Subject: [PATCH 06/15] KVM: ARM: Initial skeleton to compile KVM support

From: [email-masked] (Christoffer Dall)
Date: Tue, 25 Sep 2012 21:43:14 -0400

On 09/25/2012 11:20 AM, Will Deacon wrote:
> On Sat, Sep 15, 2012 at 04:35:08PM +0100, Christoffer Dall wrote:
>> Targets KVM support for Cortex A-15 processors.
>>
>> Contains all the framework components, make files, header files, some
>> tracing functionality, and basic user space API.
>>
>> Only supported core is Cortex-A15 for now.
>>
>> Most functionality is in arch/arm/kvm/* or arch/arm/include/asm/kvm_*.h.
>>
>> ?Nothing to see here. Move along, move along..."
>
> [...]
>
>> diff --git a/arch/arm/include/asm/kvm.h b/arch/arm/include/asm/kvm.h
>> new file mode 100644
>> index 0000000..a13b582
>> --- /dev/null
>> +++ b/arch/arm/include/asm/kvm.h
>> @@ -0,0 +1,88 @@
>> +/*
>> + * Copyright (C) 2012 - Virtual Open Systems and Columbia University
>> + * Author: Christoffer Dall <[email-masked]>
>> + *
>> + * 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.
>> + */
>> +
>> +#ifndef __ARM_KVM_H__
>> +#define __ARM_KVM_H__
>> +
>> +#include <asm/types.h>
>> +
>> +#define __KVM_HAVE_GUEST_DEBUG
>> +
>> +#define KVM_REG_SIZE(id)                                               \
>> +       (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT))
>> +
>> +struct kvm_regs {
>> +       __u32 usr_regs[15];     /* R0_usr - R14_usr */
>> +       __u32 svc_regs[3];      /* SP_svc, LR_svc, SPSR_svc */
>> +       __u32 abt_regs[3];      /* SP_abt, LR_abt, SPSR_abt */
>> +       __u32 und_regs[3];      /* SP_und, LR_und, SPSR_und */
>> +       __u32 irq_regs[3];      /* SP_irq, LR_irq, SPSR_irq */
>> +       __u32 fiq_regs[8];      /* R8_fiq - R14_fiq, SPSR_fiq */
>> +       __u32 pc;               /* The program counter (r15) */
>> +       __u32 cpsr;             /* The guest CPSR */
>> +};
>> +
>> +/* Supported Processor Types */
>> +#define KVM_ARM_TARGET_CORTEX_A15      (0xC0F)
>
> So there's this define...
>
>> diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
>> new file mode 100644
>> index 0000000..2f9d28e
>> --- /dev/null
>> +++ b/arch/arm/include/asm/kvm_arm.h
>> @@ -0,0 +1,28 @@
>> +/*
>> + * Copyright (C) 2012 - Virtual Open Systems and Columbia University
>> + * Author: Christoffer Dall <[email-masked]>
>> + *
>> + * 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.
>> + */
>> +
>> +#ifndef __ARM_KVM_ARM_H__
>> +#define __ARM_KVM_ARM_H__
>> +
>> +/* Supported Processor Types */
>> +#define CORTEX_A15     (0xC0F)
>
> ... and then this one. Do we really need both?
>

no, we don't

>> +/* Multiprocessor Affinity Register */
>> +#define MPIDR_CPUID    (0x3 << 0)
>
> I'm fairly sure we already have code under arch/arm/ for dealing with the
> mpidr. Let's re-use that rather than reinventing it here.
>

I see some defines in topology.c - do you want some of these factored 
out into a header file that we can then also use from kvm? If so, where?

>> diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
>> new file mode 100644
>> index 0000000..44591f9
>> --- /dev/null
>> +++ b/arch/arm/include/asm/kvm_asm.h
>> @@ -0,0 +1,30 @@
>> +/*
>> + * Copyright (C) 2012 - Virtual Open Systems and Columbia University
>> + * Author: Christoffer Dall <[email-masked]>
>> + *
>> + * 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.
>> + */
>> +
>> +#ifndef __ARM_KVM_ASM_H__
>> +#define __ARM_KVM_ASM_H__
>> +
>> +#define ARM_EXCEPTION_RESET      0
>> +#define ARM_EXCEPTION_UNDEFINED   1
>> +#define ARM_EXCEPTION_SOFTWARE    2
>> +#define ARM_EXCEPTION_PREF_ABORT  3
>> +#define ARM_EXCEPTION_DATA_ABORT  4
>> +#define ARM_EXCEPTION_IRQ        5
>> +#define ARM_EXCEPTION_FIQ        6
>
> Again, you have these defines (which look more suited to an enum type), but
> later (in kvm_host.h) you have:

well, unless I miss some known trick, assembly code doesn't like enums?

>
>> +#define EXCEPTION_NONE      0
>> +#define EXCEPTION_RESET     0x80
>> +#define EXCEPTION_UNDEFINED 0x40
>> +#define EXCEPTION_SOFTWARE  0x20
>> +#define EXCEPTION_PREFETCH  0x10
>> +#define EXCEPTION_DATA      0x08
>> +#define EXCEPTION_IMPRECISE 0x04
>> +#define EXCEPTION_IRQ       0x02
>> +#define EXCEPTION_FIQ       0x01
>
> Why the noise?
>

these are simply cruft from a previous life of KVM/ARM.

>> diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
>> new file mode 100644
>> index 0000000..9e29335
>> --- /dev/null
>> +++ b/arch/arm/include/asm/kvm_emulate.h
>> @@ -0,0 +1,108 @@
>> +/*
>> + * Copyright (C) 2012 - Virtual Open Systems and Columbia University
>> + * Author: Christoffer Dall <[email-masked]>
>> + *
>> + * 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.
>> + */
>> +
>> +#ifndef __ARM_KVM_EMULATE_H__
>> +#define __ARM_KVM_EMULATE_H__
>> +
>> +#include <linux/kvm_host.h>
>> +#include <asm/kvm_asm.h>
>> +
>> +u32 *vcpu_reg_mode(struct kvm_vcpu *vcpu, u8 reg_num, enum vcpu_mode mode);
>> +
>> +static inline u8 __vcpu_mode(u32 cpsr)
>> +{
>> +       u8 modes_table[32] = {
>> +               0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf,
>> +               0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf,
>> +               MODE_USR,       /* 0x0 */
>> +               MODE_FIQ,       /* 0x1 */
>> +               MODE_IRQ,       /* 0x2 */
>> +               MODE_SVC,       /* 0x3 */
>> +               0xf, 0xf, 0xf,
>> +               MODE_ABT,       /* 0x7 */
>> +               0xf, 0xf, 0xf,
>> +               MODE_UND,       /* 0xb */
>> +               0xf, 0xf, 0xf,
>> +               MODE_SYS        /* 0xf */
>> +       };
>
> These MODE_* definitions sound like our *_MODE definitions... except they're
> not. It would probably be far more readable as a switch, but at least change
> the name of those things!

fair enough, they're renamed to VCPU_XXX_MODE

>> +static inline enum vcpu_mode vcpu_mode(struct kvm_vcpu *vcpu)
>> +{
>> +       u8 mode = __vcpu_mode(vcpu->arch.regs.cpsr);
>> +       BUG_ON(mode == 0xf);
>> +       return mode;
>> +}
>
> I noticed that you have a fair few BUG_ONs throughout the series. Fair
> enough, but for hyp code is that really the right thing to do? Killing the
> guest could make more sense, perhaps?

the idea is to have BUG_ONs that are indeed BUG_ONs that we want to 
catch explicitly on the host. We have had a pass over the code to change 
all the BUG_ONs that can be provoked by the guest and inject the proper 
exceptions into the guest in this case. If you find places where this is 
not the case, it should be changed, and do let me know.

