[PATCH v2 8/8] KVM: nSVM: Capture svm->nested.ctl as vmcb12_ctrl when preparing vmcb02

From: Sean Christopherson

Date: Wed Feb 18 2026 - 18:13:22 EST


Grab svm->nested.ctl as vmcb12_ctrl when preparing the vmcb02 controls to
make it more obvious that much of the data is coming from vmcb12 (or
rather, a snapshot of vmcb12 at the time of L1's VMRUN).

Opportunistically reorder the variable definitions to create a pretty
reverse fir tree.

No functional change intended.

Cc: Yosry Ahmed <yosry.ahmed@xxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/svm/nested.c | 39 +++++++++++++++++++--------------------
1 file changed, 19 insertions(+), 20 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index bcd6304f3c0c..1814522db6b4 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -745,11 +745,11 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
u32 int_ctl_vmcb01_bits = V_INTR_MASKING_MASK;
u32 int_ctl_vmcb12_bits = V_TPR_MASK | V_IRQ_INJECTION_BITS_MASK;

- struct kvm_vcpu *vcpu = &svm->vcpu;
- struct vmcb *vmcb01 = svm->vmcb01.ptr;
+ struct vmcb_ctrl_area_cached *vmcb12_ctrl = &svm->nested.ctl;
struct vmcb *vmcb02 = svm->nested.vmcb02.ptr;
- u32 pause_count12;
- u32 pause_thresh12;
+ struct vmcb *vmcb01 = svm->vmcb01.ptr;
+ struct kvm_vcpu *vcpu = &svm->vcpu;
+ u32 pause_count12, pause_thresh12;

nested_svm_transition_tlb_flush(vcpu);

@@ -762,7 +762,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
*/

if (guest_cpu_cap_has(vcpu, X86_FEATURE_VGIF) &&
- (svm->nested.ctl.int_ctl & V_GIF_ENABLE_MASK))
+ (vmcb12_ctrl->int_ctl & V_GIF_ENABLE_MASK))
int_ctl_vmcb12_bits |= (V_GIF_MASK | V_GIF_ENABLE_MASK);
else
int_ctl_vmcb01_bits |= (V_GIF_MASK | V_GIF_ENABLE_MASK);
@@ -820,10 +820,9 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
if (nested_npt_enabled(svm))
nested_svm_init_mmu_context(vcpu);

- vcpu->arch.tsc_offset = kvm_calc_nested_tsc_offset(
- vcpu->arch.l1_tsc_offset,
- svm->nested.ctl.tsc_offset,
- svm->tsc_ratio_msr);
+ vcpu->arch.tsc_offset = kvm_calc_nested_tsc_offset(vcpu->arch.l1_tsc_offset,
+ vmcb12_ctrl->tsc_offset,
+ svm->tsc_ratio_msr);

vmcb02->control.tsc_offset = vcpu->arch.tsc_offset;

@@ -832,13 +831,13 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
nested_svm_update_tsc_ratio_msr(vcpu);

vmcb02->control.int_ctl =
- (svm->nested.ctl.int_ctl & int_ctl_vmcb12_bits) |
+ (vmcb12_ctrl->int_ctl & int_ctl_vmcb12_bits) |
(vmcb01->control.int_ctl & int_ctl_vmcb01_bits);

- vmcb02->control.int_vector = svm->nested.ctl.int_vector;
- vmcb02->control.int_state = svm->nested.ctl.int_state;
- vmcb02->control.event_inj = svm->nested.ctl.event_inj;
- vmcb02->control.event_inj_err = svm->nested.ctl.event_inj_err;
+ vmcb02->control.int_vector = vmcb12_ctrl->int_vector;
+ vmcb02->control.int_state = vmcb12_ctrl->int_state;
+ vmcb02->control.event_inj = vmcb12_ctrl->event_inj;
+ vmcb02->control.event_inj_err = vmcb12_ctrl->event_inj_err;

/*
* next_rip is consumed on VMRUN as the return address pushed on the
@@ -849,7 +848,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
* prior to injecting the event).
*/
if (guest_cpu_cap_has(vcpu, X86_FEATURE_NRIPS))
- vmcb02->control.next_rip = svm->nested.ctl.next_rip;
+ vmcb02->control.next_rip = vmcb12_ctrl->next_rip;
else if (boot_cpu_has(X86_FEATURE_NRIPS))
vmcb02->control.next_rip = vmcb12_rip;

@@ -859,7 +858,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
svm->soft_int_csbase = vmcb12_csbase;
svm->soft_int_old_rip = vmcb12_rip;
if (guest_cpu_cap_has(vcpu, X86_FEATURE_NRIPS))
- svm->soft_int_next_rip = svm->nested.ctl.next_rip;
+ svm->soft_int_next_rip = vmcb12_ctrl->next_rip;
else
svm->soft_int_next_rip = vmcb12_rip;
}
@@ -870,11 +869,11 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
vmcb02->control.virt_ext |= VIRTUAL_VMLOAD_VMSAVE_ENABLE_MASK;

if (guest_cpu_cap_has(vcpu, X86_FEATURE_PAUSEFILTER))
- pause_count12 = svm->nested.ctl.pause_filter_count;
+ pause_count12 = vmcb12_ctrl->pause_filter_count;
else
pause_count12 = 0;
if (guest_cpu_cap_has(vcpu, X86_FEATURE_PFTHRESHOLD))
- pause_thresh12 = svm->nested.ctl.pause_filter_thresh;
+ pause_thresh12 = vmcb12_ctrl->pause_filter_thresh;
else
pause_thresh12 = 0;
if (kvm_pause_in_guest(svm->vcpu.kvm)) {
@@ -888,7 +887,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
vmcb02->control.pause_filter_thresh = vmcb01->control.pause_filter_thresh;

/* ... but ensure filtering is disabled if so requested. */
- if (vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_PAUSE)) {
+ if (vmcb12_is_intercept(vmcb12_ctrl, INTERCEPT_PAUSE)) {
if (!pause_count12)
vmcb02->control.pause_filter_count = 0;
if (!pause_thresh12)
@@ -905,7 +904,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
* L2 is the "guest").
*/
if (guest_cpu_cap_has(vcpu, X86_FEATURE_ERAPS))
- vmcb02->control.erap_ctl = (svm->nested.ctl.erap_ctl &
+ vmcb02->control.erap_ctl = (vmcb12_ctrl->erap_ctl &
ERAP_CONTROL_ALLOW_LARGER_RAP) |
ERAP_CONTROL_CLEAR_RAP;

--
2.53.0.345.g96ddfc5eaa-goog