vcpu->arch.hcr = HCR_GUEST_MASK;
}
+static inline unsigned long vcpu_get_hcr(struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.hcr;
+}
+
+static inline void vcpu_set_hcr(struct kvm_vcpu *vcpu, unsigned long hcr)
+{
+ vcpu->arch.hcr = hcr;
+}
+
static inline bool vcpu_mode_is_32bit(struct kvm_vcpu *vcpu)
{
return 1;
* Anything that is not used directly from assembly code goes
* here.
*/
- /* dcache set/way operation pending */
- int last_pcpu;
- cpumask_t require_dcache_flush;
/* Don't run the guest on this vcpu */
bool pause;
#define kvm_virt_to_phys(x) virt_to_idmap((unsigned long)(x))
-void stage2_flush_vm(struct kvm *kvm);
+void kvm_set_way_flush(struct kvm_vcpu *vcpu);
+void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled);
#endif /* !__ASSEMBLY__ */
vcpu->cpu = cpu;
vcpu->arch.host_cpu_context = this_cpu_ptr(kvm_host_cpu_state);
- /*
- * Check whether this vcpu requires the cache to be flushed on
- * this physical CPU. This is a consequence of doing dcache
- * operations by set/way on this vcpu. We do it here to be in
- * a non-preemptible section.
- */
- if (cpumask_test_and_clear_cpu(cpu, &vcpu->arch.require_dcache_flush))
- flush_cache_all(); /* We'd really want v7_flush_dcache_all() */
-
kvm_arm_set_running_vcpu(vcpu);
}
ret = kvm_call_hyp(__kvm_vcpu_run, vcpu);
vcpu->mode = OUTSIDE_GUEST_MODE;
- vcpu->arch.last_pcpu = smp_processor_id();
kvm_guest_exit();
trace_kvm_exit(*vcpu_pc(vcpu));
/*
return true;
}
-/* See note at ARM ARM B1.14.4 */
+/*
+ * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
+ */
static bool access_dcsw(struct kvm_vcpu *vcpu,
const struct coproc_params *p,
const struct coproc_reg *r)
{
- unsigned long val;
- int cpu;
-
if (!p->is_write)
return read_from_write_only(vcpu, p);
- cpu = get_cpu();
-
- cpumask_setall(&vcpu->arch.require_dcache_flush);
- cpumask_clear_cpu(cpu, &vcpu->arch.require_dcache_flush);
-
- /* If we were already preempted, take the long way around */
- if (cpu != vcpu->arch.last_pcpu) {
- flush_cache_all();
- goto done;
- }
-
- val = *vcpu_reg(vcpu, p->Rt1);
-
- switch (p->CRm) {
- case 6: /* Upgrade DCISW to DCCISW, as per HCR.SWIO */
- case 14: /* DCCISW */
- asm volatile("mcr p15, 0, %0, c7, c14, 2" : : "r" (val));
- break;
-
- case 10: /* DCCSW */
- asm volatile("mcr p15, 0, %0, c7, c10, 2" : : "r" (val));
- break;
- }
-
-done:
- put_cpu();
-
+ kvm_set_way_flush(vcpu);
return true;
}
/*
* Generic accessor for VM registers. Only called as long as HCR_TVM
- * is set.
+ * is set. If the guest enables the MMU, we stop trapping the VM
+ * sys_regs and leave it in complete control of the caches.
+ *
+ * Used by the cpu-specific code.
*/
-static bool access_vm_reg(struct kvm_vcpu *vcpu,
- const struct coproc_params *p,
- const struct coproc_reg *r)
+bool access_vm_reg(struct kvm_vcpu *vcpu,
+ const struct coproc_params *p,
+ const struct coproc_reg *r)
{
+ bool was_enabled = vcpu_has_cache_enabled(vcpu);
+
BUG_ON(!p->is_write);
vcpu->arch.cp15[r->reg] = *vcpu_reg(vcpu, p->Rt1);
if (p->is_64bit)
vcpu->arch.cp15[r->reg + 1] = *vcpu_reg(vcpu, p->Rt2);
- return true;
-}
-
-/*
- * SCTLR accessor. Only called as long as HCR_TVM is set. If the
- * guest enables the MMU, we stop trapping the VM sys_regs and leave
- * it in complete control of the caches.
