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/*
* Copyright (C) 2009, Mukesh Rathor, Oracle Corp. All rights reserved.
*
* 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, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <xen/config.h>
#include <xen/sched.h>
#include <xen/compile.h>
#include <xen/mm.h>
#include <xen/domain_page.h>
#include <xen/guest_access.h>
#include <asm/debugger.h>
#include <asm/p2m.h>
/*
* This file for general routines common to more than one debugger, like kdb,
* gdbsx, etc..
*/
#ifdef XEN_KDB_CONFIG
#include "../kdb/include/kdbdefs.h"
#include "../kdb/include/kdbproto.h"
#define DBGP(...) {(kdbdbg) ? kdbp(__VA_ARGS__):0;}
#define DBGP1(...) {(kdbdbg>1) ? kdbp(__VA_ARGS__):0;}
#define DBGP2(...) {(kdbdbg>2) ? kdbp(__VA_ARGS__):0;}
#else
#define DBGP1(...) ((void)0)
#define DBGP2(...) ((void)0)
#endif
/* Returns: mfn for the given (hvm guest) vaddr */
static unsigned long
dbg_hvm_va2mfn(dbgva_t vaddr, struct domain *dp, int toaddr,
unsigned long *gfn)
{
unsigned long mfn;
uint32_t pfec = PFEC_page_present;
p2m_type_t gfntype;
DBGP2("vaddr:%lx domid:%d\n", vaddr, dp->domain_id);
*gfn = paging_gva_to_gfn(dp->vcpu[0], vaddr, &pfec);
if ( *gfn == INVALID_GFN )
{
DBGP2("kdb:bad gfn from gva_to_gfn\n");
return INVALID_MFN;
}
mfn = mfn_x(get_gfn(dp, *gfn, &gfntype));
if ( p2m_is_readonly(gfntype) && toaddr )
{
DBGP2("kdb:p2m_is_readonly: gfntype:%x\n", gfntype);
return INVALID_MFN;
}
DBGP2("X: vaddr:%lx domid:%d mfn:%lx\n", vaddr, dp->domain_id, mfn);
return mfn;
}
/*
* pgd3val: this is the value of init_mm.pgd[3] in a PV guest. It is optional.
* This to assist debug of modules in the guest. The kernel address
* space seems is always mapped, but modules are not necessarily
* mapped in any arbitraty guest cr3 that we pick if pgd3val is 0.
* Modules should always be addressible if we use cr3 from init_mm.
* Since pgd3val is already a pgd value, cr3->pgd[3], we just need to
* do 2 level lookups.
*
* NOTE: 4 level paging works for 32 PAE guests also because cpu runs in IA32-e
* mode.
* Returns: mfn for the given (pv guest) vaddr
*/
static unsigned long
dbg_pv_va2mfn(dbgva_t vaddr, struct domain *dp, uint64_t pgd3val)
{
l4_pgentry_t l4e, *l4t;
l3_pgentry_t l3e, *l3t;
l2_pgentry_t l2e, *l2t;
l1_pgentry_t l1e, *l1t;
unsigned long cr3 = (pgd3val ? pgd3val : dp->vcpu[0]->arch.cr3);
unsigned long mfn = cr3 >> PAGE_SHIFT;
DBGP2("vaddr:%lx domid:%d cr3:%lx pgd3:%lx\n", vaddr, dp->domain_id,
cr3, pgd3val);
if ( pgd3val == 0 )
{
l4t = map_domain_page(mfn);
l4e = l4t[l4_table_offset(vaddr)];
unmap_domain_page(l4t);
mfn = l4e_get_pfn(l4e);
DBGP2("l4t:%p l4to:%lx l4e:%lx mfn:%lx\n", l4t,
l4_table_offset(vaddr), l4e, mfn);
if ( !(l4e_get_flags(l4e) & _PAGE_PRESENT) )
{
