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/*
* arch/x86/vm_event.c
*
* Architecture-specific vm_event handling routines
*
* Copyright (c) 2015 Tamas K Lengyel (tamas@tklengyel.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 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 <xen/sched.h>
#include <xen/mem_access.h>
#include <asm/vm_event.h>
/* Implicitly serialized by the domctl lock. */
int vm_event_init_domain(struct domain *d)
{
struct vcpu *v;
for_each_vcpu ( d, v )
{
if ( v->arch.vm_event )
continue;
v->arch.vm_event = xzalloc(struct arch_vm_event);
if ( !v->arch.vm_event )
return -ENOMEM;
}
return 0;
}
/*
* Implicitly serialized by the domctl lock,
* or on domain cleanup paths only.
*/
void vm_event_cleanup_domain(struct domain *d)
{
struct vcpu *v;
for_each_vcpu ( d, v )
{
xfree(v->arch.vm_event);
v->arch.vm_event = NULL;
}
d->arch.mem_access_emulate_each_rep = 0;
}
void vm_event_toggle_singlestep(struct domain *d, struct vcpu *v,
vm_event_response_t *rsp)
{
if ( !(rsp->flags & (VM_EVENT_FLAG_TOGGLE_SINGLESTEP |
VM_EVENT_FLAG_FAST_SINGLESTEP)) )
return;
if ( !is_hvm_domain(d) )
return;
ASSERT(atomic_read(&v->vm_event_pause_count));
if ( rsp->flags & VM_EVENT_FLAG_TOGGLE_SINGLESTEP )
hvm_toggle_singlestep(v);
else
hvm_fast_singlestep(v, rsp->u.fast_singlestep.p2midx);
}
void vm_event_register_write_resume(struct vcpu *v, vm_event_response_t *rsp)
{
if ( rsp->flags & VM_EVENT_FLAG_DENY )
{
struct monitor_write_data *w;
ASSERT(v->arch.vm_event);
/* deny flag requires the vCPU to be paused */
if ( !atomic_read(&v->vm_event_pause_count) )
return;
w = &v->arch.vm_event->write_data;
switch ( rsp->reason )
{
case VM_EVENT_REASON_MOV_TO_MSR:
w->do_write.msr = 0;
break;
case VM_EVENT_REASON_WRITE_CTRLREG:
switch ( rsp->u.write_ctrlreg.index )
{
case VM_EVENT_X86_CR0:
w->do_write.cr0 = 0;
break;
case VM_EVENT_X86_CR3:
w->do_write.cr3 = 0;
break;
case VM_EVENT_X86_CR4:
w->do_write.cr4 = 0;
break;
}
break;
}
}
}
void vm_event_set_registers(struct vcpu *v, vm_event_response_t *rsp)
{
ASSERT(atomic_read(&v->vm_event_pause_count));
v->arch.vm_event->gprs = rsp->data.regs.x86;
v->arch.vm_event->set_gprs = true;
}
void vm_event_monitor_next_interrupt(struct vcpu *v)
{
v->arch.monitor.next_interrupt_enabled = true;
}
void vm_event_sync_event(struct vcpu *v, bool value)
{
v->arch.vm_event->sync_event = value;
}
#ifdef CONFIG_HVM
static void vm_event_pack_segment_register(enum x86_segment segment,
struct vm_event_regs_x86 *reg)
{
struct segment_register seg;
hvm_get_segment_register(current, segment, &seg);
switch ( segment )
{
case x86_seg_ss:
reg->ss_base = seg.base;
reg->ss.limit = seg.g ? seg.limit >> 12 : seg.limit;
reg->ss.ar = seg.attr;
reg->ss_sel = seg.sel;
break;
case x86_seg_fs:
reg->fs_base = seg.base;
reg->fs.limit = seg.g ? seg.limit >> 12 : seg.limit;
reg->fs.ar = seg.attr;
reg->fs_sel = seg.sel;
break;
case x86_seg_gs:
reg->gs_base = seg.base;
reg->gs.limit = seg.g ? seg.limit >> 12 : seg.limit;
reg->gs.ar = seg.attr;
reg->gs_sel = seg.sel;
break;
case x86_seg_cs:
reg->cs_base = seg.base;
reg->cs.limit = seg.g ? seg.limit >> 12 : seg.limit;
reg->cs.ar = seg.attr;
reg->cs_sel = seg.sel;
break;
case x86_seg_ds:
reg->ds_base = seg.base;
reg->ds.limit = seg.g ? seg.limit >> 12 : seg.limit;
reg->ds.ar = seg.attr;
reg->ds_sel = seg.sel;
break;
case x86_seg_es:
reg->es_base = seg.base;
reg->es.limit = seg.g ? seg.limit >> 12 : seg.limit;
reg->es.ar = seg.attr;
reg->es_sel = seg.sel;
break;
case x86_seg_gdtr:
reg->gdtr_base = seg.base;