- *
- * Used by the cpu-specific code.
- */
-bool access_sctlr(struct kvm_vcpu *vcpu,
- const struct coproc_params *p,
- const struct coproc_reg *r)
-{
- access_vm_reg(vcpu, p, r);
-
- if (vcpu_has_cache_enabled(vcpu)) { /* MMU+Caches enabled? */
- vcpu->arch.hcr &= ~HCR_TVM;
- stage2_flush_vm(vcpu->kvm);
- }
-
+ kvm_toggle_cache(vcpu, was_enabled);
return true;
}
#define is64 .is_64 = true
#define is32 .is_64 = false
-bool access_sctlr(struct kvm_vcpu *vcpu,
- const struct coproc_params *p,
- const struct coproc_reg *r);
+bool access_vm_reg(struct kvm_vcpu *vcpu,
+ const struct coproc_params *p,
+ const struct coproc_reg *r);
#endif /* __ARM_KVM_COPROC_LOCAL_H__ */
static const struct coproc_reg a15_regs[] = {
/* SCTLR: swapped by interrupt.S. */
{ CRn( 1), CRm( 0), Op1( 0), Op2( 0), is32,
- access_sctlr, reset_val, c1_SCTLR, 0x00C50078 },
+ access_vm_reg, reset_val, c1_SCTLR, 0x00C50078 },
};
static struct kvm_coproc_target_table a15_target_table = {
static const struct coproc_reg a7_regs[] = {
/* SCTLR: swapped by interrupt.S. */
{ CRn( 1), CRm( 0), Op1( 0), Op2( 0), is32,
- access_sctlr, reset_val, c1_SCTLR, 0x00C50878 },
+ access_vm_reg, reset_val, c1_SCTLR, 0x00C50878 },
};
static struct kvm_coproc_target_table a7_target_table = {
* Go through the stage 2 page tables and invalidate any cache lines
* backing memory already mapped to the VM.
*/
-void stage2_flush_vm(struct kvm *kvm)
+static void stage2_flush_vm(struct kvm *kvm)
{
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
unmap_stage2_range(kvm, gpa, size);
spin_unlock(&kvm->mmu_lock);
}
+
+/*
+ * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
+ *
+ * Main problems:
+ * - S/W ops are local to a CPU (not broadcast)
+ * - We have line migration behind our back (speculation)
+ * - System caches don't support S/W at all (damn!)
+ *
+ * In the face of the above, the best we can do is to try and convert
+ * S/W ops to VA ops. Because the guest is not allowed to infer the
+ * S/W to PA mapping, it can only use S/W to nuke the whole cache,
+ * which is a rather good thing for us.
+ *
+ * Also, it is only used when turning caches on/off ("The expected
+ * usage of the cache maintenance instructions that operate by set/way
+ * is associated with the cache maintenance instructions associated
+ * with the powerdown and powerup of caches, if this is required by
+ * the implementation.").
+ *
+ * We use the following policy:
+ *
+ * - If we trap a S/W operation, we enable VM trapping to detect
+ * caches being turned on/off, and do a full clean.
+ *
+ * - We flush the caches on both caches being turned on and off.
+ *
+ * - Once the caches are enabled, we stop trapping VM ops.
+ */
+void kvm_set_way_flush(struct kvm_vcpu *vcpu)
+{
+ unsigned long hcr = vcpu_get_hcr(vcpu);
+
+ /*
+ * If this is the first time we do a S/W operation
+ * (i.e. HCR_TVM not set) flush the whole memory, and set the
+ * VM trapping.
