[PATCH 4.9 45/66] KVM: arm/arm64: Convert kvm_host_cpu_state to a static per-cpu allocation

From: Greg Kroah-Hartman
Date: Fri Jul 20 2018 - 08:30:37 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: James Morse <james.morse@xxxxxxx>

Commit 36989e7fd386a9a5822c48691473863f8fbb404d upstream.

kvm_host_cpu_state is a per-cpu allocation made from kvm_arch_init()
used to store the host EL1 registers when KVM switches to a guest.

Make it easier for ASM to generate pointers into this per-cpu memory
by making it a static allocation.

Signed-off-by: James Morse <james.morse@xxxxxxx>
Acked-by: Christoffer Dall <cdall@xxxxxxxxxx>
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm/kvm/arm.c | 18 +++---------------
1 file changed, 3 insertions(+), 15 deletions(-)

--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -51,8 +51,8 @@
__asm__(".arch_extension virt");
#endif

+DEFINE_PER_CPU(kvm_cpu_context_t, kvm_host_cpu_state);
static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
-static kvm_cpu_context_t __percpu *kvm_host_cpu_state;
static unsigned long hyp_default_vectors;

/* Per-CPU variable containing the currently running vcpu. */
@@ -338,7 +338,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu
}

vcpu->cpu = cpu;
- vcpu->arch.host_cpu_context = this_cpu_ptr(kvm_host_cpu_state);
+ vcpu->arch.host_cpu_context = this_cpu_ptr(&kvm_host_cpu_state);

kvm_arm_set_running_vcpu(vcpu);
}
@@ -1199,19 +1199,8 @@ static inline void hyp_cpu_pm_exit(void)
}
#endif

-static void teardown_common_resources(void)
-{
- free_percpu(kvm_host_cpu_state);
-}
-
static int init_common_resources(void)
{
- kvm_host_cpu_state = alloc_percpu(kvm_cpu_context_t);
- if (!kvm_host_cpu_state) {
- kvm_err("Cannot allocate host CPU state\n");
- return -ENOMEM;
- }
-
/* set size of VMID supported by CPU */
kvm_vmid_bits = kvm_get_vmid_bits();
kvm_info("%d-bit VMID\n", kvm_vmid_bits);
@@ -1369,7 +1358,7 @@ static int init_hyp_mode(void)
for_each_possible_cpu(cpu) {
kvm_cpu_context_t *cpu_ctxt;

- cpu_ctxt = per_cpu_ptr(kvm_host_cpu_state, cpu);
+ cpu_ctxt = per_cpu_ptr(&kvm_host_cpu_state, cpu);
err = create_hyp_mappings(cpu_ctxt, cpu_ctxt + 1, PAGE_HYP);

if (err) {
@@ -1447,7 +1436,6 @@ int kvm_arch_init(void *opaque)
out_hyp:
teardown_hyp_mode();
out_err:
- teardown_common_resources();
return err;
}