From patchwork Tue Dec 6 06:09:59 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Mackerras X-Patchwork-Id: 129556 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 9175C10156A for ; Tue, 6 Dec 2011 17:22:16 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932915Ab1LFGWC (ORCPT ); Tue, 6 Dec 2011 01:22:02 -0500 Received: from ozlabs.org ([203.10.76.45]:52323 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932880Ab1LFGV3 (ORCPT ); Tue, 6 Dec 2011 01:21:29 -0500 Received: by ozlabs.org (Postfix, from userid 1003) id 777831007DF; Tue, 6 Dec 2011 17:21:25 +1100 (EST) Date: Tue, 6 Dec 2011 17:09:59 +1100 From: Paul Mackerras To: Alexander Graf Cc: linuxppc-dev@ozlabs.org, kvm-ppc@vger.kernel.org, kvm@vger.kernel.org Subject: [PATCH 08/13] KVM: PPC: Allow I/O mappings in memory slots Message-ID: <20111206060959.GL12389@drongo> References: <20111206060156.GD12389@drongo> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20111206060156.GD12389@drongo> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org This provides for the case where userspace maps an I/O device into the address range of a memory slot using a VM_PFNMAP mapping. In that case, we work out the pfn from vma->vm_pgoff, and record the cache enable bits from vma->vm_page_prot in two low-order bits in the slot_phys array entries. Then, in kvmppc_h_enter() we check that the cache bits in the HPTE that the guest wants to insert match the cache bits in the slot_phys array entry. Signed-off-by: Paul Mackerras --- arch/powerpc/include/asm/kvm_book3s_64.h | 26 +++++++++++ arch/powerpc/include/asm/kvm_host.h | 2 + arch/powerpc/kvm/book3s_64_mmu_hv.c | 67 ++++++++++++++++++++---------- arch/powerpc/kvm/book3s_hv_rm_mmu.c | 5 +- 4 files changed, 76 insertions(+), 24 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h index d55e6b4..a98e0f6 100644 --- a/arch/powerpc/include/asm/kvm_book3s_64.h +++ b/arch/powerpc/include/asm/kvm_book3s_64.h @@ -107,6 +107,32 @@ static inline unsigned long hpte_page_size(unsigned long h, unsigned long l) return 0; /* error */ } +static inline int hpte_cache_flags_ok(unsigned long ptel, unsigned long io_type) +{ + unsigned int wimg = ptel & HPTE_R_WIMG; + + /* Handle SAO */ + if (wimg == (HPTE_R_W | HPTE_R_I | HPTE_R_M) && + cpu_has_feature(CPU_FTR_ARCH_206)) + wimg = HPTE_R_M; + + if (!io_type) + return wimg == HPTE_R_M; + + return (wimg & (HPTE_R_W | HPTE_R_I)) == io_type; +} + +/* Return HPTE cache control bits corresponding to Linux pte bits */ +static inline unsigned long hpte_cache_bits(unsigned long pte_val) +{ +#if _PAGE_NO_CACHE == HPTE_R_I && _PAGE_WRITETHRU == HPTE_R_W + return pte_val & (HPTE_R_W | HPTE_R_I); +#else + return ((pte_val & _PAGE_NO_CACHE) ? HPTE_R_I : 0) + + ((pte_val & _PAGE_WRITETHRU) ? HPTE_R_W : 0); +#endif +} + static inline bool slot_is_aligned(struct kvm_memory_slot *memslot, unsigned long pagesize) { diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index ba1da85..9b1c247 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -177,6 +177,8 @@ struct revmap_entry { /* Low-order bits in kvm->arch.slot_phys[][] */ #define KVMPPC_PAGE_ORDER_MASK 0x1f +#define KVMPPC_PAGE_NO_CACHE HPTE_R_I /* 0x20 */ +#define KVMPPC_PAGE_WRITETHRU HPTE_R_W /* 0x40 */ #define KVMPPC_GOT_PAGE 0x80 struct kvm_arch { diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index cc18f3d..b904c40 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -199,7 +199,8 @@ static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn, struct page *page, *hpage, *pages[1]; unsigned long s, pgsize; unsigned