Merge branch 'for-will/kvm/core' of git://github.com/virtualopensystems/linux-kvm-arm into for-rmk/virt/kvm/core

1 files changed, 153 insertions, 0 deletions

diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c
new file mode 100644
index 000000000000..0144baf82904
--- /dev/null
+++ b/arch/arm/kvm/mmio.c
@@ -0,0 +1,153 @@
+/*
+ * 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"
+
+/**
+ * kvm_handle_mmio_return -- Handle MMIO loads after user space emulation
+ * @vcpu: The VCPU pointer
+ * @run:  The VCPU run struct containing the mmio data
+ *
+ * This should only be called after returning from userspace for MMIO load
+ * emulation.
+ */
+int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+        __u32 *dest;
+        unsigned int len;
+        int mask;
+
+        if (!run->mmio.is_write) {
+                dest = vcpu_reg(vcpu, vcpu->arch.mmio_decode.rt);
+                memset(dest, 0, sizeof(int));
+
+                len = run->mmio.len;
+                if (len > 4)
+                        return -EINVAL;
+
+                memcpy(dest, run->mmio.data, len);
+
+                trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr,
+                                *((u64 *)run->mmio.data));
+
+                if (vcpu->arch.mmio_decode.sign_extend && len < 4) {
+                        mask = 1U << ((len * 8) - 1);
+                        *dest = (*dest ^ mask) - mask;
+                }
+        }
+
+        return 0;
+}
+
+static int decode_hsr(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
+                      struct kvm_exit_mmio *mmio)
+{
+        unsigned long rt, len;
+        bool is_write, sign_extend;
+
+        if ((vcpu->arch.hsr >> 8) & 1) {
+                /* cache operation on I/O addr, tell guest unsupported */
+                kvm_inject_dabt(vcpu, vcpu->arch.hxfar);
+                return 1;
+        }
+
+        if ((vcpu->arch.hsr >> 7) & 1) {
+                /* page table accesses IO mem: tell guest to fix its TTBR */
+                kvm_inject_dabt(vcpu, vcpu->arch.hxfar);
+                return 1;
+        }
+
+        switch ((vcpu->arch.hsr >> 22) & 0x3) {
+        case 0:
+                len = 1;
+                break;
+        case 1:
+                len = 2;
+                break;
+        case 2:
+                len = 4;
+                break;
+        default:
+                kvm_err("Hardware is weird: SAS 0b11 is reserved\n");
+                return -EFAULT;
+        }
+
+        is_write = vcpu->arch.hsr & HSR_WNR;
+        sign_extend = vcpu->arch.hsr & HSR_SSE;
+        rt = (vcpu->arch.hsr & HSR_SRT_MASK) >> HSR_SRT_SHIFT;
+
+        if (kvm_vcpu_reg_is_pc(vcpu, rt)) {
+                /* IO memory trying to read/write pc */
+                kvm_inject_pabt(vcpu, vcpu->arch.hxfar);
+                return 1;
+        }
+
+        mmio->is_write = is_write;
+        mmio->phys_addr = fault_ipa;
+        mmio->len = len;
+        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, (vcpu->arch.hsr >> 25) & 1);
+        return 0;
+}
+
+int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
+                 phys_addr_t fault_ipa)
+{
+        struct kvm_exit_mmio mmio;
+        unsigned long rt;
+        int ret;
+
+        /*
+         * Prepare MMIO operation. First stash it in a private
+         * structure that we can use for in-kernel emulation. If the
+         * kernel can't handle it, copy it into run->mmio and let user
+         * space do its magic.
+         */
+
+        if (vcpu->arch.hsr & HSR_ISV) {
+                ret = decode_hsr(vcpu, fault_ipa, &mmio);
+                if (ret)
+                        return ret;
+        } else {
+                kvm_err("load/store instruction decoding not implemented\n");
+                return -ENOSYS;
+        }
+
+        rt = vcpu->arch.mmio_decode.rt;
+        trace_kvm_mmio((mmio.is_write) ? KVM_TRACE_MMIO_WRITE :
+                                         KVM_TRACE_MMIO_READ_UNSATISFIED,
+                        mmio.len, fault_ipa,
+                        (mmio.is_write) ? *vcpu_reg(vcpu, rt) : 0);
+
+        if (mmio.is_write)
+                memcpy(mmio.data, vcpu_reg(vcpu, rt), mmio.len);
+
+        kvm_prepare_mmio(run, &mmio);
+        return 0;
+}