Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 143 insertions, 0 deletions

diff --git a/arch/mips/kvm/dyntrans.c b/arch/mips/kvm/dyntrans.c
new file mode 100644
index 000000000..d77b61b3d
--- /dev/null
+++ b/arch/mips/kvm/dyntrans.c
@@ -0,0 +1,143 @@
+/*
+ * 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: Binary Patching for privileged instructions, reduces traps.
+ *
+ * Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
+ * Authors: Sanjay Lal <sanjayl@kymasys.com>
+ */
+
+#include <linux/errno.h>
+#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/memblock.h>
+#include <asm/cacheflush.h>
+
+#include "commpage.h"
+
+/**
+ * kvm_mips_trans_replace() - Replace trapping instruction in guest memory.
+ * @vcpu:	Virtual CPU.
+ * @opc:	PC of instruction to replace.
+ * @replace:	Instruction to write
+ */
+static int kvm_mips_trans_replace(struct kvm_vcpu *vcpu, u32 *opc,
+				  union mips_instruction replace)
+{
+	unsigned long vaddr = (unsigned long)opc;
+	int err;
+
+retry:
+	/* The GVA page table is still active so use the Linux TLB handlers */
+	kvm_trap_emul_gva_lockless_begin(vcpu);
+	err = put_user(replace.word, opc);
+	kvm_trap_emul_gva_lockless_end(vcpu);
+
+	if (unlikely(err)) {
+		/*
+		 * We write protect clean pages in GVA page table so normal
+		 * Linux TLB mod handler doesn't silently dirty the page.
+		 * Its also possible we raced with a GVA invalidation.
+		 * Try to force the page to become dirty.
+		 */
+		err = kvm_trap_emul_gva_fault(vcpu, vaddr, true);
+		if (unlikely(err)) {
+			kvm_info("%s: Address unwriteable: %p\n",
+				 __func__, opc);
+			return -EFAULT;
+		}
+
+		/*
+		 * Try again. This will likely trigger a TLB refill, which will
+		 * fetch the new dirty entry from the GVA page table, which
+		 * should then succeed.
+		 */
+		goto retry;
+	}
+	__local_flush_icache_user_range(vaddr, vaddr + 4);
+
+	return 0;
+}
+
+int kvm_mips_trans_cache_index(union mips_instruction inst, u32 *opc,
+			       struct kvm_vcpu *vcpu)
+{
+	union mips_instruction nop_inst = { 0 };
+
+	/* Replace the CACHE instruction, with a NOP */
+	return kvm_mips_trans_replace(vcpu, opc, nop_inst);
+}
+
+/*
+ * Address based CACHE instructions are transformed into synci(s). A little
+ * heavy for just D-cache invalidates, but avoids an expensive trap
+ */
+int kvm_mips_trans_cache_va(union mips_instruction inst, u32 *opc,
+			    struct kvm_vcpu *vcpu)
+{
+	union mips_instruction synci_inst = { 0 };
+
+	synci_inst.i_format.opcode = bcond_op;
+	synci_inst.i_format.rs = inst.i_format.rs;
+	synci_inst.i_format.rt = synci_op;
+	if (cpu_has_mips_r6)
+		synci_inst.i_format.simmediate = inst.spec3_format.simmediate;
+	else
+		synci_inst.i_format.simmediate = inst.i_format.simmediate;
+
+	return kvm_mips_trans_replace(vcpu, opc, synci_inst);
+}
+
+int kvm_mips_trans_mfc0(union mips_instruction inst, u32 *opc,
+			struct kvm_vcpu *vcpu)
+{
+	union mips_instruction mfc0_inst = { 0 };
+	u32 rd, sel;
+
+	rd = inst.c0r_format.rd;
+	sel = inst.c0r_format.sel;
+
+	if (rd == MIPS_CP0_ERRCTL && sel == 0) {
+		mfc0_inst.r_format.opcode = spec_op;
+		mfc0_inst.r_format.rd = inst.c0r_format.rt;
+		mfc0_inst.r_format.func = add_op;
+	} else {
+		mfc0_inst.i_format.opcode = lw_op;
+		mfc0_inst.i_format.rt = inst.c0r_format.rt;
+		mfc0_inst.i_format.simmediate = KVM_GUEST_COMMPAGE_ADDR |
+			offsetof(struct kvm_mips_commpage, cop0.reg[rd][sel]);
+#ifdef CONFIG_CPU_BIG_ENDIAN
+		if (sizeof(vcpu->arch.cop0->reg[0][0]) == 8)
+			mfc0_inst.i_format.simmediate |= 4;
+#endif
+	}
+
+	return kvm_mips_trans_replace(vcpu, opc, mfc0_inst);
+}
+
+int kvm_mips_trans_mtc0(union mips_instruction inst, u32 *opc,
+			struct kvm_vcpu *vcpu)
+{
+	union mips_instruction mtc0_inst = { 0 };
+	u32 rd, sel;
+
+	rd = inst.c0r_format.rd;
+	sel = inst.c0r_format.sel;
+
+	mtc0_inst.i_format.opcode = sw_op;
+	mtc0_inst.i_format.rt = inst.c0r_format.rt;
+	mtc0_inst.i_format.simmediate = KVM_GUEST_COMMPAGE_ADDR |
+		offsetof(struct kvm_mips_commpage, cop0.reg[rd][sel]);
+#ifdef CONFIG_CPU_BIG_ENDIAN
+	if (sizeof(vcpu->arch.cop0->reg[0][0]) == 8)
+		mtc0_inst.i_format.simmediate |= 4;
+#endif
+
+	return kvm_mips_trans_replace(vcpu, opc, mtc0_inst);
+}