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KVM: VMX: require virtual NMI support

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Virtual NMIs are only missing in Prescott and Yonah chips.  Both are obsolete
for virtualization usage---Yonah is 32-bit only even---so drop vNMI emulation.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2017-03-27 14:37:28 +02:00 committed by Radim Krčmář
parent 74f169090b
commit 2c82878b0c
1 changed files with 38 additions and 105 deletions
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143
arch/x86/kvm/vmx.c
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@ -615,10 +615,6 @@ struct vcpu_vmx {
int vpid; int vpid;
bool emulation_required; bool emulation_required;
/* Support for vnmi-less CPUs */
int soft_vnmi_blocked;
ktime_t entry_time;
s64 vnmi_blocked_time;
u32 exit_reason; u32 exit_reason;
/* Posted interrupt descriptor */ /* Posted interrupt descriptor */
@ -1290,11 +1286,6 @@ static inline bool cpu_has_vmx_invpcid(void)
SECONDARY_EXEC_ENABLE_INVPCID; SECONDARY_EXEC_ENABLE_INVPCID;
} }
static inline bool cpu_has_virtual_nmis(void)
{
return vmcs_config.pin_based_exec_ctrl & PIN_BASED_VIRTUAL_NMIS;
}
static inline bool cpu_has_vmx_wbinvd_exit(void) static inline bool cpu_has_vmx_wbinvd_exit(void)
{ {
return vmcs_config.cpu_based_2nd_exec_ctrl & return vmcs_config.cpu_based_2nd_exec_ctrl &
@ -3623,9 +3614,9 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf)
&_vmexit_control) < 0) &_vmexit_control) < 0)
return -EIO; return -EIO;
min = PIN_BASED_EXT_INTR_MASK | PIN_BASED_NMI_EXITING; min = PIN_BASED_EXT_INTR_MASK | PIN_BASED_NMI_EXITING |
opt = PIN_BASED_VIRTUAL_NMIS | PIN_BASED_POSTED_INTR | PIN_BASED_VIRTUAL_NMIS;
PIN_BASED_VMX_PREEMPTION_TIMER; opt = PIN_BASED_POSTED_INTR | PIN_BASED_VMX_PREEMPTION_TIMER;
if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PINBASED_CTLS, if (adjust_vmx_controls(min, opt, MSR_IA32_VMX_PINBASED_CTLS,
&_pin_based_exec_control) < 0) &_pin_based_exec_control) < 0)
return -EIO; return -EIO;
@ -5298,8 +5289,6 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
vmx->rmode.vm86_active = 0; vmx->rmode.vm86_active = 0;
vmx->soft_vnmi_blocked = 0;
vmx->vcpu.arch.regs[VCPU_REGS_RDX] = get_rdx_init_val(); vmx->vcpu.arch.regs[VCPU_REGS_RDX] = get_rdx_init_val();
kvm_set_cr8(vcpu, 0); kvm_set_cr8(vcpu, 0);
@ -5419,8 +5408,7 @@ static void enable_irq_window(struct kvm_vcpu *vcpu)
static void enable_nmi_window(struct kvm_vcpu *vcpu) static void enable_nmi_window(struct kvm_vcpu *vcpu)
{ {
if (!cpu_has_virtual_nmis() || if (vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & GUEST_INTR_STATE_STI) {
vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & GUEST_INTR_STATE_STI) {
enable_irq_window(vcpu); enable_irq_window(vcpu);
return; return;
} }
@ -5461,19 +5449,6 @@ static void vmx_inject_nmi(struct kvm_vcpu *vcpu)
struct vcpu_vmx *vmx = to_vmx(vcpu); struct vcpu_vmx *vmx = to_vmx(vcpu);
if (!is_guest_mode(vcpu)) { if (!is_guest_mode(vcpu)) {
if (!cpu_has_virtual_nmis()) {
/*
* Tracking the NMI-blocked state in software is built upon
* finding the next open IRQ window. This, in turn, depends on
* well-behaving guests: They have to keep IRQs disabled at
* least as long as the NMI handler runs. Otherwise we may
* cause NMI nesting, maybe breaking the guest. But as this is
* highly unlikely, we can live with the residual risk.