+ *
+ * Otherwise, rely on the VM trapping to wait for the MMU +
+ * Caches to be turned off. At that point, we'll be able to
+ * clean the caches again.
+ */
+ if (!(hcr & HCR_TVM)) {
+ trace_kvm_set_way_flush(*vcpu_pc(vcpu),
+ vcpu_has_cache_enabled(vcpu));
+ stage2_flush_vm(vcpu->kvm);
+ vcpu_set_hcr(vcpu, hcr | HCR_TVM);
+ }
+}
+
+void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled)
+{
+ bool now_enabled = vcpu_has_cache_enabled(vcpu);
+
+ /*
+ * If switching the MMU+caches on, need to invalidate the caches.
+ * If switching it off, need to clean the caches.
+ * Clean + invalidate does the trick always.
+ */
+ if (now_enabled != was_enabled)
+ stage2_flush_vm(vcpu->kvm);
+
+ /* Caches are now on, stop trapping VM ops (until a S/W op) */
+ if (now_enabled)
+ vcpu_set_hcr(vcpu, vcpu_get_hcr(vcpu) & ~HCR_TVM);
+
+ trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled);
+}
__entry->vcpu_pc, __entry->r0, __entry->imm)
);
+TRACE_EVENT(kvm_set_way_flush,
+ TP_PROTO(unsigned long vcpu_pc, bool cache),
+ TP_ARGS(vcpu_pc, cache),
+
+ TP_STRUCT__entry(
+ __field( unsigned long, vcpu_pc )
+ __field( bool, cache )
+ ),
+
+ TP_fast_assign(
+ __entry->vcpu_pc = vcpu_pc;
+ __entry->cache = cache;
+ ),
+
+ TP_printk("S/W flush at 0x%016lx (cache %s)",
+ __entry->vcpu_pc, __entry->cache ? "on" : "off")
+);
+
+TRACE_EVENT(kvm_toggle_cache,
+ TP_PROTO(unsigned long vcpu_pc, bool was, bool now),
+ TP_ARGS(vcpu_pc, was, now),
+
+ TP_STRUCT__entry(
+ __field( unsigned long, vcpu_pc )
+ __field( bool, was )
+ __field( bool, now )
+ ),
+
+ TP_fast_assign(
+ __entry->vcpu_pc = vcpu_pc;
+ __entry->was = was;
+ __entry->now = now;
+ ),
+
+ TP_printk("VM op at 0x%016lx (cache was %s, now %s)",
+ __entry->vcpu_pc, __entry->was ? "on" : "off",
+ __entry->now ? "on" : "off")
+);
+
#endif /* _TRACE_KVM_H */
#undef TRACE_INCLUDE_PATH
vcpu->arch.hcr_el2 &= ~HCR_RW;
}
+static inline unsigned long vcpu_get_hcr(struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.hcr_el2;
+}
+
+static inline void vcpu_set_hcr(struct kvm_vcpu *vcpu, unsigned long hcr)
+{
+ vcpu->arch.hcr_el2 = hcr;
+}
+
static inline unsigned long *vcpu_pc(const struct kvm_vcpu *vcpu)
{
return (unsigned long *)&vcpu_gp_regs(vcpu)->regs.pc;
* Anything that is not used directly from assembly code goes
* here.
