KVM: arm/arm64: Move shared files to virt/kvm/arm

For some time now we have been having a lot of shared functionality
between the arm and arm64 KVM support in arch/arm, which not only
required a horrible inter-arch reference from the Makefile in
arch/arm64/kvm, but also created confusion for newcomers to the code
base, as was recently seen on the mailing list.

Further, it causes confusion for things like cscope, which needs special
attention to index specific shared files for arm64 from the arm tree.

Move the shared files into virt/kvm/arm and move the trace points along
with it.  When moving the tracepoints we have to modify the way the vgic
creates definitions of the trace points, so we take the chance to
include the VGIC tracepoints in its very own special vgic trace.h file.

Signed-off-by: Christoffer Dall <cdall@linaro.org>

1 files changed, 217 insertions, 0 deletions

diff --git a/virt/kvm/arm/mmio.c b/virt/kvm/arm/mmio.c
new file mode 100644
index 000000000000..b6e715fd3c90
--- /dev/null
+++ b/virt/kvm/arm/mmio.c
@@ -0,0 +1,217 @@
+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <linux/kvm_host.h>
+#include <asm/kvm_mmio.h>
+#include <asm/kvm_emulate.h>
+#include <trace/events/kvm.h>
+
+#include "trace.h"
+
+void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data)
+{
+	void *datap = NULL;
+	union {
+		u8	byte;
+		u16	hword;
+		u32	word;
+		u64	dword;
+	} tmp;
+
+	switch (len) {
+	case 1:
+		tmp.byte	= data;
+		datap		= &tmp.byte;
+		break;
+	case 2:
+		tmp.hword	= data;
+		datap		= &tmp.hword;
+		break;
+	case 4:
+		tmp.word	= data;
+		datap		= &tmp.word;
+		break;
+	case 8:
+		tmp.dword	= data;
+		datap		= &tmp.dword;
+		break;
+	}
+
+	memcpy(buf, datap, len);
+}
+
+unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len)
+{
+	unsigned long data = 0;
+	union {
+		u16	hword;
+		u32	word;
+		u64	dword;
+	} tmp;
+
+	switch (len) {
+	case 1:
+		data = *(u8 *)buf;
+		break;
+	case 2:
+		memcpy(&tmp.hword, buf, len);
+		data = tmp.hword;
+		break;
+	case 4:
+		memcpy(&tmp.word, buf, len);
+		data = tmp.word;
+		break;
+	case 8:
+		memcpy(&tmp.dword, buf, len);
+		data = tmp.dword;
+		break;
+	}
+
+	return data;
+}
+
+/**
+ * kvm_handle_mmio_return -- Handle MMIO loads after user space emulation
+ *			     or in-kernel IO emulation
+ *
+ * @vcpu: The VCPU pointer
+ * @run:  The VCPU run struct containing the mmio data
+ */
+int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	unsigned long data;
+	unsigned int len;
+	int mask;
+
+	if (!run->mmio.is_write) {
+		len = run->mmio.len;
+		if (len > sizeof(unsigned long))
+			return -EINVAL;
+
+		data = kvm_mmio_read_buf(run->mmio.data, len);
+
+		if (vcpu->arch.mmio_decode.sign_extend &&
+		    len < sizeof(unsigned long)) {
+			mask = 1U << ((len * 8) - 1);
+			data = (data ^ mask) - mask;
+		}
+
+		trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr,
+			       data);
+		data = vcpu_data_host_to_guest(vcpu, data, len);
+		vcpu_set_reg(vcpu, vcpu->arch.mmio_decode.rt, data);
+	}
+
+	return 0;
+}
+
+static int decode_hsr(struct kvm_vcpu *vcpu, bool *is_write, int *len)
+{
+	unsigned long rt;
+	int access_size;
+	bool sign_extend;
+
+	if (kvm_vcpu_dabt_iss1tw(vcpu)) {
+		/* page table accesses IO mem: tell guest to fix its TTBR */
+		kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
+		return 1;
+	}
+
+	access_size = kvm_vcpu_dabt_get_as(vcpu);
+	if (unlikely(access_size < 0))
+		return access_size;
+
+	*is_write = kvm_vcpu_dabt_iswrite(vcpu);
+	sign_extend = kvm_vcpu_dabt_issext(vcpu);
+	rt = kvm_vcpu_dabt_get_rd(vcpu);
+
+	*len = access_size;
+	vcpu->arch.mmio_decode.sign_extend = sign_extend;
+	vcpu->arch.mmio_decode.rt = rt;
+
+	/*
+	 * The MMIO instruction is emulated and should not be re-executed
+	 * in the guest.
+	 */
+	kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
+	return 0;
+}
+
+int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
+		 phys_addr_t fault_ipa)
+{
+	unsigned long data;
+	unsigned long rt;
+	int ret;
+	bool is_write;
+	int len;
+	u8 data_buf[8];
+
+	/*
+	 * Prepare MMIO operation. First decode the syndrome data we get
+	 * from the CPU. Then try if some in-kernel emulation feels
+	 * responsible, otherwise let user space do its magic.
+	 */
+	if (kvm_vcpu_dabt_isvalid(vcpu)) {
+		ret = decode_hsr(vcpu, &is_write, &len);
+		if (ret)
+			return ret;
+	} else {
+		kvm_err("load/store instruction decoding not implemented\n");
+		return -ENOSYS;
+	}
+
+	rt = vcpu->arch.mmio_decode.rt;
+
+	if (is_write) {
+		data = vcpu_data_guest_to_host(vcpu, vcpu_get_reg(vcpu, rt),
+					       len);
+
+		trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, len, fault_ipa, data);
+		kvm_mmio_write_buf(data_buf, len, data);
+
+		ret = kvm_io_bus_write(vcpu, KVM_MMIO_BUS, fault_ipa, len,
+				       data_buf);
+	} else {
+		trace_kvm_mmio(KVM_TRACE_MMIO_READ_UNSATISFIED, len,
+			       fault_ipa, 0);
+
+		ret = kvm_io_bus_read(vcpu, KVM_MMIO_BUS, fault_ipa, len,
+				      data_buf);
+	}
+
+	/* Now prepare kvm_run for the potential return to userland. */
+	run->mmio.is_write	= is_write;
+	run->mmio.phys_addr	= fault_ipa;
+	run->mmio.len		= len;
+
+	if (!ret) {
+		/* We handled the access successfully in the kernel. */
+		if (!is_write)
+			memcpy(run->mmio.data, data_buf, len);
+		vcpu->stat.mmio_exit_kernel++;
+		kvm_handle_mmio_return(vcpu, run);
+		return 1;
+	}
+
+	if (is_write)
+		memcpy(run->mmio.data, data_buf, len);
+	vcpu->stat.mmio_exit_user++;
+	run->exit_reason	= KVM_EXIT_MMIO;
+	return 0;
+}