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.
* prep_enter_smm() is to be called when injecting an SMM, before any
SMM related vcpu state has been changed
* post_leave_smm() is to be called when emulating the RSM instruction,
after all SMM related vcpu state has been restored; the function may
ask the caller to restore the vcpu state again via the reload_state
parameter
Signed-off-by: Ladi Prosek <lprosek@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_emulate.h | 3 +++
arch/x86/include/asm/kvm_host.h | 4 ++++
arch/x86/kvm/emulate.c | 30 ++++++++++++++++++++++++++----
arch/x86/kvm/svm.c | 16 ++++++++++++++++
arch/x86/kvm/vmx.c | 16 ++++++++++++++++
arch/x86/kvm/x86.c | 17 +++++++++++++++++
6 files changed, 82 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index fa2558e12024..0ba3837173fb 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -225,6 +225,9 @@ struct x86_emulate_ops {
unsigned (*get_hflags)(struct x86_emulate_ctxt *ctxt);
void (*set_hflags)(struct x86_emulate_ctxt *ctxt, unsigned hflags);
+ int (*post_leave_smm)(struct x86_emulate_ctxt *ctxt, u64 smbase,
+ bool *reload_state);
+
};
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 c73e493adf07..769de6d2e684 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1061,6 +1061,10 @@ struct kvm_x86_ops {
void (*cancel_hv_timer)(struct kvm_vcpu *vcpu);
void (*setup_mce)(struct kvm_vcpu *vcpu);
+
+ int (*prep_enter_smm)(struct kvm_vcpu *vcpu, char *smstate);
+ int (*post_leave_smm)(struct kvm_vcpu *vcpu, u64 smbase,
+ bool *reload_state);
};
struct kvm_arch_async_pf {
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index d90cdc77e077..1e6a8a824b8b 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2546,9 +2546,18 @@ static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt, u64 smbase)
return X86EMUL_CONTINUE;
}
+static int rsm_load_state(struct x86_emulate_ctxt *ctxt, u64 smbase)
+{
+ if (emulator_has_longmode(ctxt))
+ return rsm_load_state_64(ctxt, smbase + 0x8000);
+ else
+ return rsm_load_state_32(ctxt, smbase + 0x8000);
+}
+
static int em_rsm(struct x86_emulate_ctxt *ctxt)
{
unsigned long cr0, cr4, efer;
+ bool reload_state = false;
u64 smbase;
int ret;
@@ -2591,16 +2600,29 @@ static int em_rsm(struct x86_emulate_ctxt *ctxt)
ctxt->ops->set_msr(ctxt, MSR_EFER, efer);
smbase = ctxt->ops->get_smbase(ctxt);
- if (emulator_has_longmode(ctxt))
- ret = rsm_load_state_64(ctxt, smbase + 0x8000);
- else
- ret = rsm_load_state_32(ctxt, smbase + 0x8000);
+ ret = rsm_load_state(ctxt, smbase);
if (ret != X86EMUL_CONTINUE) {
/* FIXME: should triple fault */
return X86EMUL_UNHANDLEABLE;
}
+ if (ctxt->ops->post_leave_smm(ctxt, smbase, &reload_state))
+ return X86EMUL_UNHANDLEABLE;
+
+ if (reload_state) {
+ /*
+ * post_leave_smm() made changes to the vCPU (e.g. entered
+ * guest mode) and is asking us to load the SMM state-save
+ * area again.
+ */
+ ret = rsm_load_state(ctxt, smbase);
+ if (ret != X86EMUL_CONTINUE) {
+ /* FIXME: should triple fault */
+ return X86EMUL_UNHANDLEABLE;
+ }
+ }
+
if ((ctxt->ops->get_hflags(ctxt) & X86EMUL_SMM_INSIDE_NMI_MASK) == 0)
ctxt->ops->set_nmi_mask(ctxt, false);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 0e68f0b3cbf7..d9b3e1bea644 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -5393,6 +5393,19 @@ static void svm_setup_mce(struct kvm_vcpu *vcpu)
vcpu->arch.mcg_cap &= 0x1ff;
}
+static int svm_prep_enter_smm(struct kvm_vcpu *vcpu, char *smstate)
+{
+ /* TODO: Implement */
+ return 0;
+}
+
+static int svm_post_leave_smm(struct kvm_vcpu *vcpu, u64 smbase,
+ bool *reload_state)
+{
+ /* 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,
@@ -5503,6 +5516,9 @@ 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,
+
+ .prep_enter_smm = svm_prep_enter_smm,
+ .post_leave_smm = svm_post_leave_smm,
};
static int __init svm_init(void)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index a2b804e10c95..15478f413392 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -11941,6 +11941,19 @@ static void vmx_setup_mce(struct kvm_vcpu *vcpu)
~FEATURE_CONTROL_LMCE;
}
+static int vmx_prep_enter_smm(struct kvm_vcpu *vcpu, char *smstate)
+{
+ /* TODO: Implement */
+ return 0;
+}
+
+static int vmx_post_leave_smm(struct kvm_vcpu *vcpu, u64 smbase,
+ bool *reload_state)
+{
+ /* 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,
@@ -12066,6 +12079,9 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
#endif
.setup_mce = vmx_setup_mce,
+
+ .prep_enter_smm = vmx_prep_enter_smm,
+ .post_leave_smm = vmx_post_leave_smm,
};
static int __init vmx_init(void)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 03869eb7fcd6..e9aef1d858a8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5275,6 +5275,12 @@ 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_post_leave_smm(struct x86_emulate_ctxt *ctxt, u64 smbase,
+ bool *reload_state)
+{
+ return kvm_x86_ops->post_leave_smm(emul_to_vcpu(ctxt), smbase, reload_state);
+}
+
static const struct x86_emulate_ops emulate_ops = {
.read_gpr = emulator_read_gpr,
.write_gpr = emulator_write_gpr,
@@ -5316,6 +5322,7 @@ 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,
+ .post_leave_smm = emulator_post_leave_smm,
};
static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask)
@@ -6643,6 +6650,7 @@ static void enter_smm(struct kvm_vcpu *vcpu)
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
@@ -6650,6 +6658,15 @@ static void enter_smm(struct kvm_vcpu *vcpu)
kvm_vcpu_write_guest(vcpu, vcpu->arch.smbase + 0xfe00, buf, sizeof(buf));
+ /*
+ * Give prep_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. Clear HF_SMM_MASK temporarily.
+ */
+ vcpu->arch.hflags &= ~HF_SMM_MASK;
+ kvm_x86_ops->prep_enter_smm(vcpu, buf);
+ vcpu->arch.hflags |= HF_SMM_MASK;
+
if (kvm_x86_ops->get_nmi_mask(vcpu))
vcpu->arch.hflags |= HF_SMM_INSIDE_NMI_MASK;
else
--
2.13.5
