Add book3s_32 guest MMU

This patch adds an implementation for a G3/G4 MMU, so we can run G3 and
G4 guests in KVM on Book3s_64.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kvm/book3s_32_mmu.c

+/*
+ * 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.
+ *
+ * Copyright SUSE Linux Products GmbH 2009
+ *
+ * Authors: Alexander Graf <agraf@suse.de>
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <linux/highmem.h>
+
+#include <asm/tlbflush.h>
+#include <asm/kvm_ppc.h>
+#include <asm/kvm_book3s.h>
+
+/* #define DEBUG_MMU */
+/* #define DEBUG_MMU_PTE */
+/* #define DEBUG_MMU_PTE_IP 0xfff14c40 */
+
+#ifdef DEBUG_MMU
+#define dprintk(X...) printk(KERN_INFO X)
+#else
+#define dprintk(X...) do { } while(0)
+#endif
+
+#ifdef DEBUG_PTE
+#define dprintk_pte(X...) printk(KERN_INFO X)
+#else
+#define dprintk_pte(X...) do { } while(0)
+#endif
+
+#define PTEG_FLAG_ACCESSED	0x00000100
+#define PTEG_FLAG_DIRTY		0x00000080
+
+static inline bool check_debug_ip(struct kvm_vcpu *vcpu)
+{
+#ifdef DEBUG_MMU_PTE_IP
+	return vcpu->arch.pc == DEBUG_MMU_PTE_IP;
+#else
+	return true;
+#endif
+}
+
+static int kvmppc_mmu_book3s_32_xlate_bat(struct kvm_vcpu *vcpu, gva_t eaddr,
+					  struct kvmppc_pte *pte, bool data);
+
+static struct kvmppc_sr *find_sr(struct kvmppc_vcpu_book3s *vcpu_book3s, gva_t eaddr)
+{
+	return &vcpu_book3s->sr[(eaddr >> 28) & 0xf];
+}
+
+static u64 kvmppc_mmu_book3s_32_ea_to_vp(struct kvm_vcpu *vcpu, gva_t eaddr,
+					 bool data)
+{
+	struct kvmppc_sr *sre = find_sr(to_book3s(vcpu), eaddr);
+	struct kvmppc_pte pte;
+
+	if (!kvmppc_mmu_book3s_32_xlate_bat(vcpu, eaddr, &pte, data))
+		return pte.vpage;
+
+	return (((u64)eaddr >> 12) & 0xffff) | (((u64)sre->vsid) << 16);
+}
+
+static void kvmppc_mmu_book3s_32_reset_msr(struct kvm_vcpu *vcpu)
+{
+	kvmppc_set_msr(vcpu, 0);
+}
+
+static hva_t kvmppc_mmu_book3s_32_get_pteg(struct kvmppc_vcpu_book3s *vcpu_book3s,
+				      struct kvmppc_sr *sre, gva_t eaddr,
+				      bool primary)
+{
+	u32 page, hash, pteg, htabmask;
+	hva_t r;
+
+	page = (eaddr & 0x0FFFFFFF) >> 12;
+	htabmask = ((vcpu_book3s->sdr1 & 0x1FF) << 16) | 0xFFC0;
+
+	hash = ((sre->vsid ^ page) << 6);
+	if (!primary)
+		hash = ~hash;
+	hash &= htabmask;
+
+	pteg = (vcpu_book3s->sdr1 & 0xffff0000) | hash;
+
+	dprintk("MMU: pc=0x%lx eaddr=0x%lx sdr1=0x%llx pteg=0x%x vsid=0x%x\n",
+		vcpu_book3s->vcpu.arch.pc, eaddr, vcpu_book3s->sdr1, pteg,
+		sre->vsid);
+
+	r = gfn_to_hva(vcpu_book3s->vcpu.kvm, pteg >> PAGE_SHIFT);
+	if (kvm_is_error_hva(r))
+		return r;
+	return r | (pteg & ~PAGE_MASK);
+}
+
+static u32 kvmppc_mmu_book3s_32_get_ptem(struct kvmppc_sr *sre, gva_t eaddr,
+				    bool primary)
+{
+	return ((eaddr & 0x0fffffff) >> 22) | (sre->vsid << 7) |
+	       (primary ? 0 : 0x40) | 0x80000000;
+}
+
+static int kvmppc_mmu_book3s_32_xlate_bat(struct kvm_vcpu *vcpu, gva_t eaddr,
+					  struct kvmppc_pte *pte, bool data)
+{
+	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
+	struct kvmppc_bat *bat;
+	int i;
+
+	for (i = 0; i < 8; i++) {
