KVM: x86: introduce ISA specific SMM entry/exit callbacks
Entering and exiting SMM may require ISA specific handling under certain
circumstances. This commit adds two new callbacks with empty implementations.
Actual functionality will be added in following commits.
* pre_enter_smm() is to be called when injecting an SMM, before any
SMM related vcpu state has been changed
* pre_leave_smm() is to be called when emulating the RSM instruction,
when the vcpu is in real mode and before any SMM related vcpu state
has been restored
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index fa2558e..ad38c5e 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -225,6 +225,8 @@ struct x86_emulate_ops {
unsigned (*get_hflags)(struct x86_emulate_ctxt *ctxt);
void (*set_hflags)(struct x86_emulate_ctxt *ctxt, unsigned hflags);
+ int (*pre_leave_smm)(struct x86_emulate_ctxt *ctxt, u64 smbase);
+
};
typedef u32 __attribute__((vector_size(16))) sse128_t;
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c73e493..23a9a53 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1061,6 +1061,9 @@ struct kvm_x86_ops {
void (*cancel_hv_timer)(struct kvm_vcpu *vcpu);
void (*setup_mce)(struct kvm_vcpu *vcpu);
+
+ int (*pre_enter_smm)(struct kvm_vcpu *vcpu, char *smstate);
+ int (*pre_leave_smm)(struct kvm_vcpu *vcpu, u64 smbase);
};
struct kvm_arch_async_pf {
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index d90cdc7..8079d14 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2591,6 +2591,15 @@ static int em_rsm(struct x86_emulate_ctxt *ctxt)
ctxt->ops->set_msr(ctxt, MSR_EFER, efer);
smbase = ctxt->ops->get_smbase(ctxt);
+
+ /*
+ * Give pre_leave_smm() a chance to make ISA-specific changes to the
+ * vCPU state (e.g. enter guest mode) before loading state from the SMM
+ * state-save area.
+ */
+ if (ctxt->ops->pre_leave_smm(ctxt, smbase))
+ return X86EMUL_UNHANDLEABLE;
+
if (emulator_has_longmode(ctxt))
ret = rsm_load_state_64(ctxt, smbase + 0x8000);
else
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 84f1863..c4e9b99 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -5401,6 +5401,18 @@ static void svm_setup_mce(struct kvm_vcpu *vcpu)
vcpu->arch.mcg_cap &= 0x1ff;
}
+static int svm_pre_enter_smm(struct kvm_vcpu *vcpu, char *smstate)
+{
+ /* TODO: Implement */
+ return 0;
+}
+
+static int svm_pre_leave_smm(struct kvm_vcpu *vcpu, u64 smbase)
+{
+ /* TODO: Implement */
+ return 0;
+}
+
static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
.cpu_has_kvm_support = has_svm,
.disabled_by_bios = is_disabled,
@@ -5511,6 +5523,9 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
.deliver_posted_interrupt = svm_deliver_avic_intr,
.update_pi_irte = svm_update_pi_irte,
.setup_mce = svm_setup_mce,
+
+ .pre_enter_smm = svm_pre_enter_smm,
+ .pre_leave_smm = svm_pre_leave_smm,
};
static int __init svm_init(void)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c9214e3..1305bb6 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -11916,6 +11916,18 @@ static void vmx_setup_mce(struct kvm_vcpu *vcpu)
~FEATURE_CONTROL_LMCE;
}
+static int vmx_pre_enter_smm(struct kvm_vcpu *vcpu, char *smstate)
+{
+ /* TODO: Implement */
+ return 0;
+}
+
+static int vmx_pre_leave_smm(struct kvm_vcpu *vcpu, u64 smbase)
+{
+ /* TODO: Implement */
+ return 0;
+}
+
static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
.cpu_has_kvm_support = cpu_has_kvm_support,
.disabled_by_bios = vmx_disabled_by_bios,
@@ -12041,6 +12053,9 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
#endif
.setup_mce = vmx_setup_mce,
+
+ .pre_enter_smm = vmx_pre_enter_smm,
+ .pre_leave_smm = vmx_pre_leave_smm,
};
static int __init vmx_init(void)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4ac2610..9e85a69 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5281,6 +5281,11 @@ static void emulator_set_hflags(struct x86_emulate_ctxt *ctxt, unsigned emul_fla
kvm_set_hflags(emul_to_vcpu(ctxt), emul_flags);
}
+static int emulator_pre_leave_smm(struct x86_emulate_ctxt *ctxt, u64 smbase)
+{
+ return kvm_x86_ops->pre_leave_smm(emul_to_vcpu(ctxt), smbase);
+}
+
static const struct x86_emulate_ops emulate_ops = {
.read_gpr = emulator_read_gpr,
.write_gpr = emulator_write_gpr,
@@ -5322,6 +5327,7 @@ static const struct x86_emulate_ops emulate_ops = {
.set_nmi_mask = emulator_set_nmi_mask,
.get_hflags = emulator_get_hflags,
.set_hflags = emulator_set_hflags,
+ .pre_leave_smm = emulator_pre_leave_smm,
};
static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask)
@@ -6647,13 +6653,20 @@ static void enter_smm(struct kvm_vcpu *vcpu)
u32 cr0;
trace_kvm_enter_smm(vcpu->vcpu_id, vcpu->arch.smbase, true);
- vcpu->arch.hflags |= HF_SMM_MASK;
memset(buf, 0, 512);
if (guest_cpuid_has(vcpu, X86_FEATURE_LM))
enter_smm_save_state_64(vcpu, buf);
else
enter_smm_save_state_32(vcpu, buf);
+ /*
+ * Give pre_enter_smm() a chance to make ISA-specific changes to the
+ * vCPU state (e.g. leave guest mode) after we've saved the state into
+ * the SMM state-save area.
+ */
+ kvm_x86_ops->pre_enter_smm(vcpu, buf);
+
+ vcpu->arch.hflags |= HF_SMM_MASK;
kvm_vcpu_write_guest(vcpu, vcpu->arch.smbase + 0xfe00, buf, sizeof(buf));
if (kvm_x86_ops->get_nmi_mask(vcpu))