>
>> +static inline u32 *vcpu_pc(struct kvm_vcpu *vcpu)
>> +{
>> +       return vcpu_reg(vcpu, 15);
>> +}
>
> If you stick a struct pt_regs into struct kvm_regs, you could reuse ARM_pc
> here etc.
>

I prefer not to, because we'd have those registers presumably for usr 
mode and then we only define the others explicit. I think it's much 
clearer to look at kvm_regs today.

>> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
>> new file mode 100644
>> index 0000000..24959f4
>> --- /dev/null
>> +++ b/arch/arm/include/asm/kvm_host.h
>> @@ -0,0 +1,172 @@
>> +/*
>> + * Copyright (C) 2012 - Virtual Open Systems and Columbia University
>> + * Author: Christoffer Dall <[email-masked]>
>> + *
>> + * 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.
>> + */
>> +
>> +#ifndef __ARM_KVM_HOST_H__
>> +#define __ARM_KVM_HOST_H__
>> +
>> +#include <asm/kvm.h>
>> +
>> +#define KVM_MAX_VCPUS 4
>
> NR_CPUS?
>

well this is defined by KVM generic code, and is common for other 
architecture.

>> +#define KVM_MEMORY_SLOTS 32
>> +#define KVM_PRIVATE_MEM_SLOTS 4
>> +#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
>> +
>> +#define NUM_FEATURES 0
>
> Ha! No idea what that means, but hopefully there's less code to review
> because of it :)
>

that's actually true.

will rename to KVM_VCPU_MAX_FEATURES
(or do you want NR in this case? :-\)

>> +
>> +/* We don't currently support large pages. */
>> +#define KVM_HPAGE_GFN_SHIFT(x) 0
>> +#define KVM_NR_PAGE_SIZES      1
>> +#define KVM_PAGES_PER_HPAGE(x) (1UL<<31)
>> +
>> +struct kvm_vcpu;
>> +u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode);
>> +int kvm_target_cpu(void);
>> +int kvm_reset_vcpu(struct kvm_vcpu *vcpu);
>> +void kvm_reset_coprocs(struct kvm_vcpu *vcpu);
>> +
>> +struct kvm_arch {
>> +       /* The VMID generation used for the virt. memory system */
>> +       u64    vmid_gen;
>> +       u32    vmid;
>> +
>> +       /* 1-level 2nd stage table and lock */
>> +       spinlock_t pgd_lock;
>> +       pgd_t *pgd;
>> +
>> +       /* VTTBR value associated with above pgd and vmid */
>> +       u64    vttbr;
>> +};
>> +
>> +#define EXCEPTION_NONE      0
>> +#define EXCEPTION_RESET     0x80
>> +#define EXCEPTION_UNDEFINED 0x40
>> +#define EXCEPTION_SOFTWARE  0x20
>> +#define EXCEPTION_PREFETCH  0x10
>> +#define EXCEPTION_DATA      0x08
>> +#define EXCEPTION_IMPRECISE 0x04
>> +#define EXCEPTION_IRQ       0x02
>> +#define EXCEPTION_FIQ       0x01
>> +
>> +#define KVM_NR_MEM_OBJS     40
>> +
>> +/*
>> + * We don't want allocation failures within the mmu code, so we preallocate
>> + * enough memory for a single page fault in a cache.
>> + */
>> +struct kvm_mmu_memory_cache {
>> +       int nobjs;
>> +       void *objects[KVM_NR_MEM_OBJS];
>> +};
>> +
>> +/*
>> + * Modes used for short-hand mode determinition in the world-switch code and
>> + * in emulation code.
>> + *
>> + * Note: These indices do NOT correspond to the value of the CPSR mode bits!
>> + */
>> +enum vcpu_mode {
>> +       MODE_FIQ = 0,
>> +       MODE_IRQ,
>> +       MODE_SVC,
>> +       MODE_ABT,
>> +       MODE_UND,
>> +       MODE_USR,
>> +       MODE_SYS
>> +};
>
> So the need for this enum is for indexing the array of modes, right? But
> accesses to that array are already hidden behind an accessor function from
> what I can tell, so I'd rather the arithmetic from cpsr -> index was
> restricted to that function and the rest of the code just passed either the
> raw mode or the full cpsr around.
>

good point, this was really useful in that prior life of kvm/arm where 
we did a bunch of emulation and decoding all over the place. I'll send 
out a v2 with this reworked.

>> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
>> new file mode 100644
>> index 0000000..fd6fa9b
>> --- /dev/null
>> +++ b/arch/arm/kvm/arm.c
>> @@ -0,0 +1,345 @@
>> +/*
>> + * Copyright (C) 2012 - Virtual Open Systems and Columbia University
>> + * Author: Christoffer Dall <[email-masked]>
>> + *
>> + * 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/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/mman.h>
>> +#include <linux/sched.h>
>> +#include <trace/events/kvm.h>
>> +
>> +#define CREATE_TRACE_POINTS
>> +#include "trace.h"
>> +
>> +#include <asm/unified.h>
>> +#include <asm/uaccess.h>
>> +#include <asm/ptrace.h>
>> +#include <asm/mman.h>
>> +#include <asm/cputype.h>
>> +
>> +#ifdef REQUIRES_VIRT
>> +__asm__(".arch_extension       virt");
>> +#endif
>> +
>> +int kvm_arch_hardware_enable(void *garbage)
>> +{
>> +       return 0;
>> +}
>> +
>> +int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
>> +{
>> +       return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
>> +}
>> +
>> +void kvm_arch_hardware_disable(void *garbage)
>> +{
>> +}
>> +
>> +int kvm_arch_hardware_setup(void)
>> +{
>> +       return 0;
>> +}
>> +
>> +void kvm_arch_hardware_unsetup(void)
>> +{
>> +}
>> +
>> +void kvm_arch_check_processor_compat(void *rtn)
>> +{
>> +       *(int *)rtn = 0;
>> +}
>> +
>> +void kvm_arch_sync_events(struct kvm *kvm)
>> +{
>> +}
>> +
>> +int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
>> +{
>> +       if (type)
>> +               return -EINVAL;
>> +
>> +       return 0;
>> +}
>> +
>> +int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
>> +{
>> +       return VM_FAULT_SIGBUS;
>> +}
>> +
>> +void kvm_arch_free_memslot(struct kvm_memory_slot *free,
>> +                          struct kvm_memory_slot *dont)
>> +{
>> +}
>> +
>> +int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)
>> +{
>> +       return 0;
>> +}
>> +
>> +void kvm_arch_destroy_vm(struct kvm *kvm)
>> +{
>> +       int i;
>> +
>> +       for (i = 0; i < KVM_MAX_VCPUS; ++i) {
>> +               if (kvm->vcpus[i]) {
>> +                       kvm_arch_vcpu_free(kvm->vcpus[i]);
>> +                       kvm->vcpus[i] = NULL;
>> +               }
>> +       }
>> +}
>> +
>> +int kvm_dev_ioctl_check_extension(long ext)
>> +{
>> +       int r;
>> +       switch (ext) {
>> +       case KVM_CAP_USER_MEMORY:
>> +       case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
>> +       case KVM_CAP_ONE_REG:
>> +               r = 1;
>> +               break;
>> +       case KVM_CAP_COALESCED_MMIO:
>> +               r = KVM_COALESCED_MMIO_PAGE_OFFSET;
>> +               break;
>> +       default:
>> +               r = 0;
>> +               break;
>> +       }
>> +       return r;
>> +}
>> +
>> +long kvm_arch_dev_ioctl(struct file *filp,
>> +                       unsigned int ioctl, unsigned long arg)
>> +{
>> +       return -EINVAL;
>> +}
>> +
>> +int kvm_arch_set_memory_region(struct kvm *kvm,
>> +                              struct kvm_userspace_memory_region *mem,
>> +                              struct kvm_memory_slot old,
>> +                              int user_alloc)
>> +{
>> +       return 0;
>> +}
>> +
>> +int kvm_arch_prepare_memory_region(struct kvm *kvm,
>> +                                  struct kvm_memory_slot *memslot,
>> +                                  struct kvm_memory_slot old,
>> +                                  struct kvm_userspace_memory_region *mem,
>> +                                  int user_alloc)
>> +{
>> +       return 0;
>> +}
>> +
>> +void kvm_arch_commit_memory_region(struct kvm *kvm,
>> +                                  struct kvm_userspace_memory_region *mem,
>> +                                  struct kvm_memory_slot old,
>> +                                  int user_alloc)
>> +{
>> +}
>> +
>> +void kvm_arch_flush_shadow_all(struct kvm *kvm)
>> +{
>> +}
>> +
>> +void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
>> +                                  struct kvm_memory_slot *slot)
>> +{
>> +}
>> +
>> +struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
>> +{
>> +       int err;
>> +       struct kvm_vcpu *vcpu;
>> +
>> +       vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
>> +       if (!vcpu) {
>> +               err = -ENOMEM;
>> +               goto out;
>> +       }
>> +
>> +       err = kvm_vcpu_init(vcpu, kvm, id);
>> +       if (err)
>> +               goto free_vcpu;
>> +
>> +       return vcpu;
>> +free_vcpu:
>> +       kmem_cache_free(kvm_vcpu_cache, vcpu);
>> +out:
>> +       return ERR_PTR(err);
>> +}
>> +
>> +void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
>> +{
>> +}
>> +
>> +void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
>> +{
>> +       kvm_arch_vcpu_free(vcpu);
>> +}
>> +
>> +int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
>> +{
>> +       return 0;
>> +}
>> +
>> +int __attribute_const__ kvm_target_cpu(void)
>> +{
>> +       unsigned int midr;
>> +
>> +       midr = read_cpuid_id();
>> +       switch ((midr >> 4) & 0xfff) {
>> +       case KVM_ARM_TARGET_CORTEX_A15:
>> +               return KVM_ARM_TARGET_CORTEX_A15;
>
> I have this code already in perf_event.c. Can we move it somewhere common
> and share it? You should also check that the implementor field is 0x41.
>

