[PATCH 02/27] KVM: PPC: Add host MMU Support

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In order to support 32 bit Book3S, we need to add code to enable our
shadow MMU to actually add shadow PTEs. This is the module enabling
that support.

Signed-off-by: Alexander Graf <agraf@xxxxxxx>
---
 arch/powerpc/kvm/book3s_32_mmu_host.c |  480 +++++++++++++++++++++++++++++++++
 1 files changed, 480 insertions(+), 0 deletions(-)
 create mode 100644 arch/powerpc/kvm/book3s_32_mmu_host.c

diff --git a/arch/powerpc/kvm/book3s_32_mmu_host.c b/arch/powerpc/kvm/book3s_32_mmu_host.c
new file mode 100644
index 0000000..ce1bfb1
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_32_mmu_host.c
@@ -0,0 +1,480 @@
+/*
+ * Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
+ *
+ * Authors:
+ *     Alexander Graf <agraf@xxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <linux/kvm_host.h>
+
+#include <asm/kvm_ppc.h>
+#include <asm/kvm_book3s.h>
+#include <asm/mmu-hash32.h>
+#include <asm/machdep.h>
+#include <asm/mmu_context.h>
+#include <asm/hw_irq.h>
+
+/* #define DEBUG_MMU */
+/* #define DEBUG_SR */
+
+#ifdef DEBUG_MMU
+#define dprintk_mmu(a, ...) printk(KERN_INFO a, __VA_ARGS__)
+#else
+#define dprintk_mmu(a, ...) do { } while(0)
+#endif
+
+#ifdef DEBUG_SR
+#define dprintk_sr(a, ...) printk(KERN_INFO a, __VA_ARGS__)
+#else
+#define dprintk_sr(a, ...) do { } while(0)
+#endif
+
+#if PAGE_SHIFT != 12
+#error Unknown page size
+#endif
+
+#ifdef CONFIG_SMP
+#error XXX need to grab mmu_hash_lock
+#endif
+
+#ifdef CONFIG_PTE_64BIT
+#error Only 32 bit pages are supported for now
+#endif
+
+static void invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
+{
+	volatile u32 *pteg;
+
+	dprintk_mmu("KVM: Flushing SPTE: 0x%llx (0x%llx) -> 0x%llx\n",
+		    pte->pte.eaddr, pte->pte.vpage, pte->host_va);
+
+	pteg = (u32*)pte->slot;
+
+	pteg[0] = 0;
+	asm volatile ("sync");
+	asm volatile ("tlbie %0" : : "r" (pte->pte.eaddr) : "memory");
+	asm volatile ("sync");
+	asm volatile ("tlbsync");
+
+	pte->host_va = 0;
+
+	if (pte->pte.may_write)
+		kvm_release_pfn_dirty(pte->pfn);
+	else
+		kvm_release_pfn_clean(pte->pfn);
+}
+
+void kvmppc_mmu_pte_flush(struct kvm_vcpu *vcpu, u64 _guest_ea, u64 _ea_mask)
+{
+	int i;
+	u32 guest_ea = _guest_ea;
+	u32 ea_mask = _ea_mask;
+
+	dprintk_mmu("KVM: Flushing %d Shadow PTEs: 0x%x & 0x%x\n",
+		    vcpu->arch.hpte_cache_offset, guest_ea, ea_mask);
+	BUG_ON(vcpu->arch.hpte_cache_offset > HPTEG_CACHE_NUM);
+
+	guest_ea &= ea_mask;
+	for (i = 0; i < vcpu->arch.hpte_cache_offset; i++) {
+		struct hpte_cache *pte;
+
+		pte = &vcpu->arch.hpte_cache[i];
+		if (!pte->host_va)
+			continue;
+
+		if ((pte->pte.eaddr & ea_mask) == guest_ea) {
+			invalidate_pte(vcpu, pte);
+		}
+	}
+
+	/* Doing a complete flush -> start from scratch */
+	if (!ea_mask)
+		vcpu->arch.hpte_cache_offset = 0;
+}
+
+void kvmppc_mmu_pte_vflush(struct kvm_vcpu *vcpu, u64 guest_vp, u64 vp_mask)
+{
+	int i;
+
+	dprintk_mmu("KVM: Flushing %d Shadow vPTEs: 0x%llx & 0x%llx\n",
+		    vcpu->arch.hpte_cache_offset, guest_vp, vp_mask);
+	BUG_ON(vcpu->arch.hpte_cache_offset > HPTEG_CACHE_NUM);
+
+	guest_vp &= vp_mask;
+	for (i = 0; i < vcpu->arch.hpte_cache_offset; i++) {
+		struct hpte_cache *pte;
+
+		pte = &vcpu->arch.hpte_cache[i];