*/
- /* dcache set/way operation pending */
- int last_pcpu;
- cpumask_t require_dcache_flush;
/* Don't run the guest */
bool pause;
#define kvm_virt_to_phys(x) __virt_to_phys((unsigned long)(x))
-void stage2_flush_vm(struct kvm *kvm);
+void kvm_set_way_flush(struct kvm_vcpu *vcpu);
+void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled);
#endif /* __ASSEMBLY__ */
#endif /* __ARM64_KVM_MMU_H__ */
return ccsidr;
}
-static void do_dc_cisw(u32 val)
-{
- asm volatile("dc cisw, %x0" : : "r" (val));
- dsb(ish);
-}
-
-static void do_dc_csw(u32 val)
-{
- asm volatile("dc csw, %x0" : : "r" (val));
- dsb(ish);
-}
-
-/* See note at ARM ARM B1.14.4 */
+/*
+ * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
+ */
static bool access_dcsw(struct kvm_vcpu *vcpu,
const struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
- unsigned long val;
- int cpu;
-
if (!p->is_write)
return read_from_write_only(vcpu, p);
- cpu = get_cpu();
-
- cpumask_setall(&vcpu->arch.require_dcache_flush);
- cpumask_clear_cpu(cpu, &vcpu->arch.require_dcache_flush);
-
- /* If we were already preempted, take the long way around */
- if (cpu != vcpu->arch.last_pcpu) {
- flush_cache_all();
- goto done;
- }
-
- val = *vcpu_reg(vcpu, p->Rt);
-
- switch (p->CRm) {
- case 6: /* Upgrade DCISW to DCCISW, as per HCR.SWIO */
- case 14: /* DCCISW */
- do_dc_cisw(val);
- break;
-
- case 10: /* DCCSW */
- do_dc_csw(val);
- break;
- }
-
-done:
- put_cpu();
-
+ kvm_set_way_flush(vcpu);
return true;
}
/*
* Generic accessor for VM registers. Only called as long as HCR_TVM
- * is set.
+ * is set. If the guest enables the MMU, we stop trapping the VM
+ * sys_regs and leave it in complete control of the caches.
*/
static bool access_vm_reg(struct kvm_vcpu *vcpu,
const struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
unsigned long val;
+ bool was_enabled = vcpu_has_cache_enabled(vcpu);
BUG_ON(!p->is_write);
vcpu_cp15_64_low(vcpu, r->reg) = val & 0xffffffffUL;
}
- return true;
-}
-
-/*
- * SCTLR_EL1 accessor. Only called as long as HCR_TVM is set. If the
- * guest enables the MMU, we stop trapping the VM sys_regs and leave
- * it in complete control of the caches.
- */
-static bool access_sctlr(struct kvm_vcpu *vcpu,
- const struct sys_reg_params *p,
- const struct sys_reg_desc *r)
-{
- access_vm_reg(vcpu, p, r);
-
- if (vcpu_has_cache_enabled(vcpu)) { /* MMU+Caches enabled? */
- vcpu->arch.hcr_el2 &= ~HCR_TVM;
- stage2_flush_vm(vcpu->kvm);
- }
-
+ kvm_toggle_cache(vcpu, was_enabled);
return true;
}
NULL, reset_mpidr, MPIDR_EL1 },
/* SCTLR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b0001), CRm(0b0000), Op2(0b000),
- access_sctlr, reset_val, SCTLR_EL1, 0x00C50078 },
+ access_vm_reg, reset_val, SCTLR_EL1, 0x00C50078 },
/* CPACR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b0001), CRm(0b0000), Op2(0b010),
NULL, reset_val, CPACR_EL1, 0 },
* register).
*/
static const struct sys_reg_desc cp15_regs[] = {
- { Op1( 0), CRn( 1), CRm( 0), Op2( 0), access_sctlr, NULL, c1_SCTLR },
+ { Op1( 0), CRn( 1), CRm( 0), Op2( 0), access_vm_reg, NULL, c1_SCTLR },
{ Op1( 0), CRn( 2), CRm( 0), Op2( 0), access_vm_reg, NULL, c2_TTBR0 },
{ Op1( 0), CRn( 2), CRm( 0), Op2( 1), access_vm_reg, NULL, c2_TTBR1 },
{ Op1( 0), CRn( 2), CRm( 0), Op2( 2), access_vm_reg, NULL, c2_TTBCR },
projects / linux-2.6-block.git / commitdiff