}
#endif
-#if defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) && defined(CONFIG_PPC_RADIX_MMU)
-extern void radix_kvm_prefetch_workaround(struct mm_struct *mm);
-#else
-static inline void radix_kvm_prefetch_workaround(struct mm_struct *mm) { }
-#endif
-
extern void switch_cop(struct mm_struct *next);
extern int use_cop(unsigned long acop, struct mm_struct *mm);
extern void drop_cop(unsigned long acop, struct mm_struct *mm);
* KVM does not support mflags=2 (AIL=2) and AIL=1 is reserved.
* Keep this in synch with kvmppc_filter_guest_lpcr_hv.
*/
- if (mflags != 0 && mflags != 3)
+ if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG) &&
+ kvmhv_vcpu_is_radix(vcpu) && mflags == 3)
return H_UNSUPPORTED_FLAG_START;
return H_TOO_HARD;
default:
lpcr &= ~LPCR_AIL;
if ((lpcr & LPCR_AIL) != LPCR_AIL_3)
lpcr &= ~LPCR_AIL; /* LPCR[AIL]=1/2 is disallowed */
+ /*
+ * On some POWER9s we force AIL off for radix guests to prevent
+ * executing in MSR[HV]=1 mode with the MMU enabled and PIDR set to
+ * guest, which can result in Q0 translations with LPID=0 PID=PIDR to
+ * be cached, which the host TLB management does not expect.
+ */
+ if (kvm_is_radix(kvm) && cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+ lpcr &= ~LPCR_AIL;
/*
* On POWER9, allow userspace to enable large decrementer for the
vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
do {
- /*
- * The TLB prefetch bug fixup is only in the kvmppc_run_vcpu
- * path, which also handles hash and dependent threads mode.
- */
- if (kvm->arch.threads_indep && kvm_is_radix(kvm) &&
- !cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+ if (kvm->arch.threads_indep && kvm_is_radix(kvm))
r = kvmhv_run_single_vcpu(vcpu, ~(u64)0,
vcpu->arch.vcore->lpcr);
else
if (!indep_threads_mode && !cpu_has_feature(CPU_FTR_HVMODE)) {
pr_warn("KVM: Ignoring indep_threads_mode=N in nested hypervisor\n");
kvm->arch.threads_indep = true;
+ } else if (!indep_threads_mode && cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
+ pr_warn("KVM: Ignoring indep_threads_mode=N on pre-DD2.2 POWER9\n");
+ kvm->arch.threads_indep = true;
} else {
kvm->arch.threads_indep = indep_threads_mode;
}
mtspr(SPRN_AMOR, ~0UL);
+ if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+ __mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
+
switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
/*
*/
mtspr(SPRN_HDEC, hdec);
- __mtmsrd(0, 1); /* clear RI */
+ if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+ __mtmsrd(0, 1); /* clear RI */
mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
radix_clear_slb();
- __mtmsrd(msr, 0);
-
accumulate_time(vcpu, &vcpu->arch.rm_exit);
/* Advance host PURR/SPURR by the amount used by guest */
switch_mmu_to_host_radix(kvm, host_pidr);
+ /*
+ * If we are in real mode, only switch MMU on after the MMU is
+ * switched to host, to avoid the P9_RADIX_PREFETCH_BUG.
+ */
+ __mtmsrd(msr, 0);
+
end_timing(vcpu);
return trap;
eieio
tlbsync
ptesync
-
-BEGIN_FTR_SECTION
- /* Radix: Handle the case where the guest used an illegal PID */
- LOAD_REG_ADDR(r4, mmu_base_pid)
- lwz r3, VCPU_GUEST_PID(r9)
- lwz r5, 0(r4)
- cmpw cr0,r3,r5
- blt 2f
-
- /*
- * Illegal PID, the HW might have prefetched and cached in the TLB
- * some translations for the LPID 0 / guest PID combination which
- * Linux doesn't know about, so we need to flush that PID out of
- * the TLB. First we need to set LPIDR to 0 so tlbiel applies to
- * the right context.
