[PATCH 3/7] KVM: SVM: extract preparation of VMCB for nested run

From: Paolo Bonzini
Date: Fri May 15 2020 - 13:42:05 EST


Split out filling svm->vmcb.save and svm->vmcb.control before VMRUN.
Only the latter will be useful when restoring nested SVM state.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/svm/nested.c | 42 +++++++++++++++++++++++----------------
1 file changed, 25 insertions(+), 17 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index e79acc852000..7807f6cc01fc 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -246,19 +246,8 @@ static void load_nested_vmcb_control(struct vcpu_svm *svm, struct vmcb *nested_v
svm->vcpu.arch.tsc_offset += nested_vmcb->control.tsc_offset;
}

-void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
- struct vmcb *nested_vmcb)
+static void load_nested_vmcb_save(struct vcpu_svm *svm, struct vmcb *nested_vmcb)
{
- bool evaluate_pending_interrupts =
- is_intercept(svm, INTERCEPT_VINTR) ||
- is_intercept(svm, INTERCEPT_IRET);
-
- svm->nested.vmcb = vmcb_gpa;
- load_nested_vmcb_control(svm, nested_vmcb);
-
- if (nested_vmcb->control.nested_ctl & SVM_NESTED_CTL_NP_ENABLE)
- nested_svm_init_mmu_context(&svm->vcpu);
-
/* Load the nested guest state */
svm->vmcb->save.es = nested_vmcb->save.es;
svm->vmcb->save.cs = nested_vmcb->save.cs;
@@ -276,9 +265,6 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
} else
(void)kvm_set_cr3(&svm->vcpu, nested_vmcb->save.cr3);

- /* Guest paging mode is active - reset mmu */
- kvm_mmu_reset_context(&svm->vcpu);
-
svm->vmcb->save.cr2 = svm->vcpu.arch.cr2 = nested_vmcb->save.cr2;
kvm_rax_write(&svm->vcpu, nested_vmcb->save.rax);
kvm_rsp_write(&svm->vcpu, nested_vmcb->save.rsp);
@@ -291,6 +277,15 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
svm->vmcb->save.dr7 = nested_vmcb->save.dr7;
svm->vcpu.arch.dr6 = nested_vmcb->save.dr6;
svm->vmcb->save.cpl = nested_vmcb->save.cpl;
+}
+
+static void nested_prepare_vmcb_control(struct vcpu_svm *svm, struct vmcb *nested_vmcb)
+{
+ if (nested_vmcb->control.nested_ctl & SVM_NESTED_CTL_NP_ENABLE)
+ nested_svm_init_mmu_context(&svm->vcpu);
+
+ /* Guest paging mode is active - reset mmu */
+ kvm_mmu_reset_context(&svm->vcpu);

svm_flush_tlb(&svm->vcpu);
if (nested_vmcb->control.int_ctl & V_INTR_MASKING_MASK)
@@ -321,6 +316,21 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
*/
recalc_intercepts(svm);

+ mark_all_dirty(svm->vmcb);
+}
+
+void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
+ struct vmcb *nested_vmcb)
+{
+ bool evaluate_pending_interrupts =
+ is_intercept(svm, INTERCEPT_VINTR) ||
+ is_intercept(svm, INTERCEPT_IRET);
+
+ svm->nested.vmcb = vmcb_gpa;
+ load_nested_vmcb_control(svm, nested_vmcb);
+ load_nested_vmcb_save(svm, nested_vmcb);
+ nested_prepare_vmcb_control(svm, nested_vmcb);
+
/*
* If L1 had a pending IRQ/NMI before executing VMRUN,
* which wasn't delivered because it was disallowed (e.g.
@@ -336,8 +346,6 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
enable_gif(svm);
if (unlikely(evaluate_pending_interrupts))
kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
-
- mark_all_dirty(svm->vmcb);
}

int nested_svm_vmrun(struct vcpu_svm *svm)
--
2.18.2