On Thu, Sep 10, 2020 at 04:37:51PM +0800, Chenyi Qiang wrote:
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 5303dbc5c9bc..8059b8b21ecd 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -961,6 +961,9 @@ struct kvm_arch {
bool guest_can_read_msr_platform_info;
bool exception_payload_enabled;
+ /* Set when bus lock vm exit is enabled by user */
+ bool bus_lock_exit;
Maybe bus_lock_detection_enabled? Then you don't need the comment or the
accessor.
+
struct kvm_pmu_event_filter *pmu_event_filter;
struct task_struct *nx_lpage_recovery_thread;
};
@@ -1347,6 +1350,8 @@ extern u8 kvm_tsc_scaling_ratio_frac_bits;
extern u64 kvm_max_tsc_scaling_ratio;
/* 1ull << kvm_tsc_scaling_ratio_frac_bits */
extern u64 kvm_default_tsc_scaling_ratio;
+/* bus lock detection supported */
+extern bool kvm_has_bus_lock_exit;
Hrm, it'd be nice to somehow squeeze this into kvm_cpu_caps, but I can't
think of a clever/clean way to do so.
extern u64 kvm_mce_cap_supported;
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index cd7de4b401fe..93a880bc31a7 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -73,6 +73,7 @@
#define SECONDARY_EXEC_PT_USE_GPA VMCS_CONTROL_BIT(PT_USE_GPA)
#define SECONDARY_EXEC_TSC_SCALING VMCS_CONTROL_BIT(TSC_SCALING)
#define SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE VMCS_CONTROL_BIT(USR_WAIT_PAUSE)
+#define SECONDARY_EXEC_BUS_LOCK_DETECTION VMCS_CONTROL_BIT(BUS_LOCK_DETECTION)
#define PIN_BASED_EXT_INTR_MASK VMCS_CONTROL_BIT(INTR_EXITING)
#define PIN_BASED_NMI_EXITING VMCS_CONTROL_BIT(NMI_EXITING)
diff --git a/arch/x86/include/asm/vmxfeatures.h b/arch/x86/include/asm/vmxfeatures.h
index 9915990fd8cf..e80523346274 100644
--- a/arch/x86/include/asm/vmxfeatures.h
+++ b/arch/x86/include/asm/vmxfeatures.h
@@ -83,5 +83,6 @@
#define VMX_FEATURE_TSC_SCALING ( 2*32+ 25) /* Scale hardware TSC when read in guest */
#define VMX_FEATURE_USR_WAIT_PAUSE ( 2*32+ 26) /* Enable TPAUSE, UMONITOR, UMWAIT in guest */
#define VMX_FEATURE_ENCLV_EXITING ( 2*32+ 28) /* "" VM-Exit on ENCLV (leaf dependent) */
+#define VMX_FEATURE_BUS_LOCK_DETECTION ( 2*32+ 30) /* VM-Exit when bus lock caused */
#endif /* _ASM_X86_VMXFEATURES_H */
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 0780f97c1850..a1471c05f7f9 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -111,6 +111,7 @@ struct kvm_ioapic_state {
#define KVM_NR_IRQCHIPS 3
#define KVM_RUN_X86_SMM (1 << 0)
+#define KVM_RUN_BUS_LOCK (1 << 1)
/* for KVM_GET_REGS and KVM_SET_REGS */
struct kvm_regs {
diff --git a/arch/x86/include/uapi/asm/vmx.h b/arch/x86/include/uapi/asm/vmx.h
index b8ff9e8ac0d5..14c177c4afd5 100644
--- a/arch/x86/include/uapi/asm/vmx.h
+++ b/arch/x86/include/uapi/asm/vmx.h
@@ -88,6 +88,7 @@
#define EXIT_REASON_XRSTORS 64
#define EXIT_REASON_UMWAIT 67
#define EXIT_REASON_TPAUSE 68
+#define EXIT_REASON_BUS_LOCK 74
#define VMX_EXIT_REASONS \
{ EXIT_REASON_EXCEPTION_NMI, "EXCEPTION_NMI" }, \
@@ -148,7 +149,8 @@
{ EXIT_REASON_XSAVES, "XSAVES" }, \
{ EXIT_REASON_XRSTORS, "XRSTORS" }, \
{ EXIT_REASON_UMWAIT, "UMWAIT" }, \
- { EXIT_REASON_TPAUSE, "TPAUSE" }
+ { EXIT_REASON_TPAUSE, "TPAUSE" }, \
+ { EXIT_REASON_BUS_LOCK, "BUS_LOCK" }
#define VMX_EXIT_REASON_FLAGS \
{ VMX_EXIT_REASONS_FAILED_VMENTRY, "FAILED_VMENTRY" }
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index 4bbd8b448d22..aa94535e6705 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -262,6 +262,12 @@ static inline bool cpu_has_vmx_tsc_scaling(void)
SECONDARY_EXEC_TSC_SCALING;
}
+static inline bool cpu_has_vmx_bus_lock_detection(void)
+{
+ return vmcs_config.cpu_based_2nd_exec_ctrl &
+ SECONDARY_EXEC_BUS_LOCK_DETECTION;
+}
+
static inline bool cpu_has_vmx_apicv(void)
{
return cpu_has_vmx_apic_register_virt() &&
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index adc59cf9036d..5dbfee639375 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2461,7 +2461,8 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE |
SECONDARY_EXEC_PT_USE_GPA |
SECONDARY_EXEC_PT_CONCEAL_VMX |
- SECONDARY_EXEC_ENABLE_VMFUNC;
+ SECONDARY_EXEC_ENABLE_VMFUNC |
+ SECONDARY_EXEC_BUS_LOCK_DETECTION;
if (cpu_has_sgx())
opt2 |= SECONDARY_EXEC_ENCLS_EXITING;
