KVM: PPC: Book3S HV: Provide mode where all vCPUs on a core must be the same VM

[mirror_ubuntu-bionic-kernel.git] / arch / powerpc / kvm / book3s_hv.c

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index dc9eb6b495ce6c57549c121c9ddfa92f2c76d877..0c8a655c2e5decf9afc311bdacd7a702417b26ac 100644 (file)
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -103,6 +103,10 @@ static bool indep_threads_mode = true;
 module_param(indep_threads_mode, bool, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(indep_threads_mode, "Independent-threads mode (only on POWER9)");
 
+static bool one_vm_per_core;
+module_param(one_vm_per_core, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(one_vm_per_core, "Only run vCPUs from the same VM on a core (requires indep_threads_mode=N)");
+
 #ifdef CONFIG_KVM_XICS
 static struct kernel_param_ops module_param_ops = {
        .set = param_set_int,
@@ -2449,6 +2453,10 @@ static bool can_dynamic_split(struct kvmppc_vcore *vc, struct core_info *cip)
        if (!cpu_has_feature(CPU_FTR_ARCH_207S))
                return false;
 
+       /* In one_vm_per_core mode, require all vcores to be from the same vm */
+       if (one_vm_per_core && vc->kvm != cip->vc[0]->kvm)
+               return false;
+
        /* Some POWER9 chips require all threads to be in the same MMU mode */
        if (no_mixing_hpt_and_radix &&
            kvm_is_radix(vc->kvm) != kvm_is_radix(cip->vc[0]->kvm))