Add riscv minidump support to libkvm.

Submitted by:	Mitchell Horne <mhorne063@gmail.com>
Differential Revision:	https://reviews.freebsd.org/D19171

3 files changed, 379 insertions, 0 deletions

diff --git a/lib/libkvm/Makefile b/lib/libkvm/Makefile
index 8520a02d7b22d..d934690d43553 100644
--- a/lib/libkvm/Makefile
+++ b/lib/libkvm/Makefile
@@ -18,6 +18,7 @@ SRCS=	kvm.c kvm_cptime.c kvm_getloadavg.c \
 	kvm_i386.c kvm_minidump_i386.c \
 	kvm_minidump_mips.c \
 	kvm_powerpc.c kvm_powerpc64.c \
+	kvm_minidump_riscv.c \
 	kvm_sparc64.c
 INCS=	kvm.h
 
diff --git a/lib/libkvm/kvm_minidump_riscv.c b/lib/libkvm/kvm_minidump_riscv.c
new file mode 100644
index 0000000000000..ffe83b8f99cca
--- /dev/null
+++ b/lib/libkvm/kvm_minidump_riscv.c
@@ -0,0 +1,288 @@
+/*-
+ * Copyright (c) 2006 Peter Wemm
+ * Copyright (c) 2019 Mitchell Horne
+ *
+ * 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 AUTHOR 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 AUTHOR 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.
+ *
+ * From: FreeBSD: src/lib/libkvm/kvm_minidump_amd64.c r261799
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * RISC-V machine dependent routines for kvm and minidumps.
+ */
+
+#include <sys/param.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <vm/vm.h>
+#include <kvm.h>
+
+#include "../../sys/riscv/include/minidump.h"
+
+#include <limits.h>
+
+#include "kvm_private.h"
+#include "kvm_riscv.h"
+
+#define	riscv_round_page(x)	roundup2((kvaddr_t)(x), RISCV_PAGE_SIZE)
+
+struct vmstate {
+	struct minidumphdr hdr;
+};
+
+static riscv_pt_entry_t
+_riscv_pte_get(kvm_t *kd, u_long pteindex)
+{
+	riscv_pt_entry_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
+
+	return le64toh(*pte);
+}
+
+static int
+_riscv_minidump_probe(kvm_t *kd)
+{
+
+	return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_RISCV) &&
+	    _kvm_is_minidump(kd));
+}
+
+static void
+_riscv_minidump_freevtop(kvm_t *kd)
+{
+	struct vmstate *vm = kd->vmst;
+
+	free(vm);
+	kd->vmst = NULL;
+}
+
+static int
+_riscv_minidump_initvtop(kvm_t *kd)
+{
+	struct vmstate *vmst;
+	off_t off, sparse_off;
+
+	vmst = _kvm_malloc(kd, sizeof(*vmst));
+	if (vmst == NULL) {
+		_kvm_err(kd, kd->program, "cannot allocate vm");
+		return (-1);
+	}
+	kd->vmst = vmst;
+	if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
+	    sizeof(vmst->hdr)) {
+		_kvm_err(kd, kd->program, "cannot read dump header");
+		return (-1);
+	}
+	if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic,
+	    sizeof(vmst->hdr.magic)) != 0) {
+		_kvm_err(kd, kd->program, "not a minidump for this platform");
+		return (-1);
+	}
+
+	vmst->hdr.version = le32toh(vmst->hdr.version);
+	if (vmst->hdr.version != MINIDUMP_VERSION) {
+		_kvm_err(kd, kd->program, "wrong minidump version. "
+		    "Expected %d got %d", MINIDUMP_VERSION, vmst->hdr.version);
+		return (-1);
+	}
+	vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
+	vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
+	vmst->hdr.pmapsize = le32toh(vmst->hdr.pmapsize);
+	vmst->hdr.kernbase = le64toh(vmst->hdr.kernbase);
+	vmst->hdr.dmapphys = le64toh(vmst->hdr.dmapphys);
+	vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase);
+	vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend);
+
+	/* Skip header and msgbuf */
+	off = RISCV_PAGE_SIZE + riscv_round_page(vmst->hdr.msgbufsize);
+
+	/* build physical address lookup table for sparse pages */
+	sparse_off = off + riscv_round_page(vmst->hdr.bitmapsize) +
+	    riscv_round_page(vmst->hdr.pmapsize);
+	if (_kvm_pt_init(kd, vmst->hdr.bitmapsize, off, sparse_off,
+	    RISCV_PAGE_SIZE, sizeof(uint64_t)) == -1) {
+		return (-1);
+	}
+	off += riscv_round_page(vmst->hdr.bitmapsize);
+
+	if (_kvm_pmap_init(kd, vmst->hdr.pmapsize, off) == -1) {
+		return (-1);
+	}
+	off += riscv_round_page(vmst->hdr.pmapsize);
+
+	return (0);
+}
+
+static int
+_riscv_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
+{
+	struct vmstate *vm;
