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>

1 files changed, 15 insertions, 0 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 84f18634d87c..c4e9b99d48d8 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)