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/******************************************************************************
* arch/hvm/hypercall.c
*
* HVM hypercall dispatching routines
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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/>.
*
* Copyright (c) 2017 Citrix Systems Ltd.
*/
#include <xen/lib.h>
#include <xen/hypercall.h>
#include <xen/ioreq.h>
#include <xen/nospec.h>
#include <asm/hvm/emulate.h>
#include <asm/hvm/support.h>
#include <asm/hvm/viridian.h>
#include <public/hvm/hvm_op.h>
#include <public/hvm/params.h>
static long hvm_memory_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
{
long rc;
switch ( cmd & MEMOP_CMD_MASK )
{
case XENMEM_machine_memory_map:
case XENMEM_machphys_mapping:
return -ENOSYS;
}
if ( !current->hcall_compat )
rc = do_memory_op(cmd, arg);
else
rc = compat_memory_op(cmd, arg);
if ( (cmd & MEMOP_CMD_MASK) == XENMEM_decrease_reservation )
curr->domain->qemu_mapcache_invalidate = true;
return rc;
}
#ifdef CONFIG_GRANT_TABLE
static long hvm_grant_table_op(
unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) uop, unsigned int count)
{
switch ( cmd )
{
case GNTTABOP_query_size:
case GNTTABOP_setup_table:
case GNTTABOP_set_version:
case GNTTABOP_get_version:
case GNTTABOP_copy:
case GNTTABOP_map_grant_ref:
case GNTTABOP_unmap_grant_ref:
case GNTTABOP_swap_grant_ref:
break;
default: /* All other commands need auditing. */
return -ENOSYS;
}
if ( !current->hcall_compat )
return do_grant_table_op(cmd, uop, count);
else
return compat_grant_table_op(cmd, uop, count);
}
#endif
static long hvm_physdev_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
{
const struct vcpu *curr = current;
const struct domain *currd = curr->domain;
switch ( cmd )
{
case PHYSDEVOP_map_pirq:
case PHYSDEVOP_unmap_pirq:
case PHYSDEVOP_eoi:
case PHYSDEVOP_irq_status_query:
case PHYSDEVOP_get_free_pirq:
if ( !has_pirq(currd) )
return -ENOSYS;
break;
case PHYSDEVOP_pci_mmcfg_reserved:
if ( !has_vpci(currd) || !is_hardware_domain(currd) )
return -ENOSYS;
break;
default:
return -ENOSYS;
}
if ( !curr->hcall_compat )
return do_physdev_op(cmd, arg);
else
return compat_physdev_op(cmd, arg);
}
#define HYPERCALL(x) \
[ __HYPERVISOR_ ## x ] = { (hypercall_fn_t *) do_ ## x, \
(hypercall_fn_t *) do_ ## x }
#define HVM_CALL(x) \
[ __HYPERVISOR_ ## x ] = { (hypercall_fn_t *) hvm_ ## x, \
(hypercall_fn_t *) hvm_ ## x }
#define COMPAT_CALL(x) \
[ __HYPERVISOR_ ## x ] = { (hypercall_fn_t *) do_ ## x, \
(hypercall_fn_t *) compat_ ## x }
#define do_arch_1 paging_domctl_continuation
static const hypercall_table_t hvm_hypercall_table[] = {
HVM_CALL(memory_op),
#ifdef CONFIG_GRANT_TABLE
HVM_CALL(grant_table_op),
#endif
HYPERCALL(vm_assist),
COMPAT_CALL(vcpu_op),
HVM_CALL(physdev_op),
COMPAT_CALL(xen_version),
HYPERCALL(console_io),
HYPERCALL(event_channel_op),
COMPAT_CALL(sched_op),
COMPAT_CALL(set_timer_op),
HYPERCALL(xsm_op),
HYPERCALL(hvm_op),
HYPERCALL(sysctl),
HYPERCALL(domctl),
#ifdef CONFIG_ARGO
COMPAT_CALL(argo_op),
#endif
COMPAT_CALL(platform_op),
#ifdef CONFIG_PV
COMPAT_CALL(mmuext_op),
#endif
HYPERCALL(xenpmu_op),
COMPAT_CALL(dm_op),
#ifdef CONFIG_HYPFS
HYPERCALL(hypfs_op),
#endif
HYPERCALL(arch_1)
};
#undef do_arch_1
#undef HYPERCALL
#undef HVM_CALL
#undef COMPAT_CALL
int hvm_hypercall(struct cpu_user_regs *regs)
{
struct vcpu *curr = current;
struct domain *currd = curr->domain;
int mode = hvm_guest_x86_mode(curr);
unsigned long eax = regs->eax;
unsigned int token;
switch ( mode )
{
case 8:
eax = regs->rax;
/* Fallthrough to permission check. */
case 4:
case 2:
if ( currd->arch.monitor.guest_request_userspace_enabled &&
eax == __HYPERVISOR_hvm_op &&
(mode == 8 ? regs->rdi : regs->ebx) == HVMOP_guest_request_vm_event )
break;
if ( unlikely(hvm_get_cpl(curr)) )
{
default:
regs->rax = -EPERM;
return HVM_HCALL_completed;
}
case 0:
break;
}
if ( (eax & 0x80000000) && is_viridian_domain(currd) )
{
int ret;
/* See comment below. */
token = hvmemul_cache_disable(curr);
ret = viridian_hypercall(regs);
hvmemul_cache_restore(curr, token);
return ret;
}
BUILD_BUG_ON(ARRAY_SIZE(hvm_hypercall_table) >
ARRAY_SIZE(hypercall_args_table));
if ( eax >= ARRAY_SIZE(hvm_hypercall_table) )
{
regs->rax = -ENOSYS;
return HVM_HCALL_completed;
}
eax = array_index_nospec(eax, ARRAY_SIZE(hvm_hypercall_table));
if ( !hvm_hypercall_table[eax].native )
{
regs->rax = -ENOSYS;
return HVM_HCALL_completed;
}
/*
* Caching is intended for instruction emulation only. Disable it
* for any accesses by hypercall argument copy-in / copy-out.