+	riscv_physaddr_t offset;
+	riscv_pt_entry_t l3;
+	kvaddr_t l3_index;
+	riscv_physaddr_t a;
+	off_t ofs;
+
+	vm = kd->vmst;
+	offset = va & RISCV_PAGE_MASK;
+
+	if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
+		a = (va - vm->hdr.dmapbase + vm->hdr.dmapphys) &
+		    ~RISCV_PAGE_MASK;
+		ofs = _kvm_pt_find(kd, a, RISCV_PAGE_SIZE);
+		if (ofs == -1) {
+			_kvm_err(kd, kd->program, "_riscv_minidump_vatop: "
+			    "direct map address 0x%jx not in minidump",
+			    (uintmax_t)va);
+			goto invalid;
+		}
+		*pa = ofs + offset;
+		return (RISCV_PAGE_SIZE - offset);
+	} else if (va >= vm->hdr.kernbase) {
+		l3_index = (va - vm->hdr.kernbase) >> RISCV_L3_SHIFT;
+		if (l3_index >= vm->hdr.pmapsize / sizeof(l3))
+			goto invalid;
+		l3 = _riscv_pte_get(kd, l3_index);
+		if ((l3 & RISCV_PTE_V) == 0 || (l3 & RISCV_PTE_RWX) == 0) {
+			_kvm_err(kd, kd->program,
+			    "_riscv_minidump_vatop: pte not valid");
+			goto invalid;
+		}
+		a = (l3 >> RISCV_PTE_PPN0_S) << RISCV_L3_SHIFT;
+		ofs = _kvm_pt_find(kd, a, RISCV_PAGE_SIZE);
+		if (ofs == -1) {
+			_kvm_err(kd, kd->program, "_riscv_minidump_vatop: "
+			    "physical address 0x%jx not in minidump",
+			    (uintmax_t)a);
+			goto invalid;
+		}
+		*pa = ofs + offset;
+		return (RISCV_PAGE_SIZE - offset);
+	} else {
+		_kvm_err(kd, kd->program,
+	    "_riscv_minidump_vatop: virtual address 0x%jx not minidumped",
+		    (uintmax_t)va);
+		goto invalid;
+	}
+
+invalid:
+	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
+	return (0);
+}
+
+static int
+_riscv_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
+{
+
+	if (ISALIVE(kd)) {
+		_kvm_err(kd, 0,
+		    "_riscv_minidump_kvatop called in live kernel!");
+		return (0);
+	}
+	return (_riscv_minidump_vatop(kd, va, pa));
+}
+
+static int
+_riscv_native(kvm_t *kd __unused)
+{
+
+#ifdef __riscv
+	return (1);
+#else
+	return (0);
+#endif
+}
+
+static vm_prot_t
+_riscv_entry_to_prot(riscv_pt_entry_t pte)
+{
+	vm_prot_t prot = VM_PROT_READ;
+
+	if ((pte & RISCV_PTE_W) != 0)
+		prot |= VM_PROT_WRITE;
+	if ((pte & RISCV_PTE_X) != 0)
+		prot |= VM_PROT_EXECUTE;
+	return prot;
+}
+
+static int
+_riscv_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
+{
+	struct vmstate *vm = kd->vmst;
+	u_long nptes = vm->hdr.pmapsize / sizeof(riscv_pt_entry_t);
+	u_long bmindex, dva, pa, pteindex, va;
+	struct kvm_bitmap bm;
+	vm_prot_t prot;
+	int ret = 0;
+
+	if (!_kvm_bitmap_init(&bm, vm->hdr.bitmapsize, &bmindex))
+		return (0);
+
+	for (pteindex = 0; pteindex < nptes; pteindex++) {
+		riscv_pt_entry_t pte = _riscv_pte_get(kd, pteindex);
+
+		if (((pte & RISCV_PTE_V) == 0) ||
+		    ((pte & RISCV_PTE_RWX) == 0))
+			continue;
+
+		va = vm->hdr.kernbase + (pteindex << RISCV_L3_SHIFT);
+		pa = (pte >> RISCV_PTE_PPN0_S) << RISCV_L3_SHIFT;
+		dva = vm->hdr.dmapbase + pa;
+		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
+		    _riscv_entry_to_prot(pte), RISCV_PAGE_SIZE, 0)) {
+			goto out;
+		}
+	}
+
+	while (_kvm_bitmap_next(&bm, &bmindex)) {
+		pa = bmindex * RISCV_PAGE_SIZE;
+		dva = vm->hdr.dmapbase + pa;
+		if (vm->hdr.dmapend < (dva + RISCV_PAGE_SIZE))
+			break;
+		va = 0;
+		prot = VM_PROT_READ | VM_PROT_WRITE;
+		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
+		    prot, RISCV_PAGE_SIZE, 0)) {
+			goto out;
+		}
+	}
+	ret = 1;
+
+out:
+	_kvm_bitmap_deinit(&bm);
+	return (ret);
+}
+
+static struct kvm_arch kvm_riscv_minidump = {
+	.ka_probe = _riscv_minidump_probe,
+	.ka_initvtop = _riscv_minidump_initvtop,
+	.ka_freevtop = _riscv_minidump_freevtop,
+	.ka_kvatop = _riscv_minidump_kvatop,
+	.ka_native = _riscv_native,
+	.ka_walk_pages = _riscv_minidump_walk_pages,
+};
+
+KVM_ARCH(kvm_riscv_minidump);
diff --git a/lib/libkvm/kvm_riscv.h b/lib/libkvm/kvm_riscv.h
new file mode 100644
index 0000000000000..f1021f448dc06
--- /dev/null
+++ b/lib/libkvm/kvm_riscv.h
@@ -0,0 +1,90 @@
+/*-
+ * Copyright (c) 2015 John H. Baldwin <jhb@FreeBSD.org>
+ * Copyright (c) 2019 Mitchell Horne
+ * All rights reserved.
