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-rw-r--r--arch/x86/kvm/vmx.c150
1 files changed, 86 insertions, 64 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3365e5dd3360..1444e4149c4d 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -118,6 +118,18 @@ struct vmcs {
char data[0];
};
+/*
+ * Track a VMCS that may be loaded on a certain CPU. If it is (cpu!=-1), also
+ * remember whether it was VMLAUNCHed, and maintain a linked list of all VMCSs
+ * loaded on this CPU (so we can clear them if the CPU goes down).
+ */
+struct loaded_vmcs {
+ struct vmcs *vmcs;
+ int cpu;
+ int launched;
+ struct list_head loaded_vmcss_on_cpu_link;
+};
+
struct shared_msr_entry {
unsigned index;
u64 data;
@@ -126,9 +138,7 @@ struct shared_msr_entry {
struct vcpu_vmx {
struct kvm_vcpu vcpu;
- struct list_head local_vcpus_link;
unsigned long host_rsp;
- int launched;
u8 fail;
u8 cpl;
bool nmi_known_unmasked;
@@ -142,7 +152,14 @@ struct vcpu_vmx {
u64 msr_host_kernel_gs_base;
u64 msr_guest_kernel_gs_base;
#endif
- struct vmcs *vmcs;
+ /*
+ * loaded_vmcs points to the VMCS currently used in this vcpu. For a
+ * non-nested (L1) guest, it always points to vmcs01. For a nested
+ * guest (L2), it points to a different VMCS.
+ */
+ struct loaded_vmcs vmcs01;
+ struct loaded_vmcs *loaded_vmcs;
+ bool __launched; /* temporary, used in vmx_vcpu_run */
struct msr_autoload {
unsigned nr;
struct vmx_msr_entry guest[NR_AUTOLOAD_MSRS];
@@ -202,7 +219,11 @@ static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr);
static DEFINE_PER_CPU(struct vmcs *, vmxarea);
static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
-static DEFINE_PER_CPU(struct list_head, vcpus_on_cpu);
+/*
+ * We maintain a per-CPU linked-list of VMCS loaded on that CPU. This is needed
+ * when a CPU is brought down, and we need to VMCLEAR all VMCSs loaded on it.
+ */
+static DEFINE_PER_CPU(struct list_head, loaded_vmcss_on_cpu);
static DEFINE_PER_CPU(struct desc_ptr, host_gdt);
static unsigned long *vmx_io_bitmap_a;
@@ -503,6 +524,13 @@ static void vmcs_clear(struct vmcs *vmcs)
vmcs, phys_addr);
}
+static inline void loaded_vmcs_init(struct loaded_vmcs *loaded_vmcs)
+{
+ vmcs_clear(loaded_vmcs->vmcs);
+ loaded_vmcs->cpu = -1;
+ loaded_vmcs->launched = 0;
+}
+
static void vmcs_load(struct vmcs *vmcs)
{
u64 phys_addr = __pa(vmcs);
@@ -516,25 +544,24 @@ static void vmcs_load(struct vmcs *vmcs)
vmcs, phys_addr);
}
-static void __vcpu_clear(void *arg)
+static void __loaded_vmcs_clear(void *arg)
{
- struct vcpu_vmx *vmx = arg;
+ struct loaded_vmcs *loaded_vmcs = arg;
int cpu = raw_smp_processor_id();
- if (vmx->vcpu.cpu == cpu)
- vmcs_clear(vmx->vmcs);
- if (per_cpu(current_vmcs, cpu) == vmx->vmcs)
+ if (loaded_vmcs->cpu != cpu)
+ return; /* vcpu migration can race with cpu offline */
+ if (per_cpu(current_vmcs, cpu) == loaded_vmcs->vmcs)
per_cpu(current_vmcs, cpu) = NULL;
- list_del(&vmx->local_vcpus_link);
