cpu_in_guest is set to determine if a CPU needs to be IPI'ed to exit
the guest and notice the need_tlb_flush bit.
This can be implemented as a global per-CPU pointer to the currently
running guest instead of per-guest cpumasks, saving 2 atomics per
entry/exit. P7/8 doesn't require cpu_in_guest, nor does a nested HV
(only the L0 does), so move it to the P9 HV path.
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
---
arch/powerpc/include/asm/kvm_book3s_64.h | 1 -
arch/powerpc/include/asm/kvm_host.h | 1 -
arch/powerpc/kvm/book3s_hv.c | 38 +++++++++++++-----------
3 files changed, 21 insertions(+), 19 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 4b0753e03731..793aa2868c3f 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -44,7 +44,6 @@ struct kvm_nested_guest {
struct mutex tlb_lock; /* serialize page faults and tlbies */
struct kvm_nested_guest *next;
cpumask_t need_tlb_flush;
- cpumask_t cpu_in_guest;
short prev_cpu[NR_CPUS];
u8 radix; /* is this nested guest radix */
};
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 74ee3a5b110e..650e1c0d118c 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -288,7 +288,6 @@ struct kvm_arch {
u32 online_vcores;
atomic_t hpte_mod_interest;
cpumask_t need_tlb_flush;
- cpumask_t cpu_in_guest;
u8 radix;
u8 fwnmi_enabled;
u8 secure_guest;
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 2bd000e2c269..6f29fa7d77cc 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -2989,30 +2989,33 @@ static void kvmppc_release_hwthread(int cpu)
tpaca->kvm_hstate.kvm_split_mode = NULL;
}
+static DEFINE_PER_CPU(struct kvm *, cpu_in_guest);
+
static void radix_flush_cpu(struct kvm *kvm, int cpu, struct kvm_vcpu *vcpu)
{
struct kvm_nested_guest *nested = vcpu->arch.nested;
- cpumask_t *cpu_in_guest;
int i;
cpu = cpu_first_tlb_thread_sibling(cpu);
- if (nested) {
+ if (nested)
cpumask_set_cpu(cpu, &nested->need_tlb_flush);
- cpu_in_guest = &nested->cpu_in_guest;
- } else {
+ else
cpumask_set_cpu(cpu, &kvm->arch.need_tlb_flush);
- cpu_in_guest = &kvm->arch.cpu_in_guest;
- }
/*
- * Make sure setting of bit in need_tlb_flush precedes
- * testing of cpu_in_guest bits. The matching barrier on
- * the other side is the first smp_mb() in kvmppc_run_core().
+ * Make sure setting of bit in need_tlb_flush precedes testing of
+ * cpu_in_guest. The matching barrier on the other side is hwsync
+ * when switching to guest MMU mode, which happens between
+ * cpu_in_guest being set to the guest kvm, and need_tlb_flush bit
+ * being tested.
*/
smp_mb();
for (i = cpu; i <= cpu_last_tlb_thread_sibling(cpu);
- i += cpu_tlb_thread_sibling_step())
- if (cpumask_test_cpu(i, cpu_in_guest))
+ i += cpu_tlb_thread_sibling_step()) {
+ struct kvm *running = *per_cpu_ptr(&cpu_in_guest, i);
+
+ if (running == kvm)
smp_call_function_single(i, do_nothing, NULL, 1);
+ }
}
static void do_migrate_away_vcpu(void *arg)
@@ -3080,7 +3083,6 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu, struct kvmppc_vcore *vc)
{
int cpu;
struct paca_struct *tpaca;
- struct kvm *kvm = vc->kvm;
cpu = vc->pcpu;
if (vcpu) {
@@ -3091,7 +3093,6 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu, struct kvmppc_vcore *vc)
cpu += vcpu->arch.ptid;
vcpu->cpu = vc->pcpu;
vcpu->arch.thread_cpu = cpu;
- cpumask_set_cpu(cpu, &kvm->arch.cpu_in_guest);
}
tpaca = paca_ptrs[cpu];
tpaca->kvm_hstate.kvm_vcpu = vcpu;
@@ -3809,7 +3810,6 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
kvmppc_release_hwthread(pcpu + i);
if (sip && sip->napped[i])
kvmppc_ipi_thread(pcpu + i);
- cpumask_clear_cpu(pcpu + i, &vc->kvm->arch.cpu_in_guest);
}
spin_unlock(&vc->lock);
@@ -3977,8 +3977,14 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
}
} else {
+ struct kvm *kvm = vcpu->kvm;
+
kvmppc_xive_push_vcpu(vcpu);
+
+ __this_cpu_write(cpu_in_guest, kvm);
trap = kvmhv_vcpu_entry_p9(vcpu, time_limit, lpcr, tb);
+ __this_cpu_write(cpu_in_guest, NULL);
+
if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
!(vcpu->arch.shregs.msr & MSR_PR)) {
unsigned long req = kvmppc_get_gpr(vcpu, 3);
@@ -4003,7 +4009,7 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
}
kvmppc_xive_pull_vcpu(vcpu);
- if (kvm_is_radix(vcpu->kvm))
+ if (kvm_is_radix(kvm))
vcpu->arch.slb_max = 0;
}
@@ -4468,8 +4474,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
powerpc_local_irq_pmu_restore(flags);
- cpumask_clear_cpu(pcpu, &kvm->arch.cpu_in_guest);
-
preempt_enable();
/*
--
2.23.0