+		if (data)
+			bat = &vcpu_book3s->dbat[i];
+		else
+			bat = &vcpu_book3s->ibat[i];
+
+		if (vcpu->arch.msr & MSR_PR) {
+			if (!bat->vp)
+				continue;
+		} else {
+			if (!bat->vs)
+				continue;
+		}
+
+		if (check_debug_ip(vcpu))
+		{
+			dprintk_pte("%cBAT %02d: 0x%lx - 0x%x (0x%x)\n",
+				    data ? 'd' : 'i', i, eaddr, bat->bepi,
+				    bat->bepi_mask);
+		}
+		if ((eaddr & bat->bepi_mask) == bat->bepi) {
+			pte->raddr = bat->brpn | (eaddr & ~bat->bepi_mask);
+			pte->vpage = (eaddr >> 12) | VSID_BAT;
+			pte->may_read = bat->pp;
+			pte->may_write = bat->pp > 1;
+			pte->may_execute = true;
+			if (!pte->may_read) {
+				printk(KERN_INFO "BAT is not readable!\n");
+				continue;
+			}
+			if (!pte->may_write) {
+				/* let's treat r/o BATs as not-readable for now */
+				dprintk_pte("BAT is read-only!\n");
+				continue;
+			}
+
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+static int kvmppc_mmu_book3s_32_xlate_pte(struct kvm_vcpu *vcpu, gva_t eaddr,
+				     struct kvmppc_pte *pte, bool data,
+				     bool primary)
+{
+	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
+	struct kvmppc_sr *sre;
+	hva_t ptegp;
+	u32 pteg[16];
+	u64 ptem = 0;
+	int i;
+	int found = 0;
+
+	sre = find_sr(vcpu_book3s, eaddr);
+
+	dprintk_pte("SR 0x%lx: vsid=0x%x, raw=0x%x\n", eaddr >> 28,
+		    sre->vsid, sre->raw);
+
+	pte->vpage = kvmppc_mmu_book3s_32_ea_to_vp(vcpu, eaddr, data);
+
+	ptegp = kvmppc_mmu_book3s_32_get_pteg(vcpu_book3s, sre, eaddr, primary);
+	if (kvm_is_error_hva(ptegp)) {
+		printk(KERN_INFO "KVM: Invalid PTEG!\n");
+		goto no_page_found;
+	}
+
+	ptem = kvmppc_mmu_book3s_32_get_ptem(sre, eaddr, primary);
+
+	if(copy_from_user(pteg, (void __user *)ptegp, sizeof(pteg))) {
+		printk(KERN_ERR "KVM: Can't copy data from 0x%lx!\n", ptegp);
+		goto no_page_found;
+	}
+
+	for (i=0; i<16; i+=2) {
+		if (ptem == pteg[i]) {
+			u8 pp;
+
+			pte->raddr = (pteg[i+1] & ~(0xFFFULL)) | (eaddr & 0xFFF);
+			pp = pteg[i+1] & 3;
+
+			if ((sre->Kp &&  (vcpu->arch.msr & MSR_PR)) ||
+			    (sre->Ks && !(vcpu->arch.msr & MSR_PR)))
+				pp |= 4;
+
+			pte->may_write = false;
+			pte->may_read = false;
+			pte->may_execute = true;
+			switch (pp) {
+				case 0:
+				case 1:
+				case 2:
+				case 6:
+					pte->may_write = true;
+				case 3:
+				case 5:
+				case 7:
+					pte->may_read = true;
+					break;
+			}
+
+			if ( !pte->may_read )
+				continue;
+
+			dprintk_pte("MMU: Found PTE -> %x %x - %x\n",
+				    pteg[i], pteg[i+1], pp);
+			found = 1;
+			break;
+		}
+	}
+
+	/* Update PTE C and A bits, so the guest's swapper knows we used the
+	   page */
+	if (found) {
+		u32 oldpte = pteg[i+1];
+
+		if (pte->may_read)
+			pteg[i+1] |= PTEG_FLAG_ACCESSED;
+		if (pte->may_write)
+			pteg[i+1] |= PTEG_FLAG_DIRTY;
+		else
+			dprintk_pte("KVM: Mapping read-only page!\n");
+
+		/* Write back into the PTEG */
+		if (pteg[i+1] != oldpte)
+			copy_to_user((void __user *)ptegp, pteg, sizeof(pteg));
+
+		return 0;
+	}
+
+no_page_found:
