[PATCH 47/60] kvm: x86: Select a plane to run

From: Jörg Rödel

Date: Mon Jun 08 2026 - 11:17:42 EST


From: Joerg Roedel <joerg.roedel@xxxxxxx>

In the KVM_RUN path, select a runnable VCPU plane and use it to enter
the guest. Also handle KVM_REQ_PLANE_RESCHED events to switch planes
without exiting to user-space.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
arch/x86/kvm/x86.c | 29 ++++++++++++++++++++++++++++-
1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7e94a378b3d2..b9828cd31136 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11398,6 +11398,12 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
goto out;
}
}
+
+ if (kvm_check_request(KVM_REQ_PLANE_RESCHED, vcpu)) {
+ vcpu->common->plane_switch = true;
+ r = 0;
+ goto out;
+ }
}

if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win ||
@@ -12076,7 +12082,7 @@ static int kvm_x86_vcpu_pre_run(struct kvm_vcpu *vcpu)
return kvm_x86_call(vcpu_pre_run)(vcpu);
}

-int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
+static int __kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
{
struct kvm_queued_exception *ex = &vcpu->arch.exception;
struct kvm_run *kvm_run = vcpu->run;
@@ -12196,6 +12202,27 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
return r;
}

+int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu_plane0)
+{
+ struct kvm_vcpu_common *common = vcpu_plane0->common;
+ int ret;
+
+ do {
+ struct kvm_vcpu *vcpu = kvm_vcpu_select_plane(vcpu_plane0);
+
+ if (vcpu == NULL)
+ return -EINVAL;
+
+ common->plane_switch = false;
+
+ ret = __kvm_arch_vcpu_ioctl_run(vcpu);
+ if (ret)
+ break;
+ } while (vcpu_plane0->common->plane_switch);
+
+ return ret;
+}
+
static void __get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
if (vcpu->arch.emulate_regs_need_sync_to_vcpu) {
--
2.53.0