by all means, you can probably suggest a good place better than I can...

>> +       default:
>> +               return -EINVAL;
>> +       }
>> +}
>> +
>> +int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
>> +{
>> +       return 0;
>> +}
>> +
>> +void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
>> +{
>> +}
>> +
>> +void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
>> +{
>> +}
>> +
>> +void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
>> +{
>> +}
>> +
>> +int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
>> +                                       struct kvm_guest_debug *dbg)
>> +{
>> +       return -EINVAL;
>> +}
>> +
>> +
>> +int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
>> +                                   struct kvm_mp_state *mp_state)
>> +{
>> +       return -EINVAL;
>> +}
>> +
>> +int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
>> +                                   struct kvm_mp_state *mp_state)
>> +{
>> +       return -EINVAL;
>> +}
>> +
>> +int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
>> +{
>> +       return 0;
>> +}
>> +
>> +int kvm_arch_vcpu_in_guest_mode(struct kvm_vcpu *v)
>> +{
>> +       return 0;
>> +}
>> +
>> +int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
>> +{
>> +       return -EINVAL;
>> +}
>> +
>> +long kvm_arch_vcpu_ioctl(struct file *filp,
>> +                        unsigned int ioctl, unsigned long arg)
>> +{
>> +       struct kvm_vcpu *vcpu = filp->private_data;
>> +       void __user *argp = (void __user *)arg;
>> +
>> +       switch (ioctl) {
>> +       case KVM_ARM_VCPU_INIT: {
>> +               struct kvm_vcpu_init init;
>> +
>> +               if (copy_from_user(&init, argp, sizeof init))
>> +                       return -EFAULT;
>> +
>> +               return kvm_vcpu_set_target(vcpu, &init);
>> +
>> +       }
>> +       case KVM_SET_ONE_REG:
>> +       case KVM_GET_ONE_REG: {
>> +               struct kvm_one_reg reg;
>> +               if (copy_from_user(&reg, argp, sizeof(reg)))
>> +                       return -EFAULT;
>> +               if (ioctl == KVM_SET_ONE_REG)
>> +                       return kvm_arm_set_reg(vcpu, &reg);
>> +               else
>> +                       return kvm_arm_get_reg(vcpu, &reg);
>> +       }
>> +       case KVM_GET_REG_LIST: {
>> +               struct kvm_reg_list __user *user_list = argp;
>> +               struct kvm_reg_list reg_list;
>> +               unsigned n;
>> +
>> +               if (copy_from_user(&reg_list, user_list, sizeof reg_list))
>> +                       return -EFAULT;
>> +               n = reg_list.n;
>> +               reg_list.n = kvm_arm_num_regs(vcpu);
>> +               if (copy_to_user(user_list, &reg_list, sizeof reg_list))
>> +                       return -EFAULT;
>> +               if (n < reg_list.n)
>> +                       return -E2BIG;
>> +               return kvm_arm_copy_reg_indices(vcpu, user_list->reg);
>
> kvm_reg_list sounds like it could be done using a regset instead.
>
>> diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
>> new file mode 100644
>> index 0000000..690bbb3
>> --- /dev/null
>> +++ b/arch/arm/kvm/emulate.c
>> @@ -0,0 +1,127 @@
>> +/*
>> + * Copyright (C) 2012 - Virtual Open Systems and Columbia University
>> + * Author: Christoffer Dall <[email-masked]>
>> + *
>> + * 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 <asm/kvm_emulate.h>
>> +
>> +#define REG_OFFSET(_reg) \
>> +       (offsetof(struct kvm_regs, _reg) / sizeof(u32))
>> +
>> +#define USR_REG_OFFSET(_num) REG_OFFSET(usr_regs[_num])
>> +
>> +static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>> +       /* FIQ Registers */
>> +       {
>> +               USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
>> +               USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
>> +               USR_REG_OFFSET(6), USR_REG_OFFSET(7),
>> +               REG_OFFSET(fiq_regs[1]), /* r8 */
>> +               REG_OFFSET(fiq_regs[1]), /* r9 */
>> +               REG_OFFSET(fiq_regs[2]), /* r10 */
>> +               REG_OFFSET(fiq_regs[3]), /* r11 */
>> +               REG_OFFSET(fiq_regs[4]), /* r12 */
>> +               REG_OFFSET(fiq_regs[5]), /* r13 */
>> +               REG_OFFSET(fiq_regs[6]), /* r14 */
>> +               REG_OFFSET(pc)           /* r15 */
>> +       },
>> +
>> +       /* IRQ Registers */
>> +       {
>> +               USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