+		if (!pte->host_va)
+			continue;
+
+		if ((pte->pte.vpage & vp_mask) == guest_vp) {
+			invalidate_pte(vcpu, pte);
+		}
+	}
+}
+
+void kvmppc_mmu_pte_pflush(struct kvm_vcpu *vcpu, u64 pa_start, u64 pa_end)
+{
+	int i;
+
+	dprintk_mmu("KVM: Flushing %d Shadow pPTEs: 0x%llx & 0x%llx\n",
+		    vcpu->arch.hpte_cache_offset, pa_start, pa_end);
+	BUG_ON(vcpu->arch.hpte_cache_offset > HPTEG_CACHE_NUM);
+
+	for (i = 0; i < vcpu->arch.hpte_cache_offset; i++) {
+		struct hpte_cache *pte;
+
+		pte = &vcpu->arch.hpte_cache[i];
+		if (!pte->host_va)
+			continue;
+
+		if ((pte->pte.raddr >= pa_start) &&
+		    (pte->pte.raddr < pa_end)) {
+			invalidate_pte(vcpu, pte);
+		}
+	}
+}
+
+struct kvmppc_pte *kvmppc_mmu_find_pte(struct kvm_vcpu *vcpu, u64 ea, bool data)
+{
+	int i;
+	u64 guest_vp;
+
+	guest_vp = vcpu->arch.mmu.ea_to_vp(vcpu, ea, false);
+	for (i=0; i<vcpu->arch.hpte_cache_offset; i++) {
+		struct hpte_cache *pte;
+
+		pte = &vcpu->arch.hpte_cache[i];
+		if (!pte->host_va)
+			continue;
+
+		if (pte->pte.vpage == guest_vp)
+			return &pte->pte;
+	}
+
+	return NULL;
+}
+
+static int kvmppc_mmu_hpte_cache_next(struct kvm_vcpu *vcpu)
+{
+	if (vcpu->arch.hpte_cache_offset == HPTEG_CACHE_NUM)
+		kvmppc_mmu_pte_flush(vcpu, 0, 0);
+
+	return vcpu->arch.hpte_cache_offset++;
+}
+
+/* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
+ * a hash, so we don't waste cycles on looping */
+static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
+{
+	return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
+		     ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
+		     ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
+		     ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
+		     ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
+		     ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
+		     ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
+		     ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
+}
+
+
+static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
+{
+	struct kvmppc_sid_map *map;
+	u16 sid_map_mask;
+
+	if (vcpu->arch.msr & MSR_PR)
+		gvsid |= VSID_PR;
+
+	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
+	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
+	if (map->guest_vsid == gvsid) {
+		dprintk_sr("SR: Searching 0x%llx -> 0x%llx\n",
+			    gvsid, map->host_vsid);
+		return map;
+	}
+
+	map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
+	if (map->guest_vsid == gvsid) {
+		dprintk_sr("SR: Searching 0x%llx -> 0x%llx\n",
+			    gvsid, map->host_vsid);
+		return map;
+	}
+
+	dprintk_sr("SR: Searching 0x%llx -> not found\n", gvsid);
+	return NULL;
+}
+
+extern struct hash_pte *Hash;
+extern unsigned long _SDR1;
+
+static u32 *kvmppc_mmu_get_pteg(struct kvm_vcpu *vcpu, u32 vsid, u32 eaddr,
+				bool primary)
+{
+	u32 page, hash, htabmask;
+	ulong pteg = (ulong)Hash;
+
+	page = (eaddr & ~ESID_MASK) >> 12;
+
+	hash = ((vsid ^ page) << 6);
+	if (!primary)
+		hash = ~hash;
+
+	htabmask = ((_SDR1 & 0x1FF) << 16) | 0xFFC0;
+	hash &= htabmask;
+
+	pteg |= hash;
+
+	dprintk_mmu("htab: %p | hash: %x | htabmask: %x | pteg: %lx\n",
+		Hash, hash, htabmask, pteg);
+
+	return (u32*)pteg;
+}
+
+extern char etext[];
+
+int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte)