*/
vmx->soft_vnmi_blocked = 1;
vmx->vnmi_blocked_time = 0;
}
++vcpu->stat.nmi_injections; ++vcpu->stat.nmi_injections;
vmx->nmi_known_unmasked = false; vmx->nmi_known_unmasked = false;
} }
@ -5490,8 +5465,6 @@ static void vmx_inject_nmi(struct kvm_vcpu *vcpu)
static bool vmx_get_nmi_mask(struct kvm_vcpu *vcpu) static bool vmx_get_nmi_mask(struct kvm_vcpu *vcpu)
{ {
if (!cpu_has_virtual_nmis())
return to_vmx(vcpu)->soft_vnmi_blocked;
if (to_vmx(vcpu)->nmi_known_unmasked) if (to_vmx(vcpu)->nmi_known_unmasked)
return false; return false;
return vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & GUEST_INTR_STATE_NMI; return vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & GUEST_INTR_STATE_NMI;
@ -5501,20 +5474,13 @@ static void vmx_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked)
{ {
struct vcpu_vmx *vmx = to_vmx(vcpu); struct vcpu_vmx *vmx = to_vmx(vcpu);
if (!cpu_has_virtual_nmis()) { vmx->nmi_known_unmasked = !masked;
if (vmx->soft_vnmi_blocked != masked) { if (masked)
vmx->soft_vnmi_blocked = masked; vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO,
vmx->vnmi_blocked_time = 0; GUEST_INTR_STATE_NMI);
} else
} else { vmcs_clear_bits(GUEST_INTERRUPTIBILITY_INFO,
vmx->nmi_known_unmasked = !masked; GUEST_INTR_STATE_NMI);
if (masked)
vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO,
GUEST_INTR_STATE_NMI);
else
vmcs_clear_bits(GUEST_INTERRUPTIBILITY_INFO,
GUEST_INTR_STATE_NMI);
}
} }
static int vmx_nmi_allowed(struct kvm_vcpu *vcpu) static int vmx_nmi_allowed(struct kvm_vcpu *vcpu)
@ -5522,9 +5488,6 @@ static int vmx_nmi_allowed(struct kvm_vcpu *vcpu)
if (to_vmx(vcpu)->nested.nested_run_pending) if (to_vmx(vcpu)->nested.nested_run_pending)
return 0; return 0;
if (!cpu_has_virtual_nmis() && to_vmx(vcpu)->soft_vnmi_blocked)
return 0;
return !(vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & return !(vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) &
(GUEST_INTR_STATE_MOV_SS | GUEST_INTR_STATE_STI (GUEST_INTR_STATE_MOV_SS | GUEST_INTR_STATE_STI
| GUEST_INTR_STATE_NMI)); | GUEST_INTR_STATE_NMI));
@ -6269,7 +6232,6 @@ static int handle_ept_violation(struct kvm_vcpu *vcpu)
* AAK134, BY25. * AAK134, BY25.
*/ */
if (!(to_vmx(vcpu)->idt_vectoring_info & VECTORING_INFO_VALID_MASK) && if (!(to_vmx(vcpu)->idt_vectoring_info & VECTORING_INFO_VALID_MASK) &&
cpu_has_virtual_nmis() &&
(exit_qualification & INTR_INFO_UNBLOCK_NMI)) (exit_qualification & INTR_INFO_UNBLOCK_NMI))
vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO, GUEST_INTR_STATE_NMI); vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO, GUEST_INTR_STATE_NMI);
@ -7820,7 +7782,6 @@ static int handle_pml_full(struct kvm_vcpu *vcpu)
* "blocked by NMI" bit has to be set before next VM entry. * "blocked by NMI" bit has to be set before next VM entry.
*/ */
if (!(to_vmx(vcpu)->idt_vectoring_info & VECTORING_INFO_VALID_MASK) && if (!(to_vmx(vcpu)->idt_vectoring_info & VECTORING_INFO_VALID_MASK) &&
cpu_has_virtual_nmis() &&
(exit_qualification & INTR_INFO_UNBLOCK_NMI)) (exit_qualification & INTR_INFO_UNBLOCK_NMI))
vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO, vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO,
GUEST_INTR_STATE_NMI); GUEST_INTR_STATE_NMI);
@ -8492,26 +8453,6 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu)
return 0; return 0;
} }
if (unlikely(!cpu_has_virtual_nmis() && vmx->soft_vnmi_blocked &&
!(is_guest_mode(vcpu) && nested_cpu_has_virtual_nmis(
get_vmcs12(vcpu))))) {
if (vmx_interrupt_allowed(vcpu)) {
vmx->soft_vnmi_blocked = 0;
} else if (vmx->vnmi_blocked_time > 1000000000LL &&
vcpu->arch.nmi_pending) {
/*
* This CPU don't support us in finding the end of an
* NMI-blocked window if the guest runs with IRQs
* disabled. So we pull the trigger after 1 s of
* futile waiting, but inform the user about this.
