@@ -31,6 +31,7 @@
#include <linux/ftrace_event.h>
#include <linux/slab.h>
#include <linux/tboot.h>
+#include <linux/hrtimer.h>
#include "kvm_cache_regs.h"
#include "x86.h"
@@ -110,6 +111,8 @@ module_param(nested, bool, S_IRUGO);
#define RMODE_GUEST_OWNED_EFLAGS_BITS (~(X86_EFLAGS_IOPL | X86_EFLAGS_VM))
+#define VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE 5
+
/*
* These 2 parameters are used to config the controls for Pause-Loop Exiting:
* ple_gap: upper bound on the amount of time between two successive
@@ -374,6 +377,9 @@ struct nested_vmx {
*/
struct page *apic_access_page;
u64 msr_ia32_feature_control;
+
+ struct hrtimer preemption_timer;
+ bool preemption_timer_expired;
};
#define POSTED_INTR_ON 0
@@ -1047,6 +1053,12 @@ static inline bool nested_cpu_has_virtual_nmis(struct vmcs12 *vmcs12)
return vmcs12->pin_based_vm_exec_control & PIN_BASED_VIRTUAL_NMIS;
}
+static inline bool nested_cpu_has_preemption_timer(struct vmcs12 *vmcs12)
+{
+ return vmcs12->pin_based_vm_exec_control &
+ PIN_BASED_VMX_PREEMPTION_TIMER;
+}
+
static inline int nested_cpu_has_ept(struct vmcs12 *vmcs12)
{
return nested_cpu_has2(vmcs12, SECONDARY_EXEC_ENABLE_EPT);
@@ -2248,9 +2260,9 @@ static __init void nested_vmx_setup_ctls_msrs(void)
*/
nested_vmx_pinbased_ctls_low |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
nested_vmx_pinbased_ctls_high &= PIN_BASED_EXT_INTR_MASK |
- PIN_BASED_NMI_EXITING | PIN_BASED_VIRTUAL_NMIS |
+ PIN_BASED_NMI_EXITING | PIN_BASED_VIRTUAL_NMIS;
+ nested_vmx_pinbased_ctls_high |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR |
PIN_BASED_VMX_PREEMPTION_TIMER;
- nested_vmx_pinbased_ctls_high |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
/*
* Exit controls
@@ -2265,15 +2277,10 @@ static __init void nested_vmx_setup_ctls_msrs(void)
#ifdef CONFIG_X86_64
VM_EXIT_HOST_ADDR_SPACE_SIZE |
#endif
- VM_EXIT_LOAD_IA32_PAT | VM_EXIT_SAVE_IA32_PAT |
+ VM_EXIT_LOAD_IA32_PAT | VM_EXIT_SAVE_IA32_PAT;
+ nested_vmx_exit_ctls_high |= VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR |
+ VM_EXIT_LOAD_IA32_EFER | VM_EXIT_SAVE_IA32_EFER |
VM_EXIT_SAVE_VMX_PREEMPTION_TIMER;
- if (!(nested_vmx_pinbased_ctls_high & PIN_BASED_VMX_PREEMPTION_TIMER) ||
- !(nested_vmx_exit_ctls_high & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER)) {
- nested_vmx_exit_ctls_high &= ~VM_EXIT_SAVE_VMX_PREEMPTION_TIMER;
- nested_vmx_pinbased_ctls_high &= ~PIN_BASED_VMX_PREEMPTION_TIMER;
- }
- nested_vmx_exit_ctls_high |= (VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR |
- VM_EXIT_LOAD_IA32_EFER | VM_EXIT_SAVE_IA32_EFER);
/* entry controls */
rdmsr(MSR_IA32_VMX_ENTRY_CTLS,
@@ -2342,9 +2349,9 @@ static __init void nested_vmx_setup_ctls_msrs(void)
/* miscellaneous data */
rdmsr(MSR_IA32_VMX_MISC, nested_vmx_misc_low, nested_vmx_misc_high);
- nested_vmx_misc_low &= VMX_MISC_PREEMPTION_TIMER_RATE_MASK |
- VMX_MISC_SAVE_EFER_LMA;
- nested_vmx_misc_low |= VMX_MISC_ACTIVITY_HLT;
+ nested_vmx_misc_low &= VMX_MISC_SAVE_EFER_LMA;
+ nested_vmx_misc_low |= VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE |
+ VMX_MISC_ACTIVITY_HLT;
nested_vmx_misc_high = 0;
}
@@ -5702,6 +5709,18 @@ static void nested_vmx_failValid(struct kvm_vcpu *vcpu,
*/
}
+static enum hrtimer_restart vmx_preemption_timer_fn(struct hrtimer *timer)
+{
+ struct vcpu_vmx *vmx =
+ container_of(timer, struct vcpu_vmx, nested.preemption_timer);
+
+ vmx->nested.preemption_timer_expired = true;
+ kvm_make_request(KVM_REQ_EVENT, &vmx->vcpu);
+ kvm_vcpu_kick(&vmx->vcpu);
+
+ return HRTIMER_NORESTART;
+}
+
/*
* Emulate the VMXON instruction.
