3 files changed, 22 insertions, 92 deletions

diff --git a/arch/mips/kvm/dyntrans.c b/arch/mips/kvm/dyntrans.c
index 010cef240688..60ebf5862d2b 100644
--- a/arch/mips/kvm/dyntrans.c
+++ b/arch/mips/kvm/dyntrans.c
@@ -13,6 +13,7 @@
 #include <linux/err.h>
 #include <linux/highmem.h>
 #include <linux/kvm_host.h>
+#include <linux/uaccess.h>
 #include <linux/vmalloc.h>
 #include <linux/fs.h>
 #include <linux/bootmem.h>
@@ -29,28 +30,15 @@
 static int kvm_mips_trans_replace(struct kvm_vcpu *vcpu, u32 *opc,
 				  union mips_instruction replace)
 {
-	unsigned long paddr, flags;
-	void *vaddr;
-
-	if (KVM_GUEST_KSEGX((unsigned long)opc) == KVM_GUEST_KSEG0) {
-		paddr = kvm_mips_translate_guest_kseg0_to_hpa(vcpu,
-							    (unsigned long)opc);
-		vaddr = kmap_atomic(pfn_to_page(PHYS_PFN(paddr)));
-		vaddr += paddr & ~PAGE_MASK;
-		memcpy(vaddr, (void *)&replace, sizeof(u32));
-		local_flush_icache_range((unsigned long)vaddr,
-					 (unsigned long)vaddr + 32);
-		kunmap_atomic(vaddr);
-	} else if (KVM_GUEST_KSEGX((unsigned long) opc) == KVM_GUEST_KSEG23) {
-		local_irq_save(flags);
-		memcpy((void *)opc, (void *)&replace, sizeof(u32));
-		__local_flush_icache_user_range((unsigned long)opc,
-						(unsigned long)opc + 32);
-		local_irq_restore(flags);
-	} else {
+	unsigned long vaddr = (unsigned long)opc;
+	int err;
+
+	err = put_user(replace.word, opc);
+	if (unlikely(err)) {
 		kvm_err("%s: Invalid address: %p\n", __func__, opc);
-		return -EFAULT;
+		return err;
 	}
+	__local_flush_icache_user_range(vaddr, vaddr + 4);
 
 	return 0;
 }
diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
index 98f1a7715a68..c4e9c65065ea 100644
--- a/arch/mips/kvm/mmu.c
+++ b/arch/mips/kvm/mmu.c
@@ -11,6 +11,7 @@
 
 #include <linux/highmem.h>
 #include <linux/kvm_host.h>
+#include <linux/uaccess.h>
 #include <asm/mmu_context.h>
 #include <asm/pgalloc.h>
 
@@ -134,34 +135,6 @@ out:
 	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;
-}
-
 static pte_t *kvm_trap_emul_pte_for_gva(struct kvm_vcpu *vcpu,
 					unsigned long addr)
 {
@@ -551,51 +524,11 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 
 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], va)) {
-				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 {
+	int err;
+
+	err = get_user(inst, opc);
+	if (unlikely(err)) {
 		kvm_err("%s: illegal address: %p\n", __func__, opc);
 		return KVM_INVALID_INST;
 	}
diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c
index 8bb82eaa4c91..ee8b5ad8c7c5 100644
--- a/arch/mips/kvm/trap_emul.c
+++ b/arch/mips/kvm/trap_emul.c
@@ -12,6 +12,7 @@
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/kvm_host.h>
+#include <linux/uaccess.h>
 #include <linux/vmalloc.h>
 #include <asm/mmu_context.h>
 #include <asm/pgalloc.h>
@@ -798,6 +799,12 @@ static int kvm_trap_emul_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
 
 	kvm_trap_emul_vcpu_reenter(run, vcpu);
 
+	/*
+	 * We use user accessors to access guest memory, but we don't want to
+	 * invoke Linux page faulting.
+	 */
+	pagefault_disable();
+
 	/* Disable hardware page table walking while in guest */
 	htw_stop();
 
@@ -823,6 +830,8 @@ static int kvm_trap_emul_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
 
 	htw_start();
 
+	pagefault_enable();
+
 	return r;
 }