[PATCH 07/13] KVM: x86: API changes for SMM support

[Paolo Bonzini <pbonzini@redhat.com>]

This patch includes changes to the external API for SMM support.
All the changes are predicated by the availability of a new
capability, KVM_CAP_X86_SMM, which is added at the end of the
patch series.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 Documentation/virtual/kvm/api.txt | 34 ++++++++++++++++++++++++++++++----
 arch/x86/include/asm/kvm_host.h   |  1 +
 arch/x86/include/uapi/asm/kvm.h   |  7 +++++++
 arch/x86/kvm/kvm_cache_regs.h     |  5 +++++
 arch/x86/kvm/x86.c                | 30 +++++++++++++++++++++++++-----
 include/uapi/linux/kvm.h          |  5 ++++-
 6 files changed, 72 insertions(+), 10 deletions(-)

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 9fa2bf8c3f6f..c1afcb2e4b89 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -820,11 +820,19 @@ struct kvm_vcpu_events {
 	} nmi;
 	__u32 sipi_vector;
 	__u32 flags;
+	struct {
+		__u8 smm;
+		__u8 pad[3];
+	} smi;
 };
 
-KVM_VCPUEVENT_VALID_SHADOW may be set in the flags field to signal that
-interrupt.shadow contains a valid state. Otherwise, this field is undefined.
+Only two fields are defined in the flags field:
+
+- KVM_VCPUEVENT_VALID_SHADOW may be set in the flags field to signal that
+  interrupt.shadow contains a valid state.
 
+- KVM_VCPUEVENT_VALID_SMM may be set in the flags field to signal that
+  smi.smm contains a valid state.
 
 4.32 KVM_SET_VCPU_EVENTS
 
@@ -841,17 +849,20 @@ vcpu.
 See KVM_GET_VCPU_EVENTS for the data structure.
 
 Fields that may be modified asynchronously by running VCPUs can be excluded
-from the update. These fields are nmi.pending and sipi_vector. Keep the
+from the update. These fields are nmi.pending, sipi_vector, smi.smm. Keep the
 corresponding bits in the flags field cleared to suppress overwriting the
 current in-kernel state. The bits are:
 
 KVM_VCPUEVENT_VALID_NMI_PENDING - transfer nmi.pending to the kernel
 KVM_VCPUEVENT_VALID_SIPI_VECTOR - transfer sipi_vector
+KVM_VCPUEVENT_VALID_SMM         - transfer smi.smm
 
 If KVM_CAP_INTR_SHADOW is available, KVM_VCPUEVENT_VALID_SHADOW can be set in
 the flags field to signal that interrupt.shadow contains a valid state and
 shall be written into the VCPU.
 
+KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available.
+
 
 4.33 KVM_GET_DEBUGREGS
 
@@ -2978,6 +2989,16 @@ len must be a multiple of sizeof(struct kvm_s390_irq). It must be > 0
 and it must not exceed (max_vcpus + 32) * sizeof(struct kvm_s390_irq),
 which is the maximum number of possibly pending cpu-local interrupts.
 
+4.90 KVM_SMI
+
+Capability: KVM_CAP_X86_SMM
+Architectures: x86
+Type: vcpu ioctl
+Parameters: none
+Returns: 0 on success, -1 on error
+
+Queues an SMI on the thread's vcpu.
+
 5. The kvm_run structure
 ------------------------
 
@@ -3013,7 +3034,12 @@ an interrupt can be injected now with KVM_INTERRUPT.
 The value of the current interrupt flag.  Only valid if in-kernel
 local APIC is not used.
 
-	__u8 padding2[2];
+	__u16 flags;
+
+More architecture-specific flags, detailing state of the VCPU that may
+affect the device's behavior.  The only currently defined flag is
+KVM_RUN_X86_SMM, which is valid on x86 machines and is set if the
+VCPU is in system management mode.
 
 	/* in (pre_kvm_run), out (post_kvm_run) */
 	__u64 cr8;
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index b0a97b4dbde4..1171e346bb33 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1109,6 +1109,7 @@ enum {
 #define HF_NMI_MASK		(1 << 3)
 #define HF_IRET_MASK		(1 << 4)
 #define HF_GUEST_MASK		(1 << 5) /* VCPU is in guest-mode */
+#define HF_SMM_MASK		(1 << 6)
 
 /*
  * Hardware virtualization extension instructions may fault if a
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index d7dcef58aefa..0bb09e2e549e 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -106,6 +106,8 @@ struct kvm_ioapic_state {
 #define KVM_IRQCHIP_IOAPIC       2
 #define KVM_NR_IRQCHIPS          3
 
+#define KVM_RUN_X86_SMM		 (1 << 0)
+
 /* for KVM_GET_REGS and KVM_SET_REGS */
 struct kvm_regs {
 	/* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
@@ -281,6 +283,7 @@ struct kvm_reinject_control {
 #define KVM_VCPUEVENT_VALID_NMI_PENDING	0x00000001
 #define KVM_VCPUEVENT_VALID_SIPI_VECTOR	0x00000002
 #define KVM_VCPUEVENT_VALID_SHADOW	0x00000004
+#define KVM_VCPUEVENT_VALID_SMM		0x00000008
 