DBGP1("l4 PAGE not present. vaddr:%lx cr3:%lx\n", vaddr, cr3);
return INVALID_MFN;
}
l3t = map_domain_page(mfn);
l3e = l3t[l3_table_offset(vaddr)];
unmap_domain_page(l3t);
mfn = l3e_get_pfn(l3e);
DBGP2("l3t:%p l3to:%lx l3e:%lx mfn:%lx\n", l3t,
l3_table_offset(vaddr), l3e, mfn);
if ( !(l3e_get_flags(l3e) & _PAGE_PRESENT) ||
(l3e_get_flags(l3e) & _PAGE_PSE) )
{
DBGP1("l3 PAGE not present. vaddr:%lx cr3:%lx\n", vaddr, cr3);
return INVALID_MFN;
}
}
l2t = map_domain_page(mfn);
l2e = l2t[l2_table_offset(vaddr)];
unmap_domain_page(l2t);
mfn = l2e_get_pfn(l2e);
DBGP2("l2t:%p l2to:%lx l2e:%lx mfn:%lx\n", l2t, l2_table_offset(vaddr),
l2e, mfn);
if ( !(l2e_get_flags(l2e) & _PAGE_PRESENT) ||
(l2e_get_flags(l2e) & _PAGE_PSE) )
{
DBGP1("l2 PAGE not present. vaddr:%lx cr3:%lx\n", vaddr, cr3);
return INVALID_MFN;
}
l1t = map_domain_page(mfn);
l1e = l1t[l1_table_offset(vaddr)];
unmap_domain_page(l1t);
mfn = l1e_get_pfn(l1e);
DBGP2("l1t:%p l1to:%lx l1e:%lx mfn:%lx\n", l1t, l1_table_offset(vaddr),
l1e, mfn);
return mfn_valid(mfn) ? mfn : INVALID_MFN;
}
/* Returns: number of bytes remaining to be copied */
static int
dbg_rw_guest_mem(dbgva_t addr, dbgbyte_t *buf, int len, struct domain *dp,
int toaddr, uint64_t pgd3)
{
while ( len > 0 )
{
char *va;
unsigned long mfn, gfn = INVALID_GFN, pagecnt;
pagecnt = min_t(long, PAGE_SIZE - (addr & ~PAGE_MASK), len);
mfn = (dp->is_hvm
? dbg_hvm_va2mfn(addr, dp, toaddr, &gfn)
: dbg_pv_va2mfn(addr, dp, pgd3));
if ( mfn == INVALID_MFN )
break;
va = map_domain_page(mfn);
va = va + (addr & (PAGE_SIZE-1));
if ( toaddr )
{
memcpy(va, buf, pagecnt); /* va = buf */
paging_mark_dirty(dp, mfn);
}
else
{
memcpy(buf, va, pagecnt); /* buf = va */
}
unmap_domain_page(va);
if ( gfn != INVALID_GFN )
put_gfn(dp, gfn);
addr += pagecnt;
buf += pagecnt;
len -= pagecnt;
}
return len;
}
/*
* addr is hypervisor addr if domid == DOMID_IDLE, else it's guest addr
* buf is debugger buffer.
* if toaddr, then addr = buf (write to addr), else buf = addr (rd from guest)
* pgd3: value of init_mm.pgd[3] in guest. see above.
* Returns: number of bytes remaining to be copied.
*/
int
dbg_rw_mem(dbgva_t addr, dbgbyte_t *buf, int len, domid_t domid, int toaddr,
uint64_t pgd3)
{
struct domain *dp = get_domain_by_id(domid);
int hyp = (domid == DOMID_IDLE);
DBGP2("gmem:addr:%lx buf:%p len:$%d domid:%x toaddr:%x dp:%p\n",
addr, buf, len, domid, toaddr, dp);
if ( hyp )
{
if ( toaddr )
len = __copy_to_user((void *)addr, buf, len);
else
len = __copy_from_user(buf, (void *)addr, len);
}
else if ( dp )
{
if ( !dp->is_dying ) /* make sure guest is still there */
len= dbg_rw_guest_mem(addr, buf, len, dp, toaddr, pgd3);
put_domain(dp);
}
DBGP2("gmem:exit:len:$%d\n", len);
return len;
}
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