[PATCH 06/10] KVM: SVM: Simplify request+kick logic in SNP AP Creation handling

From: Sean Christopherson
Date: Tue Feb 18 2025 - 20:29:03 EST


Drop the local "kick" variable and the unnecessary "fallthrough" logic
from sev_snp_ap_creation(), and simply pivot on the request when deciding
whether or not to immediate force a state update on the target vCPU.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/svm/sev.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 8425198c5204..7f6c8fedb235 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3940,7 +3940,6 @@ static int sev_snp_ap_creation(struct vcpu_svm *svm)
struct vcpu_svm *target_svm;
unsigned int request;
unsigned int apic_id;
- bool kick;
int ret;

request = lower_32_bits(svm->vmcb->control.exit_info_1);
@@ -3958,18 +3957,10 @@ static int sev_snp_ap_creation(struct vcpu_svm *svm)

target_svm = to_svm(target_vcpu);

- /*
- * The target vCPU is valid, so the vCPU will be kicked unless the
- * request is for CREATE_ON_INIT.
- */
- kick = true;
-
mutex_lock(&target_svm->sev_es.snp_vmsa_mutex);

switch (request) {
case SVM_VMGEXIT_AP_CREATE_ON_INIT:
- kick = false;
- fallthrough;
case SVM_VMGEXIT_AP_CREATE:
if (vcpu->arch.regs[VCPU_REGS_RAX] != sev->vmsa_features) {
vcpu_unimpl(vcpu, "vmgexit: mismatched AP sev_features [%#lx] != [%#llx] from guest\n",
@@ -4014,7 +4005,11 @@ static int sev_snp_ap_creation(struct vcpu_svm *svm)

target_svm->sev_es.snp_ap_waiting_for_reset = true;

- if (kick) {
+ /*
+ * Unless Creation is deferred until INIT, signal the vCPU to update
+ * its state.
+ */
+ if (request != SVM_VMGEXIT_AP_CREATE_ON_INIT) {
kvm_make_request(KVM_REQ_UPDATE_PROTECTED_GUEST_STATE, target_vcpu);
kvm_vcpu_kick(target_vcpu);
}
--
2.48.1.601.g30ceb7b040-goog