long *physp; - unsigned int got, pgorder; + unsigned int is_io, got, pgorder; + struct vm_area_struct *vma; unsigned long pfn, i, npages; physp = kvm->arch.slot_phys[memslot->id]; @@ -208,34 +209,51 @@ static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn, if (physp[gfn - memslot->base_gfn]) return 0; + is_io = 0; + got = 0; page = NULL; pgsize = psize; + err = -EINVAL; start = gfn_to_hva_memslot(memslot, gfn); /* Instantiate and get the page we want access to */ np = get_user_pages_fast(start, 1, 1, pages); - if (np != 1) - return -EINVAL; - page = pages[0]; - got = KVMPPC_GOT_PAGE; + if (np != 1) { + /* Look up the vma for the page */ + down_read(¤t->mm->mmap_sem); + vma = find_vma(current->mm, start); + if (!vma || vma->vm_start > start || + start + psize > vma->vm_end || + !(vma->vm_flags & VM_PFNMAP)) + goto up_err; + is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot)); + pfn = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); + /* check alignment of pfn vs. requested page size */ + if (psize > PAGE_SIZE && (pfn & ((psize >> PAGE_SHIFT) - 1))) + goto up_err; + up_read(¤t->mm->mmap_sem); - /* See if this is a large page */ - s = PAGE_SIZE; - if (PageHuge(page)) { - hpage = compound_head(page); - s <<= compound_order(hpage); - /* Get the whole large page if slot alignment is ok */ - if (s > psize && slot_is_aligned(memslot, s) && - !(memslot->userspace_addr & (s - 1))) { - start &= ~(s - 1); - pgsize = s; - page = hpage; + } else { + page = pages[0]; + got = KVMPPC_GOT_PAGE; + + /* See if this is a large page */ + s = PAGE_SIZE; + if (PageHuge(page)) { + hpage = compound_head(page); + s <<= compound_order(hpage); + /* Get the whole large page if slot alignment is ok */ + if (s > psize && slot_is_aligned(memslot, s) && + !(memslot->userspace_addr & (s - 1))) { + start &= ~(s - 1); + pgsize = s; + page = hpage; + } } + if (s < psize) + goto out; + pfn = page_to_pfn(page); } - err = -EINVAL; - if (s < psize) - goto out; - pfn = page_to_pfn(page); npages = pgsize >> PAGE_SHIFT; pgorder = __ilog2(npages); @@ -243,7 +261,8 @@ static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn, spin_lock(&kvm->arch.slot_phys_lock); for (i = 0; i < npages; ++i) { if (!physp[i]) { - physp[i] = ((pfn + i) << PAGE_SHIFT) + got + pgorder; + physp[i] = ((pfn + i) << PAGE_SHIFT) + + got + is_io + pgorder; got = 0; } } @@ -257,6 +276,10 @@ static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn, put_page(page); } return err; + + up_err: + up_read(¤t->mm->mmap_sem); + return err; } /* diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c index c76305c..88d2add 100644 --- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c +++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c @@ -68,6 +68,7 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags, unsigned long g_ptel = ptel; struct kvm_memory_slot *memslot; unsigned long *physp, pte_size; + unsigned long is_io; bool realmode = vcpu->arch.vcore->vcore_state == VCORE_RUNNING; psize = hpte_page_size(pteh, ptel); @@ -95,6 +96,7 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags, pa = *physp; if (!pa) return H_TOO_HARD; + is_io = pa & (HPTE_R_I | HPTE_R_W); pte_size = PAGE_SIZE << (pa & KVMPPC_PAGE_ORDER_MASK); pa &= PAGE_MASK; @@ -107,8 +109,7 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags, ptel |= pa; /* Check WIMG */ - if ((ptel & HPTE_R_WIMG) != HPTE_R_M && - (ptel & HPTE_R_WIMG) != (HPTE_R_W | HPTE_R_I | HPTE_R_M)) + if (!hpte_cache_flags_ok(ptel, is_io)) return H_PARAMETER; pteh &= ~0x60UL; pteh |= HPTE_V_VALID;