/*
* write registers for the given vcpu
* Returns: 0 success, 1 failure with errno
*/
int
xg_regs_write(regstype_t which_regs, vcpuid_t which_vcpu,
union xg_gdb_regs *regsp, int guest_bitness)
{
union vcpu_guest_context_any anyc;
struct cpu_user_regs_x86_32 *cr32p = &anyc.ctxt32.user_regs;
struct cpu_user_regs_x86_64 *cr64p = &anyc.ctxt64.user_regs;
struct xg_gdb_regs32 *r32p = ®sp->gregs_32;
struct xg_gdb_regs64 *r64p = ®sp->gregs_64;
int rc, sz = sizeof(anyc);
if (which_regs != XG_GPRS) {
errno = EINVAL;
XGERR("regs got: %d. Expected GPRS:%d\n", which_regs, XG_GPRS);
return 1;
}
if ((rc=_get_vcpu_ctxt(which_vcpu, &anyc)))
return rc;
if (guest_bitness == 32) {
if (_32bit_hyp || !_hvm_guest)
_cp_32gdb_to_32ctxt(r32p, cr32p);
else
_cp_32gdb_to_64ctxt(r32p, cr64p);
} else
_cp_64gdb_to_64ctxt(r64p, cr64p);
/* set vcpu context back */
if ((rc =_domctl_hcall(XEN_DOMCTL_setvcpucontext, &anyc, sz))) {
XGERR("Failed hcall to set vcpu ctxt. errno:%d\n", errno);
return rc;
}
XGTRC("X:vcpu:%d bitness:%d rc:%d\n", which_vcpu, guest_bitness, rc);
return rc;
}
/*
* Returns: bytes that could not be written. 0 => wrote all bytes, ie, success.
*/
int
xg_write_mem(uint64_t guestva, char *frombuf, int buflen, uint64_t pgd3val)
{
struct xen_domctl_gdbsx_memio *iop = &domctl.u.gdbsx_guest_memio;
union {uint64_t llbuf8; char buf8[8];} u = {0};
int i, rc;
for(i=0; i < XGMIN(8, buflen); u.buf8[i]=frombuf[i], i++);
XGTRC("E:gva:%llx frombuf:%lx len:%d buf8:0x%llx\n", guestva, frombuf,
buflen, u.llbuf8);
memset(&domctl.u, 0, sizeof(domctl.u));
iop->pgd3val = pgd3val;
iop->gva = guestva;
iop->uva = (uint64_aligned_t)((unsigned long)frombuf);
iop->len = buflen;
iop->gwr = 1; /* writing to guest */
if ((rc=_domctl_hcall(XEN_DOMCTL_gdbsx_guestmemio, frombuf, buflen)))
{
XGERR("ERROR: failed to write bytes to %llx. errno:%d rc:%d\n",
guestva, errno, rc);
return buflen;
}
return iop->remain;
}
/*
* read regs for a particular vcpu. For now only GPRs, no FPRs.
* Returns: 0 success, else failure with errno set
*/
int
xg_regs_read(regstype_t which_regs, vcpuid_t which_vcpu,
union xg_gdb_regs *regsp, int guest_bitness)
{
union vcpu_guest_context_any anyc;
struct cpu_user_regs_x86_32 *cr32p = &anyc.ctxt32.user_regs;
struct cpu_user_regs_x86_64 *cr64p = &anyc.ctxt64.user_regs;
struct xg_gdb_regs32 *r32p = ®sp->gregs_32;
struct xg_gdb_regs64 *r64p = ®sp->gregs_64;
int rc;
if (which_regs != XG_GPRS) {
errno = EINVAL;
XGERR("regs got: %d. Expected GPRS:%d\n", which_regs, XG_GPRS);
return 1;
}
if ((rc=_get_vcpu_ctxt(which_vcpu, &anyc)))
return rc;
/* 64bit hyp: only 32bit PV returns 32bit context, all others 64bit.