* Currently, we just remember that VMX is active, and do not save or even
@@ -5766,6 +5785,10 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
INIT_LIST_HEAD(&(vmx->nested.vmcs02_pool));
vmx->nested.vmcs02_num = 0;
+ hrtimer_init(&vmx->nested.preemption_timer, CLOCK_MONOTONIC,
+ HRTIMER_MODE_REL);
+ vmx->nested.preemption_timer.function = vmx_preemption_timer_fn;
+
vmx->nested.vmxon = true;
skip_emulated_instruction(vcpu);
@@ -6745,9 +6768,6 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
* table is L0's fault.
*/
return 0;
- case EXIT_REASON_PREEMPTION_TIMER:
- return vmcs12->pin_based_vm_exec_control &
- PIN_BASED_VMX_PREEMPTION_TIMER;
case EXIT_REASON_WBINVD:
return nested_cpu_has2(vmcs12, SECONDARY_EXEC_WBINVD_EXITING);
case EXIT_REASON_XSETBV:
@@ -6763,27 +6783,6 @@ static void vmx_get_exit_info(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2)
*info2 = vmcs_read32(VM_EXIT_INTR_INFO);
}
-static void nested_adjust_preemption_timer(struct kvm_vcpu *vcpu)
-{
- u64 delta_tsc_l1;
- u32 preempt_val_l1, preempt_val_l2, preempt_scale;
-
- if (!(get_vmcs12(vcpu)->pin_based_vm_exec_control &
- PIN_BASED_VMX_PREEMPTION_TIMER))
- return;
- preempt_scale = native_read_msr(MSR_IA32_VMX_MISC) &
- MSR_IA32_VMX_MISC_PREEMPTION_TIMER_SCALE;
- preempt_val_l2 = vmcs_read32(VMX_PREEMPTION_TIMER_VALUE);
- delta_tsc_l1 = vmx_read_l1_tsc(vcpu, native_read_tsc())
- - vcpu->arch.last_guest_tsc;
- preempt_val_l1 = delta_tsc_l1 >> preempt_scale;
- if (preempt_val_l2 <= preempt_val_l1)
- preempt_val_l2 = 0;
- else
- preempt_val_l2 -= preempt_val_l1;
- vmcs_write32(VMX_PREEMPTION_TIMER_VALUE, preempt_val_l2);
-}
-
/*
* The guest has exited. See if we can fix it or if we need userspace
* assistance.
@@ -7196,8 +7195,6 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
atomic_switch_perf_msrs(vmx);
debugctlmsr = get_debugctlmsr();
- if (is_guest_mode(vcpu) && !vmx->nested.nested_run_pending)
- nested_adjust_preemption_timer(vcpu);
vmx->__launched = vmx->loaded_vmcs->launched;
asm(
/* Store host registers */
@@ -7594,6 +7591,28 @@ static void vmx_inject_page_fault_nested(struct kvm_vcpu *vcpu,
kvm_inject_page_fault(vcpu, fault);
}
+static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu)
+{
+ u64 preemption_timeout = get_vmcs12(vcpu)->vmx_preemption_timer_value;
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+ if (vcpu->arch.virtual_tsc_khz == 0)
+ return;
+
+ /* Make sure short timeouts reliably trigger an immediate vmexit.