+{
+	pfn_t hpaddr;
+	u64 va;
+	u64 vsid;
+	struct kvmppc_sid_map *map;
+	volatile u32 *pteg;
+	u32 eaddr = orig_pte->eaddr;
+	u32 pteg0, pteg1;
+	register int rr = 0;
+	bool primary = false;
+	bool evict = false;
+	int hpte_id;
+	struct hpte_cache *pte;
+
+	/* Get host physical address for gpa */
+	hpaddr = gfn_to_pfn(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
+	if (kvm_is_error_hva(hpaddr)) {
+		printk(KERN_INFO "Couldn't get guest page for gfn %llx!\n",
+				 orig_pte->eaddr);
+		return -EINVAL;
+	}
+	hpaddr <<= PAGE_SHIFT;
+
+	/* and write the mapping ea -> hpa into the pt */
+	vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
+	map = find_sid_vsid(vcpu, vsid);
+	if (!map) {
+		kvmppc_mmu_map_segment(vcpu, eaddr);
+		map = find_sid_vsid(vcpu, vsid);
+	}
+	BUG_ON(!map);
+
+	vsid = map->host_vsid;
+	va = (vsid << SID_SHIFT) | (eaddr & ~ESID_MASK);
+
+next_pteg:
+	if (rr == 16) {
+		primary = !primary;
+		evict = true;
+		rr = 0;
+	}
+
+	pteg = kvmppc_mmu_get_pteg(vcpu, vsid, eaddr, primary);
+
+	/* not evicting yet */
+	if (!evict && (pteg[rr] & PTE_V)) {
+		rr += 2;
+		goto next_pteg;
+	}
+
+	dprintk_mmu("KVM: old PTEG: %p (%d)\n", pteg, rr);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[0], pteg[1]);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[2], pteg[3]);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[4], pteg[5]);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[6], pteg[7]);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[8], pteg[9]);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[10], pteg[11]);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[12], pteg[13]);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[14], pteg[15]);
+
+	pteg0 = ((eaddr & 0x0fffffff) >> 22) | (vsid << 7) | PTE_V |
+		(primary ? 0 : PTE_SEC);
+	pteg1 = hpaddr | PTE_M | PTE_R | PTE_C;
+
+	if (orig_pte->may_write) {
+		pteg1 |= PP_RWRW;
+		mark_page_dirty(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
+	} else {
+		pteg1 |= PP_RWRX;
+	}
+
+	local_irq_disable();
+
+	if (pteg[rr]) {
+		pteg[rr] = 0;
+		asm volatile ("sync");
+	}
+	pteg[rr + 1] = pteg1;
+	pteg[rr] = pteg0;
+	asm volatile ("sync");
+
+	local_irq_enable();
+
+	dprintk_mmu("KVM: new PTEG: %p\n", pteg);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[0], pteg[1]);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[2], pteg[3]);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[4], pteg[5]);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[6], pteg[7]);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[8], pteg[9]);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[10], pteg[11]);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[12], pteg[13]);
+	dprintk_mmu("KVM:   %08x - %08x\n", pteg[14], pteg[15]);
+
+
+	/* Now tell our Shadow PTE code about the new page */
+
+	hpte_id = kvmppc_mmu_hpte_cache_next(vcpu);
+	pte = &vcpu->arch.hpte_cache[hpte_id];
+
+	dprintk_mmu("KVM: %c%c Map 0x%llx: [%lx] 0x%llx (0x%llx) -> %lx\n",
+		    orig_pte->may_write ? 'w' : '-',
+		    orig_pte->may_execute ? 'x' : '-',
+		    orig_pte->eaddr, (ulong)pteg, va,
+		    orig_pte->vpage, hpaddr);
+
+	pte->slot = (ulong)&pteg[rr];
+	pte->host_va = va;
+	pte->pte = *orig_pte;
+	pte->pfn = hpaddr >> PAGE_SHIFT;