- */
- li r0,0
- mtspr SPRN_LPID,r0
- isync
-
- /* Then do a congruence class local flush */
- ld r6,VCPU_KVM(r9)
- lwz r0,KVM_TLB_SETS(r6)
- mtctr r0
- li r7,0x400 /* IS field = 0b01 */
- ptesync
- sldi r0,r3,32 /* RS has PID */
-1: PPC_TLBIEL(7,0,2,1,1) /* RIC=2, PRS=1, R=1 */
- addi r7,r7,0x1000
- bdnz 1b
- ptesync
-END_FTR_SECTION_IFSET(CPU_FTR_P9_RADIX_PREFETCH_BUG)
-
-2:
#endif /* CONFIG_PPC_RADIX_MMU */
/*
}
/* Find out how many PID bits are supported */
- if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
- if (!mmu_pid_bits)
- mmu_pid_bits = 20;
- mmu_base_pid = 1;
- } else if (cpu_has_feature(CPU_FTR_HVMODE)) {
- if (!mmu_pid_bits)
- mmu_pid_bits = 20;
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+ if (!cpu_has_feature(CPU_FTR_HVMODE) &&
+ cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) {
/*
- * When KVM is possible, we only use the top half of the
- * PID space to avoid collisions between host and guest PIDs
- * which can cause problems due to prefetch when exiting the
- * guest with AIL=3
+ * Older versions of KVM on these machines perfer if the
+ * guest only uses the low 19 PID bits.
*/
- mmu_base_pid = 1 << (mmu_pid_bits - 1);
-#else
- mmu_base_pid = 1;
-#endif
- } else {
- /* The guest uses the bottom half of the PID space */
if (!mmu_pid_bits)
mmu_pid_bits = 19;
- mmu_base_pid = 1;
+ } else {
+ if (!mmu_pid_bits)
+ mmu_pid_bits = 20;
}
+ mmu_base_pid = 1;
/*
* Allocate Partition table and process table for the
: : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(0) : "memory");
asm volatile("eieio; tlbsync; ptesync": : :"memory");
}
-
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-extern void radix_kvm_prefetch_workaround(struct mm_struct *mm)
-{
- unsigned long pid = mm->context.id;
-
- if (unlikely(pid == MMU_NO_CONTEXT))
- return;
-
- if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
- return;
-
- /*
- * If this context hasn't run on that CPU before and KVM is
- * around, there's a slim chance that the guest on another
- * CPU just brought in obsolete translation into the TLB of
- * this CPU due to a bad prefetch using the guest PID on
- * the way into the hypervisor.
- *
- * We work around this here. If KVM is possible, we check if
- * any sibling thread is in KVM. If it is, the window may exist
- * and thus we flush that PID from the core.
- *
- * A potential future improvement would be to mark which PIDs
- * have never been used on the system and avoid it if the PID
- * is new and the process has no other cpumask bit set.
- */
- if (cpu_has_feature(CPU_FTR_HVMODE) && radix_enabled()) {
- int cpu = smp_processor_id();
- int sib = cpu_first_thread_sibling(cpu);
- bool flush = false;
-
- for (; sib <= cpu_last_thread_sibling(cpu) && !flush; sib++) {
- if (sib == cpu)
- continue;
- if (!cpu_possible(sib))
- continue;
- if (paca_ptrs[sib]->kvm_hstate.kvm_vcpu)
- flush = true;
- }
- if (flush)
- _tlbiel_pid(pid, RIC_FLUSH_ALL);
- }
-}
-EXPORT_SYMBOL_GPL(radix_kvm_prefetch_workaround);
-#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
if (cpu_has_feature(CPU_FTR_ALTIVEC))
asm volatile ("dssall");
- if (new_on_cpu)
- radix_kvm_prefetch_workaround(next);
- else
+ if (!new_on_cpu)
membarrier_arch_switch_mm(prev, next, tsk);
/*
projects / kernel.git / commitdiff