+ *
+ * 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 AUTHOR 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 AUTHOR 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef __KVM_RISCV_H__
+#define	__KVM_RISCV_H__
+
+#ifdef __riscv
+#include <machine/pte.h>
+#endif
+
+typedef uint64_t	riscv_physaddr_t;
+typedef uint64_t	riscv_pt_entry_t;
+
+#define	RISCV_PAGE_SHIFT	12
+#define	RISCV_PAGE_SIZE		(1 << RISCV_PAGE_SHIFT)
+#define	RISCV_PAGE_MASK		(RISCV_PAGE_SIZE - 1)
+
+/* Source: sys/riscv/include/pte.h */
+#define	RISCV_L3_SHIFT		12
+#define	RISCV_L3_SIZE		(1 << L3_SHIFT)
+#define	RISCV_L3_OFFSET 	(L3_SIZE - 1)
+
+#define	RISCV_PTE_SW_MANAGED	(1 << 9)
+#define	RISCV_PTE_SW_WIRED	(1 << 8)
+#define	RISCV_PTE_D		(1 << 7) /* Dirty */
+#define	RISCV_PTE_A		(1 << 6) /* Accessed */
+#define	RISCV_PTE_G		(1 << 5) /* Global */
+#define	RISCV_PTE_U		(1 << 4) /* User */
+#define	RISCV_PTE_X		(1 << 3) /* Execute */
+#define	RISCV_PTE_W		(1 << 2) /* Write */
+#define	RISCV_PTE_R		(1 << 1) /* Read */
+#define	RISCV_PTE_V		(1 << 0) /* Valid */
+#define	RISCV_PTE_RWX		(RISCV_PTE_R | RISCV_PTE_W | RISCV_PTE_X)
+
+#define	RISCV_PTE_PPN0_S	10
+
+#ifdef __riscv
+_Static_assert(sizeof(pt_entry_t) == sizeof(riscv_pt_entry_t),
+    "pt_entry_t size mismatch");
+
+_Static_assert(PAGE_SHIFT == RISCV_PAGE_SHIFT, "PAGE_SHIFT mismatch");
+_Static_assert(PAGE_SIZE == RISCV_PAGE_SIZE, "PAGE_SIZE mismatch");
+_Static_assert(PAGE_MASK == RISCV_PAGE_MASK, "PAGE_MASK mismatch");
+
+_Static_assert(L3_SHIFT == RISCV_L3_SHIFT, "L3_SHIFT mismatch");
+_Static_assert(L3_SIZE == RISCV_L3_SIZE, "L3_SIZE mismatch");
+_Static_assert(L3_OFFSET == RISCV_L3_OFFSET, "L3_OFFSET mismatch");
+_Static_assert(PTE_PPN0_S == RISCV_PTE_PPN0_S, "PTE_PPN0_S mismatch");
+
+_Static_assert(PTE_SW_MANAGED == RISCV_PTE_SW_MANAGED,
+    "PTE_SW_MANAGED mismatch");
+_Static_assert(PTE_SW_WIRED == RISCV_PTE_SW_WIRED, "PTE_SW_WIRED mismatch");
+_Static_assert(PTE_D == RISCV_PTE_D, "PTE_D mismatch");
+_Static_assert(PTE_A == RISCV_PTE_A, "PTE_A mismatch");
+_Static_assert(PTE_G == RISCV_PTE_G, "PTE_G mismatch");
+_Static_assert(PTE_U == RISCV_PTE_U, "PTE_U mismatch");
+_Static_assert(PTE_X == RISCV_PTE_X, "PTE_X mismatch");
+_Static_assert(PTE_W == RISCV_PTE_W, "PTE_W mismatch");
+_Static_assert(PTE_R == RISCV_PTE_R, "PTE_R mismatch");
+_Static_assert(PTE_V == RISCV_PTE_V, "PTE_V mismatch");
+_Static_assert(PTE_RWX == RISCV_PTE_RWX, "PTE_RWX mismatch");
+#endif
+
+#endif /* !__KVM_RISCV_H__ */