+
+	if (check_debug_ip(vcpu)) {
+		dprintk_pte("KVM MMU: No PTE found (sdr1=0x%llx ptegp=0x%lx)\n",
+			    to_book3s(vcpu)->sdr1, ptegp);
+		for (i=0; i<16; i+=2) {
+			dprintk_pte("   %02d: 0x%x - 0x%x (0x%llx)\n",
+				    i, pteg[i], pteg[i+1], ptem);
+		}
+	}
+
+	return -ENOENT;
+}
+
+static int kvmppc_mmu_book3s_32_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
+				      struct kvmppc_pte *pte, bool data)
+{
+	int r;
+
+	pte->eaddr = eaddr;
+	r = kvmppc_mmu_book3s_32_xlate_bat(vcpu, eaddr, pte, data);
+	if (r < 0)
+	       r = kvmppc_mmu_book3s_32_xlate_pte(vcpu, eaddr, pte, data, true);
+	if (r < 0)
+	       r = kvmppc_mmu_book3s_32_xlate_pte(vcpu, eaddr, pte, data, false);
+
+	return r;
+}
+
+
+static u32 kvmppc_mmu_book3s_32_mfsrin(struct kvm_vcpu *vcpu, u32 srnum)
+{
+	return to_book3s(vcpu)->sr[srnum].raw;
+}
+
+static void kvmppc_mmu_book3s_32_mtsrin(struct kvm_vcpu *vcpu, u32 srnum,
+					ulong value)
+{
+	struct kvmppc_sr *sre;
+
+	sre = &to_book3s(vcpu)->sr[srnum];
+
+	/* Flush any left-over shadows from the previous SR */
+
+	/* XXX Not necessary? */
+	/* kvmppc_mmu_pte_flush(vcpu, ((u64)sre->vsid) << 28, 0xf0000000ULL); */
+
+	/* And then put in the new SR */
+	sre->raw = value;
+	sre->vsid = (value & 0x0fffffff);
+	sre->Ks = (value & 0x40000000) ? true : false;
+	sre->Kp = (value & 0x20000000) ? true : false;
+	sre->nx = (value & 0x10000000) ? true : false;
+
+	/* Map the new segment */
+	kvmppc_mmu_map_segment(vcpu, srnum << SID_SHIFT);
+}
+
+static void kvmppc_mmu_book3s_32_tlbie(struct kvm_vcpu *vcpu, ulong ea, bool large)
+{
+	kvmppc_mmu_pte_flush(vcpu, ea, ~0xFFFULL);
+}
+
+static int kvmppc_mmu_book3s_32_esid_to_vsid(struct kvm_vcpu *vcpu, u64 esid,
+					     u64 *vsid)
+{
+	/* In case we only have one of MSR_IR or MSR_DR set, let's put
+	   that in the real-mode context (and hope RM doesn't access
+	   high memory) */
+	switch (vcpu->arch.msr & (MSR_DR|MSR_IR)) {
+	case 0:
+		*vsid = (VSID_REAL >> 16) | esid;
+		break;
+	case MSR_IR:
+		*vsid = (VSID_REAL_IR >> 16) | esid;
+		break;
+	case MSR_DR:
+		*vsid = (VSID_REAL_DR >> 16) | esid;
+		break;
+	case MSR_DR|MSR_IR:
+	{
+		ulong ea;
+		ea = esid << SID_SHIFT;
+		*vsid = find_sr(to_book3s(vcpu), ea)->vsid;
+		break;
+	}
+	default:
+		BUG();
+	}
+
+	return 0;
+}
+
+static bool kvmppc_mmu_book3s_32_is_dcbz32(struct kvm_vcpu *vcpu)
+{
+	return true;
+}
+
+
+void kvmppc_mmu_book3s_32_init(struct kvm_vcpu *vcpu)
+{
+	struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
+
+	mmu->mtsrin = kvmppc_mmu_book3s_32_mtsrin;
+	mmu->mfsrin = kvmppc_mmu_book3s_32_mfsrin;
+	mmu->xlate = kvmppc_mmu_book3s_32_xlate;
+	mmu->reset_msr = kvmppc_mmu_book3s_32_reset_msr;
+	mmu->tlbie = kvmppc_mmu_book3s_32_tlbie;
+	mmu->esid_to_vsid = kvmppc_mmu_book3s_32_esid_to_vsid;
+	mmu->ea_to_vp = kvmppc_mmu_book3s_32_ea_to_vp;
+	mmu->is_dcbz32 = kvmppc_mmu_book3s_32_is_dcbz32;
+
+	mmu->slbmte = NULL;
+	mmu->slbmfee = NULL;
+	mmu->slbmfev = NULL;
+	mmu->slbie = NULL;
+	mmu->slbia = NULL;
+}