From 55514893739d28f095f19b012133eea4cb4a9390 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Thu, 15 Dec 2011 02:02:47 +0000 Subject: [PATCH] KVM: PPC: Book3S HV: Use the hardware referenced bit for kvm_age_hva This uses the host view of the hardware R (referenced) bit to speed up kvm_age_hva() and kvm_test_age_hva(). Instead of removing all the relevant HPTEs in kvm_age_hva(), we now just reset their R bits if set. Also, kvm_test_age_hva() now scans the relevant HPTEs to see if any of them have R set. Signed-off-by: Paul Mackerras Signed-off-by: Alexander Graf Signed-off-by: Avi Kivity --- arch/powerpc/include/asm/kvm_book3s.h | 2 + arch/powerpc/kvm/book3s_64_mmu_hv.c | 81 ++++++++++++++++++++++++++++++----- arch/powerpc/kvm/book3s_hv_rm_mmu.c | 19 ++++++++ 3 files changed, 91 insertions(+), 11 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h index 9240ceb..33fdc09 100644 --- a/arch/powerpc/include/asm/kvm_book3s.h +++ b/arch/powerpc/include/asm/kvm_book3s.h @@ -147,6 +147,8 @@ extern void kvmppc_add_revmap_chain(struct kvm *kvm, struct revmap_entry *rev, unsigned long *rmap, long pte_index, int realmode); extern void kvmppc_invalidate_hpte(struct kvm *kvm, unsigned long *hptep, unsigned long pte_index); +void kvmppc_clear_ref_hpte(struct kvm *kvm, unsigned long *hptep, + unsigned long pte_index); extern void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long addr, unsigned long *nb_ret); extern void kvmppc_unpin_guest_page(struct kvm *kvm, void *addr); diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index aa51dde..926e2b9 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -772,16 +772,50 @@ int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, unsigned long gfn) { - if (!kvm->arch.using_mmu_notifiers) - return 0; - if (!(*rmapp & KVMPPC_RMAP_REFERENCED)) - return 0; - kvm_unmap_rmapp(kvm, rmapp, gfn); - while (test_and_set_bit_lock(KVMPPC_RMAP_LOCK_BIT, rmapp)) - cpu_relax(); - *rmapp &= ~KVMPPC_RMAP_REFERENCED; - __clear_bit_unlock(KVMPPC_RMAP_LOCK_BIT, rmapp); - return 1; + struct revmap_entry *rev = kvm->arch.revmap; + unsigned long head, i, j; + unsigned long *hptep; + int ret = 0; + + retry: + lock_rmap(rmapp); + if (*rmapp & KVMPPC_RMAP_REFERENCED) { + *rmapp &= ~KVMPPC_RMAP_REFERENCED; + ret = 1; + } + if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { + unlock_rmap(rmapp); + return ret; + } + + i = head = *rmapp & KVMPPC_RMAP_INDEX; + do { + hptep = (unsigned long *) (kvm->arch.hpt_virt + (i << 4)); + j = rev[i].forw; + + /* If this HPTE isn't referenced, ignore it */ + if (!(hptep[1] & HPTE_R_R)) + continue; + + if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { + /* unlock rmap before spinning on the HPTE lock */ + unlock_rmap(rmapp); + while (hptep[0] & HPTE_V_HVLOCK) + cpu_relax(); + goto retry; + } + + /* Now check and modify the HPTE */ + if ((hptep[0] & HPTE_V_VALID) && (hptep[1] & HPTE_R_R)) { + kvmppc_clear_ref_hpte(kvm, hptep, i); + rev[i].guest_rpte |= HPTE_R_R; + ret = 1; + } + hptep[0] &= ~HPTE_V_HVLOCK; + } while ((i = j) != head); + + unlock_rmap(rmapp); + return ret; } int kvm_age_hva(struct kvm *kvm, unsigned long hva) @@ -794,7 +828,32 @@ int kvm_age_hva(struct kvm *kvm, unsigned long hva) static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp, unsigned long gfn) { - return !!(*rmapp & KVMPPC_RMAP_REFERENCED); + struct revmap_entry *rev = kvm->arch.revmap; + unsigned long head, i, j; + unsigned long *hp; + int ret = 1; + + if (*rmapp & KVMPPC_RMAP_REFERENCED) + return 1; + + lock_rmap(rmapp); + if (*rmapp & KVMPPC_RMAP_REFERENCED) + goto out; + + if (*rmapp & KVMPPC_RMAP_PRESENT) { + i = head = *rmapp & KVMPPC_RMAP_INDEX; + do { + hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4)); + j = rev[i].forw; + if (hp[1] & HPTE_R_R) + goto out; + } while ((i = j) != head); + } + ret = 0; + + out: + unlock_rmap(rmapp); + return ret; } int kvm_test_age_hva(struct kvm *kvm, unsigned long hva) diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c index 91b45a0..5f3c60b 100644 --- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c +++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c @@ -641,6 +641,25 @@ void kvmppc_invalidate_hpte(struct kvm *kvm, unsigned long *hptep, } EXPORT_SYMBOL_GPL(kvmppc_invalidate_hpte); +void kvmppc_clear_ref_hpte(struct kvm *kvm, unsigned long *hptep, + unsigned long pte_index) +{ + unsigned long rb; + unsigned char rbyte; + + rb = compute_tlbie_rb(hptep[0], hptep[1], pte_index); + rbyte = (hptep[1] & ~HPTE_R_R) >> 8; + /* modify only the second-last byte, which contains the ref bit */ + *((char *)hptep + 14) = rbyte; + while (!try_lock_tlbie(&kvm->arch.tlbie_lock)) + cpu_relax(); + asm volatile(PPC_TLBIE(%1,%0)"; eieio; tlbsync" + : : "r" (rb), "r" (kvm->arch.lpid)); + asm volatile("ptesync" : : : "memory"); + kvm->arch.tlbie_lock = 0; +} +EXPORT_SYMBOL_GPL(kvmppc_clear_ref_hpte); + static int slb_base_page_shift[4] = { 24, /* 16M */ 16, /* 64k */ -- 2.7.4