Date: Thu, 15 May 2025 14:01:49 GMT From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: d8c4c2ce68ee - main - bhyve x86: when accessing non-backed gpa, emulate hw Message-ID: <202505151401.54FE1nTk018570@gitrepo.freebsd.org>
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The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=d8c4c2ce68eec8bac4e5cd0d133b8342e7a7f05d commit d8c4c2ce68eec8bac4e5cd0d133b8342e7a7f05d Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2025-05-04 17:01:20 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2025-05-15 14:01:40 +0000 bhyve x86: when accessing non-backed gpa, emulate hw which reads all bits one, and ignores writes. PR: 286467 Reviewed by: markj (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D50116 --- usr.sbin/bhyve/amd64/Makefile.inc | 2 +- usr.sbin/bhyve/amd64/mem_x86.c | 82 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 83 insertions(+), 1 deletion(-) diff --git a/usr.sbin/bhyve/amd64/Makefile.inc b/usr.sbin/bhyve/amd64/Makefile.inc index 0a9b13901978..92e53433ff01 100644 --- a/usr.sbin/bhyve/amd64/Makefile.inc +++ b/usr.sbin/bhyve/amd64/Makefile.inc @@ -7,7 +7,7 @@ SRCS+= \ inout.c \ ioapic.c \ kernemu_dev.c \ - mem_md.c \ + mem_x86.c \ mptbl.c \ pci_fbuf.c \ pci_gvt-d.c \ diff --git a/usr.sbin/bhyve/amd64/mem_x86.c b/usr.sbin/bhyve/amd64/mem_x86.c new file mode 100644 index 000000000000..742d827db47f --- /dev/null +++ b/usr.sbin/bhyve/amd64/mem_x86.c @@ -0,0 +1,82 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2025 The FreeBSD Foundation + * + * This software was developed by Konstantin Belousov <kib@FreeBSD.org> + * under sponsorship from the FreeBSD Foundation. + * + * 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. + */ + +#include <sys/types.h> +#include <sys/errno.h> +#include <sys/tree.h> +#include <machine/vmm.h> + +#include <stdio.h> + +#include "debug.h" +#include "mem.h" + +static int +no_mem_handler(struct vcpu *vcpu __unused, int dir, uint64_t addr __unused, + int size, uint64_t *val, void *arg1 __unused, long arg2 __unused) +{ + if (dir == MEM_F_READ) { + switch (size) { + case 1: + *val = 0xff; + break; + case 2: + *val = 0xffff; + break; + case 4: + *val = 0xffffffff; + break; + case 8: + *val = 0xffffffffffffffff; + break; + } + } + return (0); +} + +static struct mem_range fb_entry = { + .handler = no_mem_handler, + .base = 0, + .size = 0xffffffffffffffff, +}; + +/* + * x86 hardware ignores writes without receiver, and returns all 1's + * from reads without response to transaction. + */ +int +mmio_handle_non_backed_mem(struct vcpu *vcpu __unused, uint64_t paddr, + struct mem_range **mr_paramp) +{ + *mr_paramp = &fb_entry; + EPRINTLN("Emulating access to non-existent address to %#lx\n", + paddr); + return (0); +}
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