if (adjust_vmx_controls(min2, opt2,
@@ -4244,6 +4245,9 @@ static void vmx_compute_secondary_exec_control(struct vcpu_vmx *vmx)
}
}
+ if (!kvm_bus_lock_exit_enabled(vmx->vcpu.kvm))
+ exec_control &= ~SECONDARY_EXEC_BUS_LOCK_DETECTION;
+
vmx->secondary_exec_control = exec_control;
}
@@ -5685,6 +5689,14 @@ static int handle_encls(struct kvm_vcpu *vcpu)
return 1;
}
+static int handle_bus_lock(struct kvm_vcpu *vcpu)
+{
+ struct kvm_run *kvm_run = vcpu->run;
+
+ kvm_run->exit_reason = KVM_EXIT_BUS_LOCK;
No need for kvm_run, "vcpu->run->exit_reason = KVM_EXIT_BUS_LOCK" will do.
+ return 0;
+}
+
/*
* The exit handlers return 1 if the exit was handled fully and guest execution
* may resume. Otherwise they set the kvm_run parameter to indicate what needs
@@ -5741,6 +5753,7 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
[EXIT_REASON_VMFUNC] = handle_vmx_instruction,
[EXIT_REASON_PREEMPTION_TIMER] = handle_preemption_timer,
[EXIT_REASON_ENCLS] = handle_encls,
+ [EXIT_REASON_BUS_LOCK] = handle_bus_lock,
};
static const int kvm_vmx_max_exit_handlers =
@@ -5979,7 +5992,7 @@ void dump_vmcs(void)
* The guest has exited. See if we can fix it or if we need userspace
* assistance.
*/
-static int vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
+static int __vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
union vmx_exit_reason exit_reason = vmx->exit_reason;
@@ -6131,6 +6144,28 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
return 0;
}
+static int vmx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t exit_fastpath)
+{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
Personal preference, but I'd probably skip the local 'vmx' variable since
there's only a single user, i.e. "to_vmx(vcpu)->exit_reason....".
+ int ret = __vmx_handle_exit(vcpu, exit_fastpath);
+
+ /*
+ * Even when current exit reason is handled by KVM
+ * internally, we still needs to exit to user space
+ * when bus lock detected to inform that there is a
+ * bus lock in guest.
Run these lines out to the edge of 80 chars, wrapping this aggressively just
adds extra lines.
+ */
+ if (vmx->exit_reason.bus_lock_detected) {
+ if (ret > 0)
+ vcpu->run->exit_reason = KVM_EXIT_BUS_LOCK;
+ else
+ vcpu->run->flags |= KVM_RUN_BUS_LOCK;
+ return 0;
+ }
+ vcpu->run->flags &= ~KVM_RUN_BUS_LOCK;
+ return ret;
+}
+
/*
* Software based L1D cache flush which is used when microcode providing
* the cache control MSR is not loaded.
@@ -8097,6 +8132,9 @@ static __init int hardware_setup(void)
kvm_tsc_scaling_ratio_frac_bits = 48;
}
+ if (cpu_has_vmx_bus_lock_detection())
+ kvm_has_bus_lock_exit = true;
Or simply:
kvm_has_bus_lock_exit = cpu_has_vmx_bus_lock_detection();
+
set_bit(0, vmx_vpid_bitmap); /* 0 is reserved for host */
if (enable_ept)
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 8bf97a81affd..779ea3b15134 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -105,7 +105,7 @@ union vmx_exit_reason {
u32 reserved23 : 1;
u32 reserved24 : 1;
u32 reserved25 : 1;
- u32 reserved26 : 1;
+ u32 bus_lock_detected : 1;
u32 enclave_mode : 1;
u32 smi_pending_mtf : 1;
u32 smi_from_vmx_root : 1;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d39d6cf1d473..d96619ce7f66 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -134,6 +134,8 @@ u64 __read_mostly kvm_max_tsc_scaling_ratio;
EXPORT_SYMBOL_GPL(kvm_max_tsc_scaling_ratio);
u64 __read_mostly kvm_default_tsc_scaling_ratio;
EXPORT_SYMBOL_GPL(kvm_default_tsc_scaling_ratio);
+bool __read_mostly kvm_has_bus_lock_exit;
+EXPORT_SYMBOL_GPL(kvm_has_bus_lock_exit);
/* tsc tolerance in parts per million - default to 1/2 of the NTP threshold */
static u32 __read_mostly tsc_tolerance_ppm = 250;
@@ -3578,6 +3580,11 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_SMALLER_MAXPHYADDR:
r = (int) allow_smaller_maxphyaddr;
break;
+ case KVM_CAP_X86_BUS_LOCK_EXIT:
Hmm, it might make more sense to do:
if (kvm_has_bus_lock_exit)
r = KVM_BUS_LOCK_DETECTION_OFF |
KVM_BUS_LOCK_DETECTION_EXIT;
else
r = 0;
On the other hand I can see it being useful for userspace to know that
KVM itself supports bus lock detection, but hardware does not.
+ r |= KVM_BUS_LOCK_DETECTION_OFF;
+ if (kvm_has_bus_lock_exit)
+ r |= KVM_BUS_LOCK_DETECTION_EXIT;
+ break;
default:
break;
}
@@ -5030,6 +5037,20 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
kvm->arch.exception_payload_enabled = cap->args[0];
r = 0;
break;
+ case KVM_CAP_X86_BUS_LOCK_EXIT:
+ r = -EINVAL;
+ if (cap->args[0] & ~KVM_BUS_LOCK_DETECTION_VALID_MODE)
+ break;
+
+ if ((cap->args[0] & KVM_BUS_LOCK_DETECTION_OFF) &&
+ (cap->args[0] & KVM_BUS_LOCK_DETECTION_EXIT))
+ break;
+
+ if (kvm_has_bus_lock_exit &&
+ cap->args[0] & KVM_BUS_LOCK_DETECTION_EXIT)
+ kvm->arch.bus_lock_exit = true;
+ r = 0;
+ break;
default:
r = -EINVAL;
break;
@@ -7772,12 +7793,16 @@ static void post_kvm_run_save(struct kvm_vcpu *vcpu)
struct kvm_run *kvm_run = vcpu->run;
kvm_run->if_flag = (kvm_get_rflags(vcpu) & X86_EFLAGS_IF) != 0;
- kvm_run->flags = is_smm(vcpu) ? KVM_RUN_X86_SMM : 0;
kvm_run->cr8 = kvm_get_cr8(vcpu);
kvm_run->apic_base = kvm_get_apic_base(vcpu);
kvm_run->ready_for_interrupt_injection =
pic_in_kernel(vcpu->kvm) ||
kvm_vcpu_ready_for_interrupt_injection(vcpu);
+
+ if (is_smm(vcpu))
+ kvm_run->flags |= KVM_RUN_X86_SMM;
+ else
+ kvm_run->flags &= ~KVM_RUN_X86_SMM;
}
static void update_cr8_intercept(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 995ab696dcf0..54aa7712cb52 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -335,6 +335,11 @@ static inline bool kvm_cstate_in_guest(struct kvm *kvm)
return kvm->arch.cstate_in_guest;
}
+static inline bool kvm_bus_lock_exit_enabled(struct kvm *kvm)
I don't see any point in adding an accessor for a bool.
+{
+ return kvm->arch.bus_lock_exit;
+}
+
DECLARE_PER_CPU(struct kvm_vcpu *, current_vcpu);
static inline void kvm_before_interrupt(struct kvm_vcpu *vcpu)
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index f6d86033c4fa..3f0176733622 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -248,6 +248,7 @@ struct kvm_hyperv_exit {
#define KVM_EXIT_IOAPIC_EOI 26
#define KVM_EXIT_HYPERV 27
#define KVM_EXIT_ARM_NISV 28
+#define KVM_EXIT_BUS_LOCK 29
/* For KVM_EXIT_INTERNAL_ERROR */
/* Emulate instruction failed. */
@@ -1035,6 +1036,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_LAST_CPU 184
#define KVM_CAP_SMALLER_MAXPHYADDR 185
#define KVM_CAP_S390_DIAG318 186
+#define KVM_CAP_X86_BUS_LOCK_EXIT 187
#ifdef KVM_CAP_IRQ_ROUTING
@@ -1689,4 +1691,9 @@ struct kvm_hyperv_eventfd {
#define KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (1 << 0)
#define KVM_DIRTY_LOG_INITIALLY_SET (1 << 1)
+#define KVM_BUS_LOCK_DETECTION_OFF (1 << 0)
+#define KVM_BUS_LOCK_DETECTION_EXIT (1 << 1)
+#define KVM_BUS_LOCK_DETECTION_VALID_MODE (KVM_BUS_LOCK_DETECTION_OFF | \
+ KVM_BUS_LOCK_DETECTION_EXIT)
I don't think we want to define KVM_BUS_LOCK_DETECTION_VALID_MODE in the
uapi header, that should be kernel only.
+
#endif /* __LINUX_KVM_H */
--
2.17.1
