summaryrefslogtreecommitdiff
path: root/arch/mips/kvm/mmu.c
blob: d5ada83ec55cf4cb9ca06de797dd5b8d6d58370a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * KVM/MIPS MMU handling in the KVM module.
 *
 * Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
 * Authors: Sanjay Lal <sanjayl@kymasys.com>
 */

#include <linux/kvm_host.h>
#include <asm/mmu_context.h>

static u32 kvm_mips_get_kernel_asid(struct kvm_vcpu *vcpu)
{
	int cpu = smp_processor_id();

	return vcpu->arch.guest_kernel_asid[cpu] &
			cpu_asid_mask(&cpu_data[cpu]);
}

static u32 kvm_mips_get_user_asid(struct kvm_vcpu *vcpu)
{
	int cpu = smp_processor_id();

	return vcpu->arch.guest_user_asid[cpu] &
			cpu_asid_mask(&cpu_data[cpu]);
}

static int kvm_mips_map_page(struct kvm *kvm, gfn_t gfn)
{
	int srcu_idx, err = 0;
	kvm_pfn_t pfn;

	if (kvm->arch.guest_pmap[gfn] != KVM_INVALID_PAGE)
		return 0;

	srcu_idx = srcu_read_lock(&kvm->srcu);
	pfn = gfn_to_pfn(kvm, gfn);

	if (is_error_pfn(pfn)) {
		kvm_err("Couldn't get pfn for gfn %#llx!\n", gfn);
		err = -EFAULT;
		goto out;
	}

	kvm->arch.guest_pmap[gfn] = pfn;
out:
	srcu_read_unlock(&kvm->srcu, srcu_idx);
	return err;
}

/* Translate guest KSEG0 addresses to Host PA */
unsigned long kvm_mips_translate_guest_kseg0_to_hpa(struct kvm_vcpu *vcpu,
						    unsigned long gva)
{
	gfn_t gfn;
	unsigned long offset = gva & ~PAGE_MASK;
	struct kvm *kvm = vcpu->kvm;

	if (KVM_GUEST_KSEGX(gva) != KVM_GUEST_KSEG0) {
		kvm_err("%s/%p: Invalid gva: %#lx\n", __func__,
			__builtin_return_address(0), gva);
		return KVM_INVALID_PAGE;
	}

	gfn = (KVM_GUEST_CPHYSADDR(gva) >> PAGE_SHIFT);

	if (gfn >= kvm->arch.guest_pmap_npages) {
		kvm_err("%s: Invalid gfn: %#llx, GVA: %#lx\n", __func__, gfn,
			gva);
		return KVM_INVALID_PAGE;
	}

	if (kvm_mips_map_page(vcpu->kvm, gfn) < 0)
		return KVM_INVALID_ADDR;

	return (kvm->arch.guest_pmap[gfn] << PAGE_SHIFT) + offset;
}

/* XXXKYMA: Must be called with interrupts disabled */
int kvm_mips_handle_kseg0_tlb_fault(unsigned long badvaddr,
				    struct kvm_vcpu *vcpu)
{
	gfn_t gfn;
	kvm_pfn_t pfn0, pfn1;
	unsigned long vaddr = 0;
	unsigned long entryhi = 0, entrylo0 = 0, entrylo1 = 0;
	int even;
	struct kvm *kvm = vcpu->kvm;
	const int flush_dcache_mask = 0;
	int ret;

	if (KVM_GUEST_KSEGX(badvaddr) != KVM_GUEST_KSEG0) {
		kvm_err("%s: Invalid BadVaddr: %#lx\n", __func__, badvaddr);
		kvm_mips_dump_host_tlbs();
		return -1;
	}

	gfn = (KVM_GUEST_CPHYSADDR(badvaddr) >> PAGE_SHIFT);
	if (gfn >= kvm->arch.guest_pmap_npages) {
		kvm_err("%s: Invalid gfn: %#llx, BadVaddr: %#lx\n", __func__,
			gfn, badvaddr);
		kvm_mips_dump_host_tlbs();
		return -1;
	}
	even = !(gfn & 0x1);
	vaddr = badvaddr & (PAGE_MASK << 1);

	if (kvm_mips_map_page(vcpu->kvm, gfn) < 0)
		return -1;

	if (kvm_mips_map_page(vcpu->kvm, gfn ^ 0x1) < 0)
		return -1;

	if (even) {
		pfn0 = kvm->arch.guest_pmap[gfn];
		pfn1 = kvm->arch.guest_pmap[gfn ^ 0x1];
	} else {
		pfn0 = kvm->arch.guest_pmap[gfn ^ 0x1];
		pfn1 = kvm->arch.guest_pmap[gfn];
	}

	entrylo0 = mips3_paddr_to_tlbpfn(pfn0 << PAGE_SHIFT) | (0x3 << 3) |
		   (1 << 2) | (0x1 << 1);
	entrylo1 = mips3_paddr_to_tlbpfn(pfn1 << PAGE_SHIFT) | (0x3 << 3) |
		   (1 << 2) | (0x1 << 1);

