Initial import

1 files changed, 148 insertions, 0 deletions

diff --git a/arch/mips/kvm/dyntrans.c b/arch/mips/kvm/dyntrans.c
new file mode 100644
index 000000000..521121bde
--- /dev/null
+++ b/arch/mips/kvm/dyntrans.c
@@ -0,0 +1,148 @@
+/*
+ * 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/kvm_host.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <linux/bootmem.h>
+#include <asm/cacheflush.h>
+
+#include "commpage.h"
+
+#define SYNCI_TEMPLATE  0x041f0000
+#define SYNCI_BASE(x)   (((x) >> 21) & 0x1f)
+#define SYNCI_OFFSET    ((x) & 0xffff)
+
+#define LW_TEMPLATE     0x8c000000
+#define CLEAR_TEMPLATE  0x00000020
+#define SW_TEMPLATE     0xac000000
+
+int kvm_mips_trans_cache_index(uint32_t inst, uint32_t *opc,
+			       struct kvm_vcpu *vcpu)
+{
+	int result = 0;
+	unsigned long kseg0_opc;
+	uint32_t synci_inst = 0x0;
+
+	/* Replace the CACHE instruction, with a NOP */
+	kseg0_opc =
+	    CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa
+		       (vcpu, (unsigned long) opc));
+	memcpy((void *)kseg0_opc, (void *)&synci_inst, sizeof(uint32_t));
+	local_flush_icache_range(kseg0_opc, kseg0_opc + 32);
+
+	return result;
+}
+
+/*
+ * 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(uint32_t inst, uint32_t *opc,
+			    struct kvm_vcpu *vcpu)
+{
+	int result = 0;
+	unsigned long kseg0_opc;
+	uint32_t synci_inst = SYNCI_TEMPLATE, base, offset;
+
+	base = (inst >> 21) & 0x1f;
+	offset = inst & 0xffff;
+	synci_inst |= (base << 21);
+	synci_inst |= offset;
+
+	kseg0_opc =
+	    CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa
+		       (vcpu, (unsigned long) opc));
+	memcpy((void *)kseg0_opc, (void *)&synci_inst, sizeof(uint32_t));
+	local_flush_icache_range(kseg0_opc, kseg0_opc + 32);
+
+	return result;
+}
+
+int kvm_mips_trans_mfc0(uint32_t inst, uint32_t *opc, struct kvm_vcpu *vcpu)
+{
+	int32_t rt, rd, sel;
+	uint32_t mfc0_inst;
+	unsigned long kseg0_opc, flags;
+
+	rt = (inst >> 16) & 0x1f;
+	rd = (inst >> 11) & 0x1f;
+	sel = inst & 0x7;
+
+	if ((rd == MIPS_CP0_ERRCTL) && (sel == 0)) {
+		mfc0_inst = CLEAR_TEMPLATE;
+		mfc0_inst |= ((rt & 0x1f) << 16);
+	} else {
+		mfc0_inst = LW_TEMPLATE;
+		mfc0_inst |= ((rt & 0x1f) << 16);
+		mfc0_inst |=
+		    offsetof(struct mips_coproc,
+			     reg[rd][sel]) + offsetof(struct kvm_mips_commpage,
+						      cop0);
+	}
+
+	if (KVM_GUEST_KSEGX(opc) == KVM_GUEST_KSEG0) {
+		kseg0_opc =
+		    CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa
+			       (vcpu, (unsigned long) opc));
+		memcpy((void *)kseg0_opc, (void *)&mfc0_inst, sizeof(uint32_t));
+		local_flush_icache_range(kseg0_opc, kseg0_opc + 32);
+	} else if (KVM_GUEST_KSEGX((unsigned long) opc) == KVM_GUEST_KSEG23) {
+		local_irq_save(flags);
+		memcpy((void *)opc, (void *)&mfc0_inst, sizeof(uint32_t));
+		local_flush_icache_range((unsigned long)opc,
+					 (unsigned long)opc + 32);
+		local_irq_restore(flags);
+	} else {
+		kvm_err("%s: Invalid address: %p\n", __func__, opc);
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
+int kvm_mips_trans_mtc0(uint32_t inst, uint32_t *opc, struct kvm_vcpu *vcpu)
+{
+	int32_t rt, rd, sel;
+	uint32_t mtc0_inst = SW_TEMPLATE;
+	unsigned long kseg0_opc, flags;
+
+	rt = (inst >> 16) & 0x1f;
+	rd = (inst >> 11) & 0x1f;
+	sel = inst & 0x7;
+
+	mtc0_inst |= ((rt & 0x1f) << 16);
+	mtc0_inst |=
+	    offsetof(struct mips_coproc,
+		     reg[rd][sel]) + offsetof(struct kvm_mips_commpage, cop0);
+
+	if (KVM_GUEST_KSEGX(opc) == KVM_GUEST_KSEG0) {
+		kseg0_opc =
+		    CKSEG0ADDR(kvm_mips_translate_guest_kseg0_to_hpa
+			       (vcpu, (unsigned long) opc));
+		memcpy((void *)kseg0_opc, (void *)&mtc0_inst, sizeof(uint32_t));
+		local_flush_icache_range(kseg0_opc, kseg0_opc + 32);
+	} else if (KVM_GUEST_KSEGX((unsigned long) opc) == KVM_GUEST_KSEG23) {
+		local_irq_save(flags);
+		memcpy((void *)opc, (void *)&mtc0_inst, sizeof(uint32_t));
+		local_flush_icache_range((unsigned long)opc,
+					 (unsigned long)opc + 32);
+		local_irq_restore(flags);
+	} else {
+		kvm_err("%s: Invalid address: %p\n", __func__, opc);
+		return -EFAULT;
+	}
+
+	return 0;
+}