*/
token = hvmemul_cache_disable(curr);
curr->hcall_preempted = false;
if ( mode == 8 )
{
unsigned long rdi = regs->rdi;
unsigned long rsi = regs->rsi;
unsigned long rdx = regs->rdx;
unsigned long r10 = regs->r10;
unsigned long r8 = regs->r8;
unsigned long r9 = regs->r9;
HVM_DBG_LOG(DBG_LEVEL_HCALL, "hcall%lu(%lx, %lx, %lx, %lx, %lx, %lx)",
eax, rdi, rsi, rdx, r10, r8, r9);
#ifndef NDEBUG
/* Deliberately corrupt parameter regs not used by this hypercall. */
switch ( hypercall_args_table[eax].native )
{
case 0: rdi = 0xdeadbeefdeadf00dUL;
case 1: rsi = 0xdeadbeefdeadf00dUL;
case 2: rdx = 0xdeadbeefdeadf00dUL;
case 3: r10 = 0xdeadbeefdeadf00dUL;
case 4: r8 = 0xdeadbeefdeadf00dUL;
case 5: r9 = 0xdeadbeefdeadf00dUL;
}
#endif
regs->rax = hvm_hypercall_table[eax].native(rdi, rsi, rdx, r10, r8,
r9);
#ifndef NDEBUG
if ( !curr->hcall_preempted )
{
/* Deliberately corrupt parameter regs used by this hypercall. */
switch ( hypercall_args_table[eax].native )
{
case 6: regs->r9 = 0xdeadbeefdeadf00dUL;
case 5: regs->r8 = 0xdeadbeefdeadf00dUL;
case 4: regs->r10 = 0xdeadbeefdeadf00dUL;
case 3: regs->rdx = 0xdeadbeefdeadf00dUL;
case 2: regs->rsi = 0xdeadbeefdeadf00dUL;
case 1: regs->rdi = 0xdeadbeefdeadf00dUL;
}
}
#endif
}
else
{
unsigned int ebx = regs->ebx;
unsigned int ecx = regs->ecx;
unsigned int edx = regs->edx;
unsigned int esi = regs->esi;
unsigned int edi = regs->edi;
unsigned int ebp = regs->ebp;
HVM_DBG_LOG(DBG_LEVEL_HCALL, "hcall%lu(%x, %x, %x, %x, %x, %x)", eax,
ebx, ecx, edx, esi, edi, ebp);
#ifndef NDEBUG
/* Deliberately corrupt parameter regs not used by this hypercall. */
switch ( hypercall_args_table[eax].compat )
{
case 0: ebx = 0xdeadf00d;
case 1: ecx = 0xdeadf00d;
case 2: edx = 0xdeadf00d;
case 3: esi = 0xdeadf00d;
case 4: edi = 0xdeadf00d;
case 5: ebp = 0xdeadf00d;
}
#endif
curr->hcall_compat = true;
regs->rax = hvm_hypercall_table[eax].compat(ebx, ecx, edx, esi, edi,
ebp);
curr->hcall_compat = false;
#ifndef NDEBUG
if ( !curr->hcall_preempted )
{
/* Deliberately corrupt parameter regs used by this hypercall. */
switch ( hypercall_args_table[eax].compat )
{
case 6: regs->rbp = 0xdeadf00d;
case 5: regs->rdi = 0xdeadf00d;
case 4: regs->rsi = 0xdeadf00d;
case 3: regs->rdx = 0xdeadf00d;
case 2: regs->rcx = 0xdeadf00d;
case 1: regs->rbx = 0xdeadf00d;
}
}
#endif
}
hvmemul_cache_restore(curr, token);
HVM_DBG_LOG(DBG_LEVEL_HCALL, "hcall%lu -> %lx", eax, regs->rax);
if ( unlikely(currd->arch.hvm.qemu_mapcache_invalidate) &&
test_and_clear_bool(currd->arch.hvm.qemu_mapcache_invalidate) )
send_invalidate_req();
return curr->hcall_preempted ? HVM_HCALL_preempted : HVM_HCALL_completed;
}
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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