- vmx->vcpu.cpu = -1;
- vmx->launched = 0;
+ list_del(&loaded_vmcs->loaded_vmcss_on_cpu_link);
+ loaded_vmcs_init(loaded_vmcs);
}
-static void vcpu_clear(struct vcpu_vmx *vmx)
+static void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs)
{
- if (vmx->vcpu.cpu == -1)
- return;
- smp_call_function_single(vmx->vcpu.cpu, __vcpu_clear, vmx, 1);
+ if (loaded_vmcs->cpu != -1)
+ smp_call_function_single(
+ loaded_vmcs->cpu, __loaded_vmcs_clear, loaded_vmcs, 1);
}
static inline void vpid_sync_vcpu_single(struct vcpu_vmx *vmx)
@@ -973,22 +1000,22 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
if (!vmm_exclusive)
kvm_cpu_vmxon(phys_addr);
- else if (vcpu->cpu != cpu)
- vcpu_clear(vmx);
+ else if (vmx->loaded_vmcs->cpu != cpu)
+ loaded_vmcs_clear(vmx->loaded_vmcs);
- if (per_cpu(current_vmcs, cpu) != vmx->vmcs) {
- per_cpu(current_vmcs, cpu) = vmx->vmcs;
- vmcs_load(vmx->vmcs);
+ if (per_cpu(current_vmcs, cpu) != vmx->loaded_vmcs->vmcs) {
+ per_cpu(current_vmcs, cpu) = vmx->loaded_vmcs->vmcs;
+ vmcs_load(vmx->loaded_vmcs->vmcs);
}
- if (vcpu->cpu != cpu) {
+ if (vmx->loaded_vmcs->cpu != cpu) {
struct desc_ptr *gdt = &__get_cpu_var(host_gdt);
unsigned long sysenter_esp;
kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
local_irq_disable();
- list_add(&vmx->local_vcpus_link,
- &per_cpu(vcpus_on_cpu, cpu));
+ list_add(&vmx->loaded_vmcs->loaded_vmcss_on_cpu_link,
+ &per_cpu(loaded_vmcss_on_cpu, cpu));
local_irq_enable();
/*
@@ -1000,6 +1027,7 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp);
vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */
+ vmx->loaded_vmcs->cpu = cpu;
}
}
@@ -1007,7 +1035,8 @@ static void vmx_vcpu_put(struct kvm_vcpu *vcpu)
{
__vmx_load_host_state(to_vmx(vcpu));
if (!vmm_exclusive) {
- __vcpu_clear(to_vmx(vcpu));
+ __loaded_vmcs_clear(to_vmx(vcpu)->loaded_vmcs);
+ vcpu->cpu = -1;
kvm_cpu_vmxoff();
}
}
@@ -1471,7 +1500,7 @@ static int hardware_enable(void *garbage)
if (read_cr4() & X86_CR4_VMXE)
return -EBUSY;
- INIT_LIST_HEAD(&per_cpu(vcpus_on_cpu, cpu));
+ INIT_LIST_HEAD(&per_cpu(loaded_vmcss_on_cpu, cpu));
rdmsrl(MSR_IA32_FEATURE_CONTROL, old);
test_bits = FEATURE_CONTROL_LOCKED;
@@ -1495,14 +1524,14 @@ static int hardware_enable(void *garbage)
return 0;
}
-static void vmclear_local_vcpus(void)
+static void vmclear_local_loaded_vmcss(void)
{
int cpu = raw_smp_processor_id();
- struct vcpu_vmx *vmx, *n;
+ struct loaded_vmcs *v, *n;
- list_for_each_entry_safe(vmx, n, &per_cpu(vcpus_on_cpu, cpu),
- local_vcpus_link)
- __vcpu_clear(vmx);
+ list_for_each_entry_safe(v, n, &per_cpu(loaded_vmcss_on_cpu, cpu),
+ loaded_vmcss_on_cpu_link)
+ __loaded_vmcs_clear(v);
}
@@ -1517,7 +1546,7 @@ static void kvm_cpu_vmxoff(void)
static void hardware_disable(void *garbage)
{
if (vmm_exclusive) {
- vmclear_local_vcpus();
+ vmclear_local_loaded_vmcss();
kvm_cpu_vmxoff();
}
write_cr4(read_cr4() & ~X86_CR4_VMXE);
@@ -1698,6 +1727,18 @@ static void free_vmcs(struct vmcs *vmcs)