* 32bit hyp: all contexts returned are 32bit */
if (guest_bitness == 32) {
if (_32bit_hyp || !_hvm_guest)
_cp_32ctxt_to_32gdb(cr32p, r32p);
else
_cp_64ctxt_to_32gdb(cr64p, r32p);
} else
_cp_64ctxt_to_64gdb(cr64p, r64p);
XGTRC("X:vcpu:%d bitness:%d rc:%d\n", which_vcpu, guest_bitness, rc);
return rc;
}
/*
* Change the TF flag for single step. TF = (setit ? 1 : 0);
* Returns: 0 Success
*/
static int
_change_TF(vcpuid_t which_vcpu, int guest_bitness, int setit)
{
union vcpu_guest_context_any anyc;
int sz = sizeof(anyc);
/* first try the MTF for hvm guest. otherwise do manually */
if (_hvm_guest) {
domctl.u.debug_op.vcpu = which_vcpu;
domctl.u.debug_op.op = setit ? XEN_DOMCTL_DEBUG_OP_SINGLE_STEP_ON :
XEN_DOMCTL_DEBUG_OP_SINGLE_STEP_OFF;
if (_domctl_hcall(XEN_DOMCTL_debug_op, NULL, 0) == 0) {
XGTRC("vcpu:%d:MTF success setit:%d\n", which_vcpu, setit);
return 0;
}
XGTRC("vcpu:%d:MTF failed. setit:%d\n", which_vcpu, setit);
}
memset(&anyc, 0, sz);
domctl.u.vcpucontext.vcpu = (uint16_t)which_vcpu;
set_xen_guest_handle(domctl.u.vcpucontext.ctxt, &anyc.ctxt);
if (_domctl_hcall(XEN_DOMCTL_getvcpucontext, &anyc, sz)) {
XGERR("Failed hcall to get vcpu ctxt for TF. errno:%d\n",errno);
return 1;
}
if (_32bit_hyp || (guest_bitness == 32 && !_hvm_guest)) {
if (setit)
anyc.ctxt32.user_regs.eflags |= X86_EFLAGS_TF;
else
anyc.ctxt32.user_regs.eflags &= ~X86_EFLAGS_TF;
} else {
if (setit)
anyc.ctxt64.user_regs.rflags |= X86_EFLAGS_TF;
else
anyc.ctxt64.user_regs.rflags &= ~X86_EFLAGS_TF;
}
if (_domctl_hcall(XEN_DOMCTL_setvcpucontext, &anyc, sz)) {
XGERR("Failed hcall to set vcpu ctxt for TF. errno:%d\n",errno);
return 1;
}
return 0;
}
/*
* Attach to the given domid for debugging.
* Returns: max vcpu id : Success
* -1 : Failure
*/
int
xg_attach(int domid, int guest_bitness)
{
XGTRC("E:domid:%d\n", domid);
_dom_id = domctl.domain = domid;
domctl.interface_version = XEN_DOMCTL_INTERFACE_VERSION;
if (mlock(&domctl, sizeof(domctl))) {
XGERR("Unable to pin domctl in memory. errno:%d\n", errno);
return -1;
}
if (_check_hyp(guest_bitness))
return -1;
if (_domctl_hcall(XEN_DOMCTL_pausedomain, NULL, 0)) {
XGERR("Unable to pause domain:%d\n", _dom_id);
return -1;
}
memset(&domctl.u, 0, sizeof(domctl.u));
domctl.u.setdebugging.enable = 1;
if (_domctl_hcall(XEN_DOMCTL_setdebugging, NULL, 0)) {
XGERR("Unable to set domain to debug mode: errno:%d\n", errno);
_unpause_domain();
return -1;
}
memset(&domctl.u, 0, sizeof(domctl.u));
if (_domctl_hcall(XEN_DOMCTL_getdomaininfo, NULL, 0)) {
XGERR("Unable to get domain info: domid:%d errno:%d\n",
domid, errno);
_unpause_domain();
return -1;
}
if (!_domain_ok(&domctl.u.getdomaininfo)) {
_unpause_domain();
return -1;
}
_max_vcpu_id = domctl.u.getdomaininfo.max_vcpu_id;
_hvm_guest = (domctl.u.getdomaininfo.flags & XEN_DOMINF_hvm_guest);
_pvh_guest = (domctl.u.getdomaininfo.flags & XEN_DOMINF_pvh_guest);
return _max_vcpu_id;
}
/*
* Make sure we are running on hyp enabled for gdbsx. Also, note whether
* its 32bit. Fail if user typed 64bit for guest in case of 32bit hyp.
*
* RETURNS: 0 : everything OK.
*/
static int
_check_hyp(int guest_bitness)
{
xen_capabilities_info_t xen_caps = "";
privcmd_hypercall_t hypercall;
int rc;
/*
* Try to unpause an invalid vcpu. If hypervisor supports gdbsx then
* this should fail with an error other than ENOSYS.