>> +               USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
>> +               USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>> +               USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>> +               USR_REG_OFFSET(12),
>> +               REG_OFFSET(irq_regs[0]), /* r13 */
>> +               REG_OFFSET(irq_regs[1]), /* r14 */
>> +               REG_OFFSET(pc)           /* r15 */
>> +       },
>> +
>> +       /* SVC Registers */
>> +       {
>> +               USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
>> +               USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
>> +               USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>> +               USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>> +               USR_REG_OFFSET(12),
>> +               REG_OFFSET(svc_regs[0]), /* r13 */
>> +               REG_OFFSET(svc_regs[1]), /* r14 */
>> +               REG_OFFSET(pc)           /* r15 */
>> +       },
>> +
>> +       /* ABT Registers */
>> +       {
>> +               USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
>> +               USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
>> +               USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>> +               USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>> +               USR_REG_OFFSET(12),
>> +               REG_OFFSET(abt_regs[0]), /* r13 */
>> +               REG_OFFSET(abt_regs[1]), /* r14 */
>> +               REG_OFFSET(pc)           /* r15 */
>> +       },
>> +
>> +       /* UND Registers */
>> +       {
>> +               USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
>> +               USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
>> +               USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>> +               USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>> +               USR_REG_OFFSET(12),
>> +               REG_OFFSET(und_regs[0]), /* r13 */
>> +               REG_OFFSET(und_regs[1]), /* r14 */
>> +               REG_OFFSET(pc)           /* r15 */
>> +       },
>> +
>> +       /* USR Registers */
>> +       {
>> +               USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
>> +               USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
>> +               USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>> +               USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>> +               USR_REG_OFFSET(12),
>> +               REG_OFFSET(usr_regs[13]), /* r13 */
>> +               REG_OFFSET(usr_regs[14]), /* r14 */
>> +               REG_OFFSET(pc)            /* r15 */
>> +       },
>> +
>> +       /* SYS Registers */
>> +       {
>> +               USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
>> +               USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
>> +               USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>> +               USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>> +               USR_REG_OFFSET(12),
>> +               REG_OFFSET(usr_regs[13]), /* r13 */
>> +               REG_OFFSET(usr_regs[14]), /* r14 */
>> +               REG_OFFSET(pc)            /* r15 */
>> +       },
>> +};
>> +
>> +/*
>> + * Return a pointer to the register number valid in the specified mode of
>> + * the virtual CPU.
>> + */
>> +u32 *vcpu_reg_mode(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode)
>> +{
>> +       u32 *reg_array = (u32 *)&vcpu->arch.regs;
>> +
>> +       BUG_ON(reg_num > 15);
>> +       BUG_ON(mode > MODE_SYS);
>
> Again, BUG_ON seems a bit OTT here. Also, this is where the mode => idx
> calculation should happen.
>
>> +       return reg_array + vcpu_reg_offsets[mode][reg_num];
>> +}
>> diff --git a/arch/arm/kvm/exports.c b/arch/arm/kvm/exports.c
>> new file mode 100644
>> index 0000000..3e38c95
>> --- /dev/null
>> +++ b/arch/arm/kvm/exports.c
>> @@ -0,0 +1,21 @@
>> +/*
>> + * Copyright (C) 2012 - Virtual Open Systems and Columbia University
>> + * Author: Christoffer Dall <[email-masked]>
>> + *
>> + * 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/module.h>
>> +
>> +EXPORT_SYMBOL_GPL(smp_send_reschedule);
>
> Erm...
>
> We already have arch/arm/kernel/armksyms.c for exports -- please use that.
> However, exporting such low-level operations sounds like a bad idea. How
> realistic is kvm-as-a-module on ARM anyway?
>

