Adding upstream version 5.10.209.upstream/5.10.209

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

1 files changed, 195 insertions, 0 deletions

diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c
new file mode 100644
index 000000000..6a2826f1b
--- /dev/null
+++ b/arch/arm64/kvm/mmio.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.com>
+ */
+
+#include <linux/kvm_host.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
+ */
+int kvm_handle_mmio_return(struct kvm_vcpu *vcpu)
+{
+	unsigned long data;
+	unsigned int len;
+	int mask;
+
+	/* Detect an already handled MMIO return */
+	if (unlikely(!vcpu->mmio_needed))
+		return 0;
+
+	vcpu->mmio_needed = 0;
+
+	if (!kvm_vcpu_dabt_iswrite(vcpu)) {
+		struct kvm_run *run = vcpu->run;
+
+		len = kvm_vcpu_dabt_get_as(vcpu);
+		data = kvm_mmio_read_buf(run->mmio.data, len);
+
+		if (kvm_vcpu_dabt_issext(vcpu) &&
+		    len < sizeof(unsigned long)) {
+			mask = 1U << ((len * 8) - 1);
+			data = (data ^ mask) - mask;
+		}
+
+		if (!kvm_vcpu_dabt_issf(vcpu))
+			data = data & 0xffffffff;
+
+		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, kvm_vcpu_dabt_get_rd(vcpu), data);
+	}
+
+	/*
+	 * 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, phys_addr_t fault_ipa)
+{
+	struct kvm_run *run = vcpu->run;
+	unsigned long data;
+	unsigned long rt;
+	int ret;
+	bool is_write;
+	int len;
+	u8 data_buf[8];
+
+	/*
+	 * No valid syndrome? Ask userspace for help if it has
+	 * volunteered to do so, and bail out otherwise.
+	 */
+	if (!kvm_vcpu_dabt_isvalid(vcpu)) {
+		if (vcpu->kvm->arch.return_nisv_io_abort_to_user) {
+			run->exit_reason = KVM_EXIT_ARM_NISV;
+			run->arm_nisv.esr_iss = kvm_vcpu_dabt_iss_nisv_sanitized(vcpu);
+			run->arm_nisv.fault_ipa = fault_ipa;
+			return 0;
+		}
+
+		kvm_pr_unimpl("Data abort outside memslots with no valid syndrome info\n");
+		return -ENOSYS;
+	}
+
+	/*
+	 * 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.
+	 */
+	is_write = kvm_vcpu_dabt_iswrite(vcpu);
+	len = kvm_vcpu_dabt_get_as(vcpu);
+	rt = kvm_vcpu_dabt_get_rd(vcpu);
+
+	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, NULL);
+
+		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;
+	vcpu->mmio_needed	= 1;
+
+	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);
+		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;
+}