reg->gdtr_limit = seg.limit;
break;
default:
ASSERT_UNREACHABLE();
}
}
#endif
void vm_event_fill_regs(vm_event_request_t *req)
{
#ifdef CONFIG_HVM
const struct cpu_user_regs *regs = guest_cpu_user_regs();
struct hvm_hw_cpu ctxt = {};
struct vcpu *curr = current;
ASSERT(is_hvm_vcpu(curr));
/* Architecture-specific vmcs/vmcb bits */
alternative_vcall(hvm_funcs.save_cpu_ctxt, curr, &ctxt);
req->data.regs.x86.rax = regs->rax;
req->data.regs.x86.rcx = regs->rcx;
req->data.regs.x86.rdx = regs->rdx;
req->data.regs.x86.rbx = regs->rbx;
req->data.regs.x86.rsp = regs->rsp;
req->data.regs.x86.rbp = regs->rbp;
req->data.regs.x86.rsi = regs->rsi;
req->data.regs.x86.rdi = regs->rdi;
req->data.regs.x86.r8 = regs->r8;
req->data.regs.x86.r9 = regs->r9;
req->data.regs.x86.r10 = regs->r10;
req->data.regs.x86.r11 = regs->r11;
req->data.regs.x86.r12 = regs->r12;
req->data.regs.x86.r13 = regs->r13;
req->data.regs.x86.r14 = regs->r14;
req->data.regs.x86.r15 = regs->r15;
req->data.regs.x86.rflags = regs->rflags;
req->data.regs.x86.rip = regs->rip;
req->data.regs.x86.dr7 = curr->arch.dr7;
req->data.regs.x86.cr0 = curr->arch.hvm.guest_cr[0];
req->data.regs.x86.cr2 = curr->arch.hvm.guest_cr[2];
req->data.regs.x86.cr3 = curr->arch.hvm.guest_cr[3];
req->data.regs.x86.cr4 = curr->arch.hvm.guest_cr[4];
req->data.regs.x86.sysenter_cs = ctxt.sysenter_cs;
req->data.regs.x86.sysenter_esp = ctxt.sysenter_esp;
req->data.regs.x86.sysenter_eip = ctxt.sysenter_eip;
req->data.regs.x86.msr_efer = curr->arch.hvm.guest_efer;
req->data.regs.x86.msr_star = ctxt.msr_star;
req->data.regs.x86.msr_lstar = ctxt.msr_lstar;
vm_event_pack_segment_register(x86_seg_fs, &req->data.regs.x86);
vm_event_pack_segment_register(x86_seg_gs, &req->data.regs.x86);
vm_event_pack_segment_register(x86_seg_cs, &req->data.regs.x86);
vm_event_pack_segment_register(x86_seg_ss, &req->data.regs.x86);
vm_event_pack_segment_register(x86_seg_ds, &req->data.regs.x86);
vm_event_pack_segment_register(x86_seg_es, &req->data.regs.x86);
vm_event_pack_segment_register(x86_seg_gdtr, &req->data.regs.x86);
req->data.regs.x86.shadow_gs = ctxt.shadow_gs;
req->data.regs.x86.dr6 = ctxt.dr6;
if ( hvm_vmtrace_output_position(curr, &req->data.regs.x86.vmtrace_pos) != 1 )
req->data.regs.x86.vmtrace_pos = ~0;
#endif
}
void vm_event_emulate_check(struct vcpu *v, vm_event_response_t *rsp)
{
if ( !(rsp->flags & VM_EVENT_FLAG_EMULATE) )
{
v->arch.vm_event->emulate_flags = 0;
return;
}
#ifdef CONFIG_HVM
switch ( rsp->reason )
{
case VM_EVENT_REASON_MEM_ACCESS:
/*
* Emulate iff this is a response to a mem_access violation and there
* are still conflicting mem_access permissions in-place.
*/
if ( p2m_mem_access_emulate_check(v, rsp) )
{
if ( rsp->flags & VM_EVENT_FLAG_SET_EMUL_READ_DATA )
v->arch.vm_event->emul.read = rsp->data.emul.read;
v->arch.vm_event->emulate_flags = rsp->flags;
}
break;
case VM_EVENT_REASON_SOFTWARE_BREAKPOINT:
if ( rsp->flags & VM_EVENT_FLAG_SET_EMUL_INSN_DATA )
{
v->arch.vm_event->emul.insn = rsp->data.emul.insn;
v->arch.vm_event->emulate_flags = rsp->flags;
}
break;
case VM_EVENT_REASON_DESCRIPTOR_ACCESS:
if ( rsp->flags & VM_EVENT_FLAG_SET_EMUL_READ_DATA )
v->arch.vm_event->emul.read = rsp->data.emul.read;
v->arch.vm_event->emulate_flags = rsp->flags;
break;
default:
break;
};
#endif
}
void vm_event_reset_vmtrace(struct vcpu *v)
{
#ifdef CONFIG_HVM
hvm_vmtrace_reset(v);
#endif
}
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* indent-tabs-mode: nil
* End:
*/
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