	preempt_disable();
	entryhi = (vaddr | kvm_mips_get_kernel_asid(vcpu));
	ret = kvm_mips_host_tlb_write(vcpu, entryhi, entrylo0, entrylo1,
				      flush_dcache_mask);
	preempt_enable();

	return ret;
}

int kvm_mips_handle_mapped_seg_tlb_fault(struct kvm_vcpu *vcpu,
					 struct kvm_mips_tlb *tlb,
					 unsigned long *hpa0,
					 unsigned long *hpa1)
{
	unsigned long entryhi = 0, entrylo0 = 0, entrylo1 = 0;
	struct kvm *kvm = vcpu->kvm;
	kvm_pfn_t pfn0, pfn1;
	int ret;

	if ((tlb->tlb_hi & VPN2_MASK) == 0) {
		pfn0 = 0;
		pfn1 = 0;
	} else {
		if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo0)
					   >> PAGE_SHIFT) < 0)
			return -1;

		if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo1)
					   >> PAGE_SHIFT) < 0)
			return -1;

		pfn0 = kvm->arch.guest_pmap[mips3_tlbpfn_to_paddr(tlb->tlb_lo0)
					    >> PAGE_SHIFT];
		pfn1 = kvm->arch.guest_pmap[mips3_tlbpfn_to_paddr(tlb->tlb_lo1)
					    >> PAGE_SHIFT];
	}

	if (hpa0)
		*hpa0 = pfn0 << PAGE_SHIFT;

	if (hpa1)
		*hpa1 = pfn1 << PAGE_SHIFT;

	/* Get attributes from the Guest TLB */
	entrylo0 = mips3_paddr_to_tlbpfn(pfn0 << PAGE_SHIFT) | (0x3 << 3) |
		   (tlb->tlb_lo0 & MIPS3_PG_D) | (tlb->tlb_lo0 & MIPS3_PG_V);
	entrylo1 = mips3_paddr_to_tlbpfn(pfn1 << PAGE_SHIFT) | (0x3 << 3) |
		   (tlb->tlb_lo1 & MIPS3_PG_D) | (tlb->tlb_lo1 & MIPS3_PG_V);

	kvm_debug("@ %#lx tlb_lo0: 0x%08lx tlb_lo1: 0x%08lx\n", vcpu->arch.pc,
		  tlb->tlb_lo0, tlb->tlb_lo1);

	preempt_disable();
	entryhi = (tlb->tlb_hi & VPN2_MASK) | (KVM_GUEST_KERNEL_MODE(vcpu) ?
					       kvm_mips_get_kernel_asid(vcpu) :
					       kvm_mips_get_user_asid(vcpu));
	ret = kvm_mips_host_tlb_write(vcpu, entryhi, entrylo0, entrylo1,
				      tlb->tlb_mask);
	preempt_enable();

	return ret;
}

void kvm_get_new_mmu_context(struct mm_struct *mm, unsigned long cpu,
			     struct kvm_vcpu *vcpu)
{
	unsigned long asid = asid_cache(cpu);

	asid += cpu_asid_inc();
	if (!(asid & cpu_asid_mask(&cpu_data[cpu]))) {
		if (cpu_has_vtag_icache)
			flush_icache_all();

		kvm_local_flush_tlb_all();      /* start new asid cycle */

		if (!asid)      /* fix version if needed */
			asid = asid_first_version(cpu);
	}

	cpu_context(cpu, mm) = asid_cache(cpu) = asid;
}

/**
 * kvm_mips_migrate_count() - Migrate timer.
 * @vcpu:	Virtual CPU.
 *
 * Migrate CP0_Count hrtimer to the current CPU by cancelling and restarting it
 * if it was running prior to being cancelled.
 *
 * Must be called when the VCPU is migrated to a different CPU to ensure that
 * timer expiry during guest execution interrupts the guest and causes the
 * interrupt to be delivered in a timely manner.
 */
static void kvm_mips_migrate_count(struct kvm_vcpu *vcpu)
{
	if (hrtimer_cancel(&vcpu->arch.comparecount_timer))
		hrtimer_restart(&vcpu->arch.comparecount_timer);
}

/* Restore ASID once we are scheduled back after preemption */
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
	unsigned long asid_mask = cpu_asid_mask(&cpu_data[cpu]);
	unsigned long flags;
	int newasid = 0;

	kvm_debug("%s: vcpu %p, cpu: %d\n", __func__, vcpu, cpu);