free_pages((unsigned long)vmcs, vmcs_config.order);
}
+/*
+ * Free a VMCS, but before that VMCLEAR it on the CPU where it was last loaded
+ */
+static void free_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
+{
+ if (!loaded_vmcs->vmcs)
+ return;
+ loaded_vmcs_clear(loaded_vmcs);
+ free_vmcs(loaded_vmcs->vmcs);
+ loaded_vmcs->vmcs = NULL;
+}
+
static void free_kvm_area(void)
{
int cpu;
@@ -4169,6 +4210,7 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
vmx_set_interrupt_shadow(vcpu, 0);
+ vmx->__launched = vmx->loaded_vmcs->launched;
asm(
/* Store host registers */
"push %%"R"dx; push %%"R"bp;"
@@ -4239,7 +4281,7 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
"pop %%"R"bp; pop %%"R"dx \n\t"
"setbe %c[fail](%0) \n\t"
: : "c"(vmx), "d"((unsigned long)HOST_RSP),
- [launched]"i"(offsetof(struct vcpu_vmx, launched)),
+ [launched]"i"(offsetof(struct vcpu_vmx, __launched)),
[fail]"i"(offsetof(struct vcpu_vmx, fail)),
[host_rsp]"i"(offsetof(struct vcpu_vmx, host_rsp)),
[rax]"i"(offsetof(struct vcpu_vmx, vcpu.arch.regs[VCPU_REGS_RAX])),
@@ -4279,7 +4321,7 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
vmx->idt_vectoring_info = vmcs_read32(IDT_VECTORING_INFO_FIELD);
asm("mov %0, %%ds; mov %0, %%es" : : "r"(__USER_DS));
- vmx->launched = 1;
+ vmx->loaded_vmcs->launched = 1;
vmx->exit_reason = vmcs_read32(VM_EXIT_REASON);
@@ -4291,41 +4333,17 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
#undef R
#undef Q
-static void vmx_free_vmcs(struct kvm_vcpu *vcpu)
-{
- struct vcpu_vmx *vmx = to_vmx(vcpu);
-
- if (vmx->vmcs) {
- vcpu_clear(vmx);
- free_vmcs(vmx->vmcs);
- vmx->vmcs = NULL;
- }
-}
-
static void vmx_free_vcpu(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
free_vpid(vmx);
- vmx_free_vmcs(vcpu);
+ free_loaded_vmcs(vmx->loaded_vmcs);
kfree(vmx->guest_msrs);
kvm_vcpu_uninit(vcpu);
kmem_cache_free(kvm_vcpu_cache, vmx);
}
-static inline void vmcs_init(struct vmcs *vmcs)
-{
- u64 phys_addr = __pa(per_cpu(vmxarea, raw_smp_processor_id()));
-
- if (!vmm_exclusive)
- kvm_cpu_vmxon(phys_addr);
-
- vmcs_clear(vmcs);
-
- if (!vmm_exclusive)
- kvm_cpu_vmxoff();
-}
-
static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
{
int err;
@@ -4347,11 +4365,15 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
goto uninit_vcpu;
}
- vmx->vmcs = alloc_vmcs();
- if (!vmx->vmcs)
+ vmx->loaded_vmcs = &vmx->vmcs01;
+ vmx->loaded_vmcs->vmcs = alloc_vmcs();
+ if (!vmx->loaded_vmcs->vmcs)
goto free_msrs;
-
- vmcs_init(vmx->vmcs);
+ if (!vmm_exclusive)
+ kvm_cpu_vmxon(__pa(per_cpu(vmxarea, raw_smp_processor_id())));
+ loaded_vmcs_init(vmx->loaded_vmcs);
+ if (!vmm_exclusive)
+ kvm_cpu_vmxoff();
cpu = get_cpu();
vmx_vcpu_load(&vmx->vcpu, cpu);
@@ -4380,7 +4402,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
return &vmx->vcpu;
free_vmcs:
- free_vmcs(vmx->vmcs);
+ free_vmcs(vmx->loaded_vmcs->vmcs);
free_msrs:
kfree(vmx->guest_msrs);
uninit_vcpu: