Module Name:    src
Committed By:   jym
Date:           Tue Oct  5 23:48:16 UTC 2010

Modified Files:
        src/lib/libkvm: Makefile kvm_i386.c
        src/sys/arch/i386/i386: dumpsys.c
        src/sys/arch/i386/include: kcore.h
Added Files:
        src/lib/libkvm: kvm_i386pae.c

Log Message:
Import PAE support for kvm(3):
- add kvm_i386pae.c (used for PAE memory translations), and update Makefile
  for libkvm build.
- in pdppaddr: pass a flag to indicate PAE mode. Use a bit ignored
  by the MMU. Mask address with PG_FRAME to avoid side effects.

Tested with vmstat(1)/netstat(1) to debug core files of PAE and !PAE
kernels. Older kernel dumps will default to native i386 (!PAE) mode.

XXX Currently, savecore(8) will fail to dump a PAE kernel in a !PAE
    environment (and reciprocally). So you need to sync and reboot
    with a kernel of the same mode as the one that crashed. Once the dump
    is successful, this does not matter anymore.


To generate a diff of this commit:
cvs rdiff -u -r1.45 -r1.46 src/lib/libkvm/Makefile
cvs rdiff -u -r1.28 -r1.29 src/lib/libkvm/kvm_i386.c
cvs rdiff -u -r0 -r1.1 src/lib/libkvm/kvm_i386pae.c
cvs rdiff -u -r1.10 -r1.11 src/sys/arch/i386/i386/dumpsys.c
cvs rdiff -u -r1.4 -r1.5 src/sys/arch/i386/include/kcore.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

Modified files:

Index: src/lib/libkvm/Makefile
diff -u src/lib/libkvm/Makefile:1.45 src/lib/libkvm/Makefile:1.46
--- src/lib/libkvm/Makefile:1.45	Sat Oct 25 23:59:42 2008
+++ src/lib/libkvm/Makefile	Tue Oct  5 23:48:16 2010
@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.45 2008/10/25 23:59:42 mrg Exp $
+#	$NetBSD: Makefile,v 1.46 2010/10/05 23:48:16 jym Exp $
 #	from: @(#)Makefile	8.1 (Berkeley) 6/4/93
 
 USE_FORT?= yes	# used primarily by setgid programs
@@ -7,9 +7,6 @@
 
 LIB=	kvm
 CPPFLAGS+=-DLIBC_SCCS -I${NETBSDSRCDIR}/sys
-.if ${MACHINE_ARCH} == "i386"
-LINTFLAGS+=-w
-.endif
 
 SRCS=	kvm.c kvm_file.c kvm_getloadavg.c kvm_proc.c
 
@@ -31,6 +28,11 @@
 	@false
 .endif
 
+.if ${MACHINE_ARCH} == "i386"
+LINTFLAGS+=-w
+SRCS+=	kvm_i386pae.c # Hook PAE support in the i386 build
+.endif
+
 # Additional modules needed for m68k
 .if (${MACHINE_ARCH} == "m68k" || ${MACHINE_CPU} == "m68k")
 SRCS+=	kvm_m68k_cmn.c kvm_sun2.c kvm_sun3.c kvm_sun3x.c

Index: src/lib/libkvm/kvm_i386.c
diff -u src/lib/libkvm/kvm_i386.c:1.28 src/lib/libkvm/kvm_i386.c:1.29
--- src/lib/libkvm/kvm_i386.c:1.28	Mon Sep 20 23:23:16 2010
+++ src/lib/libkvm/kvm_i386.c	Tue Oct  5 23:48:16 2010
@@ -1,4 +1,4 @@
-/*	$NetBSD: kvm_i386.c,v 1.28 2010/09/20 23:23:16 jym Exp $	*/
+/*	$NetBSD: kvm_i386.c,v 1.29 2010/10/05 23:48:16 jym Exp $	*/
 
 /*-
  * Copyright (c) 1989, 1992, 1993
@@ -38,7 +38,7 @@
 #if 0
 static char sccsid[] = "@(#)kvm_hp300.c	8.1 (Berkeley) 6/4/93";
 #else
-__RCSID("$NetBSD: kvm_i386.c,v 1.28 2010/09/20 23:23:16 jym Exp $");
+__RCSID("$NetBSD: kvm_i386.c,v 1.29 2010/10/05 23:48:16 jym Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -74,6 +74,16 @@
 #define	ptob(x)		((caddr_t)((x) << PGSHIFT))	/* XXX */
 #endif
 
+/*
+ * Indicates whether PAE is in use for the kernel image
+ * 0: native i386 memory mappings
+ * 1: i386 PAE mappings
+ */
+static int i386_use_pae;
+
+int _kvm_kvatop_i386(kvm_t *, vaddr_t, paddr_t *);
+int _kvm_kvatop_i386pae(kvm_t *, vaddr_t, paddr_t *);
+
 void
 _kvm_freevtop(kvm_t *kd)
 {
@@ -87,6 +97,11 @@
 int
 _kvm_initvtop(kvm_t *kd)
 {
+	cpu_kcore_hdr_t *cpu_kh = kd->cpu_data;
+
+	i386_use_pae = 0; /* default: non PAE mode */
+	if ((cpu_kh->pdppaddr & I386_KCORE_PAE) == I386_KCORE_PAE)
+		i386_use_pae = 1;
 
 	return 0;
 }
@@ -97,24 +112,44 @@
 int
 _kvm_kvatop(kvm_t *kd, vaddr_t va, paddr_t *pa)
 {
-	cpu_kcore_hdr_t *cpu_kh;
-	u_long page_off;
-	pd_entry_t pde;
-	pt_entry_t pte;
-	paddr_t pde_pa, pte_pa;
 
 	if (ISALIVE(kd)) {
 		_kvm_err(kd, 0, "vatop called in live kernel!");
 		return 0;
 	}
 
+	switch (i386_use_pae) {
+	default:
+	case 0:
+		return _kvm_kvatop_i386(kd, va, pa);
+	case 1:
+		return _kvm_kvatop_i386pae(kd, va, pa);
+	}
+	
+}
+
+/*
+ * Used to translate a virtual address to a physical address for systems
+ * with PAE mode disabled. Only two levels of virtual memory pages are
+ * dereferenced (L2 PDEs, then L1 PTEs).
+ */
+int
+_kvm_kvatop_i386(kvm_t *kd, vaddr_t va, paddr_t *pa)
+{
+	cpu_kcore_hdr_t *cpu_kh;
+	u_long page_off;
+	pd_entry_t pde;
+	pt_entry_t pte;
+	paddr_t pde_pa, pte_pa;
+
 	cpu_kh = kd->cpu_data;
 	page_off = va & PGOFSET;
 
 	/*
 	 * Find and read the page directory entry.
+	 * pdppaddr being PAGE_SIZE aligned, we mask the option bits.
 	 */
-	pde_pa = cpu_kh->pdppaddr + (pl2_pi(va) * sizeof(pd_entry_t));
+	pde_pa = (cpu_kh->pdppaddr & PG_FRAME) + (pl2_pi(va) * sizeof(pde));
 	if (_kvm_pread(kd, kd->pmfd, (void *)&pde, sizeof(pde),
 	    _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
 		_kvm_syserr(kd, 0, "could not read PDE");

Index: src/sys/arch/i386/i386/dumpsys.c
diff -u src/sys/arch/i386/i386/dumpsys.c:1.10 src/sys/arch/i386/i386/dumpsys.c:1.11
--- src/sys/arch/i386/i386/dumpsys.c:1.10	Sat Oct  2 22:54:47 2010
+++ src/sys/arch/i386/i386/dumpsys.c	Tue Oct  5 23:48:16 2010
@@ -1,4 +1,4 @@
-/*	$NetBSD: dumpsys.c,v 1.10 2010/10/02 22:54:47 jym Exp $	*/
+/*	$NetBSD: dumpsys.c,v 1.11 2010/10/05 23:48:16 jym Exp $	*/
 
 /*-
  * Copyright (c) 1996, 1997, 1998, 2000, 2004, 2006, 2008 The NetBSD Foundation, Inc.
@@ -69,7 +69,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: dumpsys.c,v 1.10 2010/10/02 22:54:47 jym Exp $");
+__KERNEL_RCSID(0, "$NetBSD: dumpsys.c,v 1.11 2010/10/05 23:48:16 jym Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -628,6 +628,8 @@
 	 * Add the machine-dependent header info.
 	 */
 	cpuhdr.pdppaddr = PDPpaddr;
+	if (i386_use_pae == 1)
+		cpuhdr.pdppaddr |= I386_KCORE_PAE;
 	cpuhdr.nmemsegs = dump_nmemsegs;
 	(void)dump_header_addbytes(&cpuhdr, ALIGN(sizeof(cpuhdr)));
 

Index: src/sys/arch/i386/include/kcore.h
diff -u src/sys/arch/i386/include/kcore.h:1.4 src/sys/arch/i386/include/kcore.h:1.5
--- src/sys/arch/i386/include/kcore.h:1.4	Sat Jan 12 20:03:42 2008
+++ src/sys/arch/i386/include/kcore.h	Tue Oct  5 23:48:16 2010
@@ -1,4 +1,4 @@
-/*	$NetBSD: kcore.h,v 1.4 2008/01/12 20:03:42 ad Exp $	*/
+/*	$NetBSD: kcore.h,v 1.5 2010/10/05 23:48:16 jym Exp $	*/
 
 /*
  * Copyright (c) 1996 Carnegie-Mellon University.
@@ -43,6 +43,15 @@
 #endif
 } cpu_kcore_hdr_t;
 
+/*
+ * Used to indicate that PAE should be used for virtual address
+ * translation. As PDPpaddr is expected to be PAGE_SIZE aligned,
+ * this can be safely OR'ed in pdppaddr.
+ * To avoid any kind of conflict with existing MMU bits, we chose one
+ * ignored by hardware
+ */
+#define I386_KCORE_PAE	PG_AVAIL1
+
 #ifdef _KERNEL
 void	dumpsys(void);
 

Added files:

Index: src/lib/libkvm/kvm_i386pae.c
diff -u /dev/null src/lib/libkvm/kvm_i386pae.c:1.1
--- /dev/null	Tue Oct  5 23:48:16 2010
+++ src/lib/libkvm/kvm_i386pae.c	Tue Oct  5 23:48:16 2010
@@ -0,0 +1,131 @@
+/* $NetBSD: kvm_i386pae.c,v 1.1 2010/10/05 23:48:16 jym Exp $ */
+
+/*
+ * Copyright (c) 2010 Jean-Yves Migeon.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__RCSID("$NetBSD: kvm_i386pae.c,v 1.1 2010/10/05 23:48:16 jym Exp $");
+
+/*
+ * This will expose PAE functions, macros, definitions and constants.
+ * Note: this affects all virtual memory related functions. Only their
+ * PAE versions can be used below.
+ */
+#define PAE
+
+#include <sys/param.h>
+#include <sys/user.h>
+#include <sys/stat.h>
+#include <sys/kcore.h>
+#include <sys/types.h>
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <nlist.h>
+#include <kvm.h>
+
+#include <uvm/uvm_extern.h>
+
+#include <limits.h>
+#include <db.h>
+
+#include "kvm_private.h"
+
+#include <i386/kcore.h>
+#include <i386/pmap.h>
+#include <i386/pte.h>
+#include <i386/vmparam.h>
+
+int _kvm_kvatop_i386pae(kvm_t *, vaddr_t, paddr_t *);
+
+/*
+ * Used to translate a virtual address to a physical address for systems
+ * running under PAE mode. Three levels of virtual memory pages are handled
+ * here: the per-CPU L3 page, the 4 L2 PDs and the PTs.
+ */
+int
+_kvm_kvatop_i386pae(kvm_t *kd, vaddr_t va, paddr_t *pa)
+{
+	cpu_kcore_hdr_t *cpu_kh;
+	u_long page_off;
+	pd_entry_t pde;
+	pt_entry_t pte;
+	paddr_t pde_pa, pte_pa;
+
+	cpu_kh = kd->cpu_data;
+	page_off = va & PGOFSET;
+	
+	/*
+	 * Find and read the PDE. Ignore the L3, as it is only a per-CPU
+	 * page, not needed for kernel VA => PA translations.
+	 * Remember that the 4 L2 pages are contiguous, so it is safe
+	 * to increment pdppaddr to compute the address of the PDE.
+	 * pdppaddr being PAGE_SIZE aligned, we mask the option bits.
+	 */
+	pde_pa = (cpu_kh->pdppaddr & PG_FRAME) + (pl2_pi(va) * sizeof(pde));
+	if (_kvm_pread(kd, kd->pmfd, (void *)&pde, sizeof(pde),
+	    _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
+		_kvm_syserr(kd, 0, "could not read PDE");
+		goto lose;
+	}
+
+	/*
+	 * Find and read the page table entry.
+	 */
+	if ((pde & PG_V) == 0) {
+		_kvm_err(kd, 0, "invalid translation (invalid PDE)");
+		goto lose;
+	}
+	if ((pde & PG_PS) != 0) {
+		/*
+		 * This is a 2MB page.
+		 */
+		page_off = va & ((vaddr_t)~PG_LGFRAME);
+		*pa = (pde & PG_LGFRAME) + page_off;
+		return (int)(NBPD_L2 - page_off);
+	}
+
+	pte_pa = (pde & PG_FRAME) + (pl1_pi(va) * sizeof(pt_entry_t));
+	if (_kvm_pread(kd, kd->pmfd, (void *) &pte, sizeof(pte),
+	    _kvm_pa2off(kd, pte_pa)) != sizeof(pte)) {
+		_kvm_syserr(kd, 0, "could not read PTE");
+		goto lose;
+	}
+
+	/*
+	 * Validate the PTE and return the physical address.
+	 */
+	if ((pte & PG_V) == 0) {
+		_kvm_err(kd, 0, "invalid translation (invalid PTE)");
+		goto lose;
+	}
+	*pa = (pte & PG_FRAME) + page_off;
+	return (int)(NBPG - page_off);
+
+lose:
+	*pa = (paddr_t)~0L;
+	return 0;
+
+}

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