at this point it's broken, so I'll just remove this and leave this for a 
fun project for some poor soul at some point if anyone ever needs half 
the code outside the kernel as a module (the other half needs to be 
compiled in anyway)

>> diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
>> new file mode 100644
>> index 0000000..19a5389
>> --- /dev/null
>> +++ b/arch/arm/kvm/guest.c
>> @@ -0,0 +1,211 @@
>> +/*
>> + * Copyright (C) 2012 - Virtual Open Systems and Columbia University
>> + * Author: Christoffer Dall <[email-masked]>
>> + *
>> + * 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/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/uaccess.h>
>> +#include <asm/kvm.h>
>> +#include <asm/kvm_asm.h>
>> +#include <asm/kvm_emulate.h>
>> +
>> +#define VM_STAT(x) { #x, offsetof(struct kvm, stat.x), KVM_STAT_VM }
>> +#define VCPU_STAT(x) { #x, offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU }
>> +
>> +struct kvm_stats_debugfs_item debugfs_entries[] = {
>> +       { NULL }
>> +};
>> +
>> +int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
>> +{
>> +       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)
>> +{
>> +       u32 __user *uaddr = (u32 __user *)(long)reg->addr;
>> +       struct kvm_regs *regs = &vcpu->arch.regs;
>> +       u64 off;
>> +
>> +       if (KVM_REG_SIZE(reg->id) != 4)
>> +               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(((u32 *)regs)[off], uaddr);
>> +}
>> +
>> +static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
>> +{
>> +       u32 __user *uaddr = (u32 __user *)(long)reg->addr;
>> +       struct kvm_regs *regs = &vcpu->arch.regs;
>> +       u64 off, val;
>> +
>> +       if (KVM_REG_SIZE(reg->id) != 4)
>> +               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(cpsr)) {
>> +               if (__vcpu_mode(val) == 0xf)
>> +                       return -EINVAL;
>> +       }
>> +
>> +       ((u32 *)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;
>> +}
>
> Again, all looks like this should be implemented using regsets from what I
> can tell.
>