 /* Interrupt shadow states */
 #define KVM_X86_SHADOW_INT_MOV_SS	0x01
@@ -309,6 +312,10 @@ struct kvm_vcpu_events {
 	} nmi;
 	__u32 sipi_vector;
 	__u32 flags;
+	struct {
+		__u8 smm;
+		__u8 pad[3];
+	} smi;
 	__u32 reserved[10];
 };
 
diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index 544076c4f44b..e1e89ee4af75 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -99,4 +99,9 @@ static inline bool is_guest_mode(struct kvm_vcpu *vcpu)
 	return vcpu->arch.hflags & HF_GUEST_MASK;
 }
 
+static inline bool is_smm(struct kvm_vcpu *vcpu)
+{
+	return vcpu->arch.hflags & HF_SMM_MASK;
+}
+
 #endif
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6009e6a0e406..c088b057aad5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3032,6 +3032,11 @@ static int kvm_vcpu_ioctl_nmi(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+static int kvm_vcpu_ioctl_smi(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+
 static int vcpu_ioctl_tpr_access_reporting(struct kvm_vcpu *vcpu,
 					   struct kvm_tpr_access_ctl *tac)
 {
@@ -3116,29 +3121,31 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
 					       struct kvm_vcpu_events *events)
 {
 	process_nmi(vcpu);
+
+	memset(events, 0, sizeof(*events));
 	events->exception.injected =
 		vcpu->arch.exception.pending &&
 		!kvm_exception_is_soft(vcpu->arch.exception.nr);
 	events->exception.nr = vcpu->arch.exception.nr;
 	events->exception.has_error_code = vcpu->arch.exception.has_error_code;
-	events->exception.pad = 0;
 	events->exception.error_code = vcpu->arch.exception.error_code;
 
 	events->interrupt.injected =
 		vcpu->arch.interrupt.pending && !vcpu->arch.interrupt.soft;
 	events->interrupt.nr = vcpu->arch.interrupt.nr;
-	events->interrupt.soft = 0;
 	events->interrupt.shadow = kvm_x86_ops->get_interrupt_shadow(vcpu);
 
 	events->nmi.injected = vcpu->arch.nmi_injected;
 	events->nmi.pending = vcpu->arch.nmi_pending != 0;
 	events->nmi.masked = kvm_x86_ops->get_nmi_mask(vcpu);
-	events->nmi.pad = 0;
 
 	events->sipi_vector = 0; /* never valid when reporting to user space */
 
+	events->smi.smm = is_smm(vcpu);
+
 	events->flags = (KVM_VCPUEVENT_VALID_NMI_PENDING
-			 | KVM_VCPUEVENT_VALID_SHADOW);
+			 | KVM_VCPUEVENT_VALID_SHADOW
+			 | KVM_VCPUEVENT_VALID_SMM);
 	memset(&events->reserved, 0, sizeof(events->reserved));
 }
 
@@ -3147,7 +3154,8 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
 {
 	if (events->flags & ~(KVM_VCPUEVENT_VALID_NMI_PENDING
 			      | KVM_VCPUEVENT_VALID_SIPI_VECTOR
-			      | KVM_VCPUEVENT_VALID_SHADOW))
+			      | KVM_VCPUEVENT_VALID_SHADOW
+			      | KVM_VCPUEVENT_VALID_SMM))
 		return -EINVAL;
 
 	process_nmi(vcpu);
@@ -3172,6 +3180,13 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
 	    kvm_vcpu_has_lapic(vcpu))
 		vcpu->arch.apic->sipi_vector = events->sipi_vector;
 
+	if (events->flags & KVM_VCPUEVENT_VALID_SMM) {
+		if (events->smi.smm)
+			vcpu->arch.hflags |= HF_SMM_MASK;
+		else
+			vcpu->arch.hflags &= ~HF_SMM_MASK;
+	}
+
 	kvm_make_request(KVM_REQ_EVENT, vcpu);
 
 	return 0;
@@ -3431,6 +3446,10 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 		r = kvm_vcpu_ioctl_nmi(vcpu);
 		break;
 	}
+	case KVM_SMI: {
+		r = kvm_vcpu_ioctl_smi(vcpu);
+		break;
+	}
 	case KVM_SET_CPUID: {
 		struct kvm_cpuid __user *cpuid_arg = argp;
 		struct kvm_cpuid cpuid;
@@ -6067,6 +6086,7 @@ 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);
 	if (irqchip_in_kernel(vcpu->kvm))
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 4b60056776d1..cd51f0289e9f 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -202,7 +202,7 @@ struct kvm_run {
 	__u32 exit_reason;
 	__u8 ready_for_interrupt_injection;
 	__u8 if_flag;
-	__u8 padding2[2];
+	__u16 flags;
 
 	/* in (pre_kvm_run), out (post_kvm_run) */
 	__u64 cr8;
@@ -814,6 +814,7 @@ struct kvm_ppc_smmu_info {
 #define KVM_CAP_S390_INJECT_IRQ 113
 #define KVM_CAP_S390_IRQ_STATE 114
 #define KVM_CAP_PPC_HWRNG 115
+#define KVM_CAP_X86_SMM 120
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -1199,6 +1200,8 @@ struct kvm_s390_ucas_mapping {
 /* Available with KVM_CAP_S390_IRQ_STATE */
 #define KVM_S390_SET_IRQ_STATE	  _IOW(KVMIO, 0xb5, struct kvm_s390_irq_state)
 #define KVM_S390_GET_IRQ_STATE	  _IOW(KVMIO, 0xb6, struct kvm_s390_irq_state)
+/* Available with KVM_CAP_X86_SMM */
+#define KVM_SMI                   _IO(KVMIO,   0xb7)
 
 #define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)
 #define KVM_DEV_ASSIGN_PCI_2_3		(1 << 1)
-- 
1.8.3.1