[PATCH 14/29] arm64: KVM: guest one-reg interface

Marc Zyngier
2013-03-05T03:55:16Z

Let userspace play with the guest registers.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/kvm/guest.c | 240 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 240 insertions(+)
create mode 100644 arch/arm64/kvm/guest.c

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
new file mode 100644
index 0000000..2a8aaf8
--- /dev/null
+++ b/arch/arm64/kvm/guest.c
@@ -0,0 +1,240 @@
+/*
+ * Copyright (C) 2012 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * Derived from arch/arm/kvm/guest.c:
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#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 <asm/cputype.h>
+#include <asm/uaccess.h>
+#include <asm/kvm.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_coproc.h>
+
+struct kvm_stats_debugfs_item debugfs_entries[] = {
+ { NULL }
+};
+
+int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS;
+ return 0;
+}
+
+static u64 core_reg_offset_from_id(u64 id)
+{
+ return id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK | KVM_REG_ARM_CORE);
+}
+
+static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
+ unsigned long __user *uaddr = (unsigned long __user *)(unsigned long)reg->addr;
+ struct kvm_regs *regs = &vcpu->arch.regs;
+ u64 off;
+
+ if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
+ return -ENOENT;
+
+ /* Our ID is an index into the kvm_regs struct. */
+ off = core_reg_offset_from_id(reg->id);
+ if (off >= sizeof(*regs) / KVM_REG_SIZE(reg->id))
+ return -ENOENT;
+
+ return put_user(((unsigned long *)regs)[off], uaddr);
+}
+
+static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
+ unsigned long __user *uaddr = (unsigned long __user *)(unsigned long)reg->addr;
+ struct kvm_regs *regs = &vcpu->arch.regs;
+ u64 off, val;
+
+ if (KVM_REG_SIZE(reg->id) != sizeof(unsigned long))
+ return -ENOENT;
+
+ /* Our ID is an index into the kvm_regs struct. */
+ off = core_reg_offset_from_id(reg->id);
+ if (off >= sizeof(*regs) / KVM_REG_SIZE(reg->id))
+ return -ENOENT;
+
+ if (get_user(val, uaddr) != 0)
+ return -EFAULT;
+
+ if (off == KVM_REG_ARM_CORE_REG(regs.pstate)) {
+ unsigned long mode = val & COMPAT_PSR_MODE_MASK;
+ switch (mode) {
+ case PSR_MODE_EL0t:
+ case PSR_MODE_EL1t:
+ case PSR_MODE_EL1h:
+ break;
+ default:
+ return -EINVAL;
+ }
+ }
+
+ ((unsigned long *)regs)[off] = val;
+ return 0;
+}
+
+int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+ return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+ return -EINVAL;
+}
+
+static unsigned long num_core_regs(void)
+{
+ return sizeof(struct kvm_regs) / sizeof(unsigned long);
+}
+
+/**
+ * kvm_arm_num_regs - how many registers do we present via KVM_GET_ONE_REG
+ *
+ * This is for all registers.
+ */
+unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
+{
+ return num_core_regs() + kvm_arm_num_sys_reg_descs(vcpu);
+}
+
+/**
+ * kvm_arm_copy_reg_indices - get indices of all registers.
+ *
+ * We do core registers right here, then we apppend system regs.
+ */
+int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
+{
+ unsigned int i;
+ const u64 core_reg = KVM_REG_ARM64 | KVM_REG_SIZE_U64 | KVM_REG_ARM_CORE;
+
+ for (i = 0; i < sizeof(struct kvm_regs)/sizeof(unsigned long); i++) {
+ if (put_user(core_reg | i, uindices))
+ return -EFAULT;
+ uindices++;
+ }
+
+ return kvm_arm_copy_sys_reg_indices(vcpu, uindices);
+}
+
+int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
+ /* We currently use nothing arch-specific in upper 32 bits */
+ if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
+ return -EINVAL;
+
+ /* Register group 16 means we want a core register. */
+ if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
+ return get_core_reg(vcpu, reg);
+
+ return kvm_arm_sys_reg_get_reg(vcpu, reg);
+}
+
+int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
+ /* We currently use nothing arch-specific in upper 32 bits */
+ if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
+ return -EINVAL;
+
+ /* Register group 16 means we set a core register. */
+ if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE)
+ return set_core_reg(vcpu, reg);
+
+ return kvm_arm_sys_reg_set_reg(vcpu, reg);
+}
+
+int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
+ struct kvm_sregs *sregs)
+{
+ return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
+ struct kvm_sregs *sregs)
+{
+ return -EINVAL;
+}
+
+int __attribute_const__ kvm_target_cpu(void)
+{
+ unsigned long implementor = read_cpuid_implementor();
+ unsigned long part_number = read_cpuid_part_number();
+
+ if (implementor != ARM_CPU_IMP_ARM)
+ return -EINVAL;
+
+ switch (part_number) {
+ case ARM_CPU_PART_AEM_V8:
+ case ARM_CPU_PART_FOUNDATION:
+ /* Treat the models just as an A57 for the time being */
+ case ARM_CPU_PART_CORTEX_A57:
+ return KVM_ARM_TARGET_CORTEX_A57;
+ default:
+ return -EINVAL;
+ }
+}
+
+int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
+ const struct kvm_vcpu_init *init)
+{
+ unsigned int i;
+
+ /* We can only do a cortex A57 for now. */
+ if (init->target != kvm_target_cpu())
+ return -EINVAL;
+
+ vcpu->arch.target = init->target;
+ bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
+
+ /* -ENOENT for unknown features, -EINVAL for invalid combinations. */
+ for (i = 0; i < sizeof(init->features)*8; i++) {
+ if (init->features[i / 32] & (1 << (i % 32))) {
+ if (i >= KVM_VCPU_MAX_FEATURES)
+ return -ENOENT;
+ set_bit(i, vcpu->arch.features);
+ }
+ }
+
+ /* Now we know what it is, we can reset it. */
+ return kvm_reset_vcpu(vcpu);
+}
+
+int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
+{
+ return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
+{
+ return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
+ struct kvm_translation *tr)
+{
+ return -EINVAL;
+}
--
1.7.12.4