diff options
Diffstat (limited to 'arch/powerpc/kvm')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rm_mmu.c | 63 |
1 files changed, 34 insertions, 29 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c index 84dae821b230..a28a6030ec90 100644 --- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c +++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c @@ -53,26 +53,6 @@ static void *real_vmalloc_addr(void *x) return __va(addr); } -#define HPTE_V_HVLOCK 0x40UL - -static inline long lock_hpte(unsigned long *hpte, unsigned long bits) -{ - unsigned long tmp, old; - - asm volatile(" ldarx %0,0,%2\n" - " and. %1,%0,%3\n" - " bne 2f\n" - " ori %0,%0,%4\n" - " stdcx. %0,0,%2\n" - " beq+ 2f\n" - " li %1,%3\n" - "2: isync" - : "=&r" (tmp), "=&r" (old) - : "r" (hpte), "r" (bits), "i" (HPTE_V_HVLOCK) - : "cc", "memory"); - return old == 0; -} - long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags, long pte_index, unsigned long pteh, unsigned long ptel) { @@ -126,24 +106,49 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags, pteh &= ~0x60UL; ptel &= ~(HPTE_R_PP0 - kvm->arch.ram_psize); ptel |= pa; + if (pte_index >= HPT_NPTE) return H_PARAMETER; if (likely((flags & H_EXACT) == 0)) { pte_index &= ~7UL; hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4)); - for (i = 0; ; ++i) { - if (i == 8) - return H_PTEG_FULL; + for (i = 0; i < 8; ++i) { if ((*hpte & HPTE_V_VALID) == 0 && - lock_hpte(hpte, HPTE_V_HVLOCK | HPTE_V_VALID)) + try_lock_hpte(hpte, HPTE_V_HVLOCK | HPTE_V_VALID)) break; hpte += 2; } + if (i == 8) { + /* + * Since try_lock_hpte doesn't retry (not even stdcx. + * failures), it could be that there is a free slot + * but we transiently failed to lock it. Try again, + * actually locking each slot and checking it. + */ + hpte -= 16; + for (i = 0; i < 8; ++i) { + while (!try_lock_hpte(hpte, HPTE_V_HVLOCK)) + cpu_relax(); + if ((*hpte & HPTE_V_VALID) == 0) + break; + *hpte &= ~HPTE_V_HVLOCK; + hpte += 2; + } + if (i == 8) + return H_PTEG_FULL; + } pte_index += i; } else { hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4)); - if (!lock_hpte(hpte, HPTE_V_HVLOCK | HPTE_V_VALID)) - return H_PTEG_FULL; + if (!try_lock_hpte(hpte, HPTE_V_HVLOCK | HPTE_V_VALID)) { + /* Lock the slot and check again */ + while (!try_lock_hpte(hpte, HPTE_V_HVLOCK)) + cpu_relax(); + if (*hpte & HPTE_V_VALID) { + *hpte &= ~HPTE_V_HVLOCK; + return H_PTEG_FULL; + } + } } /* Save away the guest's idea of the second HPTE dword */ @@ -189,7 +194,7 @@ long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags, if (pte_index >= HPT_NPTE) return H_PARAMETER; hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4)); - while (!lock_hpte(hpte, HPTE_V_HVLOCK)) + while (!try_lock_hpte(hpte, HPTE_V_HVLOCK)) cpu_relax(); if ((hpte[0] & HPTE_V_VALID) == 0 || ((flags & H_AVPN) && (hpte[0] & ~0x7fUL) != avpn) || @@ -248,7 +253,7 @@ long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu) break; } hp = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4)); - while (!lock_hpte(hp, HPTE_V_HVLOCK)) + while (!try_lock_hpte(hp, HPTE_V_HVLOCK)) cpu_relax(); found = 0; if (hp[0] & HPTE_V_VALID) { @@ -310,7 +315,7 @@ long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags, if (pte_index >= HPT_NPTE) return H_PARAMETER; hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4)); - while (!lock_hpte(hpte, HPTE_V_HVLOCK)) + while (!try_lock_hpte(hpte, HPTE_V_HVLOCK)) cpu_relax(); if ((hpte[0] & HPTE_V_VALID) == 0 || ((flags & H_AVPN) && (hpte[0] & ~0x7fUL) != avpn)) { |