*/
printk(KERN_WARNING "%s: Breaking out of NMI-blocked "
"state on VCPU %d after 1 s timeout\n",
__func__, vcpu->vcpu_id);
vmx->soft_vnmi_blocked = 0;
}
}
if (exit_reason < kvm_vmx_max_exit_handlers if (exit_reason < kvm_vmx_max_exit_handlers
&& kvm_vmx_exit_handlers[exit_reason]) && kvm_vmx_exit_handlers[exit_reason])
return kvm_vmx_exit_handlers[exit_reason](vcpu); return kvm_vmx_exit_handlers[exit_reason](vcpu);
@ -8787,37 +8728,33 @@ static void vmx_recover_nmi_blocking(struct vcpu_vmx *vmx)
idtv_info_valid = vmx->idt_vectoring_info & VECTORING_INFO_VALID_MASK; idtv_info_valid = vmx->idt_vectoring_info & VECTORING_INFO_VALID_MASK;
if (cpu_has_virtual_nmis()) { if (vmx->nmi_known_unmasked)
if (vmx->nmi_known_unmasked) return;
return; /*
/* * Can't use vmx->exit_intr_info since we're not sure what
* Can't use vmx->exit_intr_info since we're not sure what * the exit reason is.
* the exit reason is. */
*/ exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO); unblock_nmi = (exit_intr_info & INTR_INFO_UNBLOCK_NMI) != 0;
unblock_nmi = (exit_intr_info & INTR_INFO_UNBLOCK_NMI) != 0; vector = exit_intr_info & INTR_INFO_VECTOR_MASK;
vector = exit_intr_info & INTR_INFO_VECTOR_MASK; /*
/* * SDM 3: 27.7.1.2 (September 2008)
* SDM 3: 27.7.1.2 (September 2008) * Re-set bit "block by NMI" before VM entry if vmexit caused by
* Re-set bit "block by NMI" before VM entry if vmexit caused by * a guest IRET fault.
* a guest IRET fault. * SDM 3: 23.2.2 (September 2008)
* SDM 3: 23.2.2 (September 2008) * Bit 12 is undefined in any of the following cases:
* Bit 12 is undefined in any of the following cases: * If the VM exit sets the valid bit in the IDT-vectoring
* If the VM exit sets the valid bit in the IDT-vectoring * information field.
* information field. * If the VM exit is due to a double fault.
* If the VM exit is due to a double fault. */
*/ if ((exit_intr_info & INTR_INFO_VALID_MASK) && unblock_nmi &&
if ((exit_intr_info & INTR_INFO_VALID_MASK) && unblock_nmi && vector != DF_VECTOR && !idtv_info_valid)
vector != DF_VECTOR && !idtv_info_valid) vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO,
vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO, GUEST_INTR_STATE_NMI);
GUEST_INTR_STATE_NMI); else
else vmx->nmi_known_unmasked =
vmx->nmi_known_unmasked = !(vmcs_read32(GUEST_INTERRUPTIBILITY_INFO)
!(vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & GUEST_INTR_STATE_NMI);
& GUEST_INTR_STATE_NMI);
} else if (unlikely(vmx->soft_vnmi_blocked))
vmx->vnmi_blocked_time +=
ktime_to_ns(ktime_sub(ktime_get(), vmx->entry_time));
} }
static void __vmx_complete_interrupts(struct kvm_vcpu *vcpu, static void __vmx_complete_interrupts(struct kvm_vcpu *vcpu,
@ -8934,10 +8871,6 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
struct vcpu_vmx *vmx = to_vmx(vcpu); struct vcpu_vmx *vmx = to_vmx(vcpu);
unsigned long debugctlmsr, cr4; unsigned long debugctlmsr, cr4;
/* Record the guest's net vcpu time for enforced NMI injections. */
if (unlikely(!cpu_has_virtual_nmis() && vmx->soft_vnmi_blocked))
vmx->entry_time = ktime_get();
/* Don't enter VMX if guest state is invalid, let the exit handler /* Don't enter VMX if guest state is invalid, let the exit handler
start emulation until we arrive back to a valid state */ start emulation until we arrive back to a valid state */
if (vmx->emulation_required) if (vmx->emulation_required)