*/
domctl.u.gdbsx_pauseunp_vcpu.vcpu = ~0u;
(void)_domctl_hcall(XEN_DOMCTL_gdbsx_unpausevcpu, NULL, 0);
if (errno == ENOSYS) {
XGERR("Hyp is NOT enabled for gdbsx\n");
return -1;
}
if (mlock(&xen_caps, sizeof(xen_caps))) {
XGERR("Unable to pin xen_caps in memory. errno:%d\n", errno);
return -1;
}
memset(&xen_caps, 0, sizeof(xen_caps));
hypercall.op = __HYPERVISOR_xen_version;
hypercall.arg[0] = (unsigned long)XENVER_capabilities;
hypercall.arg[1] = (unsigned long)&xen_caps;
rc = ioctl(_dom0_fd, IOCTL_PRIVCMD_HYPERCALL, &hypercall);
munlock(&xen_caps, sizeof(xen_caps));
XGTRC("XENCAPS:%s\n", xen_caps);
if (rc != 0) {
XGERR("Failed xen_version hcall. errno:%d\n", errno);
return -1;
}
_32bit_hyp = (strstr(xen_caps, "x86_64") == NULL);
if (_32bit_hyp && guest_bitness !=32) {
XGERR("32bit hyp can only run 32bit guests\n");
return -1;
}
return 0;
}
/* Returns: 1 : domain is paused. 0 otherwise */
static int
_domain_is_paused(void)
{
memset(&domctl.u, 0, sizeof(domctl.u));
if (_domctl_hcall(XEN_DOMCTL_getdomaininfo, NULL, 0)) {
XGERR("ERROR: Unable to get domain paused info:%d\n", _dom_id);
return 0;
}
return (domctl.u.getdomaininfo.flags & XEN_DOMINF_paused);
}
/* Returns: 0 : success */
static int
_unpause_domain(void)
{
memset(&domctl.u, 0, sizeof(domctl.u));
if (_domctl_hcall(XEN_DOMCTL_unpausedomain, NULL, 0)) {
XGERR("Unable to unpause domain:%d errno:%d\n", _dom_id, errno);
return -1;
}
return 0;
}
/* check if domain is alive and well
* returns : 0 if domain is not alive and well
*/
static int
_domain_ok(struct xen_domctl_getdomaininfo *domp)
{
int rc = 0;
if (domp->flags & XEN_DOMINF_dying)
XGERR("Invalid domain (state dying)...\n");
else
rc = 1;
return rc;
}
/*
* check if any one of the vcpus is in a breakpoint
* Returns: vcpuid : if a vcpu found in a bp
* -1 : otherwise
*/
static vcpuid_t
_vcpu_in_bp(void)
{
memset(&domctl.u, 0, sizeof(domctl.u));
if (_domctl_hcall(XEN_DOMCTL_gdbsx_domstatus, NULL, 0)) {
XGERR("ERROR: Unable to check vcpu bp status:%d errno:%d\n",
_dom_id, errno);
return -1;
}
return domctl.u.gdbsx_domstatus.vcpu_id;
}
/* Detach from guest for debugger exit */
void
xg_detach_deinit(void)
{
memset(&domctl.u, 0, sizeof(domctl.u));
domctl.u.setdebugging.enable = 0;
if (_domctl_hcall(XEN_DOMCTL_setdebugging, NULL, 0)) {
XGERR("Unable to reset domain debug mode: errno:%d\n", errno);
}
if (_domain_is_paused())
_unpause_domain();
close(_dom0_fd);
}
/* get vcpu context from xen and return it in *ctxtp
* RETURNS: 0 for success
*/
static int
_get_vcpu_ctxt(vcpuid_t vcpu_id, union vcpu_guest_context_any *anycp)
{
int sz = sizeof(union vcpu_guest_context_any);
memset(anycp, 0, sz);
domctl.u.vcpucontext.vcpu = (uint16_t)vcpu_id;
set_xen_guest_handle(domctl.u.vcpucontext.ctxt, &anycp->ctxt);
if (_domctl_hcall(XEN_DOMCTL_getvcpucontext, anycp, sz)) {
XGERR("Failed hcall to get vcpu ctxt. errno:%d\n", errno);
return 1;
}
return 0;
}
/* Do the given DOMCTL hcall action(pause or unpause) on all but the given vcpu
* Returns: 0 success */
static int
_allbutone_vcpu(uint32_t hcall, vcpuid_t which_vcpu)
{
int i;
for (i=0; i <= _max_vcpu_id; i++) {
if (i == which_vcpu)
continue;
memset(&domctl.u, 0, sizeof(domctl.u));
domctl.u.gdbsx_pauseunp_vcpu.vcpu = i;
if (_domctl_hcall(hcall, NULL, 0)) {
XGERR("Unable to do:%d vcpu:%d errno:%d\n",
hcall, i, errno);
return 1;
}
}
return 0;
}
/*
* Precondition: domctl global struct must be filled
* Returns : 0 Success, failure otherwise with errno set
*/
static int
_domctl_hcall(uint32_t cmd, /* which domctl hypercall */
void *domctlarg, /* arg/buf to domctl to pin in mem */
int sz) /* size of *domctlarg */
{
privcmd_hypercall_t hypercall;
int rc;
if (domctlarg && sz && mlock(domctlarg, sz)) {
XGERR("Unable to pin domctl arg. p:%p sz:%d errno:%d\n",
domctlarg, sz, errno);
return 1;
}
domctl.cmd = cmd;
hypercall.op = __HYPERVISOR_domctl;
hypercall.arg[0] = (unsigned long)&domctl;
rc = ioctl(_dom0_fd, IOCTL_PRIVCMD_HYPERCALL, &hypercall);
if (domctlarg && sz)
munlock(domctlarg, sz);
return rc;
}