+
+	return 0;
+}
+
+static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
+{
+	struct kvmppc_sid_map *map;
+	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
+	u16 sid_map_mask;
+	static int backwards_map = 0;
+
+	if (vcpu->arch.msr & MSR_PR)
+		gvsid |= VSID_PR;
+
+	/* We might get collisions that trap in preceding order, so let's
+	   map them differently */
+
+	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
+	if (backwards_map)
+		sid_map_mask = SID_MAP_MASK - sid_map_mask;
+
+	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
+
+	/* Make sure we're taking the other map next time */
+	backwards_map = !backwards_map;
+
+	/* Uh-oh ... out of mappings. Let's flush! */
+	if (vcpu_book3s->vsid_next >= vcpu_book3s->vsid_max) {
+		vcpu_book3s->vsid_next = vcpu_book3s->vsid_first;
+		memset(vcpu_book3s->sid_map, 0,
+		       sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
+		kvmppc_mmu_pte_flush(vcpu, 0, 0);
+		kvmppc_mmu_flush_segments(vcpu);
+	}
+	map->host_vsid = vcpu_book3s->vsid_next;
+
+	/* Would have to be 111 to be completely aligned with the rest of
+	   Linux, but that is just way too little space! */
+	vcpu_book3s->vsid_next+=1;
+
+	map->guest_vsid = gvsid;
+	map->valid = true;
+
+	return map;
+}
+
+int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
+{
+	u32 esid = eaddr >> SID_SHIFT;
+	u64 gvsid;
+	u32 sr;
+	struct kvmppc_sid_map *map;
+	struct kvmppc_book3s_shadow_vcpu *svcpu = to_svcpu(vcpu);
+
+	if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
+		/* Invalidate an entry */
+		svcpu->sr[esid] = SR_INVALID;
+		return -ENOENT;
+	}
+
+	map = find_sid_vsid(vcpu, gvsid);
+	if (!map)
+		map = create_sid_map(vcpu, gvsid);
+
+	map->guest_esid = esid;
+	sr = map->host_vsid | SR_KP;
+	svcpu->sr[esid] = sr;
+
+	dprintk_sr("MMU: mtsr %d, 0x%x\n", esid, sr);
+
+	return 0;
+}
+
+void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
+{
+	int i;
+	struct kvmppc_book3s_shadow_vcpu *svcpu = to_svcpu(vcpu);
+
+	dprintk_sr("MMU: flushing all segments (%d)\n", ARRAY_SIZE(svcpu->sr));
+	for (i = 0; i < ARRAY_SIZE(svcpu->sr); i++)
+		svcpu->sr[i] = SR_INVALID;
+}
+
+void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
+{
+	kvmppc_mmu_pte_flush(vcpu, 0, 0);
+	preempt_disable();
+	__destroy_context(to_book3s(vcpu)->context_id);
+	preempt_enable();
+}
+
+/* From mm/mmu_context_hash32.c */
+#define CTX_TO_VSID(ctx) (((ctx) * (897 * 16)) & 0xffffff)
+
+int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
+{
+	struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
+	int err;
+
+	err = __init_new_context();
+	if (err < 0)
+		return -1;
+	vcpu3s->context_id = err;
+
+	vcpu3s->vsid_max = CTX_TO_VSID(vcpu3s->context_id + 1) - 1;
+	vcpu3s->vsid_first = CTX_TO_VSID(vcpu3s->context_id);
+
+#if 0 /* XXX still doesn't guarantee uniqueness */
+	/* We could collide with the Linux vsid space because the vsid
+	 * wraps around at 24 bits. We're safe if we do our own space
+	 * though, so let's always set the highest bit. */
+
+	vcpu3s->vsid_max |= 0x00800000;
+	vcpu3s->vsid_first |= 0x00800000;
+#endif
+	BUG_ON(vcpu3s->vsid_max < vcpu3s->vsid_first);
+
+	vcpu3s->vsid_next = vcpu3s->vsid_first;
+
+	return 0;
+}
-- 
1.6.0.2

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