Date: Wed, 21 Apr 2021 12:27:04 +0000 From: bugzilla-noreply@freebsd.org To: virtualization@FreeBSD.org Subject: [Bug 255191] Booting DragonFlyBSD results in Failed to emulate instruction sequence output Message-ID: <bug-255191-27103-Hjhd7DKuTr@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-255191-27103@https.bugs.freebsd.org/bugzilla/> References: <bug-255191-27103@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D255191 Peter Grehan <grehan@FreeBSD.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |grehan@FreeBSD.org --- Comment #3 from Peter Grehan <grehan@FreeBSD.org> --- I looked into this a while back: there are 2 issues - DFly is accessing memory beyond 4G when there is < 4G configured. This appears to be an array access in sys/platform/pc64/x86_64/mptable.c:mptable_search_sig() However, in PC-land this is allowed and accesses beyond the end of RAM w= ill return 0xff's on a read. - bhyve does return 0xff's for reads beyond the end of memory, but doesn't implement that particular instruction (cmpl $0x5f504d5f,(%rax,%rcx,4)) Rather than having to implement that instruction for such an edge condition, I'll try and resurrect the patch I once had (unfortunately lost) and get the fix into DFly. --=20 You are receiving this mail because: You are the assignee for the bug.=
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