	/* Allocate new kernel and user ASIDs if needed */

	local_irq_save(flags);

	if ((vcpu->arch.guest_kernel_asid[cpu] ^ asid_cache(cpu)) &
						asid_version_mask(cpu)) {
		kvm_get_new_mmu_context(&vcpu->arch.guest_kernel_mm, cpu, vcpu);
		vcpu->arch.guest_kernel_asid[cpu] =
		    vcpu->arch.guest_kernel_mm.context.asid[cpu];
		kvm_get_new_mmu_context(&vcpu->arch.guest_user_mm, cpu, vcpu);
		vcpu->arch.guest_user_asid[cpu] =
		    vcpu->arch.guest_user_mm.context.asid[cpu];
		newasid++;

		kvm_debug("[%d]: cpu_context: %#lx\n", cpu,
			  cpu_context(cpu, current->mm));
		kvm_debug("[%d]: Allocated new ASID for Guest Kernel: %#x\n",
			  cpu, vcpu->arch.guest_kernel_asid[cpu]);
		kvm_debug("[%d]: Allocated new ASID for Guest User: %#x\n", cpu,
			  vcpu->arch.guest_user_asid[cpu]);
	}

	if (vcpu->arch.last_sched_cpu != cpu) {
		kvm_debug("[%d->%d]KVM VCPU[%d] switch\n",
			  vcpu->arch.last_sched_cpu, cpu, vcpu->vcpu_id);
		/*
		 * Migrate the timer interrupt to the current CPU so that it
		 * always interrupts the guest and synchronously triggers a
		 * guest timer interrupt.
		 */
		kvm_mips_migrate_count(vcpu);
	}

	if (!newasid) {
		/*
		 * If we preempted while the guest was executing, then reload
		 * the pre-empted ASID
		 */
		if (current->flags & PF_VCPU) {
			write_c0_entryhi(vcpu->arch.
					 preempt_entryhi & asid_mask);
			ehb();
		}
	} else {
		/* New ASIDs were allocated for the VM */

		/*
		 * Were we in guest context? If so then the pre-empted ASID is
		 * no longer valid, we need to set it to what it should be based
		 * on the mode of the Guest (Kernel/User)
		 */
		if (current->flags & PF_VCPU) {
			if (KVM_GUEST_KERNEL_MODE(vcpu))
				write_c0_entryhi(vcpu->arch.
						 guest_kernel_asid[cpu] &
						 asid_mask);
			else
				write_c0_entryhi(vcpu->arch.
						 guest_user_asid[cpu] &
						 asid_mask);
			ehb();
		}
	}

	/* restore guest state to registers */
	kvm_mips_callbacks->vcpu_set_regs(vcpu);

	local_irq_restore(flags);

}

/* ASID can change if another task is scheduled during preemption */
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
	unsigned long flags;
	int cpu;

	local_irq_save(flags);

	cpu = smp_processor_id();

	vcpu->arch.preempt_entryhi = read_c0_entryhi();
	vcpu->arch.last_sched_cpu = cpu;

	/* save guest state in registers */
	kvm_mips_callbacks->vcpu_get_regs(vcpu);

	if (((cpu_context(cpu, current->mm) ^ asid_cache(cpu)) &
	     asid_version_mask(cpu))) {
		kvm_debug("%s: Dropping MMU Context:  %#lx\n", __func__,
			  cpu_context(cpu, current->mm));
		drop_mmu_context(current->mm, cpu);
	}
	write_c0_entryhi(cpu_asid(cpu, current->mm));
	ehb();

	local_irq_restore(flags);
}

u32 kvm_get_inst(u32 *opc, struct kvm_vcpu *vcpu)
{
	struct mips_coproc *cop0 = vcpu->arch.cop0;
	unsigned long paddr, flags, vpn2, asid;
	u32 inst;
	int index;

	if (KVM_GUEST_KSEGX((unsigned long) opc) < KVM_GUEST_KSEG0 ||
	    KVM_GUEST_KSEGX((unsigned long) opc) == KVM_GUEST_KSEG23) {
		local_irq_save(flags);
		index = kvm_mips_host_tlb_lookup(vcpu, (unsigned long) opc);
		if (index >= 0) {
			inst = *(opc);
		} else {
			vpn2 = (unsigned long) opc & VPN2_MASK;
			asid = kvm_read_c0_guest_entryhi(cop0) &
						KVM_ENTRYHI_ASID;
			index = kvm_mips_guest_tlb_lookup(vcpu, vpn2 | asid);
			if (index < 0) {
				kvm_err("%s: get_user_failed for %p, vcpu: %p, ASID: %#lx\n",
					__func__, opc, vcpu, read_c0_entryhi());
				kvm_mips_dump_host_tlbs();
				local_irq_restore(flags);
				return KVM_INVALID_INST;
			}
			kvm_mips_handle_mapped_seg_tlb_fault(vcpu,
							     &vcpu->arch.
							     guest_tlb[index],
							     NULL, NULL);
			inst = *(opc);
		}
		local_irq_restore(flags);
	} else if (KVM_GUEST_KSEGX(opc) == KVM_GUEST_KSEG0) {
		paddr =
		    kvm_mips_translate_guest_kseg0_to_hpa(vcpu,
							  (unsigned long) opc);
		inst = *(u32 *) CKSEG0ADDR(paddr);
	} else {
		kvm_err("%s: illegal address: %p\n", __func__, opc);
		return KVM_INVALID_INST;
	}

	return inst;
}