this API has been discussed to death on the KVM lists, and we can of 
course revive that if the regset makes it nicer - I'd prefer getting 
this upstream the way that it is now though, where GET_REG / SET_REG 
seems to be the way forward from a KVM perspective.

>> diff --git a/arch/arm/kvm/reset.c b/arch/arm/kvm/reset.c
>> new file mode 100644
>> index 0000000..290a13d
>> --- /dev/null
>> +++ b/arch/arm/kvm/reset.c
>> @@ -0,0 +1,74 @@
>> +/*
>> + * Copyright (C) 2012 - Virtual Open Systems and Columbia University
>> + * Author: Christoffer Dall <[email-masked]>
>> + *
>> + * 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/compiler.h>
>> +#include <linux/errno.h>
>> +#include <linux/sched.h>
>> +#include <linux/kvm_host.h>
>> +#include <linux/kvm.h>
>> +
>> +#include <asm/unified.h>
>> +#include <asm/ptrace.h>
>> +#include <asm/cputype.h>
>> +#include <asm/kvm_arm.h>
>> +#include <asm/kvm_coproc.h>
>> +
>> +/******************************************************************************
>> + * Cortex-A15 Reset Values
>> + */
>> +
>> +static const int a15_max_cpu_idx = 3;
>> +
>> +static struct kvm_regs a15_regs_reset = {
>> +       .cpsr = SVC_MODE | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT,
>> +};
>> +
>> +
>> +/*******************************************************************************
>> + * Exported reset function
>> + */
>> +
>> +/**
>> + * kvm_reset_vcpu - sets core registers and cp15 registers to reset value
>> + * @vcpu: The VCPU pointer
>> + *
>> + * This function finds the right table above and sets the registers on the
>> + * virtual CPU struct to their architectually defined reset values.
>> + */
>> +int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
>> +{
>> +       struct kvm_regs *cpu_reset;
>> +
>> +       switch (vcpu->arch.target) {
>> +       case KVM_ARM_TARGET_CORTEX_A15:
>> +               if (vcpu->vcpu_id > a15_max_cpu_idx)
>> +                       return -EINVAL;
>> +               cpu_reset = &a15_regs_reset;
>> +               vcpu->arch.midr = read_cpuid_id();
>> +               break;
>> +       default:
>> +               return -ENODEV;
>> +       }
>> +
>> +       /* Reset core registers */
>> +       memcpy(&vcpu->arch.regs, cpu_reset, sizeof(vcpu->arch.regs));
>> +
>> +       /* Reset CP15 registers */
>> +       kvm_reset_coprocs(vcpu);
>> +
>> +       return 0;
>> +}
>
> This is a nice way to plug in new CPUs but the way the rest of the code is
> currently written, all the ARMv7 and Cortex-A15 code is merged together. I
> *strongly* suggest you isolate this from the start, as it will help you see
> what is architected and what is implementation-specific.
>

not entirely sure what you mean. You want a separate coproc.c file for 
Cortex-A15 specific stuff like coproc_a15.c?

Thanks a bunch for the review!
-Christoffer