_unrhdr(vm_maxcpu + 1, 0xffff, NULL);
}
static void
diff --git a/sys/amd64/vmm/vmm.c b/sys/amd64/vmm/vmm.c
index 7cde7b4005c4..0ebf80e94131 100644
--- a/sys/amd64/vmm/vmm.c
+++ b/sys/amd64/vmm/vmm.c
@@ -186,7 +186,7 @@ struct vm {
struct mem_seg mem_segs[VM_MAX_MEMSEGS]; /* (o) [m+v] guest memory regions */
struct vmspace *vmspace; /* (o) guest's address space */
char name[VM_MAX_NAMELEN+1]; /* (o) virtual machine name */
- struct vcpu *vcpu[VM_MAXCPU]; /* (x) guest vcpus */
+ struct vcpu **vcpu; /* (o) guest vcpus */
/* The following describe the vm cpu topology */
uint16_t sockets; /* (o) num of sockets */
uint16_t cores; /* (o) num of cores/socket */
@@ -295,10 +295,22 @@ static int trap_wbinvd;
SYSCTL_INT(_hw_vmm, OID_AUTO, trap_wbinvd, CTLFLAG_RDTUN, &trap_wbinvd, 0,
"WBINVD triggers a VM-exit");
+u_int vm_maxcpu;
+SYSCTL_UINT(_hw_vmm, OID_AUTO, maxcpu, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
+ &vm_maxcpu, 0, "Maximum number of vCPUs");
+
static void vm_free_memmap(struct vm *vm, int ident);
static bool sysmem_mapping(struct vm *vm, struct mem_map *mm);
static void vcpu_notify_event_locked(struct vcpu *vcpu, bool lapic_intr);
+/*
+ * Upper limit on vm_maxcpu. Limited by use of uint16_t types for CPU
+ * counts as well as range of vpid values for VT-x and by the capacity
+ * of cpuset_t masks. The call to new_unrhdr() in vpid_init() in
+ * vmx.c requires 'vm_maxcpu + 1 <= 0xffff', hence the '- 1' below.
+ */
+#define VM_MAXCPU MIN(0xffff - 1, CPU_SETSIZE)
+
#ifdef KTR
static const char *
vcpu_state2str(enum vcpu_state state)
@@ -395,6 +407,16 @@ vmm_init(void)
if (!vmm_is_hw_supported())
return (ENXIO);
+ vm_maxcpu = mp_ncpus;
+ TUNABLE_INT_FETCH("hw.vmm.maxcpu", &vm_maxcpu);
+
+ if (vm_maxcpu > VM_MAXCPU) {
+ printf("vmm: vm_maxcpu clamped to %u\n", VM_MAXCPU);
+ vm_maxcpu = VM_MAXCPU;
+ }
+ if (vm_maxcpu == 0)
+ vm_maxcpu = 1;
+
vmm_host_state_init();
vmm_ipinum = lapic_ipi_alloc(pti ? &IDTVEC(justreturn1_pti) :
@@ -579,11 +601,13 @@ vm_create(const char *name, struct vm **retvm)
mtx_init(&vm->rendezvous_mtx, "vm rendezvous lock", 0, MTX_DEF);
sx_init(&vm->mem_segs_lock, "vm mem_segs");
sx_init(&vm->vcpus_init_lock, "vm vcpus");
+ vm->vcpu = malloc(sizeof(*vm->vcpu) * vm_maxcpu, M_VM, M_WAITOK |
+ M_ZERO);
vm->sockets = 1;
vm->cores = cores_per_package; /* XXX backwards compatibility */
vm->threads = threads_per_core; /* XXX backwards compatibility */
- vm->maxcpus = VM_MAXCPU; /* XXX temp to keep code working */
+ vm->maxcpus = vm_maxcpu;
vm_init(vm, true);
@@ -669,6 +693,7 @@ vm_cleanup(struct vm *vm, bool destroy)
vmmops_vmspace_free(vm->vmspace);
vm->vmspace = NULL;
+ free(vm->vcpu, M_VM);
sx_destroy(&vm->vcpus_init_lock);
sx_destroy(&vm->mem_segs_lock);
mtx_destroy(&vm->rendezvous_mtx);
diff --git a/sys/amd64/vmm/vmm_stat.c b/sys/amd64/vmm/vmm_stat.c
index 168a380b221b..2750982185aa 100644
--- a/sys/amd64/vmm/vmm_stat.c
+++ b/sys/amd64/vmm/vmm_stat.c
@@ -71,7 +71,7 @@ vmm_stat_register(void *arg)
return;
if (vst->nelems == VMM_STAT_NELEMS_VCPU)
- vst->nelems = VM_MAXCPU;
+ vst->nelems = vm_maxcpu;
if (vst_num_elems + vst->nelems >= MAX_VMM_STAT_ELEMS) {
printf("Cannot accommodate vmm stat type \"%s\"!\n", vst->desc);