1 files changed, 395 insertions, 0 deletions

diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
new file mode 100644
index 000000000..121008c0f
--- /dev/null
+++ b/arch/mips/kvm/mmu.c
@@ -0,0 +1,395 @@
+/*
+ * 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/highmem.h>
+#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_noslot_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;
+	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 | 1) >= kvm->arch.guest_pmap_npages) {
+		kvm_err("%s: Invalid gfn: %#llx, BadVaddr: %#lx\n", __func__,
+			gfn, badvaddr);
+		kvm_mips_dump_host_tlbs();
+		return -1;
+	}
+	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;
+
+	pfn0 = kvm->arch.guest_pmap[gfn & ~0x1];
+	pfn1 = kvm->arch.guest_pmap[gfn | 0x1];
+
+	entrylo0 = mips3_paddr_to_tlbpfn(pfn0 << PAGE_SHIFT) |
+		((_page_cachable_default >> _CACHE_SHIFT) << ENTRYLO_C_SHIFT) |
+		ENTRYLO_D | ENTRYLO_V;
+	entrylo1 = mips3_paddr_to_tlbpfn(pfn1 << PAGE_SHIFT) |
+		((_page_cachable_default >> _CACHE_SHIFT) << ENTRYLO_C_SHIFT) |
+		ENTRYLO_D | ENTRYLO_V;
+
+	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 entryhi = 0, entrylo0 = 0, entrylo1 = 0;
+	struct kvm *kvm = vcpu->kvm;
+	kvm_pfn_t pfn0, pfn1;
+	gfn_t gfn0, gfn1;
+	long tlb_lo[2];
+	int ret;
+
+	tlb_lo[0] = tlb->tlb_lo[0];
+	tlb_lo[1] = tlb->tlb_lo[1];
+
+	/*
+	 * The commpage address must not be mapped to anything else if the guest
+	 * TLB contains entries nearby, or commpage accesses will break.
+	 */
+	if (!((tlb->tlb_hi ^ KVM_GUEST_COMMPAGE_ADDR) &
+			VPN2_MASK & (PAGE_MASK << 1)))
+		tlb_lo[(KVM_GUEST_COMMPAGE_ADDR >> PAGE_SHIFT) & 1] = 0;
+
+	gfn0 = mips3_tlbpfn_to_paddr(tlb_lo[0]) >> PAGE_SHIFT;
+	gfn1 = mips3_tlbpfn_to_paddr(tlb_lo[1]) >> PAGE_SHIFT;
+	if (gfn0 >= kvm->arch.guest_pmap_npages ||
+	    gfn1 >= kvm->arch.guest_pmap_npages) {
+		kvm_err("%s: Invalid gfn: [%#llx, %#llx], EHi: %#lx\n",
+			__func__, gfn0, gfn1, tlb->tlb_hi);
+		kvm_mips_dump_guest_tlbs(vcpu);
+		return -1;
+	}
+
+	if (kvm_mips_map_page(kvm, gfn0) < 0)
+		return -1;
+
+	if (kvm_mips_map_page(kvm, gfn1) < 0)
+		return -1;
+
+	pfn0 = kvm->arch.guest_pmap[gfn0];
+	pfn1 = kvm->arch.guest_pmap[gfn1];
+
+	/* Get attributes from the Guest TLB */
+	entrylo0 = mips3_paddr_to_tlbpfn(pfn0 << PAGE_SHIFT) |
+		((_page_cachable_default >> _CACHE_SHIFT) << ENTRYLO_C_SHIFT) |
+		(tlb_lo[0] & ENTRYLO_D) |
+		(tlb_lo[0] & ENTRYLO_V);
+	entrylo1 = mips3_paddr_to_tlbpfn(pfn1 << PAGE_SHIFT) |
+		((_page_cachable_default >> _CACHE_SHIFT) << ENTRYLO_C_SHIFT) |
+		(tlb_lo[1] & ENTRYLO_D) |
+		(tlb_lo[1] & ENTRYLO_V);
+
+	kvm_debug("@ %#lx tlb_lo0: 0x%08lx tlb_lo1: 0x%08lx\n", vcpu->arch.pc,
+		  tlb->tlb_lo[0], tlb->tlb_lo[1]);
+
+	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;
+	unsigned long va = (unsigned long)opc;
+	void *vaddr;
+	u32 inst;
+	int index;
+
+	if (KVM_GUEST_KSEGX(va) < KVM_GUEST_KSEG0 ||
+	    KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG23) {
+		local_irq_save(flags);
+		index = kvm_mips_host_tlb_lookup(vcpu, va);
+		if (index >= 0) {
+			inst = *(opc);
+		} else {
+			vpn2 = va & 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();
+				kvm_mips_dump_guest_tlbs(vcpu);
+				local_irq_restore(flags);
+				return KVM_INVALID_INST;
+			}
+			if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu,
+						&vcpu->arch.guest_tlb[index])) {
+				kvm_err("%s: handling mapped seg tlb fault failed for %p, index: %u, vcpu: %p, ASID: %#lx\n",
+					__func__, opc, index, vcpu,
+					read_c0_entryhi());
+				kvm_mips_dump_guest_tlbs(vcpu);
+				local_irq_restore(flags);
+				return KVM_INVALID_INST;
+			}
+			inst = *(opc);
+		}
+		local_irq_restore(flags);
+	} else if (KVM_GUEST_KSEGX(va) == KVM_GUEST_KSEG0) {
+		paddr = kvm_mips_translate_guest_kseg0_to_hpa(vcpu, va);
+		vaddr = kmap_atomic(pfn_to_page(PHYS_PFN(paddr)));
+		vaddr += paddr & ~PAGE_MASK;
+		inst = *(u32 *)vaddr;
+		kunmap_atomic(vaddr);
+	} else {
+		kvm_err("%s: illegal address: %p\n", __func__, opc);
+		return KVM_INVALID_INST;
+	}
+
+	return inst;
+}