[PATCH 06/12] KVM: x86: API changes for SMM support

From: Paolo Bonzini
Date: Fri May 08 2015 - 07:24:30 EST


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@xxxxxxxxxx>
---
RFC->v1: add smi.pending and smi.rsm_unmasks_nmi fields, reduce padding
in struct kvm_vcpu_events; remove memset of events struct,
instead zero smi.pad. KVM_CAP_X86_SMM frozen at 117.
---
Documentation/virtual/kvm/api.txt | 40 +++++++++++++++++++++++++++++++++------
arch/x86/include/asm/kvm_host.h | 3 +++
arch/x86/include/uapi/asm/kvm.h | 11 ++++++++++-
arch/x86/kvm/kvm_cache_regs.h | 5 +++++
arch/x86/kvm/x86.c | 34 +++++++++++++++++++++++++++++++--
include/uapi/linux/kvm.h | 5 ++++-
6 files changed, 88 insertions(+), 10 deletions(-)

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 695544420ff2..51523b70b6b2 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -820,11 +820,21 @@ struct kvm_vcpu_events {
} nmi;
__u32 sipi_vector;
__u32 flags;
+ struct {
+ __u8 smm;
+ __u8 pending;
+ __u8 smm_inside_nmi;
+ __u8 pad;
+ } 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 contains a valid state.

4.32 KVM_SET_VCPU_EVENTS

@@ -841,17 +851,20 @@ 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
-corresponding bits in the flags field cleared to suppress overwriting the
-current in-kernel state. The bits are:
+from the update. These fields are nmi.pending, sipi_vector, smi.smm,
+smi.pending. 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 the smi sub-struct.

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

@@ -2979,6 +2992,16 @@ 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
------------------------

@@ -3014,7 +3037,12 @@ 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 6487ffc95b0a..a1bef695dc99 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -469,6 +469,7 @@ struct kvm_vcpu_arch {
atomic_t nmi_queued; /* unprocessed asynchronous NMIs */
unsigned nmi_pending; /* NMI queued after currently running handler */
bool nmi_injected; /* Trying to inject an NMI this entry */
+ bool smi_pending; /* SMI queued after currently running handler */

struct mtrr_state_type mtrr_state;
u64 pat;
@@ -1112,6 +1113,8 @@ 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)
+#define HF_SMM_INSIDE_NMI_MASK (1 << 7)

/*
* 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 2fec75e4b1e1..30100a3c1bed 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
@@ -309,7 +312,13 @@ struct kvm_vcpu_events {
} nmi;
__u32 sipi_vector;
__u32 flags;
- __u32 reserved[10];
+ struct {
+ __u8 smm;
+ __u8 pending;
+ __u8 smm_inside_nmi;
+ __u8 pad;
+ } smi;
+ __u32 reserved[9];
};

/* for KVM_GET/SET_DEBUGREGS */
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 7d311a0de84c..8015c67a6d07 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3037,6 +3037,11 @@ 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)
{
@@ -3142,8 +3147,15 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,

events->sipi_vector = 0; /* never valid when reporting to user space */

+ events->smi.smm = is_smm(vcpu);
+ events->smi.pending = vcpu->arch.smi_pending;
+ events->smi.smm_inside_nmi =
+ !!(vcpu->arch.hflags & HF_SMM_INSIDE_NMI_MASK);
+ events->smi.pad = 0;
+
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));
}

@@ -3152,7 +3164,8 @@ 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);
@@ -3177,6 +3190,18 @@ 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;
+ vcpu->arch.smi_pending = events->smi.pending;
+ if (events->smi.smm_inside_nmi)
+ vcpu->arch.hflags |= ~HF_SMM_INSIDE_NMI_MASK;
+ else
+ vcpu->arch.hflags &= ~HF_SMM_INSIDE_NMI_MASK;
+ }
+
kvm_make_request(KVM_REQ_EVENT, vcpu);

return 0;
@@ -3436,6 +3461,10 @@ 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;
@@ -6118,6 +6147,7 @@ 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 75bd9f7fd846..eace8babd227 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;
@@ -815,6 +815,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_S390_IRQ_STATE 114
#define KVM_CAP_PPC_HWRNG 115
#define KVM_CAP_DISABLE_QUIRKS 116
+#define KVM_CAP_X86_SMM 117

#ifdef KVM_CAP_IRQ_ROUTING

@@ -1200,6 +1201,8 @@ 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


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