+ * hrtimer_start does not guarantee this. */
+ if (preemption_timeout <= 1) {
+ vmx_preemption_timer_fn(&vmx->nested.preemption_timer);
+ return;
+ }
+
+ preemption_timeout <<= VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE;
+ preemption_timeout *= 1000000;
+ do_div(preemption_timeout, vcpu->arch.virtual_tsc_khz);
+ hrtimer_start(&vmx->nested.preemption_timer,
+ ns_to_ktime(preemption_timeout), HRTIMER_MODE_REL);
+}
+
/*
* prepare_vmcs02 is called when the L1 guest hypervisor runs its nested
* L2 guest. L1 has a vmcs for L2 (vmcs12), and this function "merges" it
@@ -7607,7 +7626,6 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 exec_control;
- u32 exit_control;
vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector);
vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector);
@@ -7665,13 +7683,14 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
vmcs_write64(VMCS_LINK_POINTER, -1ull);
- vmcs_write32(PIN_BASED_VM_EXEC_CONTROL,
- (vmcs_config.pin_based_exec_ctrl |
- vmcs12->pin_based_vm_exec_control));
+ exec_control = vmcs12->pin_based_vm_exec_control;
+ exec_control |= vmcs_config.pin_based_exec_ctrl;
+ exec_control &= ~PIN_BASED_VMX_PREEMPTION_TIMER;
+ vmcs_write32(PIN_BASED_VM_EXEC_CONTROL, exec_control);
- if (vmcs12->pin_based_vm_exec_control & PIN_BASED_VMX_PREEMPTION_TIMER)
- vmcs_write32(VMX_PREEMPTION_TIMER_VALUE,
- vmcs12->vmx_preemption_timer_value);
+ vmx->nested.preemption_timer_expired = false;
+ if (nested_cpu_has_preemption_timer(vmcs12))
+ vmx_start_preemption_timer(vcpu);
/*
* Whether page-faults are trapped is determined by a combination of
@@ -7699,7 +7718,7 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
enable_ept ? vmcs12->page_fault_error_code_match : 0);
if (cpu_has_secondary_exec_ctrls()) {
- u32 exec_control = vmx_secondary_exec_control(vmx);
+ exec_control = vmx_secondary_exec_control(vmx);
if (!vmx->rdtscp_enabled)
exec_control &= ~SECONDARY_EXEC_RDTSCP;
/* Take the following fields only from vmcs12 */
@@ -7786,10 +7805,7 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
* we should use its exit controls. Note that VM_EXIT_LOAD_IA32_EFER
* bits are further modified by vmx_set_efer() below.
*/
- exit_control = vmcs_config.vmexit_ctrl;
- if (vmcs12->pin_based_vm_exec_control & PIN_BASED_VMX_PREEMPTION_TIMER)
- exit_control |= VM_EXIT_SAVE_VMX_PREEMPTION_TIMER;
- vm_exit_controls_init(vmx, exit_control);
+ vmcs_write32(VM_EXIT_CONTROLS, vmcs_config.vmexit_ctrl);
/* vmcs12's VM_ENTRY_LOAD_IA32_EFER and VM_ENTRY_IA32E_MODE are
* emulated by vmx_set_efer(), below.
@@ -8137,6 +8153,14 @@ static int vmx_check_nested_events(struct kvm_vcpu *vcpu, bool external_intr)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
+ if (nested_cpu_has_preemption_timer(get_vmcs12(vcpu)) &&
+ vmx->nested.preemption_timer_expired) {
+ if (vmx->nested.nested_run_pending)
+ return -EBUSY;
+ nested_vmx_vmexit(vcpu, EXIT_REASON_PREEMPTION_TIMER, 0, 0);
+ return 0;
+ }
+
if (vcpu->arch.nmi_pending && nested_exit_on_nmi(vcpu)) {
if (vmx->nested.nested_run_pending)
return -EBUSY;
@@ -8162,6 +8186,20 @@ static int vmx_check_nested_events(struct kvm_vcpu *vcpu, bool external_intr)
return 0;
}
+static u32 vmx_get_preemption_timer_value(struct kvm_vcpu *vcpu)
+{
+ ktime_t remaining =
+ hrtimer_get_remaining(&to_vmx(vcpu)->nested.preemption_timer);
+ u64 value;
+
+ if (ktime_to_ns(remaining) <= 0)
+ return 0;
+
+ value = ktime_to_ns(remaining) * vcpu->arch.virtual_tsc_khz;
+ do_div(value, 1000000);
+ return value >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE;
+}
+
/*
* prepare_vmcs12 is part of what we need to do when the nested L2 guest exits
* and we want to prepare to run its L1 parent. L1 keeps a vmcs for L2 (vmcs12),
@@ -8232,10 +8270,13 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
else
vmcs12->guest_activity_state = GUEST_ACTIVITY_ACTIVE;
- if ((vmcs12->pin_based_vm_exec_control & PIN_BASED_VMX_PREEMPTION_TIMER) &&
- (vmcs12->vm_exit_controls & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER))
- vmcs12->vmx_preemption_timer_value =
- vmcs_read32(VMX_PREEMPTION_TIMER_VALUE);
+ if (nested_cpu_has_preemption_timer(vmcs12)) {
+ if (vmcs12->vm_exit_controls &
+ VM_EXIT_SAVE_VMX_PREEMPTION_TIMER)
+ vmcs12->vmx_preemption_timer_value =
+ vmx_get_preemption_timer_value(vcpu);
+ hrtimer_cancel(&to_vmx(vcpu)->nested.preemption_timer);
+ }
/*
* In some cases (usually, nested EPT), L2 is allowed to change its